DOES SELF-ADMINISTRATION OF A QUALITY-OF-LIFE INDEX FOR INFLAMMATORY BOWEL-DISEASE CHANGE THE RESULTS

We assessed the effect of self administration of a disease-specific he alth-related quality of life instrument, the Inflammatory Bowel Diseas e Questionnaire (IBDQ), on score results. Patients were assessed at tw o visits in two tertiary centers. ''Experienced'' patients (N = 31) wi th Crohn's disease had previously completed the IBDQ several times whi le ''novices'' (N = 37) with Crohn's disease or ulcerative colitis had no prior exposure to the IBDQ. At each visit a self-administered IBDQ followed by a nurse administered IBDQ (score range, 1-7; absolute sco re range, 32-224) and disease activity were assessed. At visit 1, the mean rates of discrepant responses between nurse and self administered scores were 24 +/- 15% in experienced patients and 34 +/- 17% in novi ce patients (p = 0.018), which fell to 21 +/- 16 and 23 +/- 10%, respe ctively, by visit 2 (p = NS). However, discrepancy rates were not sign ificantly different between novice and experienced patients when adjus ted by center. Discrepancies occurred randomly in all 32 IBDQ items. E ighty percent of all discrepant responses differed by only one grade o f a seven-point Likert scale. Baseline self-administered scores for al l patients were 4.80 +/- 1.24 (absolute score, 153.0 +/- 39.9). Mean s core differences at each visit (nurse minus self) were very small, ran ging from 0.029 to 0.136, and would not be considered clinically impor tant. Intraclass correlation coefficients between the nurse and self-a dministered IBDQ and the four dimensional scores were greater than or equal to 0.97 by visit 2, indicating excellent concordance and minimal observer error. Mean changes in score over time were of comparable ma gnitude for both self (0.320 +/- 0.819) and nurse (0.260 +/- 0.831) as sessments. We conclude that the IBDQ may be reliably used as a self-ad ministered instrument in clinical trials.