A validation study of the Chinese wearing off questionnaire 9-symptom for Parkinson's disease.

OBJECTIVE: Development of wearing off (WO) often goes unnoticed for both patients with Parkinson's disease (PD) and physicians due to the complexity of this phenomenon. A brief 9-symptom WO questionnaire (WOQ-9) was recently found to be highly sensitive in its detection. We aimed to validate a Chinese version WOQ-9 (CWOQ-9) among Chinese patients with PD. METHODS: We recruited 101 literate Chinese PD patients among 4 different neurology or movement disorders clinics in Hong Kong to participate in this study by completing the CWOQ-9. Clinical judgment by the specialists was considered the gold standard for diagnosing WO. RESULTS: The mean age (±SD) of the patients was 61 (±9) years and 35 (34.7%) of them were female. The disease duration was 7.4 (±5.4) years and 69 (68.3%) of them were diagnosed clinically to have WO by the specialists. The positive and negative predictive values, sensitivity and specificity of CWOQ-9 were 86%, 71%, 87%, and 69% respectively. The area under curve (AUC) was 0.78 (p<0.001). CONCLUSION: This simple patient questionnaire is a valid tool for the detection of WO among Chinese PD patients.