Hearing protection field attenuation estimation systems and associated training for reducing workers' exposure to noise.

BACKGROUND: Global Burden of Disease studies identify hearing loss as the third leading cause of years lived with a disability. Their estimates point to large societal and individual costs from unaddressed hearing difficulties. Workplace noise is an important modifiable risk factor; if addressed, it could significantly reduce the global burden of disease. In practice, providing hearing protection devices (HPDs) is the most common intervention to reduce noise exposure at work. However, lack of fit of HPDs, especially earplugs, can greatly limit their effectiveness. This may be the case for 40% of users. Testing the fit and providing instructions to improve noise attenuation might be effective. In the past two decades, hearing protection fit-test systems have been developed and evaluated in the field. They are called field attenuation estimation systems. They measure the noise attenuation obtained by individual workers using HPDs. If there is a lack of fit, instruction for better fit is provided, and may lead to better noise attenuation obtained by HPDs. OBJECTIVES: To assess: (1) the effects of field attenuation estimation systems and associated training on the noise attenuation obtained by HPDs compared to no instruction or to less instruction in workers exposed to noise; and (2) whether these interventions promote adherence to HPD use. SEARCH METHODS: We used CENTRAL, MEDLINE, five other databases, and two trial registers, together with reference checking, citation searching, and contact with study authors to identify studies. We imposed no language or date restrictions. The latest search date was February 2024. SELECTION CRITERIA: We included randomised controlled trials (RCTs), cluster-RCTs, controlled before-after studies (CBAs), and interrupted time-series studies (ITSs) exploring HPD fit testing in workers exposed to noise levels of more than 80 A-weighted decibels (or dBA) who use hearing protection devices. The unit 'dBA' reports on the use of a frequency-weighting filter to adjust sound measurement results to better reflect how human ears process sound. The outcome noise attenuation had to be measured either as a personal attenuation rating (PAR), PAR pass rate, or both. PAR pass rate is the percentage of workers who passed a pre-established level of sufficient attenuation from their HPDs, identified on the basis of their individual noise exposure. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed study eligibility, risk of bias, and extracted data. We categorised interventions as fit testing of HPDs with instructions at different levels (no instructions, simple instructions, and extensive instructions). MAIN RESULTS: We included three RCTs (756 participants). We did not find any studies that examined whether fit testing and training contributed to hearing protector use, nor any studies that examined whether age, gender, or HPD experience influenced attenuation. We would have included any adverse effects if mentioned by the trial authors, but none reported them. None of the included studies blinded participants; two studies blinded those who delivered the intervention. Effects of fit testing of HPDs with instructions (simple or extensive) versus fit testing of HPDs without instructions Testing the fit of foam and premoulded earplugs accompanied by simple instructions probably does not improve their noise attenuation in the short term after the test (1-month follow-up: mean difference (MD) 1.62 decibels (dB), 95% confidence interval (CI) -0.93 to 4.17; 1 study, 209 participants; 4-month follow-up: MD 0.40 dB, 95% CI -2.28 to 3.08; 1 study, 197 participants; both moderate-certainty evidence). The intervention probably does not improve noise attenuation in the long term (MD 0.15 dB, 95% CI -3.44 to 3.74; 1 study, 103 participants; moderate-certainty evidence). Fit testing of premoulded earplugs with extensive instructions on the fit of the earplugs may improve their noise attenuation at the immediate retest when compared to fit testing without instructions (MD 8.34 dB, 95% CI 7.32 to 9.36; 1 study, 100 participants; low-certainty evidence). Effects of fit testing of HPDs with extensive instructions versus fit testing of HPDs with simple instructions Fit testing of foam earplugs with extensive instructions probably improves their attenuation (MD 8.62 dB, 95% CI 6.31 to 10.93; 1 study, 321 participants; moderate-certainty evidence) and also the pass rate of sufficient attenuation (risk ratio (RR) 1.75, 95% CI 1.44 to 2.11; 1 study, 321 participants; moderate-certainty evidence) when compared to fit testing with simple instructions immediately after the test. This is significant because every 3 dB decrease in noise exposure level halves the sound energy entering the ear. No RCTs reported on the long-term effectiveness of the HPD fit testing with extensive instructions. AUTHORS' CONCLUSIONS: HPD fit testing accompanied by simple instructions probably does not improve noise attenuation from foam and premoulded earplugs. Testing the fit of foam and premoulded earplugs with extensive instructions probably improves attenuation and PAR pass rate immediately after the test. The effects of fit testing associated with training to improve attenuation may vary with types of HPDs and training methods. Better-designed trials with larger sample sizes are required to increase the certainty of the evidence.

Personal protective equipment for preventing asbestos exposure in workers.

BACKGROUND: Asbestos exposure can lead to asbestos-related diseases. The European Union (EU) has adopted regulations for workplaces where asbestos is present. The EU occupational exposure limit (OEL) for asbestos is 0.1 fibres per cubic centimetre of air (f/cm3) as an eight-hour average. Different types of personal protective equipment (PPE) are available to provide protection and minimise exposure; however, their effectiveness is unclear. OBJECTIVES: To assess the effects of personal protective equipment (PPE), including donning and doffing procedures and individual hygienic behaviour, compared to no availability and use of such equipment or alternative equipment, on asbestos exposure in workers in asbestos demolition and repair work. SEARCH METHODS: We searched MEDLINE, Embase, CENTRAL, and Scopus (September 2022), and we checked the reference lists of included studies. SELECTION CRITERIA: We included studies that measured asbestos concentration outside and inside PPE (considering outside concentration a surrogate for no PPE), exposure to asbestos after doffing PPE, donning and doffing errors, nonadherence to regulations, and adverse effects of PPE. DATA COLLECTION AND ANALYSIS: Two review authors selected studies, extracted data, and assessed risk of bias using ROBINS-I. We categorised PPE as full-face filtering masks, supplied air respirators (SARs), and powered air-purifying respirators (PAPRs). Values for asbestos outside and inside PPE were transformed to logarithmic values for random-effects meta-analysis. Pooled logarithmic mean differences (MDs) were exponentiated to obtain the ratio of means (RoM) and 95% confidence interval (95% CI). The RoM shows the degree of protection provided by the respirators (workplace protection factor). Since the RoM is likely to be much higher at higher outside concentrations, we presented separate results according to the outside asbestos concentration, as follows. • Below 0.01 f/cm3 (band 1) • 0.01 f/cm3 to below 0.1 f/cm3 (band 2) • 0.1 f/cm3 to below 1 f/cm3 (band 3) • 1 f/cm3 to below 10 f/cm3 (band 4) • 10 f/cm3 to below 100 f/cm3 (band 5) • 100 f/cm3 to below 1000 f/cm3 (band 6) Additionally, we determined whether the inside concentrations per respirator and concentration band complied with the current EU OEL (0.1 f/cm3) and proposed EU OEL (0.01 f/cm3). MAIN RESULTS: We identified six studies that measured asbestos concentrations outside and inside respiratory protective equipment (RPE) and one cross-over study that compared the effect of two different coveralls on body temperature. No studies evaluated the remaining predefined outcomes. Most studies were at overall moderate risk of bias due to insufficient reporting. The cross-over study was at high risk of bias. Full-face filtering masks Two studies evaluated full-face filtering masks. They provided insufficient data for band 1 and band 6. The results for the remaining bands were as follows. • Band 2: RoM 19 (95% CI 17.6 to 20.1; 1 study, 3 measurements; moderate certainty) • Band 3: RoM 69 (95% CI 26.6 to 175.9; 2 studies, 17 measurements; very low certainty) • Band 4: RoM 455 (95% CI 270.4 to 765.1; 1 study, 16 measurements; low certainty) • Band 5: RoM 2752 (95% CI 1236.5 to 6063.2;1 study, 3 measurements; low certainty) The inside measurements in band 5 did not comply with the EU OEL of 0.1 f/cm3, and no inside measurements complied with the proposed EU OEL of 0.01 f/cm3. Supplied air respirators Two studies evaluated supplied air respirators. They provided no data for band 6. The results for the remaining bands were as follows. • Band 1: RoM 11 (95% CI 7.6 to 14.9; 1 study, 134 measurements; moderate certainty) • Band 2: RoM 63 (95% CI 43.8 to 90.9; 1 study, 17 measurements; moderate certainty) • Band 3: RoM 528 (95% CI 368.7 to 757.5; 1 study, 38 measurements; moderate certainty) • Band 4: RoM 4638 (95% CI 3071.7 to 7044.5; 1 study, 49 measurements; moderate certainty) • Band 5: RoM 26,134 (16,647.2 to 41,357.1; 1 study, 22 measurements; moderate certainty) All inside measurements complied with the current OEL of 0.1 f/cm3 and the proposed OEL of 0.01 f/cm3. Powered air-purifying respirators Three studies evaluated PAPRs. The results per band were as follows. • Band 1: RoM 8 (95% CI 3.7 to 19.1; 1 study, 23 measurements; moderate certainty) • Band 2: RoM 90 (95% CI 64.7 to 126.5; 1 study, 17 measurements; moderate certainty) • Band 3: RoM 104 (95% CI 23.1 to 464.1; 3 studies, 14 measurements; very low certainty) • Band 4: RoM 706 (95% CI 219.2 to 2253.0; 2 studies, 43 measurements; very low certainty) • Band 5: RoM 1366 (544.6 to 3428.9; 2 studies, 8 measurements; low certainty) • Band 6: RoM 18,958 (95% CI 4023.9 to 90,219.4; 2 studies, 13 measurements; very low certainty) All inside measurements complied with the 0.1 f/cm3 OEL when the outside concentration was below 10 f/cm3 (band 1 to band 4). From band 3, no measurements complied with the proposed OEL of 0.01 f/cm3. Different types of coveralls One study reported the adverse effects of coveralls. A polyethylene suit may increase the body temperature more than a ventilated impermeable polyvinyl (PVC) coverall, but the evidence is very uncertain (MD 0.17 °C, 95% CI -0.08 to 0.42; 1 study, 11 participants; very low certainty). AUTHORS' CONCLUSIONS: Where the outside asbestos concentration is below 0.1 f/cm3, SARS and PAPRs likely reduce exposure to below the proposed OEL of 0.01 f/cm3. For outside concentrations up to 10 f/cm3, all respirators may reduce exposure below the current OEL, but only SAR also below the proposed OEL. In band 5 (10 to < 100 f/cm3), full-face filtering masks may not reduce asbestos exposure below either OEL, SARs likely reduce exposure below both OELs, and there were no data for PAPRs. In band 6 (100 f/cm3 to < 1000 f/cm3), PAPRs may not reduce exposure below either OEL, and there were no data for full-face filtering masks or SARs. Some coveralls may increase body temperature more than others. Randomised studies are needed to directly compare PAPRs and SARs at higher asbestos concentrations and to assess adverse effects. Future studies should assess the effects of doffing procedures.

