Association between face mask use and risk of SARS-CoV-2 infection: Cross-sectional study.

We examined the association between face masks and risk of infection with SARS-CoV-2 using cross-sectional data from 3,209 participants in a randomized trial exploring the effectiveness of glasses in reducing the risk of SARS-CoV-2 infection. Face mask use was based on participants' response to the end-of-follow-up survey. We found that the incidence of self-reported COVID-19 was 33% (aRR 1.33; 95% CI 1.03-1.72) higher in those wearing face masks often or sometimes, and 40% (aRR 1.40; 95% CI 1.08-1.82) higher in those wearing face masks almost always or always, compared to participants who reported wearing face masks never or almost never. We believe the observed increase in the incidence of infection associated with wearing a face mask is likely due to unobservable and hence nonadjustable differences between those wearing and not wearing a mask. Observational studies reporting on the relationship between face mask use and risk of respiratory infections should be interpreted cautiously, and more randomized trials are needed.

Reviewer training for improving grant and journal peer review.

BACKGROUND: Funders and scientific journals use peer review to decide which projects to fund or articles to publish. Reviewer training is an intervention to improve the quality of peer review. However, studies on the effects of such training yield inconsistent results, and there are no up-to-date systematic reviews addressing this question. OBJECTIVES: To evaluate the effect of peer reviewer training on the quality of grant and journal peer review. SEARCH METHODS: We used standard, extensive Cochrane search methods. The latest search date was 27 April 2022. SELECTION CRITERIA: We included randomized controlled trials (RCTs; including cluster-RCTs) that evaluated peer review with training interventions versus usual processes, no training interventions, or other interventions to improve the quality of peer review. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. Our primary outcomes were 1. completeness of reporting and 2. peer review detection of errors. Our secondary outcomes were 1. bibliometric scores, 2. stakeholders' assessment of peer review quality, 3. inter-reviewer agreement, 4. process-centred outcomes, 5. peer reviewer satisfaction, and 6. completion rate and speed of funded projects. We used the first version of the Cochrane risk of bias tool to assess the risk of bias, and we used GRADE to assess the certainty of evidence. MAIN RESULTS: We included 10 RCTs with a total of 1213 units of analysis. The unit of analysis was the individual reviewer in seven studies (722 reviewers in total), and the reviewed manuscript in three studies (491 manuscripts in total). In eight RCTs, participants were journal peer reviewers. In two studies, the participants were grant peer reviewers. The training interventions can be broadly divided into dialogue-based interventions (interactive workshop, face-to-face training, mentoring) and one-way communication (written information, video course, checklist, written feedback). Most studies were small. We found moderate-certainty evidence that emails reminding peer reviewers to check items of reporting checklists, compared with standard journal practice, have little or no effect on the completeness of reporting, measured as the proportion of items (from 0.00 to 1.00) that were adequately reported (mean difference (MD) 0.02, 95% confidence interval (CI) -0.02 to 0.06; 2 RCTs, 421 manuscripts). There was low-certainty evidence that reviewer training, compared with standard journal practice, slightly improves peer reviewer ability to detect errors (MD 0.55, 95% CI 0.20 to 0.90; 1 RCT, 418 reviewers). We found low-certainty evidence that reviewer training, compared with standard journal practice, has little or no effect on stakeholders' assessment of review quality in journal peer review (standardized mean difference (SMD) 0.13 standard deviations (SDs), 95% CI -0.07 to 0.33; 1 RCT, 418 reviewers), or change in stakeholders' assessment of review quality in journal peer review (SMD -0.15 SDs, 95% CI -0.39 to 0.10; 5 RCTs, 258 reviewers). We found very low-certainty evidence that a video course, compared with no video course, has little or no effect on inter-reviewer agreement in grant peer review (MD 0.14 points, 95% CI -0.07 to 0.35; 1 RCT, 75 reviewers). There was low-certainty evidence that structured individual feedback on scoring, compared with general information on scoring, has little or no effect on the change in inter-reviewer agreement in grant peer review (MD 0.18 points, 95% CI -0.14 to 0.50; 1 RCT, 41 reviewers, low-certainty evidence). AUTHORS' CONCLUSIONS: Evidence from 10 RCTs suggests that training peer reviewers may lead to little or no improvement in the quality of peer review. There is a need for studies with more participants and a broader spectrum of valid and reliable outcome measures. Studies evaluating stakeholders' assessments of the quality of peer review should ensure that these instruments have sufficient levels of validity and reliability.

