Multimorbidity Trends in United States Adults, 1988-2014

Importance: The simultaneous presence of multiple conditions in one patient (multi-morbidity) is a key challenge facing primary care.

Objective: The purpose of this study was to determine the prevalence of multi-morbidity and to document changes in prevalence during the last 25 years.

Design/setting: Cross-sectional study using multiple years (1988-2014) of the National Health and Nutrition Examination Survey (NHANES) were analyzed.

Setting: Multiple years (1988 to 2014) of the National Health and Nutrition Examination Survey (NHANES) from the United States were analyzed.

Participants: Noninstitutionalized adults.

Main outcomes and measures: Number of chronic conditions per individual analyzed by age, race, gender, and socioeconomic factors.

Results: A total of 57,303 individuals were surveyed regarding the presence of multi-morbidity in separate surveys spanning 1988-2014. The overall current prevalence in 2013-2014 of >2 morbidities was 59.6% (95% CI 58.1%-61.1%), 38.5% had 3 or more, and 22.7% had 4 or more morbidities, which was significantly higher than in 1988 (45.7%, 95% CI 43.5%-47.8%, with >2 morbidities). Among individuals with 2 or more morbidities, 54.1% have obesity compared to 41.9% in 1988. Among adults age >65, prevalence was 91.8% for 2 or more morbidities. Whites and Blacks had significantly higher prevalence (59.2% and 60.1%) than Hispanic or "other" race (45.0%, P < .0001). Women (58.4%) had more current multi-morbidities (>2) than men (55.9%, P = .01).

Conclusions and relevance: Multimorbidity is common and has been increasing over the last 25 years. This finding has implications for public health policy and anticipated health costs for the coming years.