If All States had Stricter COVID-19 Measures it Could Have Reduced Excess Mortality Rates

The approach to the US response to COVID-19 restrictions have been the source of debate across the country for years. On the public health side, measures such as masks, social distancing, requiring vaccines, and children going to school remotely were all put in place with the goal to reduce the spread of the virus, and prevent severe illness and death. On the other side of the argument has been the potential detrimental effects of these measures on children in terms of hurting their education and social skills as well as seniors who were in long-term care facilities and isolated from loved ones.

Although the federal government provided guidance on restrictions, the way states decided to enforce such restrictions varied greatly, thus seeing a difference in incidence rates and now a new confirmation of excess mortality.

“Excess mortality is measured as the difference between the reported number of deaths in a given week or month (depending on the country) in 2020–2024 and an estimate of the expected deaths for that period had the COVID-19 pandemic not occurred,” as written on Our World in Data’s site.¹

A new analysis published in JAMA Health Forum shows that had their been greater, consistent restrictions across all the states, it could have lowered the excess mortality by 10% to 21% of the 1.18 million deaths during a 2-year period (July 2020-June 2022).²

“Stronger restrictions were associated with lower monthly excess death rates and ratios in virtually every month from July 2020 to June 2022, with the largest gaps during the second half of 2020, when the virus first became widespread, and in September through December 2021 when the delta variant became dominant,” the author, Christopher Ruhm, PhD, professor of Public Policy & Economics at the University of Virginia wrote.²

“If all states had adopted restrictions similar to the 10 most restrictive states, there would have been 271 and 447 thousand fewer deaths than if all states had restrictions similar to the 10 least restrictive states,” tweeted on X (Twitter), last week. “Behavior changes probably played an important explanatory role.”

In the study, he points out the great variation on mortality rates in the individual states. “With the exception of Hawaii, the states with the lowest excess death rates and ratios were in the Northeast region, while a mix of Southern and Western states had the highest rates and ratios. At the extreme, the excess death rate in Massachusetts was less than one-fifth that of Mississippi (115 vs 590 per 100 000),” the author wrote.²

In regression models controlling for a single restriction variable, mask requirements and vaccine or school mask mandates were associated with reductions in estimated excess death rates and ratios; prohibitions on mask or vaccine mandates were positively associated with them, he wrote.

He does point out that restrictions were not equally effective and wrote that school closings, “likely provided minimal benefit while imposing substantial cost.“

Study Parameters and Other Takeaways

This was a cross-sectional study using the Centers for Disease Control and Prevention’s state-level mortality and population data during 2020 to 2022 compared with baseline information for 2017 to 2019. Ruhm examined data including the total US population, with separate estimates for different age groups including younger than 45 years, 45 to 64 years, 65 to 84 years, and 85 years or older used to construct age-standardized measures.²

"Age-standardized excess mortality rates and ratios for July 2020 to June 2022 were calculated and compared with pre-pandemic baseline rates. Excess death rates and ratios were then regressed on single or multiple restrictions, while controlling for excess death rates or ratios, from March 2020 to June 2020,” he wrote. “Estimated values of the dependent variables were calculated for packages of weak vs strong state restrictions. Behavioral changes were investigated as a potential mechanism for the overall effects.”²

Limitations

Ruhm acknowledges some limitations to the analyses, including that he examined the data beginning in July 2020, a few months after the first substantial COVID-19 fatalities in the US. He explained there was limited policy variation across the US during these months, and that deaths during this period were probably “largely idiosyncratic—reflecting factors such as initial infections in areas that were travel destinations—and so were not strongly reflective of these policies, which also likely impacted mortality with a delay.” ²

He also points out previous studies were likely incomplete, leaving open the possibility of considerable omitted variables bias.

Overall he believes this study shows how restrictions in states reduced mortality. “These study findings do not support the views of those opposing COVID-19 restrictions who erroneously believe the restrictions did not work,” Ruhm wrote. “To the contrary, the package of policies implemented by some states probably saved many lives. However, all restrictions were not equally successful. Evidence of protective effects was weakest for activity limitations. This may have partially concealed benefits at the start of the pandemic, before the analysis period, or reflected reverse causation given that most activity limitations were implemented before political considerations dominated, when states were likely to be especially responsive to local variations in infection rates.”²

References
1.Giattino C, et al. Excess mortality during the Coronavirus pandemic (COVID-19). Our World in Data. July 26, 2024. Accessed July 28, 2024.
2. Ruhm CJ. US State Restrictions and Excess COVID-19 Pandemic Deaths. JAMA Health Forum. 2024;5(7):e242006. doi:10.1001/jamahealthforum.2024.2006