Longitudinal assessment of the health-related quality of life among older people with diabetes: results of a nationwide study in New Zealand

BACKGROUND: The current work examined experiences of Health-Related Quality of Life (HRQOL) among older adults with a diagnosis of Diabetes Mellitus (DM) over time compared to those without a diagnoses DM. METHODS: The sample was drawn from six biennial waves of the New Zealand Health, Work and Retirement survey, a prospective population-based cohort study of older adults 55–70 years at baseline. Data on sociodemographic factors, health behaviours, chronic disease diagnoses and physical and mental HRQOL (SF-12v2) were obtained using six biennial surveys administered 2006–2016. Generalised Estimating Equation models, adjusted for time-constant and -varying factors, were employed to compare HRQOL and its determinants over time for older adults with and without a diagnosis of DM. RESULTS: DM was negatively associated with physical HRQOL [β (95% CI) − 7.43 (− 8.41, − 6.44)] with older adults affected by DM reporting scores 7.4 points lower than those without DM. Similarly, the mean Mental HRQOL score was lower among those affected by DM [β = − 4.97 (− 5.93, − 4.01)] however, scores increased over time for both groups (p < 0.001). Greater age, more chronic conditions, sight and sleep problems, obesity, lower annual income, and fewer years of education were predictors of poorer HRQOL among older adults. CONCLUSIONS: Older adults affected by diabetes experienced poorer physical and mental HRQOL compared to those not affected when controlling for a range of sociodemographic and health related indices. A management aim must be to minimise the gap between two groups, particularly as people age.