Introduction: To compare responsiveness and minimal clinically important differences (MCID) between the Gastrointestinal Quality of Life (GIQLI) and the Short Form 36 (SF-36), we prospectively analyze 159 patients undergoing cholecystectomy at two tertiary academic hospitals.
Patients and methods: All patients completed the disease-specific GIQLI and the generic SF-36 before and 3 months after surgery. Scores using these instruments were interpreted by generalized estimating equation before and after cholecystectomy. The bootstrap estimation was used to derive 95% confidence intervals for differences in the responsiveness estimates.
Results and discussion: Mean changes in all GIQLI and the SF-36 subscales were statistically significant (p < 0.05). Comparisons of effect size (ES), standardized response means (SRM), and relative efficiency (>1) indicated that the responsiveness of the GIQLI was superior to that of the SF-36. In the equivalence test, all lower or upper confidence limits presented no equivalence (>5), indicating good MCID. The ES and SRM for emotions and physical function in the GIQLI significantly differed from those of the SF-36 (p < 0.05).
Conclusion: The data in this study indicate that clinicians and health researchers should weight disease-specific measures more heavily than generic measures when evaluating treatment outcomes.