Intermethod agreement of self-reports compared to register data collection for return to work and sickness absence: a systematic review and meta-analysis.

OBJECTIVES: To determine the intermethod agreement of self-reported vs. register data of 'sickness absence' (SA) and 'return to work' (RTW) outcome measurements. STUDY DESIGN AND SETTING: We conducted a systematic review and a meta-analysis of studies reporting mean differences (MDs) and sensitivity and specificity for self-report vs. register data and an inductive analysis of the self-report question formulations. An information specialist searched Medline, Embase, PsycINFO for studies published from inception to November 2022. Screening and data extraction was done by two authors independently. RESULTS: Twenty-three studies were included of which eighteen with an overall high risk of bias. Self-reports had a pooled MD of 1.84 SA days (95% confidence interval [CI] 0.26-3.41, I2 98%, 18 studies, 38,716 participants) compared to registries which varied among studies from 204 more to 17 days less. The median average sick leave in studies in the self-report group was 8 days (interquartile range 4-23 days). Being absent from work measured with self-report had a sensitivity of 0.83 (0.76-0.88 95% CI) and a specificity of 0.92 (0.88-0.94 95% CI) compared to registry data. The high heterogeneity amongst the studies could not be explained by recall time, gender, register type, prospective or retrospective self-reports, health problem, SA at baseline or risk of bias. Studies lacked standard outcome reporting, had unclearly formulated questions in self-reports and there was little information on the registers' quality. CONCLUSION: Current self-reports may differ from register-based absence data but in an inconsistent way. Due to inconsistency and high risk of bias the evidence is judged to be of very low certainty. Further research is needed to develop clear standard questions which can be used for SA and RTW self-reports. Quality of registers needs to be better evaluated. Percentage positive and negative agreement, MDs and 2 × 2 tables should be reported for studies investigating agreement between SA and RTW outcome measures.

Which outcomes should always be measured in intervention studies for improving work participation for people with a health problem? An international multistakeholder Delphi study to develop a core outcome set for Work participation (COS for Work).

OBJECTIVE: Synthesising evidence of the effects of interventions to improve work participation among people with health problems is currently difficult due to heterogeneity in outcome measurements. A core outcome set for work participation is needed. STUDY DESIGN AND SETTING: Following the Core Outcome Measures in Effectiveness Trials methodology, we used a five-step approach to reach international multistakeholder consensus on a core outcome set for work participation. Five subgroups of stakeholders took part in two rounds of discussions and completed two Delphi voting rounds on 26 outcomes. A consensus of ≥80% determined core outcomes and 50%-80% consensus was required for candidate outcomes. RESULTS: Fifty-eight stakeholders took part in the Delphi rounds. Core outcomes were: 'any type of employment including self-employment', 'proportion of workers that return to work after being absent because of illness' and 'time to return to work'. Ten candidate outcomes were proposed, among others: 'sustainable employment', 'work productivity' and 'workers' perception of return to work'. CONCLUSION: As a minimum, all studies evaluating the impact of interventions on work participation should include one employment outcome and two return to work outcomes if workers are on sick leave prior to the intervention.

A general framework for selecting work participation outcomes in intervention studies among persons with health problems: a concept paper.

BACKGROUND: Work participation is important for health and can be considered as engagement in a major area of life which is of significance for most people, but it can also be thought of as fulfilling or discharging a role. Currently, academic research lacks a comprehensive classification of work participation outcomes. The International Classification of Functioning is the foremost model in defining work functioning and its counterpart work disability, but it does not provide a critical (core) set of outcomes. Standardizing the definitions and nomenclature used in the research of work participation would ensure that the outcomes of studies are comparable, and practitioners and guideline developers can better decide what works best. As work participation is a broad umbrella term including outcome categories which need unambiguous differentiation, a framework needs to be developed first. AIM: To propose a framework which can be used to develop a generic core outcome set for work participation. METHODS: First, we performed a systematic literature search on the concept of (work) participation, views on how to measure it, and on existing classifications for outcome measurements. Next, we derived criteria for the framework and proposed a framework based on the criteria. Last, we applied the framework to six case studies as a proof of concept. RESULTS: Our literature search provided 2106 hits and we selected 59 studies for full-text analysis. Based on the literature and the developed criteria we propose four overarching outcome categories: (1) initiating employment, (2) having employment, (3) increasing or maintaining productivity at work, and (4) return to employment. These categories appeared feasible in our proof-of-concept assessment with six different case studies. CONCLUSION: We propose to use the framework for work participation outcomes to develop a core outcome set for intervention studies to improve work participation.

Preprocedural mouth rinses for preventing transmission of infectious diseases through aerosols in dental healthcare providers.

