Downsides of face masks and possible mitigation strategies: a systematic review and meta-analysis

Abstract

ObjectiveTo identify, appraise and synthesise studies evaluating the downsides of wearing face masks in any setting. We also discuss potential strategies to mitigate these downsides.DesignSystematic review and meta-analysis.Data sourcesPubMed, Embase, CENTRAL and EuropePMC were searched (inception–18 May 2020), and clinical registries were searched via CENTRAL. We also did a forward–backward citation search of the included studies.Inclusion criteriaWe included randomised controlled trials and observational studies comparing face mask use to any active intervention or to control.Data extraction and analysisTwo author pairs independently screened articles for inclusion, extracted data and assessed the quality of included studies. The primary outcomes were compliance, discomforts, harms and adverse events of wearing face masks.ResultsWe screened 5471 articles, including 37 (40 references); 11 were meta-analysed. For mask wear adherence, 47% (95% CI 25% to 68%, p<0.0001), more people wore face masks in the face mask group compared with control; adherence was significantly higher (26%, 95% CI 8% to 46%, p<0.01) in the surgical/medical mask group than in N95/P2 group. The largest number of studies reported on the discomfort and irritation outcome (20 studies); fewest reported on the misuse of masks, and none reported on mask contamination or risk compensation behaviour. Risk of bias was generally high for blinding of participants and personnel and low for attrition and reporting biases.ConclusionsThere are insufficient data to quantify all of the adverse effects that might reduce the acceptability, adherence and effectiveness of face masks. New research on face masks should assess and report the harms and downsides. Urgent research is also needed on methods and designs to mitigate the downsides of face mask wearing, particularly the assessment of possible alternatives.Systematic review registrationOpen Science Framework website https://osf.io/sa6kf/ (timestamp 20-05-2020).

COVID-19 false dichotomies and a comprehensive review of the evidence regarding public health, COVID-19 symptomatology, SARS-CoV-2 transmission, mask wearing, and reinfection

“…Since households may represent scenarios where routine appropriate masking is impractical for members, the case for mask wearing in households is strongest when non-household members are visiting or when a household member (who lives with other people) is infected or has been potentially exposed to SARS-CoV-2 because of a recent potential exposure (e.g., occupational exposure, crowded settings, travel) [ 31 , 55 ]. Mask policies directed toward high-risk settings, and not toward low-risk activities, are expected to foster mask adherence and acceptance and decrease mask-related discomfort and fatigue [ 54 , 59 , 570 ].…”

“…Some uncertainties still exist regarding the wearing of face masks and coverings as a measure to prevent or mitigate SARS-CoV-2 transmission. There are COVID-19 research opportunities to obtain direct and actionable evidence on the effectiveness of specific cloth face covering designs in community scenarios, extended use and reuse of cloth face coverings, the impact of diverse approaches to mask adoption, alternatives that are more comfortable and more environmentally friendly, downsides of masking, additive effectiveness of cloth face coverings and face shields in the community, and attitudes, beliefs, and behaviors toward masking in the long term [ 57 , 59 , 510 , 517 , 524 ].…”

“…Recommended bibliography: [54][55][56][57][58][59][60] • "Smart masking" is a more accurate term than "universal masking. "…”

“…Some scientists and academics have invoked the precautionary principle 21 , not only to advocate changes in TBPs and to guide public health policies in general [263-265, 419, 529, 530], but also to argue the case for universal masking [432,439,[531][532][533]. If the benefits of masks are to be considered (i.e., reduction of respiratory infectious disease transmission, mutual protection, positive prosocial signaling), potential downsides should not be utterly disregarded [55,59]. The latter include shortage of medical masks and FFRs for HCWs [534,535], cross-contamination due to inappropriate mask wearing [536,537], risk compensation or complacency toward other preventive measures (evidence in favor [538][539][540], evidence against [541][542][543][544][545][546][547]), psychosocial effects (e.g., threats to autonomy, psychological relatedness, competence) [455,548,549], communication and learning difficulties [518,[550][551][552][553][554][555], physiological effects (e.g., subjective breathing discomfort or difficulties 22 , skin problems, headache, ocular dryness and irritation; these effects are more likely if there is a related predisposing condition) [454,455,556,[562][563]…”

How efficient are facial masks against COVID-19? Evaluating the mask use of various communities one year into the pandemic

“…In places without significant community transmission of COVID-19, the potential harms and costs may outweigh the benefits [17,18]. In implementing policies on the widespread use of face masks for the prevention of COVID-19 in the community, these potential barriers and adverse effects should also be considered [19].…”