Normative values and sociodemographic correlates of health-related quality of life among Nigerians using the SF-36 Health Questionnaire

Abstract

Abstract Background and objective Extrapolation of psychosocial health reference data across populations is constrained by several issues, of which cultural factors are important. In view of the dearth of population-specific reference data in sub-Saharan Africa, this study aimed to provide normative values and correlates of Health-Related Quality of Life (HRQoL) among adults in Ile-Ife, Osun State, Nigeria, based on the SF-36 Health Questionnaire. Methods A cross-sectional study was conducted among 2,087 apparently healthy adults aged 18–74 years recruited from Obafemi Awolowo University and communities within Ife Central Local Government Area, Osun State, Nigeria, using a multistage random sampling technique. Health-related quality of life was assessed using the Short Form-36 version 2 (SF-36v2) Health Questionnaire, while socio-demographic characteristics were obtained using a structured proforma. Mean, standard deviation, and percentile values were calculated for HRQoL. Spearman’s rank correlation was used to examine sociodemographic correlates of HRQoL. Statistical significance was set at p < 0.05. Results The mean age of the respondents was 33.2 ± 15.1 years. Males had significantly higher HRQoL scores than females across most SF-36 domains ( p < 0.05). HRQoL declined significantly with increasing age ( p < 0.05), with the highest Physical Component Summary (PCS = 83.7) and Mental Component Summary (MCS = 77.7) scores observed among participants aged 18–24 years and the lowest among those aged ≥ 65 years (PCS = 51.1; MCS = 57.5). Age, sex, marital status, and education were significantly but weakly associated with most HRQoL domains and summary scores, while religion showed weak associations with general health, vitality, mental health, and the mental component summary ( p < 0.05). Age- and sex-specific normative SF-36 reference values and percentile distributions were established. Conclusion This study provides age- and sex-specific normative SF-36 reference values for adults in Ile-Ife, Osun State, Nigeria. Younger age, male sex, religion, and education were significant but weak correlates of HRQoL. Further studies involving nationally representative samples are needed to establish comprehensive normative HRQoL reference values for Nigeria.