BACKGROUND: Aerosols and spatter are generated in a dental clinic during aerosol-generating procedures (AGPs) that use high-speed hand pieces. Dental healthcare providers can be at increased risk of transmission of diseases such as tuberculosis, measles and severe acute respiratory syndrome (SARS) through droplets on mucosae, inhalation of aerosols or through fomites on mucosae, which harbour micro-organisms. There are ways to mitigate and contain spatter and aerosols that may, in turn, reduce any risk of disease transmission. In addition to personal protective equipment (PPE) and aerosol-reducing devices such as high-volume suction, it has been hypothesised that the use of mouth rinse by patients before dental procedures could reduce the microbial load of aerosols that are generated during dental AGPs. OBJECTIVES: To assess the effects of preprocedural mouth rinses used in dental clinics to minimise incidence of infection in dental healthcare providers and reduce or neutralise contamination in aerosols. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 4 February 2022. SELECTION CRITERIA: We included randomised controlled trials and excluded laboratory-based studies. Study participants were dental patients undergoing AGPs. Studies compared any preprocedural mouth rinse used to reduce contaminated aerosols versus placebo, no mouth rinse or another mouth rinse. Our primary outcome was incidence of infection of dental healthcare providers and secondary outcomes were reduction in the level of contamination of the dental operatory environment, cost, change in mouth microbiota, adverse events, and acceptability and feasibility of the intervention. DATA COLLECTION AND ANALYSIS: Two review authors screened search results, extracted data from included studies, assessed the risk of bias in the studies and judged the certainty of the available evidence. We used mean differences (MDs) and 95% confidence intervals (CIs) as the effect estimate for continuous outcomes, and random-effects meta-analysis to combine data  MAIN RESULTS:  We included 17 studies with 830 participants aged 18 to 70 years. We judged three trials at high risk of bias, two at low risk and 12 at unclear risk of bias.  None of the studies measured our primary outcome of the incidence of infection in dental healthcare providers.  The primary outcome in the studies was reduction in the level of bacterial contamination measured in colony-forming units (CFUs) at distances of less than 2 m (intended to capture larger droplets) and 2 m or more (to capture droplet nuclei from aerosols arising from the participant's oral cavity). It is unclear what size of CFU reduction represents a clinically significant amount. There is low- to very low-certainty evidence that chlorhexidine (CHX) may reduce bacterial contamination, as measured by CFUs, compared with no rinsing or rinsing with water. There were similar results when comparing cetylpyridinium chloride (CPC) with no rinsing and when comparing CPC, essential oils/herbal mouthwashes or boric acid with water. There is very low-certainty evidence that tempered mouth rinses may provide a greater reduction in CFUs than cold mouth rinses. There is low-certainty evidence that CHX may reduce CFUs more than essential oils/herbal mouthwashes. The evidence for other head-to-head comparisons was limited and inconsistent.  The studies did not provide any information on costs, change in micro-organisms in the patient's mouth or adverse events such as temporary discolouration, altered taste, allergic reaction or hypersensitivity. The studies did not assess acceptability of the intervention to patients or feasibility of implementation for dentists.  AUTHORS' CONCLUSIONS: None of the included studies measured the incidence of infection among dental healthcare providers. The studies measured only reduction in level of bacterial contamination in aerosols. None of the studies evaluated viral or fungal contamination. We have only low to very low certainty for all findings. We are unable to draw conclusions regarding whether there is a role for preprocedural mouth rinses in reducing infection risk or the possible superiority of one preprocedural rinse over another. Studies are needed that measure the effect of rinses on infectious disease risk among dental healthcare providers and on contaminated aerosols at larger distances with standardised outcome measurement.

Workplace interventions to reduce the risk of SARS-CoV-2 infection outside of healthcare settings.

BACKGROUND: Although many people infected with SARS-CoV-2 (severe acute respiratory syndrome coronavirus-2) experience no or mild symptoms, some individuals can develop severe illness and may die, particularly older people and those with underlying medical problems. Providing evidence-based interventions to prevent SARS-CoV-2 infection has become more urgent with the spread of more infectious SARS-CoV-2 variants of concern (VoC), and the potential psychological toll imposed by the coronavirus disease 2019 (COVID-19) pandemic.   Controlling exposures to occupational hazards is the fundamental method of protecting workers. When it comes to the transmission of viruses, such as SARS-CoV-2, workplaces should first consider control measures that can potentially have the most significant impact. According to the hierarchy of controls, one should first consider elimination (and substitution), then engineering controls, administrative controls, and lastly, personal protective equipment (PPE). OBJECTIVES: To assess the benefits and harms of interventions in non-healthcare-related workplaces to reduce the risk of SARS-CoV-2 infection relative to other interventions, or no intervention. SEARCH METHODS: We searched MEDLINE, Embase, Web of Science, Cochrane COVID-19 Study Register, the Canadian Centre for Occupational Health and Safety (CCOHS), Clinicaltrials.gov, and the International Clinical Trials Registry Platform to 14 September 2021. We will conduct an update of this review in six months. SELECTION CRITERIA: We included randomised control trials (RCT) and planned to include non-randomised studies of interventions. We included adult workers, both those who come into close contact with clients or customers (e.g. public-facing employees, such as cashiers or taxi drivers), and those who do not, but who could be infected by co-workers. We excluded studies involving healthcare workers. We included any intervention to prevent or reduce workers' exposure to SARS-CoV-2 in the workplace, defining categories of intervention according to the hierarchy of hazard controls, i.e. elimination; engineering controls; administrative controls; personal protective equipment. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were incidence rate of SARS-CoV-2 infection (or other respiratory viruses), SARS-CoV-2-related mortality, adverse events, and absenteeism from work. Our secondary outcomes were all-cause mortality, quality of life, hospitalisation, and uptake, acceptability, or adherence to strategies. We used the Cochrane RoB 2 tool to assess the risk of bias, and GRADE methods to assess the certainty of evidence for each outcome. MAIN RESULTS: Elimination of exposure interventions We included one study examining an intervention that focused on elimination of hazards. This study is an open-label, cluster-randomised, non-inferiority trial, conducted in England in 2021. The study compared standard 10-day self-isolation after contact with an infected person to a new strategy of daily rapid antigen testing and staying at work if the test is negative (test-based attendance). The trialists hypothesised that this would lead to a similar rate of infections, but lower COVID-related absence. Staff (N = 11,798) working at 76 schools were assigned to standard isolation, and staff (N = 12,229) at 86 schools to the test-based attendance strategy.  The results between test-based attendance and standard 10-day self-isolation were inconclusive for the rate of symptomatic PCR-positive SARS-COV-2 infection rate ratio ((RR) 1.28, 95% confidence interval (CI) 0.74 to 2.21; 1 study, very low-certainty evidence)). The results between test-based attendance and standard 10-day self-isolation were inconclusive for the rate of any PCR-positive SARS-COV-2 infection (RR 1.35, 95% CI 0.82 to 2.21; 1 study, very low-certainty evidence). COVID-related absenteeism rates were 3704 absence days in 566,502 days-at-risk (6.5 per 1000 days at risk) in the control group and 2932 per 539,805 days-at-risk (5.4 per 1000 days at risk) in the intervention group (RR 0.83; 95% CI 0.55 to 1.25). The certainty of the evidence was downgraded to low, due to imprecision. Uptake of the intervention was 71 % in the intervention group, but not reported for the control intervention.  The trial did not measure other outcomes, SARS-CoV-2-related mortality, adverse events, all-cause mortality, quality of life, and hospitalisation. We found one ongoing RCT about screening in schools, using elimination of hazard strategies. Personal protective equipment We found one ongoing non-randomised study on the effects of closed face shields to prevent COVID-19 transmission. Other intervention categories We did not find studies in the other intervention categories. AUTHORS' CONCLUSIONS: We are uncertain whether a test-based attendance policy affects rates of PCR-postive SARS-CoV-2 infection (any infection; symptomatic infection) compared to standard 10-day self-isolation amongst school and college staff. Test-based attendance policy may result in little to no difference in absence rates compared to standard 10-day self-isolation. As a large part of the population is exposed in the case of a pandemic, an apparently small relative effect that would not be worthwhile from the individual perspective may still affect many people, and thus, become an important absolute effect from the enterprise or societal perspective.  The included study did not report on any other primary outcomes of our review, i.e. SARS-CoV-2-related mortality and adverse events. No completed studies were identified on any other interventions specified in this review, but two eligible studies are ongoing. More controlled studies are needed on testing and isolation strategies, and working from home, as these have important implications for work organisations.

