Timing of Enacting, Lifting, and Reenacting the Non-Pharmaceutical Mitigation Interventions

Backgrounds and Purpose: This study aims to examine the timing of six types of mitigation interventions implemented in all 50 states and DC during the study window (i.e., 12 PM on March 13, 2020 to 11:59 PM on January 5, 2021, U.S. Eastern time). We employ a bivariate Cox regression to examine the state governors’ awareness of the scope of the COVID-19 pandemic, and to examine whether a decision about the implementation of a mitigation was made swiftly and promptly.

Methods: A descriptive analysis of event episodes and bivariate proportional hazards models were employed to address the research questions.

Results: 1) Stay-at-home order: 43 states took an average of 1420.05 hours (SD=2504.34) to enact the stay-at-home order. These states on average implemented the order for 1389.24 hours (SD=11.43.92). 15 states then enacted the stay-at-home advisory, and 2 states lifted the advisory by the end of the study window. 2) Public school closure: All 50 states and DC closed public K-12 schools since March 13, 2020, and the average time taking to make this decision is 98 hours (SD=65.96). All states reopened public k-12 schools prior to the Thanksgiving Day, and on average the reopening time is 3732.35 hours (SD=445.66). 3) Restaurant/bar limits: Except Kansas, all states took an average of 271.48 hours (SD=987.74) to enact the restaurant/bar limits, and the policy was effective for 1578.51 hours on average (SD=676.37). 4) Large gathering ban of more than 10 people: Except North Dakota, 49 states and DC enacted this order, with a mean time issuing the order of 468.85 hours (SD=1236.04). On average, this order was implemented for 1686.03 hours, while New Mexico did not lift the intervention by January 5, 2021. To prevent the transmission of COVID-19, 21 states re-issued large gathering ban of more than 10 people after its rescindment. 5) Non-essential business closure: 45 states closed non-essential business since the national emergency, with a mean time issuing the measure of 1115.74 hours (SD=2232.65). These states on average implemented the order for 1279.32 hours (SD=372.27). 6) Face covering requirement: 40 states enacted mask mandate, with a mean time taking to issue the mandate of 3972.77 hours (SD=2180.32). All these states, except Mississippi, maintained the intervention by the end of study window. Mississippi rescinded the order in October 2020.

The COVID-19 counts five days prior to the decision-making time are significant predictors of the Cox regression analyzing the determinants of mitigation interventions. The bivariate models show that, for instance, every one-case increase in the confirmed cases per 10,000 population decreases the hazard of enacting the stay-at-home order by 66.62% (p<.001). These findings indicate that states with high COVID-19 counts adopted mitigation interventions in a delayed fashion.

The bivariate models also show that states with high level of COVID-19 prevalence rate lifted the mitigation interventions in a delayed fashion, that is, they made this decision more carefully.

Conclusions and Implications: There exists a wide variation on the timing and pattern of implementing the mitigation interventions among all 50 states and DC.