Exploring Changes Observed in Health-Related Quality of Life of Australian Adults with Psychological Distress: Results from Sixteen Years Longitudinal Study

OBJECTIVES: Substantial evidence exists on the contemporaneous association between psychological distress (PD) and health related quality of life (HRQoL). However, there remains a gap in understanding how this relationship evolves overtime and how different severity classifications of PD impact the overall HRQoL and its various aspects such as physical function (PF), role physical (RP), mental health (MH) and role emotional (RP).

METHODS:

We estimate five mixed effects linear mixed models, each with health state utilities (HSUs), PF, RP, MH, and RE as dependent variables. We further examine the key sociodemographic and clinical determinants of HRQoL (measured in terms of HSU, PF, RP, MH and RE scores) including age, sex, marital status, education, employment status, body mass index, physical activity level and others.

RESULTS: Our simple model shows that HRQoL declines over time however, with the introduction of other sources of HRQoL variations in the model, both fixed and random effects, a remarkable shift occurs, and time coefficients become statistically and clinically insignificant while some other variables such as different PD severity classifications, age, and sex, emerge as strong predictors of HRQoL. Our results reveal that different PD severity classifications and HRQoL are negatively associated. The greater impact of increasing PD severity was observed on MH (-.364) and RE (-.525) than PF (-.114) and RF (-.257). HRQoL also differed by age and sex groups, with female sex (-.012) and higher age (-.016 in 25-44 years vs. -.059 in 65+ years) attracting lower HSUs.

CONCLUSIONS: To improve HRQoL of people with PD, health interventions should be tailored to the severity levels, and other factors e.g., age and sex of patients, with more attention given to females and older individuals. Moreover, a coordinated effort across different sectors, involving government agencies, healthcare providers, educators, employers, and communities is required.