The Risk Factors for the Wearing-off Phenomenon in Parkinson's Disease in Japan: A Cross-sectional, Multicenter Study

OBJECTIVE: Parkinson's disease (PD) is a common, progressive, neurodegenerative disorder. With progression of PD, the wearing-off phenomenon occurs more frequently as a motor complication, decreasing the patient's quality of life. The aim of this study was to investigate the risk factors for the wearing-off phenomenon in Japanese PD patients. METHODS: All of the study participants were clinically diagnosed as having PD. Each patient was assessed for the wearing-off phenomenon based on the findings of clinical assessments and interviews that were conducted during a single visit. The risk factors for wearing-off were analyzed by univariate and multivariate logistic regression analyses. RESULTS: Wearing-off was observed in 101 of the 180 (56.1%) patients who were enrolled in this study. The multivariate logistic regression analysis revealed that the onset of PD at ≥69 years of age (odds ratio [OR], 0.22; 95% confidence interval [CI], 0.05-0.88; p=0.032), female sex (OR, 6.49; 95% CI, 2.34-17.99; p<0.001), catechol-O-methyltransferase (COMT) inhibitor treatment (OR, 19.59; 95% CI, 3.55-108.11; p<0.001) and a high daily levodopa dosage (≥600 mg/day) (OR, 7.69; 95% CI, 1.41-41.84; p=0.018) were independent predictive factors for wearing-off in Japanese PD patients. CONCLUSION: Age at the symptomatic disease onset, female sex, COMT inhibitor treatment, and a high daily levodopa dose were associated with the occurrence of wearing-off in Japanese PD patients. Physicians need to consider the risk factors and carefully choose medications for PD patients to postpone the occurrence of this phenomenon for as long as possible.