An Original Investigation into the Burden and Determinants of Multimorbidity Among Older Adults in Nigeria

Multimorbidity, defined as the coexistence of two or more chronic conditions, is an emerging but understudied challenge among older Nigerians whose healthcare needs exceed the single-disease management paradigm of current PHC service organisation. This study conducted an original investigation into the burden, patterns, and determinants of multimorbidity among older adults in Nigeria. A multi-site cross-sectional study was conducted across six geopolitical zones, enrolling 1,440 adults aged 60 years and above through multistage cluster sampling in Oyo, Kano, Enugu, Rivers, Benue, and Gombe States. A comprehensive chronic disease inventory assessed the presence of sixteen chronic conditions through structured interviews and clinical measurement. Multimorbidity patterns were identified through cluster analysis and association rule mining. Determinants were assessed through multilevel logistic regression. Results showed a multimorbidity prevalence of 48.6 percent across the full sample, with significant inter-zonal variation from 38.2 percent (North East) to 61.4 percent (South West). The most common multimorbid dyads were hypertension-diabetes (prevalence 18.7 percent), hypertension-osteoarthritis (14.3 percent), and hypertension-vision impairment (12.8 percent). Age, female gender, urban residence, and higher education were significant positive predictors. Community-level healthcare facility density moderated individual-level multimorbidity effects on healthcare utilisation. The study provides the first national six-zone original investigation of multimorbidity burden in Nigerian older adults, identifying the need for person-centred multimorbidity management models in Nigerian PHC and specialist care, and recommends a national chronic disease management guideline revision incorporating multimorbidity principles.

Keywords: multimorbidity, older adults, chronic disease, Nigeria, burden and determinants