Objectives: Few longitudinal studies have evaluated health-related quality of life (HRQoL) in Parkinson's disease (PD) and these studies have not evaluated all potentially relevant domains of PD. Our objective was to identify domains at baseline that predict change in HRQoL, and to evaluate the relation between change in HRQoL and change in particular domains of PD.
Methods: A total of 336 patients who participated in the longitudinal SCOPA-PROPARK cohort study and had data from the first and third annual evaluation were included in this study. The Scales for Outcomes in Parkinson's disease (SCOPA) evaluation was used to assess impairments and disabilities. HRQoL was assessed with the EuroQol-5D visual analogue scale. Multiple linear regression analysis with "change in HRQoL" as dependent variable was used to identify factors that influence the change in HRQoL.
Results: Health-related quality of life as well as most impairment and disability domains decreased significantly from baseline to follow-up. The two regression models of "change in HRQoL," adjusted for baseline HRQoL, included 1) the baseline domains autonomic dysfunction, nighttime sleep problems, and cognitive function, and 2) "change in psychosocial problems,""change in depressive symptoms," and "change in cognitive function."
Conclusions: Patients who have autonomic dysfunction, nighttime sleep problems, and cognitive dysfunction are at risk for deterioration in HRQoL. Deterioration in HRQoL over 2-year time was associated with worsening in psychosocial well-being, mood, and cognitive function. Interventions aiming to improve these domains are important and would likely contribute to improvement in HRQoL, although more research is necessary.