Preferred Methods of Measuring Work Participation: An International Survey Among Trialists and Cochrane Systematic Reviewers.

Purpose Heterogeneity in work participation (WP) outcomes measurements hampers large scale evidence synthesis in systematic reviews of trials. In this survey we explore authors' reasons for choosing specific WP outcomes and their measurement methods, including employment status, absence from work, at-work productivity loss, and employability. Methods We contacted authors of 260 trials and 69 systematic reviews and asked closed and open-ended questions about previously used WP outcomes and measurement methods as well as their opinion on the best way to measure WP. Results In total, 91 authors from a wide range of professional backgrounds completed the survey. The majority of authors (86%) chose WP outcomes based on their use in previous similar studies. In most studies (88%), patients had not been involved in the process of selecting the WP outcome. Authors judged feasibility to be an important factor for choosing a measurement instrument (67%). Additionally, valid measurement tools should be available, easy to administer and not too time consuming. Although authors preferred registry data for long term follow-up, the availability and validity of registries was seen as a barrier. Most of the reviewers (72%) struggled to pool data because of variation in follow-up times and cut off points and varying definitions of work outcomes. Almost all (92%) respondents support the use of a Core Outcome Set for Work. Conclusions There is strong support from authors of trials and systematic reviews to develop a core outcome set on work participation outcomes for the evaluation of interventions.

Extensive variability of work participation outcomes measured in randomized controlled trials: a systematic review.

OBJECTIVE: To investigate how work participation outcomes in randomized controlled trials are measured internationally and across disciplines. STUDY DESIGN AND SETTING: We identified trials that reported on work participation in Medline, Embase, PsycINFO and Cochrane Central published between 2014 and 2019. Screening, selection, and data extraction were done by two authors independently. We grouped outcomes into four categories ("employment status", "absence from work", "at-work productivity loss," and "employability") and created subcategories according to how the outcome was measured. RESULTS: From 10,022 database hits we selected 269 trials reporting on 435 work participation outcomes. Authors used inconsistent outcome terminology to describe the measured constructs. Grouped in four main categories we identified 70 outcomes that reported on "employment status", 196 on "absence from work" and return-to-work, 132 on "at-work productivity loss," and 37 on "employability" outcomes. Variability in measurement methods existed across all categories. Employment status and absenteeism measures consisted mostly of clinimetrically unvalidated tools. "At-work productivity loss" and "employability" were measured by at least 41 different questionnaires. CONCLUSION: Extensive variability exists among trials in the measurement of outcomes, measurement methods and measurement instruments that focus on work participation. This study is a first step towards the development of a Core Outcome Set for work participation.

An approach to quantifying the potential importance of residual confounding in systematic reviews of observational studies: A GRADE concept paper.

Small relative effect sizes are common in observational studies of exposure in environmental and public health. However, such effects can still have considerable policy importance when the baseline rate of the health outcome is high, and many persons are exposed. Assessing the certainty of the evidence based on these effect sizes is challenging because they can be prone to residual confounding due to the non-randomized nature of the evidence. When applying GRADE, a precise relative risk >2.0 increases the certainty in an existing effect because residual confounding is unlikely to explain the association. GRADE also suggests rating up when opposing plausible residual confounding exists for other effect sizes. In this concept paper, we propose using the E-value, defined as the smallest effect size of a confounder that still can reduce an observed RR to the null value, and a reference confounder to assess the likelihood of residual confounding. We propose a 4-step approach. 1. Assess the association of interest for relevant exposure levels. 2. Calculate the E-value for this observed association. 3. Choose a reference confounder with sufficient strength and information and assess its effect on the observed association using the E-value. 4. Assess how likely it is that residual confounding will still bias the observed RR. We present three case studies and discuss the feasibility of the approach.

Interventions to reduce contaminated aerosols produced during dental procedures for preventing infectious diseases.

BACKGROUND: Many dental procedures produce aerosols (droplets, droplet nuclei and splatter) that harbour various pathogenic micro-organisms and may pose a risk for the spread of infections between dentist and patient. The COVID-19 pandemic has led to greater concern about this risk. OBJECTIVES: To assess the effectiveness of methods used during dental treatment procedures to minimize aerosol production and reduce or neutralize contamination in aerosols. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases on 17 September 2020: Cochrane Oral Health's Trials Register, the Cochrane Central Register of Controlled Trials (CENTRAL) (in the Cochrane Library, 2020, Issue 8), MEDLINE Ovid (from 1946); Embase Ovid (from 1980); the WHO COVID-19 Global literature on coronavirus disease; the US National Institutes of Health Trials Registry (ClinicalTrials.gov); and the Cochrane COVID-19 Study Register. We placed no restrictions on the language or date of publication. SELECTION CRITERIA: We included randomized controlled trials (RCTs) and controlled clinical trials (CCTs) on aerosol-generating procedures (AGPs) performed by dental healthcare providers that evaluated methods to reduce contaminated aerosols in dental clinics (excluding preprocedural mouthrinses). The primary outcomes were incidence of infection in dental staff or patients, and reduction in volume and level of contaminated aerosols in the operative environment. The secondary outcomes were cost, accessibility and feasibility. DATA COLLECTION AND ANALYSIS: Two review authors screened search results, extracted data from the included studies, assessed the risk of bias in the studies, and judged the certainty of the available evidence. We used mean differences (MDs) and 95% confidence intervals (CIs) as the effect estimate for continuous outcomes, and random-effects meta-analysis to combine data. We assessed heterogeneity. MAIN RESULTS: We included 16 studies with 425 participants aged 5 to 69 years. Eight studies had high risk of bias; eight had unclear risk of bias. No studies measured infection. All studies measured bacterial contamination using the surrogate outcome of colony-forming units (CFU). Two studies measured contamination per volume of air sampled at different distances from the patient's mouth, and 14 studies sampled particles on agar plates at specific distances from the patient's mouth. The results presented below should be interpreted with caution as the evidence is very low certainty due to heterogeneity, risk of bias, small sample sizes and wide confidence intervals. Moreover, we do not know the 'minimal clinically important difference' in CFU. High-volume evacuator Use of a high-volume evacuator (HVE) may reduce bacterial contamination in aerosols less than one foot (~ 30 cm) from a patient's mouth (MD -47.41, 95% CI -92.76 to -2.06; 3 RCTs, 122 participants (two studies had split-mouth design); very high heterogeneity I² = 95%), but not at longer distances (MD -1.00, -2.56 to 0.56; 1 RCT, 80 participants). One split-mouth RCT (six participants) found that HVE may not be more effective than conventional dental suction (saliva ejector or low-volume evacuator) at 40 cm (MD CFU -2.30, 95% CI -5.32 to 0.72) or 150 cm (MD -2.20, 95% CI -14.01 to 9.61). Dental isolation combination system One RCT (50 participants) found that there may be no difference in CFU between a combination system (Isolite) and a saliva ejector (low-volume evacuator) during AGPs (MD -0.31, 95% CI -0.82 to 0.20) or after AGPs (MD -0.35, -0.99 to 0.29). However, an 'n of 1' design study showed that the combination system may reduce CFU compared with rubber dam plus HVE (MD -125.20, 95% CI -174.02 to -76.38) or HVE (MD -109.30, 95% CI -153.01 to -65.59). Rubber dam One split-mouth RCT (10 participants) receiving dental treatment, found that there may be a reduction in CFU with rubber dam at one-metre (MD -16.20, 95% CI -19.36 to -13.04) and two-metre distance (MD -11.70, 95% CI -15.82 to -7.58). One RCT of 47 dental students found use of rubber dam may make no difference in CFU at the forehead (MD 0.98, 95% CI -0.73 to 2.70) and occipital region of the operator (MD 0.77, 95% CI -0.46 to 2.00). One split-mouth RCT (21 participants) found that rubber dam plus HVE may reduce CFU more than cotton roll plus HVE on the patient's chest (MD -251.00, 95% CI -267.95 to -234.05) and dental unit light (MD -12.70, 95% CI -12.85 to -12.55). Air cleaning systems One split-mouth CCT (two participants) used a local stand-alone air cleaning system (ACS), which may reduce aerosol contamination during cavity preparation (MD -66.70 CFU, 95% CI -120.15 to -13.25 per cubic metre) or ultrasonic scaling (MD -32.40, 95% CI - 51.55 to -13.25). Another CCT (50 participants) found that laminar flow in the dental clinic combined with a HEPA filter may reduce contamination approximately 76 cm from the floor (MD -483.56 CFU, 95% CI -550.02 to -417.10 per cubic feet per minute per patient) and 20 cm to 30 cm from the patient's mouth (MD -319.14 CFU, 95% CI - 385.60 to -252.68). Disinfectants ‒ antimicrobial coolants Two RCTs evaluated use of antimicrobial coolants during ultrasonic scaling. Compared with distilled water, coolant containing chlorhexidine (CHX), cinnamon extract coolant or povidone iodine may reduce CFU: CHX (MD -124.00, 95% CI -135.78 to -112.22; 20 participants), povidone iodine (MD -656.45, 95% CI -672.74 to -640.16; 40 participants), cinnamon (MD -644.55, 95% CI -668.70 to -620.40; 40 participants). CHX coolant may reduce CFU more than povidone iodine (MD -59.30, 95% CI -64.16 to -54.44; 20 participants), but not more than cinnamon extract (MD -11.90, 95% CI -35.88 to 12.08; 40 participants). AUTHORS' CONCLUSIONS: We found no studies that evaluated disease transmission via aerosols in a dental setting; and no evidence about viral contamination in aerosols. All of the included studies measured bacterial contamination using colony-forming units. There appeared to be some benefit from the interventions evaluated but the available evidence is very low certainty so we are unable to draw reliable conclusions. We did not find any studies on methods such as ventilation, ionization, ozonisation, UV light and fogging. Studies are needed that measure contamination in aerosols, size distribution of aerosols and infection transmission risk for respiratory diseases such as COVID-19 in dental patients and staff.

