Disparities in Premature Cardiac Death Among US Counties From 1999-2017: Temporal Trends and Key Drivers.

Background Disparities in premature cardiac death (PCD) might stagnate the progress toward the reduction of PCD in the United States and worldwide. We estimated disparities across US counties in PCD rates and investigated county-level factors related to the disparities. Methods and Results We used US mortality data for cause-of-death and demographic data from death certificates and county-level characteristics data from multiple databases. PCD was defined as any death that occurred at an age between 35 and 74 years with an underlying cause of death caused by cardiac disease based on International Classification of Diseases, Tenth Revision ( ICD-10 ), codes. Of the 1 598 173 PCDs that occurred during 1999-2017, 60.9% were out of hospital. Although the PCD rates declined from 1999-2017, the proportion of out-of-hospital PCDs among all cardiac deaths increased from 58.3% to 61.5%. The geographic disparities in PCD rates across counties widened from 1999 (Theil index=0.10) to 2017 (Theil index=0.23), and within-state differences accounted for the majority of disparities (57.4% in 2017). The disparities in out-of-hospital PCD rates (and in-hospital PCD rates) associated with demographic composition were 36.51% (and 37.51%), socioeconomic features were 18.64% (and 18.36%), healthcare environment were 18.64% (and 13.90%), and population health status were 23.73% (and 30.23%). Conclusions Disparities in PCD rates exist across US counties, which may be related to the decelerated trend of decline in the rates among middle-aged adults. The slower declines in out-of-hospital rates warrants more precision targeting and sustained efforts to ensure progress at better levels of health (with lower PCD rates) against PCD.