Supplementary Material for: Independent and Combined Effects of Type 2 Diabetes Mellitus and Inappropriate Medication Use on Fall Risk Among the Older People

ABSTRACT Introduction: Falls are a major cause of morbidity and mortality in older people, and type 2 diabetes mellitus (T2DM) has been identified as a key contributor. Another factor associated with increased fall risk is inappropriate medication use (IMU), which includes the use of inappropriate drugs or the omission of indicated ones. However, the independent and combined effects of T2DM and IMU on fall risk in older people remain unclear. Methods: This prospective observational study was conducted among inpatients aged 65 years and older in the internal medicine department of a tertiary hospital between November 2022 and February 2023. Sociodemographic data, Turkish Inappropriate Medication Use in the Elderly (TIME-to-START/STOP) Criteria, and the Itaki Fall Risk Scale were collected through face-to-face interviews conducted by the researcher. The study population was divided into two groups: Group 1 (patients without T2DM n=50) and Group 2 (patients with T2DM, n=58). The effects of the independent variables on fall risk were analyzed using a multivariable logistic regression model (backward Wald method, Nagelkerke R Square 62.0%) in IBM SPSS Statistics 26.0. A p-value <0.05 was considered statistically significant. Results: T2DM and age were significant predictors of fall risk [(B = 2.775, p = 0.047, OR = 16.035); (B = 0.137, p = 0.010, OR = 1.147)]. Among participants with T2DM, females had higher risk of falls compared with males (B = 2.573, OR = 13.158, p = 0.043). At least one IMU was present in 75.0% of the cases per TIME-to-START. Fall risk was significantly higher in Group 2 and in male participants who did not meet “2+” TIME-to-START criteria [(B = 2.077, OR = 8.000, p = 0.014); (B = 2.118, OR = 8.316, p = 0.006)]. IMU was not a significant fall risk predictor in either group according to TIME-to-STOP. Both T2DM and IMU identified by TIME-to-START were significant predictors of high fall risk in older people. In addition to T2DM, age and IMU, living arrangement and history of falls were significant predictors. However, the primary focus was on the independent and combined effects of T2DM and IMU. Conclusions: Our study demonstrated that both T2DM and IMU identified by TIME-to-START were significant predictors of increased fall risk in older people. This risk was especially pronounced in patients with T2DM who also had multiple instances of inappropriate medication. These findings suggest that careful medication management is particularly important for fall prevention in older T2DM patients.