Age-Adjusted All-Cause Mortality in Counties Served by PHAB-Accredited Local Health Departments Compared With Counties Served by Nonaccredited Local Health Departments: 1999 to 2020

Abstract

Objectives: To analyze trends in the age-adjusted all-cause mortality rate (AAMR) from 1999 to 2020 between counties served by a Public Health Accreditation Board (PHAB)-accredited local health department and a nonaccredited local health department to determine whether accreditation impacted the AAMR and whether there were differences in the AAMR preceding the first health departments being accredited in 2013. Design: Descriptive time trends and difference-in-differences analysis was used to explore differences in the AAMR between accredited counties and nonaccredited counties. Propensity score matching was used to develop a control group matched on county characteristics to address confounding. Setting: A national observational study using data obtained from the Centers for Disease Control and Prevention's Wide-ranging Online Data for Epidemiologic Research, the American Community Survey, and a PHAB data set on accreditation status. Participants: All US counties with data on the AAMR and county characteristics. Intervention: Accreditation by the PHAB. Main Outcome Measure: The AAMR. Results: Difference-in-differences in the AAMR between accredited and nonaccredited counties were stable following the launch of the accreditation program in 2013, except for an improvement in 2020 in the total sample (32.2 deaths per 100 000 people, 95% confidence interval: 3.8-60.6, P = .03). Age-adjusted all-cause mortality rates were lower in accredited counties across the 22-year period. This was statistically significant every year in the total sample but only statistically significant in 2020 in the matched sample (P < .05). Prior to accreditation, the AAMR improved by 24.7 deaths per 100 000 people (P = .05) and 18.0 deaths per 100 000 people (P = .24) more among accredited counties between 1999 and 2008, among the total and matched samples, respectively. Conclusion: Currently, PHAB accreditation has not had a substantial impact on the AAMR, and the AAMR was higher among nonaccredited counties preceding the first health departments being accredited in 2013.