[Adaptation of the 12-item medication adherence scale ( the Questionnaire for assessment of adherence to Medication) on a Russian-speaking sample of patients with type 1 and type 2 diabetes mellitus].

Background: Poor adherence to treatment among patients with type 1 diabetes mellitus (T1DM) and type 2 diabetes mellitus (T2DM) hinders the effective use of antidiabetic agents and the achievement of optimal glycemic control, reducing their quality of life and outcomes. Assessing adherence to treatment using a questionnaire can help identify and eliminate factors and barriers that negatively affect adherence to medical recommendations and satisfaction with treatment.

Aim: To conduct linguistic and cultural adaptation of the 12-item Medication Adherence Scale (MAS-12) questionnaire and evaluate the psychometric properties of the Russian version of the MAS-12 questionnaire among patients suffering from T1DM and T2DM.

Materials and methods: A survey of 198 patients with T1DM and T2DM was carried out, including self-completion of the MAS-12 questionnaire in Russian. Average age: 47.1±18.62 years, proportion of women - 76%. Average duration of the disease: 13.08±10.05 years. The construct validity of the MAS-12 questionnaire was assessed using confirmatory factor analysis. As an external criterion for assessing convergent validity, the KOP-25 method was used - the Russian Questionnaire for Quantitative Assessment of Treatment Adherence (KOP-25). Reliability of the MAS-12 was assessed using Cronbach's α internal consistency and participant retest after 1 to 4 months.

Results: The factor structure of the MAS-12 questionnaire is reproduced for the first time on a Russian sample of patients with diabetes. Recommended fit indicators for the measurement model (CFI=0.983, RMSEA=0.049, TLI=0.968) were achieved by excluding two items (9 and 12) that did not demonstrate statistically significant contributions to their respective subscales. The internal consistency of the subscales (α ϵ [0.522; 0.857]) and the questionnaire as a whole (α=0.766) was assessed as sufficient. Significant correlations of the adapted methodology and its subscales with the scales of the KOP-25 questionnaire were obtained. The closest connections (r ϵ [0.333; 0.431], p<0.010) are observed with the COP-25 scales related to drug therapy, which indicates good external validity of the adapted methodology.

Conclusion: The Russian version of the MAS-12 questionnaire "Questionnaire for assessing adherence to medication treatment" (PML-10), consisting of 10 questions, has good psychometric properties, is a valid and reliable tool for assessing medication adherence among patients with T1DM and T2DM and can be recommended for use in clinical practice, including for monitoring treatment adherence in Russia.