Interventions to improve return to work in depressed people.

BACKGROUND: Work disability such as sickness absence is common in people with depression. OBJECTIVES: To evaluate the effectiveness of interventions aimed at reducing work disability in employees with depressive disorders. SEARCH METHODS: We searched CENTRAL (The Cochrane Library), MEDLINE, Embase, CINAHL, and PsycINFO until April 4th 2020. SELECTION CRITERIA: We included randomised controlled trials (RCTs) and cluster-RCTs of work-directed and clinical interventions for depressed people that included days of sickness absence or being off work as an outcome. We also analysed the effects on depression and work functioning. DATA COLLECTION AND ANALYSIS: Two review authors independently extracted the data and rated the certainty of the evidence using GRADE. We used standardised mean differences (SMDs) or risk ratios (RR) with 95% confidence intervals (CI) to pool study results in studies we judged to be sufficiently similar.  MAIN RESULTS: In this update, we added 23 new studies. In total, we included 45 studies with 88 study arms, involving 12,109 participants with either a major depressive disorder or a high level of depressive symptoms. Risk of bias The most common types of bias risk were detection bias (27 studies) and attrition bias (22 studies), both for the outcome of sickness absence. Work-directed interventions Work-directed interventions combined with clinical interventions A combination of a work-directed intervention and a clinical intervention probably reduces days of sickness absence within the first year of follow-up (SMD -0.25, 95% CI -0.38 to -0.12; 9 studies; moderate-certainty evidence). This translates back to 0.5 fewer (95% CI -0.7 to -0.2) sick leave days in the past two weeks or 25 fewer days during one year (95% CI -37.5 to -11.8). The intervention does not lead to fewer persons being off work beyond one year follow-up (RR 0.96, 95% CI 0.85 to 1.09; 2 studies, high-certainty evidence). The intervention may reduce depressive symptoms (SMD -0.25, 95% CI -0.49 to -0.01; 8 studies, low-certainty evidence) and probably has a small effect on work functioning (SMD -0.19, 95% CI -0.42 to 0.06; 5 studies, moderate-certainty evidence) within the first year of follow-up.  Stand alone work-directed interventions A specific work-directed intervention alone may increase the number of sickness absence days compared with work-directed care as usual (SMD 0.39, 95% CI 0.04 to 0.74; 2 studies, low-certainty evidence) but probably does not lead to more people being off work within the first year of follow-up (RR 0.93, 95% CI 0.77 to 1.11; 1 study, moderate-certainty evidence) or beyond (RR 1.00, 95% CI 0.82 to 1.22; 2 studies, moderate-certainty evidence). There is probably no effect on depressive symptoms (SMD -0.10, 95% -0.30 CI to 0.10; 4 studies, moderate-certainty evidence) within the first year of follow-up and there may be no effect on depressive symptoms beyond that time (SMD 0.18, 95% CI -0.13 to 0.49; 1 study, low-certainty evidence). The intervention may also not lead to better work functioning (SMD -0.32, 95% CI -0.90 to 0.26; 1 study, low-certainty evidence) within the first year of follow-up.   Psychological interventions A psychological intervention, either face-to-face, or an E-mental health intervention, with or without professional guidance, may reduce the number of sickness absence days, compared with care as usual (SMD -0.15, 95% CI -0.28 to -0.03; 9 studies, low-certainty evidence). It may also reduce depressive symptoms (SMD -0.30, 95% CI -0.45 to -0.15, 8 studies, low-certainty evidence). We are uncertain whether these psychological interventions improve work ability (SMD -0.15 95% CI -0.46 to 0.57; 1 study; very low-certainty evidence). Psychological intervention combined with antidepressant medication Two studies compared the effect of a psychological intervention combined with antidepressants to antidepressants alone. One study combined psychodynamic therapy with tricyclic antidepressant (TCA) medication and another combined telephone-administered cognitive behavioural therapy (CBT) with a selective serotonin reuptake inhibitor (SSRI). We are uncertain if this intervention reduces the number of sickness absence days (SMD -0.38, 95% CI -0.99 to 0.24; 2 studies, very low-certainty evidence) but found that there may be no effect on depressive symptoms (SMD -0.19, 95% CI -0.50 to 0.12; 2 studies, low-certainty evidence). Antidepressant medication only Three studies compared the effectiveness of SSRI to selective norepinephrine reuptake inhibitor (SNRI) medication on reducing sickness absence and yielded highly inconsistent results. Improved care Overall, interventions to improve care did not lead to fewer days of sickness absence, compared to care as usual (SMD -0.05, 95% CI -0.16 to 0.06; 7 studies, moderate-certainty evidence). However, in studies with a low risk of bias, the intervention probably leads to fewer days of sickness absence in the first year of follow-up (SMD -0.20, 95% CI -0.35 to -0.05; 2 studies; moderate-certainty evidence). Improved care probably leads to fewer depressive symptoms (SMD -0.21, 95% CI -0.35 to -0.07; 7 studies, moderate-certainty evidence) but may possibly lead to a decrease in work-functioning (SMD 0.5, 95% CI 0.34 to 0.66; 1 study; moderate-certainty evidence). Exercise Supervised strength exercise may reduce sickness absence, compared to relaxation (SMD -1.11; 95% CI -1.68 to -0.54; one study, low-certainty evidence). However, aerobic exercise probably is not more effective than relaxation or stretching (SMD -0.06; 95% CI -0.36 to 0.24; 2 studies, moderate-certainty evidence). Both studies found no differences between the two conditions in depressive symptoms. AUTHORS' CONCLUSIONS: A combination of a work-directed intervention and a clinical intervention probably reduces the number of sickness absence days, but at the end of one year or longer follow-up, this does not lead to more people in the intervention group being at work. The intervention may also reduce depressive symptoms and probably increases work functioning more than care as usual. Specific work-directed interventions may not be more effective than usual work-directed care alone. Psychological interventions may reduce the number of sickness absence days, compared with care as usual. Interventions to improve clinical care probably lead to lower sickness absence and lower levels of depression, compared with care as usual. There was no evidence of a difference in effect on sickness absence of one antidepressant medication compared to another. Further research is needed to assess which combination of work-directed and clinical interventions works best.

