Intolerancia al metotrexato en pacientes con artritis inflamatoria que acuden a consulta externa de reumatología en Guayaquil durante el periodo 2019 - 2020, mediante el cuestionario de escala de gravedad de intolerancia al metotrexato, tras su traducción, adaptación cultural y validación.

Abstract

Background: Intolerance to methotrexate (MTX) is one of the causes that limits the use of the drug. The Methotrexate Intolerance Severity Score (MISS) questionnaire is an English-speaking tool used to identify intolerance related to the use of MTX. Objectives: Validate and adapt the MISS questionnaire into the Spanish language. Materials and methods: An observational, prospective, cross-sectional and analytical study was carried out, in which the translation of the MISS questionnaire was made forwards and backwards from English to Spanish. It was divided into two phases, the first phase included 308 Ecuadorian who answered the comprehension pretest, and in the second phase, 110 patients with Inflammatory Arthritis (IA) who answered the final questionnaire were included. Results: During the first phase, the median and mode of intelligibility was 1 (little confusing). The questionnaire effectively discriminates between tolerant versus intolerant patients to MTX, Cronbach's alpha was 0.87, Cohen's Kappa coefficient 0.752, the cutoff point was ≥8, sensitivity was 100% and a specificity was 93 %. Of the 110 patients, 18% showed intolerance according to the EGIM questionnaire, the subcutaneous route was the one with the greatest intolerance (21.4%), and in <53 years [(30.4% intolerant), p = 0.001)]. Conclusion: The Spanish version, of the MISS questionnaire is a valid and reliable tool for detection of intolerance to MTX.