A Latent Class Analysis of Multimorbidity and the Relationship to Socio-Demographic Factors and Health-Related Quality of Life. A National Population-Based Study of 162,283 Danish Adults

OBJECTIVES To identify patterns of multimorbidity in the general population and examine how these patterns are related to socio-demographic factors and health-related quality of life. STUDY DESIGN AND SETTING We used latent class analysis to identify subgroups with statistically distinct and clinically meaningful disease patterns in a nationally representative sample of Danish adults (N = 162,283) aged 16+ years. The analysis was based on 15 chronic diseases. RESULTS Seven classes with different disease patterns were identified: a class with no or only a single chronic condition (59% of the population) labeled "1) Relatively Healthy" and six classes with a very high prevalence of multimorbidity labeled; "2) Hypertension" (14%); "3) Musculoskeletal Disorders" (10%); "4) Headache-Mental Disorders" (7%); "5) Asthma-Allergy" (6%); "6) Complex Cardiometabolic Disorders" (3%); and "7) Complex Respiratory Disorders" (2%). Female gender was associated with an increased likelihood of belonging to any of the six multimorbidity classes except for class 2 (Hypertension). Low educational attainment predicted membership of all of the multimorbidity classes except for class 5 (Asthma-Allergy). Marked differences in health-related quality of life between the seven latent classes were found. Poor health-related quality of life was highly associated with membership of class 6 (Complex Cardiometabolic Disorders) and class 7 (Complex Respiratory Disorders). Despite different disease patterns, these two classes had nearly identical profiles in relation to health-related quality of life. CONCLUSION The results clearly support that diseases tend to compound and interact, which suggests that a differentiated public health and treatment approach towards multimorbidity is needed.