Relevance and paucity of evidence: a dental perspective on personal protective equipment during the COVID-19 pandemic.

The global COVID-19 pandemic, caused by the SARS-CoV-2 virus, has highlighted the importance of personal protective equipment (PPE) for health and social care personnel. This is a really important issue for dentistry, where we place great emphasis on infection control and universal precautions, given the nature of care provided. Cochrane have recently updated their review of PPE for preventing highly infectious diseases due to exposure to contaminated body fluids in healthcare staff. It examined evidence on which type of full body PPE and which method of donning (putting on) or doffing (removing) are most effective, while having the least risk of contamination or infection for healthcare workers, as well as which training methods increase compliance with PPE protocols. The objective of this paper is to raise awareness of the above review of PPE, its findings and their relevance to dentistry as outlined in the Cochrane Oral Health website.The available evidence comes from healthcare generally, mostly involving simulation exercises, and is of low or very low certainty. None of the evidence specifically comes from dentistry.The findings in relation to the nature of PPE, methods of donning and doffing, and the importance of training are all of practical relevance to dentistry. Research is critically important to provide evidence for future decision making in support of patients and staff.

Personal protective equipment for preventing highly infectious diseases due to exposure to contaminated body fluids in healthcare staff.

BACKGROUND: In epidemics of highly infectious diseases, such as Ebola, severe acute respiratory syndrome (SARS), or coronavirus (COVID-19), healthcare workers (HCW) are at much greater risk of infection than the general population, due to their contact with patients' contaminated body fluids. Personal protective equipment (PPE) can reduce the risk by covering exposed body parts. It is unclear which type of PPE protects best, what is the best way to put PPE on (i.e. donning) or to remove PPE (i.e. doffing), and how to train HCWs to use PPE as instructed. OBJECTIVES: To evaluate which type of full-body PPE and which method of donning or doffing PPE have the least risk of contamination or infection for HCW, and which training methods increase compliance with PPE protocols. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase and CINAHL to 20 March 2020. SELECTION CRITERIA: We included all controlled studies that evaluated the effect of full-body PPE used by HCW exposed to highly infectious diseases, on the risk of infection, contamination, or noncompliance with protocols. We also included studies that compared the effect of various ways of donning or doffing PPE, and the effects of training on the same outcomes. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, extracted data and assessed the risk of bias in included trials. We conducted random-effects meta-analyses were appropriate. MAIN RESULTS: Earlier versions of this review were published in 2016 and 2019. In this update, we included 24 studies with 2278 participants, of which 14 were randomised controlled trials (RCT), one was a quasi-RCT and nine had a non-randomised design. Eight studies compared types of PPE. Six studies evaluated adapted PPE. Eight studies compared donning and doffing processes and three studies evaluated types of training. Eighteen studies used simulated exposure with fluorescent markers or harmless microbes. In simulation studies, median contamination rates were 25% for the intervention and 67% for the control groups. Evidence for all outcomes is of very low certainty unless otherwise stated because it is based on one or two studies, the indirectness of the evidence in simulation studies and because of risk of bias. Types of PPE The use of a powered, air-purifying respirator with coverall may protect against the risk of contamination better than a N95 mask and gown (risk ratio (RR) 0.27, 95% confidence interval (CI) 0.17 to 0.43) but was more difficult to don (non-compliance: RR 7.5, 95% CI 1.81 to 31.1). In one RCT (59 participants) coveralls were more difficult to doff than isolation gowns (very low-certainty evidence). Gowns may protect better against contamination than aprons (small patches: mean difference (MD) -10.28, 95% CI -14.77 to -5.79). PPE made of more breathable material may lead to a similar number of spots on the trunk (MD 1.60, 95% CI -0.15 to 3.35) compared to more water-repellent material but may have greater user satisfaction (MD -0.46, 95% CI -0.84 to -0.08, scale of 1 to 5). According to three studies that tested more recently introduced full-body PPE ensembles, there may be no difference in contamination. Modified PPE versus standard PPE The following modifications to PPE design may lead to less contamination compared to standard PPE: sealed gown and glove combination (RR 0.27, 95% CI 0.09 to 0.78), a better fitting gown around the neck, wrists and hands (RR 0.08, 95% CI 0.01 to 0.55), a better cover of the gown-wrist interface (RR 0.45, 95% CI 0.26 to 0.78, low-certainty evidence), added tabs to grab to facilitate doffing of masks (RR 0.33, 95% CI 0.14 to 0.80) or gloves (RR 0.22, 95% CI 0.15 to 0.31). Donning and doffing Using Centers for Disease Control and Prevention (CDC) recommendations for doffing may lead to less contamination compared to no guidance (small patches: MD -5.44, 95% CI -7.43 to -3.45). One-step removal of gloves and gown may lead to less bacterial contamination (RR 0.20, 95% CI 0.05 to 0.77) but not to less fluorescent contamination (RR 0.98, 95% CI 0.75 to 1.28) than separate removal. Double-gloving may lead to less viral or bacterial contamination compared to single gloving (RR 0.34, 95% CI 0.17 to 0.66) but not to less fluorescent contamination (RR 0.98, 95% CI 0.75 to 1.28). Additional spoken instruction may lead to fewer errors in doffing (MD -0.9, 95% CI -1.4 to -0.4) and to fewer contamination spots (MD -5, 95% CI -8.08 to -1.92). Extra sanitation of gloves before doffing with quaternary ammonium or bleach may decrease contamination, but not alcohol-based hand rub. Training The use of additional computer simulation may lead to fewer errors in doffing (MD -1.2, 95% CI -1.6 to -0.7). A video lecture on donning PPE may lead to better skills scores (MD 30.70, 95% CI 20.14 to 41.26) than a traditional lecture. Face-to-face instruction may reduce noncompliance with doffing guidance more (odds ratio 0.45, 95% CI 0.21 to 0.98) than providing folders or videos only. AUTHORS' CONCLUSIONS: We found low- to very low-certainty evidence that covering more parts of the body leads to better protection but usually comes at the cost of more difficult donning or doffing and less user comfort. More breathable types of PPE may lead to similar contamination but may have greater user satisfaction. Modifications to PPE design, such as tabs to grab, may decrease the risk of contamination. For donning and doffing procedures, following CDC doffing guidance, a one-step glove and gown removal, double-gloving, spoken instructions during doffing, and using glove disinfection may reduce contamination and increase compliance. Face-to-face training in PPE use may reduce errors more than folder-based training. We still need RCTs of training with long-term follow-up. We need simulation studies with more participants to find out which combinations of PPE and which doffing procedure protects best. Consensus on simulation of exposure and assessment of outcome is urgently needed. We also need more real-life evidence. Therefore, the use of PPE of HCW exposed to highly infectious diseases should be registered and the HCW should be prospectively followed for their risk of infection.

Personal protective equipment for preventing highly infectious diseases due to exposure to contaminated body fluids in healthcare staff.

