Purpose <p>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.</p> Methods <p>We conducted a retrospective cohort study using a cross-sectional population-level health survey (2022–2023) linked to administrative hospital data for adults 18&#xa0;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.</p> Results <p>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&#xa0;days for CHD to 36.5&#xa0;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.</p> Conclusion <p>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.</p>