Abstract
Purpose:
The purpose of this study was to ascertain language adaptation (validation) of Glaucoma Quality of Life Questionnaire (GQL-15) for Mexican population.<br />
Methods:
Linguistic Validation: Based on the MAPI Institute guidelines, the linguistic validation procedures consisted of 7 steps. Every step was reviewed by the Glaucoma Interdisciplinary Investigation Committee conformed by 6 glaucoma specialists, a health care professional and a psychologist.<br /> Reliability: Cronbach’s α coefficient was used as an index of internal consistency for each subscale. The optimal range of Cronbach’s α was above 0.70. To quantify test-retest reliability, intraclass correlation coefficients were used. Reliability coefficients above 0.70 were considered satisfactory.<br />
Results:
Administration of the GQL-15 questionnaire took about 5 minutes, on average.<br /> Linguistic Validation: During the forward translation step analysis, we dont have any troubles; and the backward translation was almost identical to the original questionnaire in English. In the cognitive interview step, 26 subjects did not have any difficulty while responding the 15-questions of GQL-15, and the consultants did not suggested amendments of words or phrases; and all was accepted by the Glaucoma Interdiciplanary Investigation Committee<br /> Reliability: The Cronbach’s α coefficient (internal consistency index) was 0.95 for the overall analyses and ranged from 0.75 to 0.91 for the subscales. The test-retest reliability, as estimated by the intraclass correlation coefficients, were greater than 0.70 for all subscales<br />
Conclusions:
MAPI methodology proved to be a reliable strategy for transcultural Glaucoma Quality of Life Questionnaire (GQL-15) translation; showed psychometric properties comparable to those of the original English version, and could be used as a reliable and valid tool for assessment of Quality of Life in Mexican glaucoma patients.<br /> Now we can apply this validated questionnaire to determine the quality of life and relate with the severity in our patients with glaucoma in the Mexican population.<br />