Precarious employment and the workplace transmission of COVID-19: evidence from workers' compensation claims in Ontario, Canada.

OBJECTIVE: To examine the association between precarious employment and risk of work-related COVID-19 infection in Ontario, Canada. METHODS: We combined data from an administrative census of workers' compensation claims with corresponding labour force statistics to estimate rates of work-related COVID-19 infection between April 2020 and April 2022. Precarious employment was imputed using a job exposure matrix capturing temporary employment, low wages, irregular hours, involuntary part-time employment and a multidimensional indicator of 'low', 'medium', 'high' and 'very high' overall exposure to precarious employment. We used negative binomial regression models to quantify associations between precarious employment and accepted compensation claims for COVID-19. RESULTS: We observed a monotonic association between precarious employment and work-related COVID-19 claims. Workers with 'very high' exposure to precarious employment presented a nearly fivefold claim risk in models controlling for age, sex and pandemic wave (rate ratio (RR): 4.90, 95% CI 4.07 to 5.89). Further controlling for occupational exposures (public facing work, working in close proximity to others, indoor work) somewhat attenuated observed associations. After accounting for these factors, workers with 'very high' exposure to precarious employment were still nearly four times as likely to file a successful claim for COVID-19 (RR: 3.78, 95% CI 3.28 to 4.36). CONCLUSIONS: During the first 2 years of the pandemic, precariously employed workers were more likely to acquire a work-related COVID-19 infection resulting in a successful lost-time compensation claim. Strategies aiming to promote an equitable and sustained recovery from the pandemic should consider and address the notable risks associated with precarious employment.

Is precarious employment an occupational hazard? Evidence from Ontario, Canada.

OBJECTIVES: To examine the association between precarious employment and risk of occupational injury or illness in Ontario, Canada. METHODS: We combined accepted lost-time compensation claims from the Workplace Safety and Insurance Board with labour force statistics to estimate injury and illness rates between January 2016 and December 2019. Precarious employment was imputed using a job exposure matrix and operationalised in terms of temporary employment, low wages, irregular hours, involuntary part-time employment and a multidimensional measure of 'low', 'medium', 'high' and 'very high' probabilities of exposure to precarious employment. Negative binomial regression models examined exposure to precarious employment in relation to risk of occupational injury or illness. RESULTS: After adjusting for age, sex and year, all indicators of precarious employment were associated with increased risk of injury or illness. Workers with 'high' and 'very' high' exposure to precarious employment presented a nearly threefold risk of injury or illness (rate ratio (RR): 2.81, 95% CI 2.73 to 2.89; RR: 2.82, 95% CI 2.74 to 2.90). Further adjustment for physical demands and workplace hazards attenuated associations, though a statistically and substantively significant exposure-outcome relationship persisted for workers with 'high' and 'very high' exposures to precarious employment (RR: 1.65, 95% CI 1.58 to 1.72; RR: 2.00, 95% CI 1.92 to 2.08). CONCLUSIONS: Workers exposed to precarious employment are more likely to sustain a lost-time injury or illness in Ontario, Canada. Workplace health and safety strategies should consider the role of precarious employment as an occupational hazard and a marker of work injury risk.

Improving prevalence estimates of mental health and well-being indicators among Sexual Minority Men: A Propensity Weighting Approach.

The prevalence and relative disparities of mental health outcomes and well-being indicators are often inconsistent across studies of Sexual Minority Men (SMM) due to selection biases in community-based surveys (non-probability sample), as well as misclassification biases in population-based surveys where some SMM often conceal their sexual orientation identities. The current paper estimated the prevalence of mental health related outcomes (depressive symptoms, mental health service use [MHSU], anxiety) and well-being indicators (loneliness and self-rated mental health) among SMM, broken down by sexual orientation using the Adjusted Logistic Propensity score (ALP) weighting. We applied the ALP to correct for selection biases in the 2019 Sex Now data (a community-based survey of SMMs in Canada) by reweighting it to the 2015-2018 Canadian Community Health Survey (a population survey from Statistics Canada). For all SMMs, the ALP-weighted prevalence of depressive symptoms is 15.96% (95% CI: 11.36%, 23.83%), while for MHSU, it is 32.13% (95% CI: 26.09, 41.20). The ALP estimates lie in between the crude estimates from the two surveys. This method was successful in providing a more accurate estimate than relying on results from one survey alone. We recommend to the use of ALP on other minority populations under certain assumptions.