Effect modification in network meta-analyses for relapsed/refractory multiple myeloma: systematic review and meta-analysis.

OBJECTIVES: To systematically review and meta-analyse the evidence for effect modification by refractory status and number of treatment lines in relapsed/refractory multiple myeloma (RRMM); and to assess whether effect modification is likely to invalidate network meta-analyses (NMA) that assume negligible modification. DESIGN: Systematic review, meta-analysis and simulation. DATA SOURCES: We systematically searched the literature (e.g., OVID Medline) to identify eligible publications in February 2020 and regularly updated the search until January 2022. We also contacted project stakeholders (including industry) ELIGIBILITY CRITERIA: Phase 2 and 3 randomised controlled trials reporting stratified estimates for comparisons with at least one of a prespecified set of treatments relevant for use in Norwegian RRMM patients. OUTCOMES: We used meta-analysis to estimate relative HRs (RHRs) for overall survival (OS) and progression-free survival (PFS) with respect to refractory status and number of treatment lines. We used the estimated RHRs in simulations to estimate the percentage of NMA results expected to differ significantly in the presence versus absence of effect modification. RESULTS: Among the 42 included publications, stratified estimates were published by and extracted from up to 18 (43%) publications and on as many as 8364 patients. Within-study evidence for effect modification is very weak (p>0.05 for 47 of 49 sets of stratified estimates). The largest RHR estimated was 1.32 (95% CI 1.18 to 1.49) for the modifying effect of refractory status on HR for PFS. Simulations suggest that, in the worst case, this would result in only 4.48% (95% CI 4.42% to 4.54%) of NMA estimates differing statistically significantly in the presence versus absence of effect modification. CONCLUSIONS: Based on the available evidence, effect modification appears to be sufficiently small that it can be neglected in adequately performed NMAs. NMAs can probably be relied on to provide estimates of HRs for OS and PFS in RRMM, subject to caveats discussed herein.

GP phone calls to improve COVID-19 vaccine uptake among patients at increased risk of severe COVID-19: a randomised trial.

BACKGROUND: English media have reported that many unvaccinated individuals took the COVID-19 vaccine after receiving a phone call from their GP. AIM: To determine whether phone calls from GPs to unvaccinated patients at increased risk of severe COVID-19 improves uptake of the COVID-19 vaccine. DESIGN & SETTING: Randomised trial where 202 participants were allocated to receive a phone call from their GP, and 452 participants were allocated to not get the call. Twenty-five GPs at 11 medical centres in Norway took part. The post-trial focus group discussion was with five GPs. METHOD: Participants were sourced from the GP electronic medical record system, which communicates with the Norwegian Immunisation Registry and can generate a list of the GPs' unvaccinated patients at increased risk of severe COVID-19. RESULTS: The GPs managed to speak over the phone with 154 (76%) patients allocated to receiving a phone call. At follow-up (average 7.5 weeks), 8.9% in the intervention group and 5.3% in the control group had been vaccinated (odds ratio [OR] 1.72; 95% confidence interval [CI] = 0.90 to 3.28). Findings from the focus group discussion suggested the timing of the intervention as a likely key reason for its limited success. CONCLUSION: An increase in the proportion of patients who took the COVID-19 vaccine in the intervention group was observed, but the difference was smaller than anticipated, and may be a chance finding. The effect of this type of intervention will likely vary across contexts and may have proved more effective if a larger proportion of the population were unvaccinated.

