New directions in incidence and prevalence of diagnosed diabetes in the USA

Objective To determine whether diabetes prevalence and incidence has remained flat or changed direction during the past 5 years. Research design and methods We calculated annual prevalence and incidence of diagnosed diabetes (type 1 and type 2 combined) for civilian, non-institutionalized adults aged 18-79 years using annual, nationally representative cross-sectional survey data from the National Health Interview Survey from 1980 to 2017. Trends in rates by age group, sex, race/ethnicity, and education were calculated using annual percentage change (APC). Results Overall, the prevalence of age-adjusted, diagnosed diabetes did not change significantly from 1980 to 1990, but increased significantly (APC 4.4%) from 1990 to 2009 to a peak of 8.2 per 100 adults (95% CI 7.8 to 8.6), and then plateaued through 2017. The incidence of age-adjusted, diagnosed diabetes did not change significantly from 1980 to 1990, but increased significantly (APC 4.8%) from 1990 to 2007 to 7.8 per 1000 adults (95% CI 6.7 to 9.0), and then decreased significantly (APC -3.1%) to 6.0 (95% CI 4.9 to 7.3) in 2017. The decrease in incidence appears to be driven by non-Hispanic whites with an APC of -5.1% (p= 0.002) after 2008. Conclusions After an almost 20-year increase in the national prevalence and incidence of diagnosed diabetes, an 8-year period of stable prevalence and a decrease in incidence has occurred. Causes of the plateauing and decrease are unclear but the overall burden of diabetes remains high and deserves continued monitoring and intervention.