[Translation and linguistic validation of the Japanese version of the wearing-off questionnaires(WOQ-19 and WOQ-9)].

Levodopa remains the most effective drug for the treatment of Parkinson disease (PD). Long-term levodopa treatment of PD is associated with the development of motor complications, the first of which to occur is the wearing-off phenomenon. In routine clinical practice, poor patient education, communication difficulties, and lack of awareness often hamper detection of the wearing-off phenomenon. Failure to recognize wearing-off may lead to incorrect therapeutic dicision-making and/or decline in the patient's quality of life. In order to develop a Japanese version of the 19-symptom and 9-symptom Wearing-off Questionnaires (WOQ-19 and WOQ-9), a linguistic validation was performed to validate the translated version according to the internationally recognized procedure. Forward translation was made independently by 2 Japanese translators with medical knowledge. The Japanese translations were consolidated and revised by the authors into the Japanese draft version. The Japanese draft version was modified into the Japanese final draft by reference to the results of PD patients' surveys. The Japanese final draft was back-translated into English by 2 native translators, and negotiated with the original developers. We thus developed a linguistically validated Japanese version of the WOQ-19 and the WOQ-9. (Received: February 3, 2011, Accepted: March 29, 2011).