Abstract：
The purpose of this study was to describe and evaluate the nature and methodology of reports and appropriateness of conclusions in The Morbidity and Mortality Weekly Report (MMWR) pertaining to masks. Because MMWR has substantial influence on United States health policy and is not externally peer-reviewed, it is critical to understand the scientific process within the journal. Mask policies have been highly influenced by data published in the MMWR.
Retrospective cross-sectional study of MMWR publications pertaining to masks through 2023. Outcomes included study design, whether the study was able to assess mask effectiveness, if results were statistically significant, if masks were concluded to be effective, if randomized evidence or conflicting data were mentioned or cited, and appropriateness of causal statements.
There were 77 studies, all published after 2019, that met our inclusion criteria. The most common study design was observational without a comparator group: 22/77 (28.6%); 0/77 were randomized; 23/77 (29.9%) assessed mask effectiveness; 11/77 (14.3%) were statistically significant, but 58/77 (75.3%) stated that masks were effective. Of these, 41/58 (70.7%) used causal language. One mannequin study used causal language appropriately (1.3%). None cited randomized data; 1/77 (1.3%) cited conflicting evidence.
MMWR publications pertaining to masks drew positive conclusions about mask effectiveness >75% of the time despite only 30% testing masks and <15% having statistically significant results. No studies were randomized, yet over half drew causal conclusions. The level of evidence generated was low and the conclusions were most often unsupported by the data. Our findings raise concern about the reliability of the journal for informing health policy.
Retrospective cross-sectional study of MMWR publications pertaining to masks through 2023. Outcomes included study design, whether the study was able to assess mask effectiveness, if results were statistically significant, if masks were concluded to be effective, if randomized evidence or conflicting data were mentioned or cited, and appropriateness of causal statements.
There were 77 studies, all published after 2019, that met our inclusion criteria. The most common study design was observational without a comparator group: 22/77 (28.6%); 0/77 were randomized; 23/77 (29.9%) assessed mask effectiveness; 11/77 (14.3%) were statistically significant, but 58/77 (75.3%) stated that masks were effective. Of these, 41/58 (70.7%) used causal language. One mannequin study used causal language appropriately (1.3%). None cited randomized data; 1/77 (1.3%) cited conflicting evidence.
MMWR publications pertaining to masks drew positive conclusions about mask effectiveness >75% of the time despite only 30% testing masks and <15% having statistically significant results. No studies were randomized, yet over half drew causal conclusions. The level of evidence generated was low and the conclusions were most often unsupported by the data. Our findings raise concern about the reliability of the journal for informing health policy.
摘要：
目的：描述和评估MMWR中与口罩有关的报告的性质和方法以及结论的适当性。
背景：因为发病率和死亡率每周报告（MMWR）对美国卫生政策有重大影响，了解期刊中的科学过程至关重要。蒙版政策受到MMWR中发布的数据的高度影响。
方法：对1978年至2023年与口罩有关的MMWR出版物进行回顾性横断面研究。结果包括研究设计，该研究是否能够评估口罩的有效性，如果结果具有统计学意义，如果口罩被认为是有效的，如果提到或引用了随机证据或相互矛盾的数据，以及因果陈述的适当性。
结果：77项研究，全部在2019年后发布,符合我们的纳入标准.最常见的研究设计是无对照观察组22/77(28.6%)。0/77随机分组。23/77（29.9%）评估了口罩的有效性。11/77（14.3%）有统计学意义，但58/77（75.3％）表示口罩有效。其中,41/58（70.7%）使用因果语言。一项人体模型研究适当地使用了因果语言（1.3％）。没有引用随机数据。1/77（1.3％）引用了相互矛盾的证据。
结论：关于口罩的MMWR出版物在75％的时间内得出了关于口罩有效性的积极结论，尽管只有30％的测试口罩和<15％的测试结果具有统计学意义。没有随机研究，然而，超过一半的人得出了因果结论。产生的证据水平很低，结论通常没有数据支持。我们的发现引起了人们对该期刊在卫生政策方面的可靠性的关注。
背景：因为发病率和死亡率每周报告（MMWR）对美国卫生政策有重大影响，了解期刊中的科学过程至关重要。蒙版政策受到MMWR中发布的数据的高度影响。
方法：对1978年至2023年与口罩有关的MMWR出版物进行回顾性横断面研究。结果包括研究设计，该研究是否能够评估口罩的有效性，如果结果具有统计学意义，如果口罩被认为是有效的，如果提到或引用了随机证据或相互矛盾的数据，以及因果陈述的适当性。
结果：77项研究，全部在2019年后发布,符合我们的纳入标准.最常见的研究设计是无对照观察组22/77(28.6%)。0/77随机分组。23/77（29.9%）评估了口罩的有效性。11/77（14.3%）有统计学意义，但58/77（75.3％）表示口罩有效。其中,41/58（70.7%）使用因果语言。一项人体模型研究适当地使用了因果语言（1.3％）。没有引用随机数据。1/77（1.3％）引用了相互矛盾的证据。
结论：关于口罩的MMWR出版物在75％的时间内得出了关于口罩有效性的积极结论，尽管只有30％的测试口罩和<15％的测试结果具有统计学意义。没有随机研究，然而，超过一半的人得出了因果结论。产生的证据水平很低，结论通常没有数据支持。我们的发现引起了人们对该期刊在卫生政策方面的可靠性的关注。
