Multimorbidity and subjective cognitive complaints: Findings from 48 low- and middle-income countries of the World Health Survey 2002-2004

Background: Data on the association between multimorbidity and subjective cognitive complaints (SCC) are lacking from low- and middle-income countries (LMICs). Objective: To assess the association between multimorbidity and SCC among adults from 48 LMICs. Methods: Cross-sectional, community-based data were analyzed from the World Health Survey 2002–2004. Ten chronic conditions (angina, arthritis, asthma, chronic back pain, depression, diabetes, edentulism, hearing problems, tuberculosis, visual impairment) were assessed. Two questions on subjective memory and learning complaints in the past 30 days were used to create a SCC scale ranging from 0 (No SCC) to 100 (worse SCC). Multivariable linear regression and mediation analyses were conducted to explore the associations. Results: A total of 224,842 individuals aged≥18 years [mean (SD) age 38.3 (16.0) years; 49.3% males] constituted the final sample. Compared to no chronic conditions, the mean SCC score was higher by 7.13 (95% CI = 6.57–7.69), 14.84 (95% CI = 13.91–15.77), 21.10 (95% CI = 19.49–22.70), 27.48 (95% CI = 25.20–29.76), and 33.99 (95% CI = 31.45–36.53) points for 1, 2, 3, 4, and≥5 chronic conditions. Estimates by sex and age groups (18–44, 45–64,≥65 years) were similar. Nearly 30% of the association between multimorbidity (i.e.,≥2 chronic conditions) and SCC was explained by psychological factors (i.e., perceived stress, sleep problems, anxiety symptoms). Conclusion: Multimorbidity is associated with SCC among adults in LMICs. Future studies should investigate whether addressing psychological factors in people with multimorbidity can improve cognitive function, and whether screening for SCC in individuals with multimorbidity can be a useful tool to identify individuals at particularly high risk for future cognitive decline.