(063) Psychometric properties of the Treatment Satisfaction with Medicine Questionnaire (SATMED-Q) in Indonesian patients with type 2 diabetes

Background: The SATMED-Q instrument has been translated and culturally adapted into an Indonesian version, but the psychometric properties have not been investigated.

Objectives: This study aimed to evaluate the psychometric properties of the Indonesian version of SATMED-Q in patients with type 2 diabetic (T2D).

Methods: Patients with T2D completed the SATMED-Q, the Medication Adherence Report Scale (MARS-5), and quality of life instrument (EQ5D and EQVAS) in five community health centres. We examined the structural, convergent and known-group validity, internal consistency and test-retest reliability.

Results: Overall, 486 patients (mean age 59 years old, 73.3% female) participated in this study. The median SATMED-Q score was 81.9 (range 50-100). Confirmatory factor analysis showed a validated well-fitted model (SRMR=0.051, RMSEA 0.074, CFI 0.968, TLI 0.958). Exploratory factor analysis showed the original six domain with loading factors exceeding 0.4. There was a positive correlation between SATMED-Q and MARS-5 (r=0.340; p-value < 0.001), EQ-VAS (r=0.320; p-value < 0.001), and EQ5D (r=0.142; p-value 0.002), indicating convergent validity. Known group validity was as expected for most characteristics (age, glycemic control and undesirable side effect experience), but not for comorbidities and number of glucose regulating medication. Patients without comorbidities and on fewer glucose regulating medications expressed lower satisfaction with their treatment. Internal reliability, as measured by Cronbach’s alpha and omega values, indicated strong consistency. Additionally, test-retest reliability demonstrated good consistency (ICC=0.827, p-value 0.216) and no floor or ceiling effects ( < 10%) were observed.

Conclusions: Satisfaction with medication was high in this Indonesian population. The Indonesian SATMED-Q was a valid and reliable instrument to assess satisfaction with medication. It can be used to capture the patient perspective in taking medicines to shape policies and enhance initiatives for quality improvement in patients with T2D, a rapidly growing patient group in Indonesia.