Factors impacting on quality of life in Parkinson's disease: Results from an international survey

Abstract

Current management guidelines for the treatment of patients with Parkinson's disease (PD) are limited due to the lack of knowledge of factors that influence health-related quality of life (HRQL). To assess the HRQL of people with PD, and to systematically identify and evaluate those factors (other than disease severity and medication, which could have an impact), we undertook a cross-sectional, randomized selection, multicenter international survey of patients with PD, caregivers, and clinicians. Face-to-face interviews were conducted with subjects in six countries. Disease severity, medication, and other factors hypothesized to influence HRQL were assessed using a combination of specially developed questionnaires and validated instruments including the Parkinson's Disease Questionnaire-39 (HRQL), Hoehn and Yahr Stage (disease severity), and Beck's Depression Inventory (BDI; depression). Multiple linear regression models were used to demonstrate whether the factors investigated contribute significantly to HRQL. The results obtained indicated that Hoehn and Yahr stage and medication explained only 17.3% of the variability in HRQL of patients with PD, although both were significant (R(2) = 0.173, P < 0.05). Other factors increased the explanatory power to adjusted R(2) = 0.597, with BDI being the most significant predictor of variability in HRQL (adjusted R(2) = 0.582; P < 0.001), followed by "Satisfaction with the explanation of the condition at diagnosis" and "Current feelings of optimism" (both P < 0.05). These factors, in addition to disease severity and medication, explain 59.7% of the variability in HRQL across the population. In conclusion, depression (as measured by the BDI) in PD, "satisfaction with the explanation of the condition at diagnosis" and "current feelings of optimism" have a significant impact on HRQL. The completion of this initial analysis is the first step towards developing management guidelines that truly influence the HRQL of patients with PD.

Treatment of Early Parkinson’s Disease

“…Until recently, the majority of PD clinical trials were designed to assess the efficacy of novel therapeutic agents for motor disability; however, based on the results of a large survey of PD patients, depression and non-motor disability were found to be the major contributing factors to impairments in disease-related quality of life [39]. The scope of non-motor manifestations of PD is broad, and includes disturbances in mood, cognition, autonomic function, sleep, perceptual changes and impulse control.…”

Associations between Severity of Motor Function and Nonmotor Symptoms in Parkinson's Disease: A Post Hoc Analysis of the RECOVER Study

“…NMS have traditionally received little attention from health care professionals [3,4] but are now known to be major predictors of morbidity [1,5,6,7] that may be more important than the motor symptoms of PD in determining quality of life, disease costs, and institutionalization rates [8,9,10,11,12]. PD literature increasingly emphasizes the need for physicians to be aware of the importance of evaluating and treating patients for NMS to achieve a holistic approach to the management of PD [7].…”

The Assessment of Non-Motor Symptoms in Idiopathic Parkinson’s Disease

“…Hence, since patient loses the chance of adequate treatment, care costs increase and the duration of hospitalization is prolonged. Some studies have demonstrated that in NMS, distress, impairment in quality of life and economic burden are more significant than motor symptoms [14][15][16] . NMSs have major negative effects on the lives of patients and their families and contribute to impairment of quality of life and severe disability.…”