Trends in severity of work-related traumatic injury and musculoskeletal disorder, Ontario 2004-2017.

OBJECTIVES: Traumatic injury surveillance can be enhanced by describing injury severity trends. This study reports trends in work-related injury severity for males and females over the period 2004-2017 in Ontario, Canada. METHODS: A weighted measure of workers' compensation benefit expenditures was used to define injury severity, obtained from the linkage of workers' compensation claims to emergency department (ED) records where the main injury or illness was attributed to work. Denominator counts were obtained from Statistics Canada's Labor Force Survey. Trends in the annual incidence of injury, classified as low, moderate, or high severity, were examined using regression modeling, stratified by age and sex. RESULTS: Over a 14-year observation period, there were 1,636,866 ED records included in the analyses. Overall, 57.6% of occupational injury records were classified as low severity, 29.5% as moderate severity, and 12.8% as high severity conditions. There was an increase in the incidence of high severity injuries among females (annual percent change (APC): 1.52%; 95% CI: 0.77, 2.28), while the incidence of low and moderate severity injuries generally declined for males and females. Among females, injuries attributed to animate mechanical forces and assault increased as causes of low, moderate, and high severity injuries. The incidence of concussion increased for both males (APC: 10.51%; 95% CI: 8.18, 12.88) and females (APC: 16.37%; 95% CI: 13.37, 19.45). CONCLUSION: The incidence of severe work-related injuries increased among females in Ontario between 2004 and 2017. The methods applied in this surveillance study of traumatic injury severity are plausibly generalizable to applications in other jurisdictions.

Variation in occupational exposure risk for COVID-19 workers' compensation claims across pandemic waves in Ontario.

OBJECTIVES: To understand rates of work-related COVID-19 (WR-C19) infection by occupational exposures across waves of the COVID-19 pandemic in Ontario, Canada. METHODS: We combined workers' compensation claims for COVID-19 with data from Statistics Canada's Labour Force Survey, to estimate rates of WR-C19 among workers spending the majority of their working time at the workplace between 1 April 2020 and 30 April 2022. Occupational exposures, imputed using a job exposure matrix, were whether the occupation was public facing, proximity to others at work, location of work and a summary measure of low, medium and high occupational exposure. Negative binomial regression models examined the relationship between occupational exposures and risk of WR-C19, adjusting for covariates. RESULTS: Trends in rates of WR-C19 differed from overall COVID-19 cases among the working-aged population. All occupational exposures were associated with increased risk of WR-C19, with risk ratios for medium and high summary exposures being 1.30 (95% CI 1.09 to 1.55) and 2.46 (95% CI 2.10 to 2.88), respectively, in fully adjusted models. The magnitude of associations between occupational exposures and risk of WR-C19 differed across waves of the pandemic, being weakest for most exposures in period March 2021 to June 2021, and highest at the start of the pandemic and during the Omicron wave (December 2021 to April 2022). CONCLUSIONS: Occupational exposures were consistently associated with increased risk of WR-C19, although the magnitude of this relationship differed across pandemic waves in Ontario. Preparation for future pandemics should consider more accurate reporting of WR-C19 infections and the potential dynamic nature of occupational exposures.

Evaluation of the Ontario Mandatory Working-at-Heights Training Requirement in Construction, 2012‒2019.

The province of Ontario, Canada, implemented mandatory day-long training for construction workers required to use fall-protection equipment. More than 400 000 training sessions were completed by 2017 when the requirement took full effect. The lost-time workers' compensation claim incidence rate attributable to falls targeted by the training was 19% lower in 2017-2019 than in 2012-2014. Rates for two comparator injuries increased or stayed the same. The decline in targeted fall claim incidence rate of the other Canadian provinces was 6%. (Am J Public Health. 2024;114(1):38-41. https://doi.org/10.2105/AJPH.2023.307440).

Workplace and non-workplace cannabis use and the risk of workplace injury: Findings from a longitudinal study of Canadian workers.

