Incidence and predictors of multimorbidity among a multiethnic population in Malaysia: a community-based longitudinal study.

Background: Multimorbidity in older adults needs to be assessed as it is a risk factor for disability, cognitive decline, and mortality.

Aims: A community-based longitudinal study was performed to determine the incidence and to identify possible predictors of multimorbidity among multiethnic older adults population in Malaysia.

Methods: Comprehensive interview-based questionnaires were administered among 729 participants aged 60 years and above. Data were analyzed from the baseline data of older adults participating in the Towards Useful Aging (TUA) study (2014-2016) who were not affected by multimorbidity (349 without any chronic diseases and 380 with one disease). Multimorbidity was considered present in an individual reporting two or more chronic diseases.

Results: After 1½ years of follow-up, 18.8% of participants who were initially free of any diseases and 40.9% of those with one disease at baseline, developed multimorbidity. The incidence rates were 13.7 per 100 person-years and 34.2 per 100 person-years, respectively. Female gender, smoking, and irregular preparing of food (lifestyle) were predictors for incidence of multimorbidity, especially in those without any disease, while Body Mass Index (BMI) 22-27 kg/m and inadequate daily intake of iron were identified as predictors of multimorbidity among participants who already have one disease.

Conclusions: The incidence rates of multimorbidity among Malaysian older adults were between the ranges of 14-34 per 100 person-years at a 1½-year follow-up. Gender, smoking, BMI 22-27 kg/m, inadequate daily intake of iron and lack of engagement in leisure or lifestyle physical activities were possible predictors in the development of multimorbidity. There is a need to formulate effective preventive management strategies to decelerate multimorbidity among older adults.