Chronic Medication Burden and Complexity for US Patients with Type 2 Diabetes Treated with Glucose-Lowering Agents

Abstract

Introduction: Most adults with type 2 diabetes (T2D) have several chronic conditions treated with complex regimens and multiple medications. The burden and complexity of multiple medication use are associated with worse patient outcomes, including reduced adherence and increased costs, hospitalizations, mortality rates, and HbA1c. This study quantifies the chronic medication burden, regimen complexity, and potential medication interactions in patients with T2D using a nationwide claims database in the USA.

Methods: Adults with T2D treated for greater than half of the year with at least one glucose-lowering agent (GLA) in 2017 were included in this descriptive study. Chronic medications were defined as all GLAs and non-GLA medications prescribed for at least 90 days in 2017 to at least 2% of the cohort. Medication burden, defined as the number of medications prescribed, was examined. Medication complexity, proxied by the Medication Regimen Complexity Index (MRCI), and potential use of interacting medications were also examined. Results were investigated for all chronic medications and were reported on the basis of the disease treated (diabetes or other condition) and the route of administration (oral or other).

Results: On average, in 2017, the 814,156 patients included in the study filled prescriptions for 4.1 chronic medications (standard deviation [SD] = 2.0), 3.7 oral chronic medications (SD = 1.9), 1.5 GLAs (SD = 0.8), and 1.1 oral GLAs (SD = 0.7). The average MRCI was 14.7 for all chronic medications (SD = 7.4), with a mean of 12.4 for all oral chronic medications (SD = 6.3), 6.6 for all GLAs (SD = 3.8), and 4.9 for oral GLAs (SD = 2.6).

Conclusion: On average, patients with T2D used multiple medications, had a complex medication regimen, and were at potential risk of medication interactions. These findings suggest that patients, practitioners, pharmacists, and payers may benefit from interventions which decrease medication burden, complexity, and/or adverse events related to the treatment of T2D.

Keywords: Chronic medications; Glucose-lowering agents; Medication burden; Medication interactions; Medication regimen complexity index; Polypharmacy; Type 2 diabetes.

Fig. 1

Average daily medication burden for patients with type 2 diabetes. This figure illustrates the average number of medications prescribed in 2017 for all chronic medications with an oral route of administration, all glucose-lowering agents and glucose-lowering agents with an oral route of administration. See Supplementary Table 1 for a complete listing of these medications. Mean ± standard deviation (in error bars) reported in figure. Medians (interquartile range): all chronic medications= 3.9 (2.7–5.3); all chronic oral medications = 3.6 (2.4–4.9); all glucose-lowering agents = 1.2 (0.9–1.9); oral glucose-lowering agents = 1.0 (0.8–1.6)

Fig. 2

Distribution of average days of medication use for patients with type 2 diabetes. Graphs represent the average percentage of days patients treated with number of medications of interest in 2017 for all chronic medications with an oral route of administration, all glucose-lowering agents, and glucose-lowering agents with an oral route of administration. See Supplementary Table 1 for a complete listing of these medications

Fig. 3

Average medication regimen complexity index score for patients with type 2 diabetes. This figure illustrates the average Medication Regiment Complexity Index (MRCI) score in 2017 for all chronic medications, all chronic medications with an oral route of administration, all glucose-lowering agents, and glucose-lowering agents with an oral route of administration. See Supplementary Table 1 for a complete listing of these medications and Supplementary Table 5 for a description of how the MRCI is scored. Mean ± standard deviation (in error bars) reported in figure. Medians (interquartile range): all chronic medications= 1.35 (9.1–19.0); all chronic oral medications = 11.5 (7.7–16.1); all glucose-lowering agents = 5.5 (3.7–8.7); oral glucose-lowering agents = 4.1 (3.0–6.4)