METHODS: Using a test-negative design case-control study, we estimated the OR of infection by job category, site, test reason, sex, vaccination status, vulnerability, site outage and site COVID-19 weekly risk rating, adjusting for age, test date and test type.
RESULTS: From an original 80 077 COVID-19 tests, there were 70 646 included in the final analysis. Most exclusions were due to being visitor tests (5030) or tests after an individual first tested positive (2968).Women were less likely to test positive than men (OR=0.71; 95% CI 0.58 to 0.86). Test reason was strongly associated with positivity and although not a cause of infection itself, due to differing test regimes by area, it was a strong confounder for other variables. Compared with routine tests, tests due to symptoms were highest risk (94.99; 78.29 to 115.24), followed by close contact (16.73; 13.80 to 20.29) and broader-defined work contact 2.66 (1.99 to 3.56). After adjustment, we found little difference in risk by job category, but some differences by site with three sites showing substantially lower risks, and one site showing higher risks in the final model.
CONCLUSIONS: In general, infection risk was not associated with job category. Vulnerable individuals were at slightly lower risk, tests during outages were higher risk, vaccination showed no evidence of an effect on testing positive, and site COVID-19 risk rating did not show an ordered trend in positivity rates.
方法:使用测试阴性设计病例对照研究,我们按工作类别估计了感染的OR,site,测试原因,性别,疫苗接种状况,脆弱性,站点停机和站点COVID-19每周风险评级,调整年龄,试验日期和试验类型。
结果:从原始的8077项COVID-19测试中,最终分析包括70646人。大多数排除是由于访客测试(5030)或个人首次测试呈阳性(2968)之后的测试。与男性相比,女性检测阳性的可能性较小(OR=0.71;95%CI0.58至0.86)。测试原因与阳性密切相关,尽管不是感染本身的原因,由于不同地区的测试制度不同,这对其他变量来说是一个很强的混淆。与常规测试相比,由于症状而进行的测试风险最高(94.99;78.29至115.24),其次是密切接触(16.73;13.80至20.29)和更广泛定义的工作接触2.66(1.99至3.56)。调整后,我们发现不同工作类别的风险差异不大,但不同地点的一些差异,三个地点显示出相当低的风险,一个网站在最终模型中显示出更高的风险。
结论:一般来说,感染风险与工作类别无关.弱势群体的风险略低,中断期间的测试风险更高,疫苗接种没有证据表明对检测呈阳性有影响,和站点COVID-19风险评级未显示阳性率的有序趋势。