Dermatology Life Quality Index: Influence of an illustrated version

Background An illustrated version of the Dermatology Life Quality Index (DLQI) was developed in order to improve the ease with which this standard questionnaire is answered. Objectives To compare the illustrated version with the text-only version of the DLQI. Methods The two versions were administered to 206 patients attending Dermatology outpatient clinics. The time taken to complete either the illustrated or the text-only version was noted in 52 additional patients. Results One hundred and ninety-one of 206 patients completed both questionnaires satisfactorily. Their mean DLQI scores were 6.4 (median 4.0, lower quartile 1.0, upper quartile 11.0) for the illustrated version and 6.3 (median 4.0, lower quartile 1.0, upper quartile 10.0) for the text-only version. For the 98 patients who answered the illustrated version first, the mean DLQI scores were 6.9 (median 4.0, lower quartile 1.9, upper quartile 11.9) for the illustrated version and 6.4 (median 4.0, lower quartile 1.8, upper quartile 11.0) for the text-only version. For the 93 patients who answered the text-only version first, the mean DLQI scores were 5.9 (median 4.0, lower quartile 1.7, upper quartile 10.2) for the illustrated version and 6.2 (median 5.0, lower quartile 0.5, upper quartile 9.5) for the text-only version. The median time taken to complete the text-only version was 124 s (mean+/-SD 126+/-65, n=27) and 88 s (mean+/-SD 101+/-52, n=25) for the illustrated version (P=0.08). There was a very close correlation (r=0.98) between the scores of the text-only and the illustrated versions; 82.2% of patients either scored the same or had a DLQI score difference of only 1. One hundred and seven (59.8%) patients preferred using the illustrated version and 66 (36.9%) preferred the text-only version. One hundred and four (57.5%) found the illustrated version easier to use. Conclusions The illustrated version was superior to the text-only version in terms of patient preference and ease of use, but it was not possible to demonstrate exact equivalence between the two versions.