Background Rheumatoid Arthritis (RA) is a systemic inflammatory disease where its physiopathology is based on immunological activity. It has been determined that an early therapy with Disease-Modifying Antirheumatic Drugs (DMARDs) stops the progression of this disease. One of the main limitations to achieve this objective is guarantee compliance to DMARDs. Several methods have been designed to measure compliance such as CQR that provides quick and concise information about medication compliance.
Objectives To develop an initial linguistic and psychometric validation of the CQR questionnaire in patients with RA.
Methods A validation study was conducted at San Ignacio University Hospital. Steps suggested by ISPOR Task Force for Translation and Cultural Adaptation were followed, and a final Spanish version for Colombia was created with semantic and content equivalence to the original version. Data collection was performed in four outpatient rheumatology wards. The data collection form completed by the patients included demographic data, CQR19, analog scale of compliance, adverse effects associated with the medication; while doctors registered DAS-28, rheumatoid factor, anti-citrulline antibodies and current treatment. Psychometric validation was evaluated from a hypothesis of correlation between compliance (CQR score) and the level of activity of the disease (DAS-28). The association between compliance, the presence of adverse events, and the amount of medication was also evaluated.
Results CQR19 was completed by 233 patients with RA diagnosis (Female 75.1%) taking some type of pharmaceutical treatment (single or combined), with a mean of 11.3 years (SD 9.6) into the disease. Correlation between CQR19 score and DAS-28 activity categories was -0.64 (95% CI: -0.71to-0.56). Despite this result, correlation between CQR19 categories [satisfactory compliance (>80%) and unsatisfactory compliance (≤80%)] and DAS-28 was -0.16 (95% CI: -0.28 to -0.03). 97.8% of the patients were classified as satisfactory compliance. All analyses were conducted with Spearman's rank correlation coefficient based on Fisher transformation. Exploratory analysis showed that association between CQR19 score and adverse events was -0.05 (95% CI: -0.18to0.08), while the association between CQR19 score and the amount of medication was -0.34 (95% CI: -0.45to-0.22).
Conclusions CQR19 score relates to DAS-28 categories activity indicating that patients with less activity have higher compliance scores. However, this relationship was not evident when applying the compliance categories established by the CQR19 authors (compliance limit of 80%). Validations of CQR19 scores as a measure of compliance do not allow using this instrument in our local clinical practice in a regular basis. Further studies are necessary to evaluate the ability of CQR19 scores to indicate compliance to the treatment beyond just taking the medication in patients with RA. We suggest exploring other sources of evidence to validate this questionnaire.
De.Klerk E, et al. The compliance-questionnaire-rheumatology compared with electronic medication event monitoring: a validation study. J. Rheumatol. 30, 2469–2475 (2003).
Disclosure of Interest None declared