Background: Multimorbidity, an important health indicator, is a contributor to and result of health inequity. We sought to determine if gaps in multimorbidity by race and ethnicity are decreasing over time.
Methods: Serial cross-sectional analysis of the National Health Interview Survey, 1999 to 2018. The study included individuals older than 18 years old, categorized by self-reported race, ethnicity, age, and income. The main outcomes were trends in the prevalence of multimorbidity, defined as 2 or more concurrent chronic conditions.
Results: The study included 596,355 adults (4.7% Asian, 11.8% Black, 13.8% Latino/Hispanic, and 69.7% White). In 1999, the estimated prevalence of multimorbidity was 5.9% among Asian, 17.4% among Black, 10.7% among Latino/Hispanic, and 13.5% among White individuals. Prevalence increased for all racial/ethnic groups during the study period (P<0.005 for each), with no significant change in the differences between them. In 2018, when compared with White people, multimorbidity was more prevalent among Black individuals (+2.5 percent points [95% CI: +0.5, +4.6]) and less prevalent among Asian and Latino individuals (-6.6 points [-8.8, -4.4] and -2.1 points [-4.0, -0.2], respectively). The estimated prevalence of reporting at least 1, 2, 3, or 4 conditions all increased with age across all groups, with Black individuals having the greatest prevalence in each age category. Among those older than 35 years, Black people had multimorbidity rates equivalent to those of Latino/Hispanic and White people aged 5 years older, and Asian people aged 10 years older.
Conclusions: Over 2 decades, there was no significant progress in eliminating disparities in multimorbidity between Black and White people.