Relationship of Self Efficacy in Medication Understanding with Quality of Life among Elderly with Type 2 Diabetes Mellitus on Polypharmacy in Malaysia

Self-efficacy (SE) has been shown to be positively correlated with quality of life (QOL) among patients with type 2 diabetes mellitus (T2DM). Medication understanding (MU) on the other hand, leads to good adherence that indirectly improves QOL. Measuring self-efficacy in medication understanding is useful to ascertain patient’s confidence in medication adherence. However, there is a lack of studies on the relationship between self-efficacy in medication understanding with QOL. This study aimed to determine the relationship between self-efficacy in medication understanding and QOL, and the factors associated with QOL in elderly with T2DM on polypharmacy. A cross-sectional study was conducted on these populations at primary care specialist clinic. Malay version of MU in SE questionnaire (MUSE) was used. Higher scores showed a better understanding. A revised Version Diabetic Quality of Life-13 (RVDQOL-13) questionnaire was used with lower scores indicating higher QOL. A total of 321 patients participated, with the majority being male (58.3%), Malay (84.7%), a predominant age group of 60–69 (75.7%) with mean age (±SD) of 66.7 (±0.286) years old. The median (IQR) of MUSE was high—30 (4)—while the RVDQOL-13 was low—19 (8)—which demonstrated high QOL. Inverse correlation was found between MUSE and QOL (r −0.14, p < 0.01). Multiple linear regression analysis demonstrated that MUSE score (β −0.282; 95% CI: (−5.438, −2.581); p < 0.001), low-income group (β −0.144; 95% CI: (−3.118, −0.534); p = 0.006) and duration of medications ≥240 days (β −0.282; 95% CI: (−5.438, −2.581); p < 0.001) were associated with better QOL, while medications ≥10 (β 0.109; 95% CI: 0.214, 4.462; p = 0.031) and those with pills and insulin (β 0.193; 95% CI: 1.206, 3.747; p < 0.001) were associated with poor QOL. In conclusion, higher MUSE is associated with better QOL. Findings suggest emphasizing self-efficacy in medication understanding in the management of elderly with T2DM on polypharmacy to improve QOL.