Cross-sectional and temporal differences in health-related quality of life of people with and without osteoarthritis: a 10-year prospective study.

OBJECTIVE: To describe the impact of OA on health-related quality of life (HRQoL) in the forms of health state utilities (HSUs) and health-dimension scores, and to compare the longitudinal changes in HRQoL for people with and without OA, using an Australian population-based longitudinal cohort. METHODS: Participants of the Tasmanian Older Adult Cohort with data on OA diagnosis and HRQoL were included [interviewed at baseline (n = 1093), 2.5 years (n = 871), 5 years (n = 760) and 10 years (n = 562)]. HRQoL was assessed using the Assessment of Quality of Life four-dimensions and analysed using multivariable linear mixed regressions. RESULTS: Compared with participants without OA, HSUs for those with OA were 0.07 (95% confidence interval: 0.09, 0.05) units lower on average over 10 years. HSUs for participants with knee and/or hip OA were similar to those with other types of OA at the 2.5 year follow-up and then diverged, with HSUs of the former being up to 0.09 units lower than the latter. Those with OA had lower scores for psychological wellness, independent living and social relationships compared with those without OA. Independent living and social relationships were mainly impacted by knee and/or hip OA, with the effect on the former increasing over time. CONCLUSION: Interventions to improve HRQoL should be tailored to specific OA types, health dimensions, and times. Support for maintaining psychological wellness should be provided, irrespective of OA type and duration. However, support for maintaining independent living could be more relevant to knee and/or hip OA patients living with the disease for longer.

The impact of comorbidities on health-related quality of life of people with osteoarthritis over 10 years.

OBJECTIVE: To investigate the impact of total number and patterns of comorbidities on health-related quality of life (HRQoL) and identify the most prevalent and influential comorbidity patterns in people with OA over 10 years. METHODS: Participants from the Tasmanian Older Adult Cohort aged 50-80 years, with self-reported OA and data on comorbidities and HRQoL were included. Participants were interviewed at baseline (n = 398), 2.5 (n = 304), 5 (n = 269) and 10 years (n = 191). Data on the self-reported presence of 10 chronic comorbidities were collected at baseline. HRQoL was assessed using the Assessment of Quality of Life-4-Dimensions. The long-term impacts of the number and of the nine most prevalent combinations of cardiovascular (CVD), non-OA musculoskeletal (Ms), metabolic and respiratory comorbidities on HRQoL over 10 years were analysed using linear mixed regressions. RESULTS: Compared with comorbidity-free OA participants, the health state utility (HSU) of those with 2 or ≥3 comorbidities was respectively -0.07 and -0.13 units lower over 10 years, largely driven by reduced scores for independent living, social relationships and psychological wellness. Comorbidity patterns including 'CVD+Ms' were most influential, and associated with up to 0.13 units lower HSU, mostly through negative impacts on independent living (up to -0.12), psychological wellness (up to -0.08) and social relationship (up to -0.06). CONCLUSION: Having more comorbidities negatively impacted OA patients' long-term HRQoL. OA patients with CVD and non-OA musculoskeletal conditions had the largest HSU impairment, and therefore optimal management and prevention of these conditions may yield improvements in OA patients' HRQoL.