OBJECTIVES: Findings of previous studies examining the relationship between cannabis use and workplace injury have been conflicting, likely due to methodological shortcomings, including cross-sectional designs and exposure measures that lack consideration for timing of use. The objective was to estimate the association between workplace cannabis use (before and/or at work) and non-workplace use and the risk of workplace injury. METHODS: Canadian workers participating in a yearly longitudinal study (from 2018 to 2020) with at least two adjacent years of survey data comprised the analytic sample (n = 2745). The exposure was past-year workplace cannabis use (no past-year use, non-workplace use, workplace use). The outcome was past-year workplace injury (yes/no). Absolute risks and relative risks (RR) with 95% confidence intervals (CIs) were estimated between workplace and non-workplace cannabis use at one time point and workplace injury at the following time point. Models were adjusted for personal and work variables and were also stratified by whether respondents' jobs were safety-sensitive. RESULTS: Compared to no past-year cannabis use, there was no difference in workplace injury risk for non-workplace cannabis use (RR 1.09, 95%CI 0.83-1.44). However, workplace use was associated with an almost two-fold increased risk of experiencing a workplace injury (RR 1.97, 95%CI 1.32-2.93). Findings were similar for workers in safety-sensitive and non-safety-sensitive work. CONCLUSION: It is important to distinguish between non-workplace and workplace use when considering workplace safety impacts of cannabis use. Findings have implications for workplace cannabis use policies and substantiate the need for worker education on the risks of workplace cannabis use.

RéSUMé: OBJECTIFS: Les résultats d'études antérieures portant sur la relation entre la consommation de cannabis et les accidents du travail sont contradictoires, probablement en raison de lacunes méthodologiques, notamment les études transversales et les mesures de l'exposition qui ne tiennent pas compte du moment de la consommation. L'objectif était d'estimer l'association entre la consommation de cannabis sur le lieu de travail (avant et/ou pendant le travail) et la consommation en dehors du lieu de travail et le risque d'accident du travail. MéTHODES: Les travailleurs canadiens participant à une étude longitudinale annuelle (de 2018 à 2020) avec au moins deux années adjacentes de données d'enquête constituaient l'échantillon analytique (n = 2 745). L'exposition était la consommation de cannabis au travail au cours de l'année écoulée (pas de consommation au cours de l'année écoulée, consommation en dehors du lieu de travail, consommation sur le lieu de travail). Le résultat était l'accident du travail de l'année écoulée (oui/non). Les risques absolus et les risques relatifs (RR) avec des intervalles de confiance (IC) de 95% ont été estimés entre la consommation de cannabis sur le lieu de travail et en dehors du lieu de travail à un moment donné et l'accident du travail au moment suivant. Les modèles ont été ajustés pour tenir compte des variables personnelles et professionnelles et ont également été stratifiés selon que les emplois des répondants étaient ou non sensibles à la sécurité. RéSULTATS: Par rapport à l'absence de consommation de cannabis au cours de l'année écoulée, il n'y avait pas de différence dans le risque d'accident du travail en cas de consommation de cannabis en dehors du lieu de travail (RR 1,09, IC à 95% 0,83­1,44). Cependant, la consommation sur le lieu de travail était associée à un risque presque deux fois plus élevé de subir un accident du travail (RR 1,97, IC à 95% 1,32­2,93). Les résultats étaient similaires pour les travailleurs exerçant des activités sensibles à la sécurité et pour ceux qui ne le sont pas. CONCLUSION: Il est important de distinguer entre la consommation en dehors du lieu de travail et la consommation sur le lieu de travail lorsqu'on étudie les effets de la consommation de cannabis sur la sécurité sur le lieu de travail. Les résultats ont des implications pour les politiques relatives à la consommation de cannabis sur le lieu de travail et justifient la nécessité d'informer les travailleurs sur les risques liés à la consommation de cannabis sur le lieu de travail.

Updating the Know Your Chances Website to Include Smoking Status as a Risk Factor for Mortality Estimates.