Effect of Wearing Glasses on Risk of Infection With SARS-CoV-2 in the Community: A Randomized Clinical Trial.

Importance: Observational studies have reported an association between the use of eye protection and reduced risk of infection with SARS-CoV-2 and other respiratory viruses, but, as with most infection control measures, no randomized clinical trials have been conducted. Objectives: To evaluate the effectiveness of wearing glasses in public as protection against being infected with SARS-CoV-2 and other respiratory viruses. Design, Setting, and Participants: A randomized clinical trial was conducted in Norway from February 2 to April 24, 2022; all adult members of the public who did not regularly wear glasses, had no symptoms of COVID-19, and did not have COVID-19 in the last 6 weeks were eligible. Intervention: Wearing glasses (eg, sunglasses) when close to others in public spaces for 2 weeks. Main Outcomes and Measures: The primary outcome was a positive COVID-19 test result reported to the Norwegian Surveillance System for Communicable Diseases. Secondary outcomes included a positive COVID-19 test result and respiratory infection based on self-report. All analyses adhered to the intention-to-treat principle. Results: A total of 3717 adults (2439 women [65.6%]; mean [SD] age, 46.9 [15.1] years) were randomized. All were identified and followed up in the registries, and 3231 (86.9%) responded to the end of study questionnaire. The proportions with a reported positive COVID-19 test result in the national registry were 3.7% (68 of 1852) in the intervention group and 3.5% (65 of 1865) in the control group (absolute risk difference, 0.2%; 95% CI, -1.0% to 1.4%; relative risk, 1.10; 95% CI, 0.75-1.50). The proportions with a positive COVID-19 test result based on self-report were 9.6% (177 of 1852) in the intervention group and 11.5% (214 of 1865) in the control group (absolute risk difference, -1.9%; 95% CI, -3.9% to 0.1%; relative risk, 0.83; 95% CI, 0.69-1.00). The risk of respiratory infections based on self-reported symptoms was lower in the intervention group (30.8% [571 of 1852]) than in the control group (34.1% [636 of 1865]; absolute risk difference, -3.3%; 95% CI, -6.3% to -0.3%; relative risk, 0.90; 95% CI, 0.82-0.99). Conclusions and Relevance: In this randomized clinical trial, wearing glasses in the community was not protective regarding the primary outcome of a reported positive COVID-19 test. However, results were limited by a small sample size and other issues. Glasses may be worth considering as one component in infection control, pending further studies. Trial Registration: ClinicalTrials.gov Identifier: NCT05217797.

The Evaluation of a Social Media Campaign to Increase COVID-19 Testing in Migrant Groups: Cluster Randomized Trial.

BACKGROUND: A low test positivity rate is key to keeping the COVID-19 pandemic under control. Throughout the pandemic, several migrant groups in Norway have seen higher rates of confirmed COVID-19 and related hospitalizations, while test positivity has remained high in the same groups. The Norwegian government has used several platforms for communication, and targeted social media advertisements have in particular been an important part of the communication strategy to reach these groups. OBJECTIVE: In this study, we aimed to investigate whether such a targeted Facebook campaign increased the rate of COVID-19 tests performed in certain migrant groups. METHODS: We randomly assigned 386 Norwegian municipalities and city districts to intervention or control groups. Individuals born in Eritrea, Iraq, Pakistan, Poland, Russia, Somalia, Syria, and Turkey residing in intervention areas were targeted with a social media campaign aiming at increasing the COVID-19 test rate. The campaign message was in a simple language and conveyed in the users' main language or in English. RESULTS: During the 2-week follow-up period, the predicted probability of having a COVID-19 test taken was 4.82% (95% CI 4.47%-5.18%) in the control group, and 5.58% (95% CI 5.20%-5.99%) in the intervention group (P=.004). CONCLUSIONS: Our targeted social media intervention led to a modest increase in test rates among certain migrant groups in Norway. TRIAL REGISTRATION: ClinicalTrials.gov NCT04866589; https://clinicaltrials.gov/ct2/show/NCT04866589.

