Global patterns of multimorbidity: a comparison of 28 countries using the World Health Surveys

Multimorbidity , defined as the coexistence of two or more chronic diseases in one individual, is increasing in prevalence globally. This study compares the prevalence of multimorbidity across low and middle income countries (LMICs) ; with stratification by age, sex and socio-economic status (SES). Population-based chronic disease data from 28 countries of the World Health Survey (WHS) 2003 were used (27 LMICs and 1 HICs). Inter-country socio-economic differences were examined using gross domestic product (GDP). Regression analyses were used to examine associations of SES with multimorbidity by region and by age. The mean world standardized prevalence of multimorbidity was 7.8 % (95 % CI, 7.79–7.83 %). Multimorbidity was positively associated with the female sex and with age, although it was common among younger adults in LMICs. A positive but non–linear relationship was found between country GDP and multimorbidity prevalence. Multimorbidity was inversely associated with SES in countries with the highest GDP; this gradient was flatter, and sometimes reversed, in countries with lower GDP. Higher SES was significantly associated with a decreased risk of multimorbidity in the all-region analyses. Multimorbidity is a global phenomenon not just affecting older adults in HICs. Policy makers worldwide need to address this combination of chronic diseases in the individual—which is contributing to health inequalities—and to support the complex health care service needs of a growing multimorbid population