Overtreatment and associated risk factors among multimorbid older patients with diabetes

Background: In multimorbid older patients with type 2 diabetes mellitus (T2DM), the intensity of glucose-lowering medication (GLM) should be focused on attaining a suitable level of glycated hemoglobin (HbA_1c) while avoiding side effects. We aimed at identifying patients with overtreatment of T2DM as well as associated risk factors. Methods: In a secondary analysis of a multicenter study of multimorbid older patients, we evaluated HbA_1c levels among patients with T2DM. Patients were aged ≥70 years, with multimorbidity (≥3 chronic diagnoses) and polypharmacy (≥5 chronic medications), enrolled in four university medical centers across Europe (Belgium, Ireland, Netherlands, and Switzerland). We defined overtreatment as HbA_1c < 7.5% with ≥1 GLM other than metformin, as suggested by Choosing Wisely and used prevalence ratios (PRs) to evaluate risk factors of overtreatment in age- and sex-adjusted analyses. Results: Among the 564 patients with T2DM (median age 78 years, 39% women), mean ± standard deviation HbA_1c was 7.2 ± 1.2%. Metformin (prevalence 51%) was the most frequently prescribed GLM and 199 (35%) patients were overtreated. The presence of severe renal impairment (PR 1.36, 1.21–1.53) and outpatient physician (other than general practitioner [GP], i.e. specialist) or emergency department visits (PR 1.22, 1.03–1.46 for 1–2 visits, and PR 1.35, 1.19–1.54 for ≥3 visits versus no visits) were associated with overtreatment. These factors remained associated with overtreatment in multivariable analyses. Conclusions: In this multicountry study of multimorbid older patients with T2DM, more than one third were overtreated, highlighting the high prevalence of this problem. Careful balancing of benefits and risks in the choice of GLM may improve patient care, especially in the context of comorbidities such as severe renal impairment, and frequent non-GP healthcare contacts.