Recent Patterns of Multimorbidity Among Older Adults in High-Income Countries

Population aging along with the rising burden of chronic medical conditions (CMCs) is challenging the sustainability of health care systems globally. The authors sought to characterize contemporary patterns of multimorbidity among older adults (aged >= 65 years) in high-income countries (HICs). Medline, EMBASE, CINAHL, PsycINFO, and Web of Science were searched in January 2018 for English-language articles that reported the prevalence of multimorbidity (defined as co-occurrence of >= 2 CMCs in an individual without defining an index disease) among older adults in HICs, or the proportions with >= 3 or >= 5 CMCs. Only studies that utilized data collected during January 2007-December 2017 were included. A total of 52 articles (45 studies) that reported data among >60 million older adults in 30 HICs were included. The overall prevalence of multimorbidity was 66.1% (interquartile range [IQR] 54.4-76.6). The multimorbidity prevalence increased with age as well as with the number of CMCs included in the assessment. The prevalence of >= 3 or >= 5 CMCs was 44.2% (IQR 34.0-70.3) and 12.3% (IQR 8.7-19.1), respectively. The multimorbidity prevalence was also higher among females as well as among studies using care-based data rather than self-reported data. The prevalence of hypertension, dyslipidemia, diabetes, pain disorders, depression, heart failure, cancer, and dementia among the older adults was 60.6%, 51.2%, 25.2%, 34.0%, 12.0%, 14.0%, 8.6%, and 8.4%, respectively. The available data suggest a high prevalence of multimorbidity among older adults. There is a need for increased research into understanding the causal mechanisms that underlie multimorbidity toward supporting the development of cost-effective interventions. In addition, the study results reiterate the need for preventive health care to move beyond targeting single diseases in favor of directing efforts toward reducing overall morbidity among this population.