All-Cause Mortality Trajectories Among U.S. Counties

 

Objectives: We examined overall and geographic variation in all-cause mortality rate trajectories in U.S. counties from 1999-2010. 

Methods: Discrete mixture models were estimated using county level mortality data for the years 1999 to 2010 obtained from the US Centers for Disease Control and Prevention's public Wide-ranging Online Data for Epidemiologic Research Internet site. Proc Traj in SAS(v. 9.2) was used to detect how counties trajectory data cluster together into groups based on similar intercepts and slopes, and higher order terms.  The trajectory groups were then mapped using ArcGIS.

Results: Two outlying trajectory groups were detected, group 1 (14 counties) with a very low baseline rate and a relative steep decline and a group 8 (4 counties) with very high rates that were relatively unstable.  Counties with a lower baseline rate tended to have a steeper decline in rates.  At baseline, the average mortality rate for group 2 is 774.82 deaths per 100,000 per year decreasing by 10.39 deaths per year, while group 7 has a baseline rate of 1212.40 decreasing 5.57 deaths per year. Much of the Southeastern U.S.  is characterized by counties with worse mortality rate trajectories, while better trajectories tend to be found in the Northeast and the upper Midwest and the West Coast. 

Conclusions:  Disparities in all-cause mortality rates at the county level are in increasing.  Geographic patterns exist but so do geographic outliers.  Further investigation of the demographic, social, and health care system environment that is associated with each of the mortality rate trajectories is warranted.