Health communication in and out of public health emergencies: to persuade or to inform?

Much health communication during the COVID-19 pandemic has been designed to persuade people more than to inform them. For example, messages like "masks save lives" are intended to compel people to wear face masks, not to enable them to make an informed decision about whether to wear a face mask or to understand the justification for a mask mandate. Both persuading people and informing them are reasonable goals for health communication. However, those goals can sometimes be in conflict. In this article, we discuss potential conflicts between seeking to persuade or to inform people, the use of spin to persuade people, the ethics of persuasion, and implications for health communication in the context of the pandemic and generally. Decisions to persuade people rather than enable them to make an informed choice may be justified, but the basis for those decisions should be transparent and the evidence should not be distorted. We suggest nine principles to guide decisions by health authorities about whether to try to persuade people.

Covid-19 transmission in fitness centers in Norway - a randomized trial.

BACKGROUND: Closed fitness centers during the Covid-19 pandemic may negatively impact health and wellbeing. We assessed whether training at fitness centers increases the risk of SARS-CoV-2 virus infection. METHODS: In a two-group parallel randomized controlled trial, fitness center members aged 18 to 64 without Covid-19-relevant comorbidities, were randomized to access to training at a fitness center or no-access. Fitness centers applied physical distancing (1 m for floor exercise, 2 m for high-intensity classes) and enhanced hand and surface hygiene. Primary outcomes were SARS-CoV-2 RNA status by polymerase chain reaction (PCR) after 14 days, hospital admission after 21 days. The secondary endpoint was SARS-CoV-2 antibody status after 1 month. RESULTS: 3764 individuals were randomized; 1896 to the training arm and 1868 to the no-training arm. In the training arm, 81.8% trained at least once, and 38.5% trained ≥six times. Of 3016 individuals who returned the SARS-CoV-2 RNA tests (80.5%), there was one positive test in the training arm, and none in the no-training arm (risk difference 0.053%; 95% CI - 0.050 to 0.156%; p = 0.32). Eleven individuals in the training arm (0.8% of tested) and 27 in the no-training arm (2.4% of tested) tested positive for SARS-CoV-2 antibodies (risk difference - 0.87%; 95%CI - 1.52% to - 0.23%; p = 0.001). No outpatient visits or hospital admissions due to Covid-19 occurred in either arm. CONCLUSION: Provided good hygiene and physical distancing measures and low population prevalence of SARS-CoV-2 infection, there was no increased infection risk of SARS-CoV-2 in fitness centers in Oslo, Norway for individuals without Covid-19-relevant comorbidities. TRIAL REGISTRATION: The trial was prospectively registered in ClinicalTrials.gov on May 13, 2020. Due to administrative issues it was first posted on the register website on May 29, 2020: NCT04406909 .

Increased COVID-19 Testing Rates Following Combined Door-to-Door and Mobile Testing Facility Campaigns in Oslo, Norway, a Difference-in-Difference Analysis.

High testing rates limit COVID-19 transmission. Attempting to increase testing rates, Stovner District in Oslo, Norway, combined door-to-door campaigns with easy access testing facilities. We studied the intervention's impact on COVID-19 testing rates. The Stovner District administration executed three door-to-door campaigns promoting COVID-19 testing accompanied by drop-in mobile COVID-19 testing facilities in different areas at 2-week intervals. We calculated testing rates pre- and post-campaigns using data from the Norwegian emergency preparedness register for COVID-19 (Beredt C19). We applied a difference-in-difference approach using ordinary least square regression models and robust standard errors to estimate changes in COVID-19 testing rates. Door-to-door visits reached around one of three households. Intervention and comparison areas had identical testing rates before the intervention, and we observed an increase in intervention areas after the campaigns. We estimate a 43% increase in testing rates over the first three days following the door-to-door campaigns (p = 0.28), corresponding to an additional 79 (95% confidence interval, -54 to 175) people tested. Considering the shape of the time series curves and the large effect estimate, we find it highly likely that the campaigns had a substantial positive impact on COVID-19 testing rates, despite a p-value above the conventional levels for statistical significance. The results and the feasibility of the intervention suggest that it may be worth implementing in similar settings.