Importance: To make wise decisions about the health risks they face, people need information about the magnitude of the threats as well as the context, such as how risks compare. Such information is often presented by age, sex, and race but rarely accounts for smoking status, a major risk factor for many causes of death. Objective: To update the National Cancer Institute's Know Your Chances website to present mortality estimates for a broad set of causes of death and all causes combined by smoking status in addition to age, sex, and race. Design, Setting, and Participants: In this cohort study, mortality estimates using life table methods were calculated with the National Cancer Institute's DevCan software package, combining data from the US National Vital Statistics System, National Health Interview Survey-Linked Mortality Files, National Institutes of Health-AARP (American Association of Retired Persons), Cancer Prevention Study II, Nurses' Health and Health Professions follow-up studies, and Women's Health Initiative. Data were collected from January 1, 2009, to December 31, 2018, and analyzed from August 27, 2019, to February 28, 2023. Main Outcomes and Measures: Age-conditional probabilities of dying due to various causes and all causes combined, accounting for competing causes of death, for people aged 20 to 75 years over the next 5, 10, or 20 years by sex, race, and smoking status. Results: A total of 954 029 individuals aged 55 years or older (55.8% women) were included in the analysis. Regardless of sex or race, for never-smokers, coronary heart disease represented the highest 10-year chance of death after about 50 years of age, which is higher than for any malignant neoplasm. Among current smokers, the 10-year chance of death due to lung cancer was almost as high as for coronary heart disease in each group. For Black and White female current smokers aged from the mid-40s onward, the 10-year probability of death due to lung cancer was substantially higher than for breast cancer. After 40 years of age, the observed effect of never vs current smoking on the 10-year chance of death due to all causes approximated adding 10 years of age. After 40 years of age when conditioning on smoking status, mortality risk for Black individuals was approximately that of White individuals 5 years older. Conclusions and Relevance: Using life table methods and accounting for competing risks, the revised Know Your Chances website presents age-conditional mortality estimates according to smoking status for a broad set of causes in the context of other conditions and all-cause mortality. The findings of this cohort study suggest that failing to account for smoking status results in inaccurate mortality estimates for many causes-namely, they are too low for smokers and too high for nonsmokers.

Relationship Between Location of Pregnancy-Related and Postpartum-Related Back Pain and Limitations of Daily Activities and Work Participation.

OBJECTIVE: The aims of this study were to (1) examine if the location of pregnancy-related back pain impacts activities of daily living and absence from work and (2) determine which types of pain were more likely to persist postpartum. METHODS: This was a secondary analysis of data from an observational cohort study. Data were collected in Ontario between 2013 and 2014. Four pain location groups were identified, including low back pain (LBP), pelvic girdle pain (PGP), combined pain, and mixed pain. Logistic regression models were used to examine the impact of pain location on activity and absence from work. Descriptive analyses explored the association between pregnancy pain location and postpartum pain patterns. RESULTS: We surveyed 305 pregnant participants and followed up with 80 of these participants up to 6 months postpartum. Data analysis showed approximately a 2-fold increase in interference with employment (outside the home) and self-grooming for those with combined pain compared to those only experiencing LBP. Respondents with PGP and combined PGP and LBP had approximately a 5-fold increased likelihood of absence from work compared to respondents with only LBP; those with a mixture of LBP and PGP had a 13-fold increase in likelihood. Approximately 50% of respondents reported being pain-free, 16% experienced lingering pain, and 38% experienced persistent pain within 6 months postpartum. Those with combined pain during pregnancy continued to have persistent pain up to 6 months postpartum. CONCLUSION: The results suggest that the location of pregnancy-related back pain is associated with interference in daily activities, an increase in absence from work, and the persistence of postpartum pain. For this cohort, back pain did not always resolve after delivery, and those experiencing pregnancy-related combined pain continued to experience symptoms postpartum.

Cannabis use and workplace cannabis availability, perceptions and policies among Canadian workers: a comparison before and after the legalisation of non-medical cannabis.

OBJECTIVES: Little data exist examining the impact of non-medical (recreational) cannabis legalisation among a working population. The objective was to compare cannabis use patterns and workplace risk perceptions, cannabis availability and workplace use policies before and almost 1 year after legalisation in Canadian workers. METHODS: Two overlapping cross-sectional samples of Canadian workers were surveyed 4 months before legalisation (time 1 (T1), n=2011) and 9-11 months after legalisation (time 2 (T2), n=4032), gathering information on cannabis use (overall and workplace use), workers' perceptions regarding risks of workplace use, availability of cannabis at work and awareness of workplace substance use policies. The marginal distributions of these variables at T1 and T2 were compared, adjusting for sociodemographic, work and health and lifestyle factors. RESULTS: Cannabis use status changed from prelegalisation to postlegalisation (p<0.0001), with fewer respondents reporting former use (ie, more than 1 year ago; 40.4% at T1, 33.0% at T2) and a greater proportion of workers reporting past-year use (30.4% at T1, 39.3% at T2). Never use remained stable (29.2% at T1, 27.6% at T2). Workplace cannabis use also remained stable (9.4% at T1, 9.1% at T2; p=0.4580). At T1, 62.7% of respondents reported being aware of their workplace having a substance use policy, increasing to 79.0% at T2 (p<0.0001). Small magnitude changes occurred in perceptions of risk and workplace availability. CONCLUSIONS: Results point to a lack of substantive changes in the short-term from prelegalisation to postlegalisation. Longer-term data among workers are needed given the evolving nature of this legislative policy.

