A brief cancer pain assessment tool in Japanese: the utility of the Japanese Brief Pain Inventory--BPI-J.

Despite recognition that pain management is an important component in the treatment of Japanese cancer patients, progress in this area has been slowed by the lack of an appropriate measure of pain. In a prospective, single-institution study, a Japanese translation of the Brief Pain Inventory (BPI-J) was administered to 121 patients to assess the intensity and impact of cancer-related pain. After an analysis of the instrument's reliability and validity, this study tested the utility of the new measure in an analysis of the adequacy of analgesic prescription. Results were compared with predictive models from studies using non-Japanese patient groups. Factor analysis of the BPI items resulted in two factors, pain severity and pain interference, showing consistency with other language versions of the tool. Coefficient alphas of greater than 0.80 for the items comprising these two subscales indicate a reliable self-report pain instrument. After establishing the validity and reliability of the BPI-J, we examined possible predictors of inadequate pain management in these Japanese cancer patients. Similar to studies done in other countries, women patients and those whose pain severity was underestimated by their physician were more likely to be undermanaged for pain. The results of this study support the utility of the Japanese BPI for studies of the epidemiology of cancer pain in Japan, as well as for the assessment of pain treatment outcome in Japanese-speaking patients.