Health-related quality of life among adults with chronic diseases: a linked, retrospective cohort study using the EQ-5D-5L in Queensland, Australia

People with chronic diseases are known to have lower EQ-5D-5L utility scores, but data are not readily available in an Australian context. Using linked administrative hospital and population survey data, we aimed to calculate utility scores for adults with different disease profiles. We conducted a retrospective cohort study using a cross-sectional population-level health survey (2022–2023) linked to administrative hospital data for adults 18 years and older in Queensland, Australia to assess: (1) chronic disease and comorbidity prevalence, (2) Health-related quality of life (HRQoL) differences among adults with pre-existing chronic conditions, and (3) to model differences in disutility days by chronic diseases. The mean EQ-5D-5L utility score for the cohort was 0.917, but was lower among those with chronic diseases, for example chronic obstructive pulmonary disease (COPD), coronary heart disease (CHD) and diabetes had corresponding mean values of 0.780, 0.850 and 0.832, respectively. After adjustment, on average the disutility days that could be averted by preventing chronic diseases equalled approximately a month annually for some conditions, ranging from 14.8 days for CHD to 36.5 days for COPD. Prevalence estimates using linked administrative hospital data were comparable to results from the National Health Survey, which used self-report, although comorbidity was found to be substantially higher in the current study. People living with chronic diseases have substantially higher number of disutility days annually. Preventing or delaying onset of chronic conditions would likely improve HRQoL and positively impact individuals, society and the economy. Why is this study needed? Health-related quality of life (HRQoL) is lower among those with chronic diseases than those without. While there are methods to evaluate HRQoL numerically, estimates for people living with chronic diseases are not available in an Australian context. What is the key problem/issue/question this manuscript addresses? The key questions this manuscript addresses are to: (1) assess chronic disease and comorbidity prevalence using population-level survey data linked to administrative health records, (2) quantify HRQoL differences among adults with pre-existing chronic conditions, and (3) model differences in disutility days by listed chronic diseases. What is the main point of your study? Using a population health survey linked to hospital admission and emergency presentation data, this study estimated the prevalence of selected chronic diseases in Queensland, Australia, and evaluated differences in HRQoL scores and the number of days not in optimal health (disutility day) among people with different disease profiles. What are your main results and what do they mean? Survey data linked to administrative hospital data provided chronic disease prevalence estimates comparable to a national health survey, although multimorbidity estimates were higher. Multimorbidity is commonly associated with higher health care costs and utilisation, and is a growing challenge to healthcare sector sustainability. Robust multimorbidity prevalence better informs healthcare system planning. Population-level HRQoL scores were also lower among Queensland adults with chronic diseases. A high number of disutility days could be avoided if chronic disease onset could be averted or delayed.