Comparison of Estimated Rates of Coronavirus Disease 2019 (COVID-19) in Border Counties in Iowa Without a Stay-at-Home Order and Border Counties in Illinois With a Stay-at-Home Order
Comparison of Estimated Rates of Coronavirus Disease 2019 (COVID-19) in Border Counties in Iowa Without a Stay-at-Home Order and Border Counties in Illinois With a Stay-at-Home Order
复制标题
DOI：
10.1001/jamanetworkopen.2020.11102
复制
发表时间：
2020-05-15
影响因子：
13.8
通讯作者：
Wehby, George L.
中科院分区：
文献类型：
--
作者：
Lyu, Wei;Wehby, George L.
爱荷华州是美国在2019冠状病毒病（COVID-19）大流行期间没有发布居家令的五个州之一。没有经验证据表明，在爱荷华州发布居家令是否与该州COVID-19感染率下降有关。目的比较未发布居家令的爱荷华州边境县与发布居家令的伊利诺伊州边境县的新冠肺炎病例。设计、环境和参与者这项采用差异中差异设计的横断面研究比较了2020年3月21日伊利诺伊州发布居家令前后，爱荷华州与伊利诺伊州接壤的8个爱荷华州县每1万名居民中COVID-19病例的每日变化。还进行了额外的敏感性分析，以解释两个州之间关闭学校和非必要企业的时间差异，以及县人口密度和贫困率导致的COVID-19病例趋势差异。发布居家令。爱荷华州和伊利诺伊州边境县每万居民累计COVID-19病例比较结果爱荷华州边境县共有462 445人，伊利诺伊州边境县共有272 385人。爱荷华州各县的人口密度（每平方英里114.2人）高于伊利诺伊州各县（每平方英里78.2人）。在3月21日下午5点伊利诺伊州居家令生效之前，爱荷华州和伊利诺伊州边境县每万居民累积COVID-19病例的趋势相似（3月15日至3月21日：每万居民0.024例vs每万居民0.026例）。在那之后，爱荷华州的病例增加得更快，伊利诺伊州的病例增加得更慢。在伊利诺伊州颁布居家令后的10、20和30天内，病例的差异分别为-0.51 / 10000居民（SE, 0.09; 95% CI, -0.69至-0.32;P < 0.001）、-1.15 / 10000居民（SE, 0.49; 95% CI, -2.12至-0.18;P = 0.02）和-4.71 / 10000居民（SE, 1.99; 95% CI, -8.64至-0.78;P = 0.02）。估计显示，在没有实施居家令的一个月后，爱荷华州边境县的病例增加了217例。这一超额病例估计数占到该日爱荷华州这些县716例总病例的30.4%。敏感性分析解决了两个州在关闭学校和非必要企业的时间上的差异，以及县人口密度和贫困率上的差异，支持了这些发现。这项采用差异中差异设计的横断面研究发现，在伊利诺伊州实施了而爱荷华州没有实施的居家令后，爱荷华州边境县每1万名居民中COVID-19病例的估计率比伊利诺伊州边境县有所增加。
Importance Iowa is 1 of 5 states in the US that have not issued a stay-at-home order during the coronavirus disease 2019 (COVID-19) pandemic. There is no empirical evidence on whether issuing a stay-at-home order in Iowa could have been associated with a reduced rate of COVID-19 infections in the state. Objective To compare COVID-19 cases in border counties in Iowa, which did not issue a stay-at-home order, with cases in border counties in Illinois, which did issue a stay-at-home order. Design, Setting, and Participants This cross-sectional study with a difference-in-differences design compared daily changes in COVID-19 cases per 10 000 residents in 8 Iowa counties bordering Illinois with those in the 7 Illinois counties bordering Iowa before and after Illinois issued a stay-at-home order on March 21, 2020. Additional sensitivity analyses were conducted to account for differences in timing of closing schools and nonessential businesses between the 2 states and differential trends in COVID-19 cases by county population density and poverty rates. Exposures Issuing a stay-at-home order. Main Outcomes and Measures Comparison of cumulative cases of COVID-19 per 10 000 residents in border counties in Iowa and Illinois. Results The total populations were 462 445 in the Iowa border counties and 272 385 in the Illinois border counties. Population density was higher in the Iowa counties (114.2 people per square mile) than in the Illinois counties (78.2 people per square mile). Trends of cumulative COVID-19 cases per 10 000 residents for the Iowa and Illinois border counties were comparable before the Illinois stay-at-home order, which went into effect at 5:00 pm on March 21 (March 15 to March 21: 0.024 per 10 000 residents vs 0.026 per 10 000 residents). After that, cases increased more quickly in Iowa and more slowly in Illinois. Within 10, 20, and 30 days after the enactment of the stay-at-home order in Illinois, the difference in cases was -0.51 per 10 000 residents (SE, 0.09; 95% CI, -0.69 to -0.32; P < .001), -1.15 per 10 000 residents (SE, 0.49; 95% CI, -2.12 to -0.18; P = .02), and -4.71 per 10 000 residents (SE, 1.99; 95% CI, -8.64 to -0.78; P = .02), respectively. The estimates indicate excess cases in the border Iowa counties by as many as 217 cases after 1 month without a stay-at-home order. This estimate of excess cases represents 30.4% of the 716 total cases in those Iowa counties by that date. Sensitivity analyses addressing differences in timing of closing schools and nonessential businesses and differences in county population density and poverty rates between the 2 states supported these findings. Conclusions and Relevance This cross-sectional study with a difference-in-differences design found an increase in estimated rates of COVID-19 cases per 10 000 residents in the border counties in Iowa compared with the border counties in Illinois following a stay-at-home order that was implemented in Illinois but not in Iowa.