The Effectiveness of Free Face Mask Distribution on Use of Face Masks. A Cluster Randomised Trial in Stovner District of Oslo, Norway.

Face masks are recommended as a means of reducing the spread of COVID-19, but there are practically no studies of interventions to increase face mask use. Over three weeks, nine grocery stores in the Stovner District of Oslo were randomly selected each day to have distribution of free face masks outside their entrance. Free face mask distribution increased the proportion of customers wearing a mask by 6.0 percentage points (adjusted, 95% CI 3.5-8.5). Mean mask usage was 91.7% in the control group and 97.1% in the treatment group (pooled SD 5.3%). Practically all those who wore masks had both nose and mouth covered. We conclude that free distribution of face masks increased their use. Similar trials can be conducted within a short period of time.

Relationship between teaching modality and COVID-19, well-being, and teaching satisfaction (campus & corona): A cohort study among students in higher education.

OBJECTIVES: Higher education institutions all over the world struggled to balance the need for infection control and educational requirements, as they prepared to reopen after the first wave of the COVID-19 pandemic. A particularly difficult choice was whether to offer for in-person or online teaching. Norwegian universities and university colleges opted for a hybrid model when they reopened for the autumn semester, with some students being offered more in-person teaching than others. We seized this opportunity to study the association between different teaching modalities and COVID-19 risk, quality of life (subjective well-being), and teaching satisfaction. STUDY DESIGN: Prospective, observational cohort study. METHODS: We recruited students in higher education institutions in Norway who we surveyed biweekly from September to December in 2020. RESULTS: 26 754 students from 14 higher education institutions provided data to our analyses. We found that two weeks of in-person teaching was negatively associated with COVID-19 risk compared to online teaching, but the difference was very uncertain (-22% relative difference; 95% CI -77%-33%). Quality of life was positively associated with in-person teaching (3%; 95% CI 2%-4%), as was teaching satisfaction (10%; 95% CI 8%-11%). CONCLUSION: The association between COVID-19 infection and teaching modality was highly uncertain. Shifting from in-person to online teaching seems to have a negative impact on the well-being of students in higher education.

Determinants of Knowledge and Attitude towards Breastfeeding in Rural Pregnant Women Using Validated Instruments in Ethiopia.

Understanding the underlying determinants of maternal knowledge and attitude towards breastfeeding guides the development of context-specific interventions to improve breastfeeding practices. This study aimed to assess the level and determinants of breastfeeding knowledge and attitude using validated instruments in pregnant women in rural Ethiopia. In total, 468 pregnant women were interviewed using the Afan Oromo versions of the Breastfeeding Knowledge Questionnaire (BFKQ-AO) and the Iowa Infant Feeding Attitude Scale (IIFAS-AO). We standardized the breastfeeding knowledge and attitude scores and fitted multiple linear regression models to identify the determinants of knowledge and attitude. 52.4% of the women had adequate knowledge, while 60.9% of the women had a neutral attitude towards breastfeeding. In a multiple linear regression model, maternal occupation was the only predictor of the BFKQ-AO score (0.56SD; 95%CI, 1.28, 4.59SD; p = 0.009). Age (0.57SD; 95%CI, 0.24, 0.90SD; p = 0.001), parity (-0.24SD; 95%CI, -0.47, -0.02SD; p = 0.034), antenatal care visits (0.41SD; 95%CI, 0.07, 0.74SD; p = 0.017) and the BFKQ-AO score (0.08SD; 95% CI, 0.06, 0.09SD; p < 0.000) were predictors of the IIFAS-AO score. Nearly half of the respondents had inadequate knowledge and most women had a neutral attitude towards breastfeeding. Policymakers and managers could address these factors when planning educational interventions to improve breastfeeding practices.