Unionisation and injury risk in construction: a replication study.

OBJECTIVE: To replicate, in a more recent time period, a previous cross-sectional study to estimate the association between unionisation and the risk of workers' compensation injury claims. METHODS: The sampling frame was workers' compensation company account records in the industrial, commercial and institutional construction sector in the province of Ontario, Canada, 2012-2018. Company unionisation status was determined through linkage with records of unionised contractors. Outcomes were cumulative counts of workers' compensation injury claims, aggregated to company business. Risk ratios were estimated with multivariable negative binomial regression models. Models were also fit separately to lost-time claims stratified by company size. RESULTS: Business unionisation was associated with a lower lost-time claim incidence (crude risk ratio, CRR=0.69, 95% CI 0.65 to 0.74); adjusted risk ratio, ARR=0.75, 95% CI 0.71 to 0.80). In subgroup analyses, the magnitude of the ARR declined as company size decreased and was not statistically significant for the smallest-sized companies of ≤4 full-time equivalent employees. Unionisation was associated (positively) with the incidence of no-lost-time claims in a crude model, but not in an adjusted one (CRR=1.80, 95% CI 1.71 to 1.89; ARR=1.04, 95% CI 0.98 to 1.09). CONCLUSIONS: Company unionisation was associated with a lower risk of lost-time workers' compensation injury claims, corroborating a similar study from an earlier time period. The protective effect of unionisation declined as company size decreased. In contrast to the previous study, a positive relationship between company unionisation and no-lost-time claim incidence was not found, due in part to a methodological refinement.

Blinding, sham, and treatment effects in randomized controlled trials for back pain in 2000-2019: A review and meta-analytic approach.

BACKGROUND: Blinding aims to minimize biases from what participants and investigators know or believe. Randomized controlled trials, despite being the gold standard to evaluate treatment effect, do not generally assess the success of blinding. We investigated the extent of blinding in back pain trials and the associations between participant guesses and treatment effects. METHODS: We did a review with PubMed/OvidMedline, 2000-2019. Eligibility criteria were back pain trials with data available on treatment effect and participants' guess of treatment. For blinding, blinding index was used as chance-corrected measure of excessive correct guess (0 for random guess). For treatment effects, within- or between-arm effect sizes were used. Analyses of investigators' guess/blinding or by treatment modality were performed exploratorily. RESULTS: Forty trials (3899 participants) were included. Active and sham treatment groups had mean blinding index of 0.26 (95% confidence interval: 0.12, 0.41) and 0.01 (-0.11, 0.14), respectively, meaning 26% of participants in active treatment believed they received active treatment, whereas only 1% in sham believed they received sham treatment, beyond chance, that is, random guess. A greater belief of receiving active treatment was associated with a larger within-arm effect size in both arms, and ideal blinding (namely, "random guess," and "wishful thinking" that signifies both groups believing they received active treatment) showed smaller effect sizes, with correlation of effect size and summary blinding indexes of 0.35 (p = 0.028) for between-arm comparison. We observed uniformly large sham treatment effects for all modalities, and larger correlation for investigator's (un)blinding, 0.53 (p = 0.046). CONCLUSION: Participants in active treatments in back pain trials guessed treatment identity more correctly, while those in sham treatments tended to display successful blinding. Excessive correct guesses (that could reflect weaker blinding and/or noticeable effects) by participants and investigators demonstrated larger effect sizes. Blinding and sham treatment effects on back pain need due consideration in individual trials and meta-analyses.

Preventing fall-from-height injuries in construction: Effectiveness of a regulatory training standard.

