Development of a medication adherence scale for familial Mediterranean fever (MASIF) in a cohort of Turkish children.

Objectives: To develop and assess the validity and reliability of an adherence scale concerning medical treatment in paediatric FMF patients.

Methods: The Medication Adherence Scale in FMF Patients (MASIF) is a 18-item questionnaire that evaluates adherence to medication in four domains. Validation of the instrument was accomplished in paediatric FMF patients (aged 2-18 years) under medication at least for 6 months. The first step was to build up the scale through qualitative approach (with interviews using semi-structured questions). Validation analyses included assessment of feasibility, face and content validity; construct validity, internal consistency and test-retest reliability.

Results: One hundred and fifty patients with FMF were enrolled in the study. The mean age of the patients was 11.11±4.02 years and 48.7% of them were male. The MASIF was found to be feasible and valid for both face and content. It correlated with the Morisky Medication Adherence Scale as a gold standard thereby demonstrating good construct validity (r=0.515, p<0.001). Assessment of content validity identified four subscales. The internal consistency, Cronbach's alpha was 0.728. There was a positive and significant correlation between test and retest scores (r=0.843; p<0.001). Also, a significant correlation between parents' and children's reports (r=0.781, p<0.001).

Conclusions: Based on these results, the use of this scale to assess and follow up the adherence to treatment in paediatric FMF patients under medical treatment is recommended.