Economic burden of Parkinson's disease in Singapore.

BACKGROUND: This study was carried out to evaluate the economic burden of Parkinson's disease (PD) and factors independently associated with individual components of total cost in Singapore. METHODS: A consecutive sample of 195 patients with PD (mean age: 68.2, men: 51.8%) attending a tertiary neuroscience clinic were identified and interviewed using standardized questionnaires including a financial burden questionnaire, two Health Related Quality of Life (HRQoL) questionnaires and the Beck Depression Inventory questionnaire. RESULTS: Annual total cost of PD from a societal perspective was SGD11345 (USD10129) per patient, with direct cost accounted for 38.5% and indirect cost 61.5%. The main cost components for direct medical cost, direct non-medical cost, and indirect cost was pharmacotherapy (50.4%), home care (76.1%), and productivity loss (97.9%), respectively. In multiple linear regression analysis, higher education, younger age and longer duration of PD were associated with higher total cost. CONCLUSIONS: Parkinson's disease exerts a considerable burden on patients, health care system and society in Singapore. As productivity loss accounts for a large share of the economic burden imposed by PD, treatments and health care programmes with potential for returning patients to higher productivity are urgently needed.

Mapping the eight-item Parkinson's Disease Questionnaire (PDQ-8) to the EQ-5D utility index.

OBJECTIVE: To develop a function for mapping the eight-item Parkinson's Disease Questionnaire (PDQ-8) to the EuroQol Group's EQ-5D utility index. METHODS: Data from two surveys of 324 patients with Parkinson's disease was divided into two groups. One was used to estimate the mapping functions by regression methods and the other was used to validate the mapping functions. RESULTS: A regression model with a non-linear trend explained 55% of the variation in EQ-5D utility values and had a mean absolute deviation (MAD) of 0.083. A regression model assuming a linear trend explained 52% of the variation and had an MAD of 0.085. In the validation sample, predicted values based on the aforementioned models respectively explained 42 and 44% of the variation in the observed EQ-5D utility values and both had MADs of about 0.1. The confidence intervals of the mean difference between these predicted values and the observed values totally fell within the pre-defined equivalence margin of 0.03 points. These predicted values were also similar to the observed EQ-5D utility values in terms of their association with clinical variables. CONCLUSION: At the group level, but not at the individual level, the mapping functions can accurately map the PDQ-8 outcomes to the EQ-5D utility index.

Factors affecting health-related quality of life amongst Asian patients with Parkinson's disease.

BACKGROUND AND PURPOSE: This cross-sectional study was carried out to identify factors predicting health-related quality of life (HRQoL) amongst Asian patients with Parkinson's disease (PD). METHODS: A total of 183 PD patients (mean age: 61 years, male: 68.9%) attending a tertiary neuroscience clinic in Singapore completed the English or Chinese version of the 8-item Parkinson's Disease Questionnaire (PDQ-8). Patients' socio-demographic characteristics and their clinical variables were analysed to identify factors influencing the PDQ-8 Summary Index and responses to its eight dimensions. RESULTS: In the multiple linear regression model, the use of Chinese survey, higher motor score and longer duration of PD were associated with poorer overall HRQoL. The multiple logistic regression analyses showed that female patients and patients with higher Hoehn and Yahr stage were more probably to report worse emotional well-being; patients who completed Chinese survey reported more problems with mobility, cognition and stigma; patients with higher motor scores were more probably to report problems with activities of daily living; patients with longer duration of PD were more probably to report problems with mobility, social support, communication and stigma. CONCLUSION: Both socio-demographic factors and disease-specific variables influence HRQoL in PD patients; the effects of culture-related factors on HRQoL should not be overlooked when assessing HRQoL in multi-cultural settings.