INTRODUCTION: A regulatory training standard for construction workers using fall protection equipment became mandatory in 2015 in the province of Ontario, Canada. By the end of the transition period in 2017, 418,000 workers had been trained to the new standard. Two primary research questions were posed: (1) To what extent does the WAH training affect practices at the worksite? and (2) Has there been a change in the incidence of fall-from-height injuries coincident with the introduction of the WAH Training Standard? MATERIALS AND METHODS: A longitudinal survey of 633 learners was conducted in 2017 at one-, four- and seven-week post-training. A quasi-experiment estimated the incidence of lost-time injuries attributed to falls from heights in 2017 compared to 2012-2014 for a census of construction workers insured for work disability in Ontario, Canada. RESULTS: Learners self-reported substantial increases in knowledge of and improvements in safe work practices when working at heights. The incidence rate of lost-time claim injuries attributed to falls targeted by the training declined by 19.6% (95% CI: 10.7, -27.6), compared to corresponding declines of 2.1% (95% CI: -6.3, 9.9) for other fall injuries and 7.2% (95% CI: 1.8, 12.3) for non-fall traumatic injuries. The observed decline was largest among the smallest employers (<5 full-time equivalent employees). CONCLUSION: The evaluation findings provide consistent support for a conclusion that the mandatory training standard was effective in reducing the incidence of injuries targeted by the training. However, the effects were modest and did not eliminate the problem. Practical application: A mandatory training standard should be considered as one approach to preventing traumatic injuries. However, other approaches higher in the hierarchy of risk controls should also be considered.

Ontario chiropractor's knowledge of exercise guidelines for pregnant patients.

OBJECTIVE: To describe the Ontario chiropractors' knowledge regarding the current guidelines for exercise during pregnancy through a knowledge score and exploring its distribution across different strata of interest including gender, experience, location of practice and type of practice. METHODS: A previously used survey was modified and sent to 500 randomly selected Ontario chiropractors. Demographic and continuing education questions were included, and the knowledge score was calculated using 10 items. RESULTS: The differences between the knowledge score values across the four strata of interest were not statistically significant. The average knowledge score in the sample of respondents was low (5.2 out of 10) and highly variable (SD=1.8). CONCLUSION: The average knowledge score of the respondents was found to be low and highly variable but not statistically or practically different across various strata of interest. A well-designed curriculum or post-graduate courses may be beneficial for practicing chiropractors in Ontario.

OBJECTIF: Décrire les connaissances des chiropraticien(ne)s de l'Ontario sur les lignes directrices actuelles en matière d'exercice pendant la grossesse au moyen d'un score de connaissances et explorer leur répartition dans différentschamps d'intérêt, notamment le sexe, l'expérience, le lieu de pratique et le type de pratique. MÉTHODOLOGIE: Un sondage (ayant déjà servi) a été modifié et envoyé à 500 chiropraticien(ne)s choisi(e) s au hasard domicilié(e)s en Ontario. Des questions démographiques et de formation continue ont été ajoutées, et le score de connaissances a été calculé selon 10 critères. RÉSULTATS: Les différences entre les valeurs du score de connaissances parmi les quatre champs d'intérêt n'étaient pas statistiquement importante. Le score moyen de connaissances dans l'échantillon des personnes interrogées était faible (5,2 sur 10) et très variable (SD= 1,8). CONCLUSION: Le score moyen de connaissances des personnes interrogées s'est avéré faible et très variable, mais pas statistiquement ou pratiquement différent parmi les différentes champs d'intérêt. Un programme d'études ou des cours universitaires supérieurs bien conçus peuvent être bénéfiques pour les chiropraticien(ne)s de l'Ontario.

What do employers spend to protect the health of workers?

