Adaptation and Validation of the Spanish Version of Decisional Conflict Scale in People with Migraine in Spain.

Abstract

We aimed to validate the Spanish version of the Decisional Conflict Scale (DCS) and analyze its psychometric properties in people with migraine. The DCS validation comprised two phases. First, a translation and cross-cultural adaptation following the International Society for Pharmacoeconomics and Outcomes Research (ISPOR) Good Practices: 1-preparation, 2-independent forward translation, 3-reconciliation, 4-back-translation, 5-harmonization, 6-clinical review, and 7-content validation in a group of migraine patients. Second, the analysis of the psychometric properties. The reliability or internal consistency of the DCS scale and subscales was assessed using Cronbach's α value. The item-subscale correlation was also evaluated. A floor and ceiling effects for DCS score was considered when at least 15% of respondents obtained DCS >90 (ceiling) or <10 (floor). The construct validity was studied through the correlation between the DCS subscales and by the correlation between the DCS and other questionnaires (Decision Self-Efficacy Scale [DSES] and 9-item Shared Decision-Making [SDM-Q-9]). Spearman's coefficients were estimated for the correlations. The cross-cultural adaptation was conducted on 17 patients who completed the questionnaire in a mean of 2.4 ±1.1 minutes. Generally, more than 75% of them considered that DCS items were adequate, easy to understand, and relevant. The psychometric properties were evaluated in a sample of n=128 patients. Accordingly, the internal consistency of DCS was high, with a Cronbach's α of 0.97 for the scale and between 0.87 to 0.96 for subscales. Also, a slight floor effect was observed, with 24.2% of patients having DCS scores <10. The correlation between subscales exceeded Spearman's coefficient of 0.7. Whereas the correlation between the DCS and the other questionnaires was generally moderate (Spearman's coefficient >0.4). The Spanish version (Spain) of the DCS has very acceptable psychometric properties (reliability and construct validity) and good potential for assessing decisional conflicts among migraine patients.