The purpose of this study was to adapt the Spitzer Quality of Life Index and evaluate its reliability in patients with low back pain. The following steps were followed: translation, back-translation, evaluation by a committee, and pretest. The reliability was estimated through stability and homogeneity assessment. The validity was tested comparing scores of the Spitzer (QLI) with the SF-36 and the Roland-Morris. The psychometric properties were evaluated by the self-application on 120 patients. Results showed that the Cronbach's Alpha was 0.77. Intraclass correlation coefficient for test-retest reliability was 0.960 (p<0.001; IC95%: 0.943; 0.972). Spearman´s correlation coefficient for test-retest reliability was 0.937 (p<0.001). There was significant correlation between the Spitzer (QLI) scores and the dimensions of the SF-36. A significant negative correlation was found between the Spitzer (QLI) and the Roland-Morris scores (r = - 0.730). The adaptation process was conducted successfully and the questionnaire presented reliable psychometric measures.
low back pain; pain; psychometrics; quality of life; validation studies