Objective This study aimed to estimate firm-level expenditures on occupational health and safety (OHS) for a representative sample of Canadian employers. Methods A cross-sectional survey of 334 employers with ≥20 employees in 18 economic sectors in the Ontario economy. Participants provided information on five dimensions of OHS expenditures: (i) organizational management and supervision; (ii) staff training in health and safety; (iii) personal protective equipment; (iv) professional services and, (v) estimates of the share of new capital investment that could be attributed to improved OHS performance. Expenditures for each of the five dimensions were summed for each organization and divided by the number of employees, resulting in an estimate of OHS expenditure per employee per year. Results The average OHS expenditure per worker per year was Can$1303 [95% confidence interval (CI) Can$1167-1454]. Expenditures were three times higher in the goods-producing sectors (Can$2417, 95% CI Can$2026-2809) relative to the service sectors (Can$847, 95% CI Can$777-915). The proportion of expenditures allocated to each of the five dimensions was generally consistent across economic sectors: 58% to organizational management and supervision, 22% to staff training in health and safety and 14% to personal protective equipment. On average, <5% of OHS expenditures per worker per year were allocated to professional services or estimated as the share of new capital investment attributed to OHS. Conclusions Employer expenditures on OHS are substantial. The results of this study are consistent with recent European estimates and strengthen understanding of the scale of employer financial expenditures to protect the health of workers.

Prevalence of Low Back Pain, Pelvic Girdle Pain, and Combination Pain in a Pregnant Ontario Population.

OBJECTIVE: The purpose of the current pilot study is to determine the point and period prevalence of site-specific back pain, low back pain (LBP), pelvic girdle pain (PGP), and combined pain (Combo Pain) in pregnant women at a large urban centre in Ontario. METHODS: Point and period prevalence for LBP, PGP, and Combo Pain were determined using a questionnaire and accompanying pain diagram. Women were included in the study if they were healthy, of child-bearing age (18-45 years), currently experiencing a singleton pregnancy (any trimester), and proficient in the English language. RESULTS: Data collected from 287 women were included in the analysis. Three-quarters of women suffered from some sort of pregnancy-related back pain. The point and period prevalences for women who were experiencing LBP, PGP, and Combo Pain were 15.7%, 17.8%, and 15.3% and 33.4%, 27.9%, and 30.7%, respectively. Secondary analyses demonstrated that increasing GA and suffering from both pains at some point prior to pregnancy (Prior Both) increased the risk of experiencing PGP and Combo Pain during pregnancy, respectively. CONCLUSION: The current study demonstrates that 76% of sampled women experienced pregnancy-related back pain and the prevalence of site-specific pain (LBP, PGP, and Combo Pain) increases with increased gestation. Risk factors include advanced GA and experiencing both types of pain prior to pregnancy (Prior Both). Furthermore, it is suggested that a standard definition of pain by location should be developed and employed so that future studies can elucidate appropriate prevention strategies and treatment options for each.

Sample size calculations for blinding assessment.

Blinding is a critical component in randomized clinical trials along with treatment effect estimation and comparisons between the treatments. Various methods have been proposed for the statistical analyses of blinding-related data, but there is little guidance for determining the sample size for this type of data, especially if blinding assessment is done in pilot studies. In this paper, we try to fill this gap and provide simple methods to address sample size calculations for a "new" study with different research questions and scenarios. The proposed methods are framed in terms of estimation/precision or statistical testing to allow investigators to choose the best suited method for their goals. We illustrate the methods using worked examples with real data.

Association of Venous Leg Ulcers With Ankle Range of Motion in People Attending Chiropractic Mobile Clinics in the Dominican Republic.

OBJECTIVE: The goal of the study was to determine if there was an association between chronic venous disorders (CVDs), particularly venous leg ulcers, and ankle range of motion (ROM) in the Dominican Republic. METHODS: Chronic venous disorders were classified using the clinical manifestations portion (C) of the CEAP (clinical manifestations, etiology, anatomy, pathophysiology) method. The legs of participants attending mobile chiropractic clinics in rural, low-income areas in the Dominican Republic were assessed for clinical signs of CVD and venous ulcers. Ankle ROM was then measured, and photographs of the legs were taken. The 6 clinical stages of CVD were divided into 3 groups: normal legs (normal), no ulcer CVD, and ulcer CVD (healed and active). Multiple linear regression of ankle ROM against CVD grouping was used to test the association. RESULTS: Eight of the 837 patients for whom CVD classification was obtained had venous ulcers (healed or active) on at least 1 leg. About 30% relative reduction in ROM (ankle dorsiflexion plus plantar flexion) was observed between the ulcer group and the normal group. Regression analysis comparing legs with ulcers to healthy legs (normal), adjusted for age, gender, indicator for obesity, and previous leg trauma, revealed a significant decrease of approximately 14° (P = .0007) in ankle ROM. Age was also found to be strongly significant in the regression analysis, 1 year of aging was associated with a decrease of 0.16° (P < .0001) in ankle ROM (approximately 1.6° in 10 years). CONCLUSION: A significant decrease was observed in ankle ROM for participants with active and healed leg venous ulcers compared with those without ulcers. There appeared to be an association between venous leg ulcers and ankle ROM in this sample.

