A Longitudinal Examination of Determinants of Quality of Life in Patients with Parkinson’s Disease

Abstract

Parkinson’s disease (PD) is one of the most common age-related neurodegenerative disorders Its clinical symptoms may lead to the limitation of activities of daily living and reduce health-related quality of life (HRQoL) HRQoL is important in that it reflects the quality of care and treatment effectiveness of the clinical medicine administered to patients with PD HRQoL measures can be categorized into two types: generic and disease-specific instruments For patients with PD the 36-item Short-Form Health Survey (SF-36) is the most frequently used generic HRQoL instrument and the 39-item Parkinson’s Disease Questionnaire (PDQ-39) is the most frequently used disease-specific HRQoL instrument They may reflect different aspects of the lives of patients with PD and thus may be associated with different determinants In addition the responsiveness of a measurement is important because it reflects the extent to which the instrument can detect changes in the progression of a disease and to which it shows longitudinal validity This dissertation includes two studies in patients with PD that were aimed at investigating these issues: the determinants of the HRQoL of patients with PD and the longitudinal validity of the SF-36 and the PDQ-39 over a one-year follow-up period The Study I identified the determinants of HRQoL based on the same set of predictors for the SF-36 and the PDQ-39 A total of 92 patients with PD were recruited The results showed that depressive symptoms and motor difficulties of daily living were the first two significant determinants for both instruments The study II used evaluations by clinicians of motor signs and a psychological measure as external criteria to evaluate the internal and external responsiveness of HRQoL measures Seventy-four patients with PD were evaluated using both the SF-36 and PDQ-39 at baseline and again after one year The results showed that both instruments were partially sensitive to change over a one-year follow-up period and that they discriminated between patients with improved and deteriorated motor signs In addition they were similarly responsive to changes in motor difficulties affecting daily living and the SF-36 was more sensitive than the PDQ-39 to changes in depressive symptoms In summary this dissertation provides important information regarding the determinants of the HRQoL of patients with PD and the longitudinal validity of the SF-36 and PDQ-39 for these patients Additional studies are needed to measure HRQoL at multiple time points include other predictors of non-motor symptoms and use a mixed-methods design for HRQoL research in patients with PD

Date of Award	2019
Original language	English
Supervisor	Hui-Ing Ma (Supervisor)