BACKGROUND: In epidemics of highly infectious diseases, such as Ebola, severe acute respiratory syndrome (SARS), or coronavirus (COVID-19), healthcare workers (HCW) are at much greater risk of infection than the general population, due to their contact with patients' contaminated body fluids. Personal protective equipment (PPE) can reduce the risk by covering exposed body parts. It is unclear which type of PPE protects best, what is the best way to put PPE on (i.e. donning) or to remove PPE (i.e. doffing), and how to train HCWs to use PPE as instructed. OBJECTIVES: To evaluate which type of full-body PPE and which method of donning or doffing PPE have the least risk of contamination or infection for HCW, and which training methods increase compliance with PPE protocols. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase and CINAHL to 20 March 2020. SELECTION CRITERIA: We included all controlled studies that evaluated the effect of full-body PPE used by HCW exposed to highly infectious diseases, on the risk of infection, contamination, or noncompliance with protocols. We also included studies that compared the effect of various ways of donning or doffing PPE, and the effects of training on the same outcomes. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies, extracted data and assessed the risk of bias in included trials. We conducted random-effects meta-analyses were appropriate. MAIN RESULTS: Earlier versions of this review were published in 2016 and 2019. In this update, we included 24 studies with 2278 participants, of which 14 were randomised controlled trials (RCT), one was a quasi-RCT and nine had a non-randomised design. Eight studies compared types of PPE. Six studies evaluated adapted PPE. Eight studies compared donning and doffing processes and three studies evaluated types of training. Eighteen studies used simulated exposure with fluorescent markers or harmless microbes. In simulation studies, median contamination rates were 25% for the intervention and 67% for the control groups. Evidence for all outcomes is of very low certainty unless otherwise stated because it is based on one or two studies, the indirectness of the evidence in simulation studies and because of risk of bias. Types of PPE The use of a powered, air-purifying respirator with coverall may protect against the risk of contamination better than a N95 mask and gown (risk ratio (RR) 0.27, 95% confidence interval (CI) 0.17 to 0.43) but was more difficult to don (non-compliance: RR 7.5, 95% CI 1.81 to 31.1). In one RCT (59 participants), people with a long gown had less contamination than those with a coverall, and coveralls were more difficult to doff (low-certainty evidence). Gowns may protect better against contamination than aprons (small patches: mean difference (MD) -10.28, 95% CI -14.77 to -5.79). PPE made of more breathable material may lead to a similar number of spots on the trunk (MD 1.60, 95% CI -0.15 to 3.35) compared to more water-repellent material but may have greater user satisfaction (MD -0.46, 95% CI -0.84 to -0.08, scale of 1 to 5). Modified PPE versus standard PPE The following modifications to PPE design may lead to less contamination compared to standard PPE: sealed gown and glove combination (RR 0.27, 95% CI 0.09 to 0.78), a better fitting gown around the neck, wrists and hands (RR 0.08, 95% CI 0.01 to 0.55), a better cover of the gown-wrist interface (RR 0.45, 95% CI 0.26 to 0.78, low-certainty evidence), added tabs to grab to facilitate doffing of masks (RR 0.33, 95% CI 0.14 to 0.80) or gloves (RR 0.22, 95% CI 0.15 to 0.31). Donning and doffing Using Centers for Disease Control and Prevention (CDC) recommendations for doffing may lead to less contamination compared to no guidance (small patches: MD -5.44, 95% CI -7.43 to -3.45). One-step removal of gloves and gown may lead to less bacterial contamination (RR 0.20, 95% CI 0.05 to 0.77) but not to less fluorescent contamination (RR 0.98, 95% CI 0.75 to 1.28) than separate removal. Double-gloving may lead to less viral or bacterial contamination compared to single gloving (RR 0.34, 95% CI 0.17 to 0.66) but not to less fluorescent contamination (RR 0.98, 95% CI 0.75 to 1.28). Additional spoken instruction may lead to fewer errors in doffing (MD -0.9, 95% CI -1.4 to -0.4) and to fewer contamination spots (MD -5, 95% CI -8.08 to -1.92). Extra sanitation of gloves before doffing with quaternary ammonium or bleach may decrease contamination, but not alcohol-based hand rub. Training The use of additional computer simulation may lead to fewer errors in doffing (MD -1.2, 95% CI -1.6 to -0.7). A video lecture on donning PPE may lead to better skills scores (MD 30.70, 95% CI 20.14 to 41.26) than a traditional lecture. Face-to-face instruction may reduce noncompliance with doffing guidance more (odds ratio 0.45, 95% CI 0.21 to 0.98) than providing folders or videos only. AUTHORS' CONCLUSIONS: We found low- to very low-certainty evidence that covering more parts of the body leads to better protection but usually comes at the cost of more difficult donning or doffing and less user comfort, and may therefore even lead to more contamination. More breathable types of PPE may lead to similar contamination but may have greater user satisfaction. Modifications to PPE design, such as tabs to grab, may decrease the risk of contamination. For donning and doffing procedures, following CDC doffing guidance, a one-step glove and gown removal, double-gloving, spoken instructions during doffing, and using glove disinfection may reduce contamination and increase compliance. Face-to-face training in PPE use may reduce errors more than folder-based training. We still need RCTs of training with long-term follow-up. We need simulation studies with more participants to find out which combinations of PPE and which doffing procedure protects best. Consensus on simulation of exposure and assessment of outcome is urgently needed. We also need more real-life evidence. Therefore, the use of PPE of HCW exposed to highly infectious diseases should be registered and the HCW should be prospectively followed for their risk of infection.

Personal protective equipment for preventing highly infectious diseases due to exposure to contaminated body fluids in healthcare staff.

BACKGROUND: In epidemics of highly infectious diseases, such as Ebola Virus Disease (EVD) or Severe Acute Respiratory Syndrome (SARS), healthcare workers (HCW) are at much greater risk of infection than the general population, due to their contact with patients' contaminated body fluids. Contact precautions by means of personal protective equipment (PPE) can reduce the risk. It is unclear which type of PPE protects best, what is the best way to remove PPE, and how to make sure HCW use PPE as instructed. OBJECTIVES: To evaluate which type of full body PPE and which method of donning or doffing PPE have the least risk of self-contamination or infection for HCW, and which training methods increase compliance with PPE protocols. SEARCH METHODS: We searched MEDLINE (PubMed up to 15 July 2018), Cochrane Central Register of Trials (CENTRAL up to 18 June 2019), Scopus (Scopus 18 June 2019), CINAHL (EBSCOhost 31 July 2018), and OSH-Update (up to 31 December 2018). We also screened reference lists of included trials and relevant reviews, and contacted NGOs and manufacturers of PPE. SELECTION CRITERIA: We included all controlled studies that compared the effects of PPE used by HCW exposed to highly infectious diseases with serious consequences, such as Ebola or SARS, on the risk of infection, contamination, or noncompliance with protocols. This included studies that used simulated contamination with fluorescent markers or a non-pathogenic virus.We also included studies that compared the effect of various ways of donning or doffing PPE, and the effects of training in PPE use on the same outcomes. DATA COLLECTION AND ANALYSIS: Two authors independently selected studies, extracted data and assessed risk of bias in included trials. We planned to perform meta-analyses but did not find sufficiently similar studies to combine their results. MAIN RESULTS: We included 17 studies with 1950 participants evaluating 21 interventions. Ten studies are Randomised Controlled Trials (RCTs), one is a quasi RCT and six have a non-randomised controlled design. Two studies are awaiting assessment.Ten studies compared types of PPE but only six of these reported sufficient data. Six studies compared different types of donning and doffing and three studies evaluated different types of training. Fifteen studies used simulated exposure with fluorescent markers or harmless viruses. In simulation studies, contamination rates varied from 10% to 100% of participants for all types of PPE. In one study HCW were exposed to Ebola and in another to SARS.Evidence for all outcomes is based on single studies and is very low quality.Different types of PPEPPE made of more breathable material may not lead to more contamination spots on the trunk (Mean Difference (MD) 1.60 (95% Confidence Interval (CI) -0.15 to 3.35) than more water repellent material but may have greater user satisfaction (MD -0.46; 95% CI -0.84 to -0.08, scale of 1 to 5).Gowns may protect better against contamination than aprons (MD large patches -1.36 95% CI -1.78 to -0.94).The use of a powered air-purifying respirator may protect better than a simple ensemble of PPE without such respirator (Relative Risk (RR) 0.27; 95% CI 0.17 to 0.43).Five different PPE ensembles (such as gown vs. coverall, boots with or without covers, hood vs. cap, length and number of gloves) were evaluated in one study, but there were no event data available for compared groups.Alterations to PPE design may lead to less contamination such as added tabs to grab masks (RR 0.33; 95% CI 0.14 to 0.80) or gloves (RR 0.22 95% CI 0.15 to 0.31), a sealed gown and glove combination (RR 0.27; 95% CI 0.09 to 0.78), or a better fitting gown around the neck, wrists and hands (RR 0.08; 95% CI 0.01 to 0.55) compared to standard PPE.Different methods of donning and doffing proceduresDouble gloving may lead to less contamination compared to single gloving (RR 0.36; 95% CI 0.16 to 0.78).Following CDC recommendations for doffing may lead to less contamination compared to no guidance (MD small patches -5.44; 95% CI -7.43 to -3.45).Alcohol-based hand rub used during the doffing process may not lead to less contamination than the use of a hypochlorite based solution (MD 4.00; 95% CI 0.47 to 34.24).Additional spoken instruction may lead to fewer errors in doffing (MD -0.9, 95% CI -1.4 to -0.4).Different types of trainingThe use of additional computer simulation may lead to fewer errors in doffing (MD -1.2, 95% CI -1.6 to -0.7).A video lecture on donning PPE may lead to better skills scores (MD 30.70; 95% CI 20.14,41.26) than a traditional lecture.Face to face instruction may reduce noncompliance with doffing guidance more (OR 0.45; 95% CI 0.21 to 0.98) than providing folders or videos only.There were no studies on effects of training in the long term or on resource use.The quality of the evidence is very low for all comparisons because of high risk of bias in all studies, indirectness of evidence, and small numbers of participants. AUTHORS' CONCLUSIONS: We found very low quality evidence that more breathable types of PPE may not lead to more contamination, but may have greater user satisfaction. Alterations to PPE, such as tabs to grab may decrease contamination. Double gloving, following CDC doffing guidance, and spoken instructions during doffing may reduce contamination and increase compliance. Face-to-face training in PPE use may reduce errors more than video or folder based training. Because data come from single small studies with high risk of bias, we are uncertain about the estimates of effects.We still need randomised controlled trials to find out which training works best in the long term. We need better simulation studies conducted with several dozen participants to find out which PPE protects best, and what is the safest way to remove PPE. Consensus on the best way to conduct simulation of exposure and assessment of outcome is urgently needed. HCW exposed to highly infectious diseases should have their use of PPE registered and should be prospectively followed for their risk of infection in the field.