Intra-examiner reliability of measurements of ankle range of motion using a modified inclinometer: a pilot study.

A modified inclinometer was designed for measuring total ankle range of motion (ROM) in the standing position for a large future study. The purpose of this pilot study was to assess the intra-examiner reliability of this new device in order to see if the examiner would be able to produce equally reliable measurements with this instrument as with a routinely used goniometer. Nineteen young healthy individuals took part in the pilot. The same examiner took the ROM measurements using both devices twice on the same day and one further time 2 or 3 days later. Test-retest reliability was measured using the intraclass correlation coefficient (ICC). The ICC values were 0.86 (95% CI=[0.67; 0.94]) and 0.83 (95% CI=[0.61; 0.93]) for the measurements taken with the goniometer on the same day and for those on two different days. The corresponding values for the modified inclinometer were 0.88 (95% CI=[0.72;0.95]) and 0.81 (95% CI=[0.57; 0.92]). Both instruments were found to have very good test-retest reliability.

On a conçu un inclinomètre modifié pour mesurer l'amplitude du mouvement (ADM) totale de la cheville en position debout pour une grande étude à venir. Cette étude pilote a pour objectif d'évaluer la fiabilité des intra-examinateurs vis-à-vis de ce nouveau dispositif afin de constater si l'examinateur serait en mesure de produire des mesures d'une fiabilité équivalente avec cet instrument par rapport au goniomètre couramment utilisé.Dix-neuf jeunes personnes en santé ont participé à l'étude pilote. Le même examinateur a pris des mesures de l'ADM avec les deux dispositifs à deux reprises le même jour et une autre fois deux ou trois jours plus tard. On a mesuré la fiabilité de test-retest au moyen du coefficient de corrélation intraclasse (CCI). Les valeurs de CCI étaient de 0,86 (IC à 95 %=[0,67; 0,94]) et de 0,83 (IC de 95 %=[0,61; 0,93]) pour les mesures prises avec le goniomètre le même jour et les mesures prises lors de deux jours différents. Les valeurs correspondantes pour l'inclinomètre modifié étaient de 0,88 (IC de 95 %=[0,72;0,95]) et de 0,81 (IC de 95 %=[0,57; 0,92]). On a constaté une très bonne fiabilité de test-retest avec les deux instruments.

21st-century hazards of smoking and benefits of cessation in the United States.

BACKGROUND: Extrapolation from studies in the 1980s suggests that smoking causes 25% of deaths among women and men 35 to 69 years of age in the United States. Nationally representative measurements of the current risks of smoking and the benefits of cessation at various ages are unavailable. METHODS: We obtained smoking and smoking-cessation histories from 113,752 women and 88,496 men 25 years of age or older who were interviewed between 1997 and 2004 in the U.S. National Health Interview Survey and related these data to the causes of deaths that occurred by December 31, 2006 (8236 deaths in women and 7479 in men). Hazard ratios for death among current smokers, as compared with those who had never smoked, were adjusted for age, educational level, adiposity, and alcohol consumption. RESULTS: For participants who were 25 to 79 years of age, the rate of death from any cause among current smokers was about three times that among those who had never smoked (hazard ratio for women, 3.0; 99% confidence interval [CI], 2.7 to 3.3; hazard ratio for men, 2.8; 99% CI, 2.4 to 3.1). Most of the excess mortality among smokers was due to neoplastic, vascular, respiratory, and other diseases that can be caused by smoking. The probability of surviving from 25 to 79 years of age was about twice as great in those who had never smoked as in current smokers (70% vs. 38% among women and 61% vs. 26% among men). Life expectancy was shortened by more than 10 years among the current smokers, as compared with those who had never smoked. Adults who had quit smoking at 25 to 34, 35 to 44, or 45 to 54 years of age gained about 10, 9, and 6 years of life, respectively, as compared with those who continued to smoke. CONCLUSIONS: Smokers lose at least one decade of life expectancy, as compared with those who have never smoked. Cessation before the age of 40 years reduces the risk of death associated with continued smoking by about 90%.