Paying for performance to improve the delivery of health interventions in low- and middle-income countries.

BACKGROUND: There is growing interest in paying for performance (P4P) as a means to align the incentives of healthcare providers with public health goals. Rigorous evidence on the effectiveness of these strategies in improving health care and health in low- and middle-income countries (LMICs) is lacking; this is an update of the 2012 review on this topic. OBJECTIVES: To assess the effects of paying for performance on the provision of health care and health outcomes in low- and middle-income countries. SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase, and 10 other databases between April and June 2018. We also searched two trial registries, websites, online resources of international agencies, organizations and universities, and contacted experts in the field. Studies identified from rerunning searches in 2020 are under 'Studies awaiting classification.' SELECTION CRITERIA: We included randomized or non-randomized trials, controlled before-after studies, or interrupted time series studies conducted in LMICs (as defined by the World Bank in 2018). P4P refers to the transfer of money or material goods conditional on taking a measurable action or achieving a predetermined performance target. To be included, a study had to report at least one of the following outcomes: patient health outcomes, changes in targeted measures of provider performance (such as the delivery of healthcare services), unintended effects, or changes in resource use. DATA COLLECTION AND ANALYSIS: We extracted data as per original review protocol and narratively synthesised findings. We used standard methodological procedures expected by Cochrane. Given diversity and variability in intervention types, patient populations, analyses and outcome reporting, we deemed meta-analysis inappropriate. We noted the range of effects associated with P4P against each outcome of interest. Based on intervention descriptions provided in documents, we classified design schemes and explored variation in effect by scheme design. MAIN RESULTS: We included 59 studies: controlled before-after studies (19), non-randomized (16) or cluster randomized trials (14);  and interrupted time-series studies (9). One study included both an interrupted time series and a controlled before-after study. Studies focused on a wide range of P4P interventions, including target payments and payment for outputs as modified by quality (or quality and equity assessments). Only one study assessed results-based aid. Many schemes were funded by national governments (23 studies) with the World Bank funding most externally funded schemes (11 studies). Targeted services varied; however, most interventions focused on reproductive, maternal and child health indicators. Participants were predominantly located in public or in a mix of public, non-governmental and faith-based facilities (54 studies). P4P was assessed predominantly at health facility level, though districts and other levels were also involved. Most studies assessed the effects of P4P against a status quo control (49 studies); however, some studies assessed effects against comparator interventions (predominantly enhanced financing intended to match P4P funds (17 studies)). Four studies reported intervention effects against both comparator and status quo. Controlled before-after studies were at higher risk of bias than other study designs. However, some randomised trials were also downgraded due to risk of bias. The interrupted time-series studies provided insufficient information on other concurrent changes in the study context. P4P compared to a status quo control For health services that are specifically targeted, P4P may slightly improve health outcomes (low certainty evidence), but few studies assessed this. P4P may also improve service quality overall (low certainty evidence); and probably increases the availability of health workers, medicines and well-functioning infrastructure and equipment (moderate certainty evidence). P4P may have mixed effects on the delivery and use of services (low certainty evidence) and may have few or no distorting unintended effects on outcomes that were not targeted (low-certainty evidence), but few studies assessed these. For secondary outcomes, P4P may make little or no difference to provider absenteeism, motivation or satisfaction (low certainty evidence); but may improve patient satisfaction and acceptability (low certainty evidence); and may positively affect facility managerial autonomy (low certainty evidence). P4P probably makes little to no difference to management quality or facility governance (low certainty evidence). Impacts on equity were mixed (low certainty evidence). For health services that are untargeted, P4P probably improves some health outcomes (moderate certainty evidence); may improve the delivery, use and quality of some health services but may make little or no difference to others (low certainty evidence); and may have few or no distorting unintended effects (low certainty evidence). The effects of P4P on the availability of medicines and other resources are uncertain (very low certainty evidence). P4P compared to other strategies For health outcomes and services that are specifically targeted, P4P may make little or no difference to health outcomes (low certainty evidence), but few studies assessed this. P4P may improve service quality (low certainty evidence); and may have mixed effects on the delivery and use of health services and on the availability of equipment and medicines (low certainty evidence). For health outcomes and services that are untargeted, P4P may make little or no difference to health outcomes and to the delivery and use of health services (low certainty evidence). The effects of P4P on service quality, resource availability and unintended effects are uncertain (very low certainty evidence). Findings of subgroup analyses Results-based aid, and schemes using payment per output adjusted for service quality, appeared to yield the greatest positive effects on outcomes. However, only one study evaluated results-based aid, so the effects may be spurious. Overall, schemes adjusting both for quality of service and rewarding equitable delivery of services appeared to perform best in relation to service utilization outcomes. AUTHORS' CONCLUSIONS: The evidence base on the impacts of P4P schemes has grown considerably, with study quality gradually increasing. P4P schemes may have mixed effects on outcomes of interest, and there is high heterogeneity in the types of schemes implemented and evaluations conducted. P4P is not a uniform intervention, but rather a range of approaches. Its effects depend on the interaction of several variables, including the design of the intervention (e.g., who receives payments ), the amount of additional funding,  ancillary components (such as technical support) and contextual factors (including organizational context).

