To perform a transcultural adaptation and validation of a Spanish version of the compliance questionnaire in rheumatology (sCQR). In this transversal study of transcultural adaptation of the sCQR, validity was evaluated in patients with rheumatoid arthritis (RA) and a minimum 6-month follow-up by determining compliance with the electronic prescription system in consuming steroids or nonbiologic disease-modifying antirheumatic drugs. A two-week retest was proposed to all patients. All patients completed the health assessment questionnaire (HAQ), and the Morisky-Green test was also performed. Reliability was analyzed using Cronbach's alpha and the intraclass correlation coefficient (ICC). Convergent construct validity was tested in the electronic prescription system using discriminative analysis, and divergent construct validity was tested by comparing it to the HAQ. Sensitivity, specificity and ROC curves were evaluated for the sCQR and the Morisky-Green test. Of 123 recruited patients, 101 fulfilled the inclusion criteria, and 61 were on biologic therapy. 23 performed the retest. Test-retest reliability (ICC) was 0.76 (Cronbach's alpha 0.86). Multiple regression analysis showed correlation with each item of the sCQR as independent variables (r2 = 0.60). No correlation was seen between total score punctuation of the sCQR and the HAQ (r2 = 0.22). Discriminative analysis weighting each sCQR item showed a cutoff point of - 0.9991 (sensibility and 58.8%, specificity 98.3%). The likelihood ratio of the sCQR to detect ≤ 80% adherence with electronic prescriptions was 35.3. The Morisky-Green test revealed sensibility and specificity were 29.4 and 83.3%, respectively. This study validates the transcultural adaptation of sCQR in RA patients. A high reliability of sCQR for measuring adherence was found. Its predictive value suggests that it could be used as a screening instrument.
Keywords: Adherence; Compliance; Questionnaire; Rheumatoid arthritis; Spanish.