Institute of Economics and Econometrics, Geneva School of Economics and Management, University of Geneva, Geneva 4, Switzerland.
BREAD, Bureau for Research and Economic Analysis of Development, E Providence, RI, USA.
Eur J Public Health. 2022 Oct 3;32(5):818-824. doi: 10.1093/eurpub/ckac123.
Whereas there is strong evidence that wearing a face mask is effective in reducing the spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), evidence on the impact of mandating the wearing of face masks on deaths from coronavirus disease 2019 (COVID-19) and all-cause mortality is more sparse and likely to vary by context. Focusing on a quasi-experimental setting in Switzerland, we aimed to determine (i) the effect of face-mask mandates for indoor public spaces on all-cause mortality; and (ii) how the effect has varied over time, and by age and sex.
Our analysis exploited the fact that between July and October 2020, nine cantons in Switzerland extended a face-mask mandate at different time points from being restricted to public transportation only to applying to all public indoor places. We used both a Difference-in-Differences approach with fixed-effects for canton and week and an event-study approach.
In our main Difference-in-Differences model, the face-mask mandate was associated with a 0.3% reduction in all-cause mortality [95% confidence interval (CI): -3.4% to 2.7%; P = 0.818]. This null effect was confirmed in the event-study approach and a variety of robustness checks. Combining the face-mask mandate with social distancing rules led to an estimated 5.1% (95% CI: -7.9% to -2.4%; P = 0.001) reduction in all-cause mortality.
Mandating face-mask use in public indoor spaces in Switzerland in mid-to-late 2020 does not appear to have resulted in large reductions in all-cause mortality in the short term. There is some suggestion that combining face-mask mandates with social distancing rules reduced all-cause mortality.
虽然有强有力的证据表明佩戴口罩可有效减少严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）的传播，但关于强制佩戴口罩对 2019 年冠状病毒病（COVID-19）和全因死亡率的影响的证据更为稀少，且可能因背景而异。本研究聚焦于瑞士的准实验环境，旨在确定：（i）室内公共场所强制佩戴口罩令对全因死亡率的影响；（ii）该影响随时间的变化情况，以及按年龄和性别划分的变化情况。
我们的分析利用了这样一个事实，即在 2020 年 7 月至 10 月期间，瑞士的九个州先后将口罩令从仅限公共交通扩展至适用于所有室内公共场所，不同的州在不同的时间点实施了这一命令。我们使用了固定效应的差分法和事件研究法。
在我们的主要差分法模型中，口罩令与全因死亡率降低 0.3%有关[95%置信区间（CI）：-3.4%至 2.7%；P=0.818]。这一无效结果在事件研究法和各种稳健性检验中得到了证实。将口罩令与社交距离规则相结合，估计可使全因死亡率降低 5.1%[95%CI：-7.9%至-2.4%；P=0.001]。
2020 年年中至年末，瑞士在室内公共场所强制佩戴口罩似乎并未在短期内显著降低全因死亡率。有一些迹象表明，将口罩令与社交距离规则相结合可降低全因死亡率。