Breastfeeding Education and Support to Improve Early Initiation and Exclusive Breastfeeding Practices and Infant Growth: A Cluster Randomized Controlled Trial from a Rural Ethiopian Setting.

Although peer-led education and support may improve breastfeeding practices, there is a paucity of evidence on the effectiveness of such interventions in the Ethiopian context. We designed a cluster-randomized trial to evaluate the efficacy of a breastfeeding education and support intervention (BFESI) on infant growth, early initiation (EI), and exclusive breastfeeding (EBF) practices. We randomly assigned 36 clusters into either an intervention group (n = 249) receiving BFESI by trained Women's Development Army (WDA) leaders or a control group (n = 219) receiving routine care. The intervention was provided from the third trimester of pregnancy until five months postpartum. Primary study outcomes were EI, EBF, and infant growth; secondary outcomes included maternal breastfeeding knowledge and attitude, and child morbidity. The intervention effect was analysed using linear regression models for the continuous outcomes, and linear probability or logistic regression models for the categorical outcomes. Compared to the control, BFESI significantly increased EI by 25.9% (95% CI: 14.5, 37.3%; p = 0.001) and EBF by 14.6% (95% CI: 3.77, 25.5%; p = 0.010). Similarly, the intervention gave higher breastfeeding attitude scores (Effect size (ES): 0.85SD; 95% CI: 0.70, 0.99SD; p < 0.001), but not higher knowledge scores (ES: 0.15SD; 95% CI: -0.10, 0.41SD; p = 0.173). From the several growth and morbidity outcomes evaluated, the only outcomes with significant intervention effect were a higher mid-upper arm circumference (ES: 0.25cm; 95% CI: 0.01, 0.49cm; p = 0.041) and a lower prevalence of respiratory infection (ES: -6.90%; 95% CI: -13.3, -0.61%; p = 0.033). Training WDA leaders to provide BFESI substantially improves EI and EBF practices and attitude towards breastfeeding.

COVID-19: underpowered randomised trials, or no randomised trials?

A recently published trial of face mask use to protect against COVID-19 demonstrated a key barrier to carrying out randomised trials in public health: the need for unattainably large sample sizes. For many public health interventions, the choice is not between sufficiently powered trials and underpowered trials, but between underpowered trials and no trials at all. Underpowered trials should be viewed as contributions to the larger body of evidence, alongside other studies of various sizes and designs, collectively assessed and synthesized in systematic reviews. Overemphasis on sample size calculation is probably more of a hindrance than a help to scientific progress.