Self-certification versus physician certification of sick leave for reducing sickness absence and associated costs.

BACKGROUND: From the societal and employers' perspectives, sickness absence has a large economic impact. Internationally, there is variation in sickness certification practices. However, in most countries a physician's certificate of illness or reduced work ability is needed at some point of sickness absence. In many countries, there is a time period of varying length called the 'self-certification period' at the beginning of sickness absence. During that time a worker is not obliged to provide his or her employer a medical certificate and it is usually enough that the employee notifies his or her supervisor when taken ill. Self-certification can be introduced at organisational, regional, or national level. OBJECTIVES: To evaluate the effects of introducing, abolishing, or changing the period of self-certification of sickness absence on: the total or average duration (number of sickness absence days) of short-term sickness absence periods; the frequency of short-term sickness absence periods; the associated costs (of sickness absence and (occupational) health care); and social climate, supervisor involvement, and workload or presenteeism (see Figure 1). SEARCH METHODS: We conducted a systematic literature search to identify all potentially eligible published and unpublished studies. We adapted the search strategy developed for MEDLINE for use in the other electronic databases. We also searched for unpublished trials on ClinicalTrials.gov and the World Health Organization International Clinical Trials Registry Platform (WHO ICTRP). We used Google Scholar for exploratory searches. SELECTION CRITERIA: We considered randomised controlled trials (RCTs), controlled before-after (CBA) studies, and interrupted time-series (ITS) studies for inclusion. We included studies carried out with individual employees or insured workers. We also included studies in which participants were addressed at the aggregate level of organisations, companies, municipalities, healthcare settings, or general populations. We included studies evaluating the effects of introducing, abolishing, or changing the period of self-certification of sickness absence. DATA COLLECTION AND ANALYSIS: We conducted a systematic literature search up to 14 June 2018. We calculated missing data from other data reported by the authors. We intended to perform a random-effects meta-analysis, but the studies were too different to enable meta-analysis. MAIN RESULTS: We screened 6091 records for inclusion. Five studies fulfilled our inclusion criteria: one is an RCT and four are CBA studies. One study from Sweden changed the period of self-certification in 1985 in two districts for all insured inhabitants. Three studies from Norway conducted between 2001 and 2014 changed the period of self-certification in municipalities for all or part of the workers. One study from 1969 introduced self-certification for all manual workers of an oil refinery in the UK.Longer compared to shorter self-certificationfor reducing sickness absence in workersOutcome: average duration of sickness absence periodsExtending the period of self-certification from one week to two weeks produced a higher mean duration of sickness absence periods: mean difference in change values between the intervention and control group (MDchange) was 0.67 days/period up to 29 days (95% confidence interval (95% CI) 0.55 to 0.79; 1 RCT; low-certainty evidence).The introduction of self-certification for a maximum of three days produced a lower mean duration of sickness absence up to three days (MDchange -0.32 days/period, 95% CI -0.39 to -0.25; 1 CBA study; very low-certainty evidence). The authors of a different study reported that prolonging self-certification from ≤ 3 days to ≤ 365 days did not lead to a change, but they did not provide numerical data (very low-certainty evidence). OUTCOME: number of sickness absence periods per workerExtending the period of self-certification from one week to two weeks resulted in no difference in the number of sickness absence periods in one RCT, but the authors did not report numerical data (low-certainty evidence).The introduction of self-certification for a maximum of three days produced a higher mean number of sickness absence periods lasting up to three days (MDchange 0.48 periods, 95% CI 0.33 to 0.63) in one CBA study (very low-certainty evidence).Extending the period of self-certification from three days to up to a year decreased the number of periods in one CBA study, but the authors did not report data (very low-certainty evidence). OUTCOME: average lost work time per 100 person-yearsExtending the period of self-certification from one week to two weeks resulted in an inferred increase in lost work time in one RCT (very low-certainty evidence).Extending the period of self-certification (introduction of self-certification for a maximum of three days (from zero to three days) and from three days to five days, respectively) resulted in more work time lost due to sickness absence periods lasting up to three days in two CBA studies that could not be pooled (MDchange 0.54 days/person-year, 95% CI 0.47 to 0.61; and MDchange 1.38 days/person-year, 95% CI 1.16 to 1.60; very low-certainty evidence).Extending the period of self-certification from three days up to 50 days led to 0.65 days less lost work time in one CBA study, based on absence periods lasting between four and 16 days. Extending the period of self-certification from three days up to 365 days resulted in less work time lost due to sickness absence periods longer than 16 days (MDchange -2.84 days, 95% CI -3.35 to -2.33; 1 CBA study; very low-certainty evidence). OUTCOME: costs of sickness absence and physician certificationOne RCT reported that the higher costs of sickness absence benefits incurred by extending the period of self-certification far outweighed the possible reduction in costs of fewer physician appointments by almost six to one (low-certainty evidence).In summary, we found very low-certainty evidence that introducing self-certification of sickness absence or prolonging the self-certification period has inconsistent effects on the mean number of sickness absence days, the number of sickness absence periods, and on lost work time due to sickness absence periods. AUTHORS' CONCLUSIONS: There is low- to very low-certainty evidence of inconsistent effects of changing the period of self-certification on the duration or frequency of short-term sickness absence periods or the amount of work time lost due to sickness absence. Because the evidence is of low or very low certainty, more and better studies are needed.