Translation and validation study of the Japanese versions of the Coronary Revascularisation Outcome Questionnaire (CROQ-J)

Background and aims: Assessing the health related quality of life (HRQOL) in patients with a disease specific scale is essential. The purpose of this study was to develop the Japanese version of the coronary revascularisation outcome questionnaire (CROQ), a disease-specific scale to measure HRQOL before and after coronary revascularisation.

Methods: The English version of the questionnaire was translated into Japanese; some terms were revised, and some items were eliminated to suit the Japanese medical environment. Eight patients filled out the questionnaire, which was then analyzed for face validity. In the field study, subjects were recruited from a university hospital in Tokyo, and questionnaires were given to fill out. In terms of statistical analysis, factor analysis, internal consistency, known-groups validity, concurrent validity with using Short-Form36 (SF-36) and Seattle Angina Questionnaire-Japanese version (SAQ-J), and test-retest reliability were assessed.

Results: Informed consents were obtained from 356 patients, and out of 325 patients responded in the field study (91.3%). The factor structure of CROQ-Japanese version (CROQ-J) was similar to that of the original version. Cronbach's α ranged from 0.78 to 0.92. The concurrent validity was mostly supported by the pattern of association between CROQ-J, SAQ-J, and SF-36. Patients without chest symptoms had significantly higher scores of CROQ-J than those with chest symptoms. On the basis of analysis of the test-retest reliability, intra-class correlation coefficients were close to 0.70.

Conclusions: The Japanese translation of CROQ is a valid and reliable scale for assessing the patient's HRQOL in CAD.