Abstract
In the present study, we developed the Japanese version of the Illness Perception Questionnaire (J-IPQ) and evaluated its reliability and validity. New items for three emotional representation dimensions (i. e., positive affect about illness, positive/negative affect about treatment) were added to the original scales of Moss-Morris et al. (2002). We administered the J-IPQ to 169 hemodialysis (HD) patients, and another 24 HD patients completed it in 4weeks interval for test-retest reliability. We also administered the J-IPQ to 30 patients with chronic respiratory disease for testing cross-validation. Factor analysis revealed that the J-IPQ generally produced the same structure as the original scales, though the “acute/chronic timeline” was divided into “acute timeline” and “chronic timeline”. The coefficients of the J-IPQ items on the test-retest showed good enough reliability (r = .42 to .86). The respiratory sample showed the overall validity of the scales (α= .68 to .97), except for the dimensions of “acute timeline” (α= .38) and “illness coherence” (α= .58). We concluded that the J-IPQ is reliable and valid for assessing Japanese patients’ illness perception in research.
