In a literature review and meta-analysis published by the John Hopkins Institute of Applied Economics, Global Health, and the Study of Business Enterprise; Herby, Jonung, and Hanke analyze the effects of lockdowns on COVID-19 mortality rates. In this article, lockdowns are defined as compulsory non-pharmaceutical interventions (NPI) involving any government mandate that “directly restricts peoples’ possibilities”. This includes a restriction to movement, mask mandates, and closing schools and businesses, etc.
Using a systematic search, the authors screened 18,590 studies from Google scholar, SCOPUS, and Covid economic with 24 studies matching the eligibility and inclusion criteria. The authors included articles that directly attempted to find a relationship between policies and mortality or excess mortality rates and excluded studies measuring other rates such as cases, hospitalizations, or other measures. Studies using models, forecasting, pre-post study design, synthetic control methods, and time-series studies were also excluded from the analysis.
All of the studies that were included in the analysis, except for one, were using data from and published in 2020. Out of the 34 studies that were eligible, 22 were peer-reviewed and 12 were working papers. The studies were predominantly observing global populations or populations living in the United States with the rest of the studies covering European countries. The studies measured the effects of stringent lockdowns (higher OxCGRT stringency index), shelter-in-place-orders (SIPO), NPI (non-pharmaceutical interventions), and length of lockdowns.
The authors report that there is an unclear relationship between lockdowns and mortality when looking at an overview of the studies; some studies did not find a statistically significant effects, others studies found a negative impact, and the rest found a positive effect. The authors included quality dimensions during the meta-analysis portion of the research to distinguish and account for the difference in study design and methodology of the articles.
Overall, the results do not confirm that lockdowns have a significant impact on mortality rates; it was found that stringent lockdowns have reduced the mortality rates by 0.2%, SIPO by 2.9%, and NPI’s have not had any effect. However, the closure of non-essential businesses have had a significant impact by producing a 10.6% reduction in mortality rates (this is likely to be attributed to the closure of bars).
Read the full review article here