Continuity of Medication Use by US Adults With Diabetes, 2005-2019

Importance: Consistent medication use is critical for diabetes management. Population surveillance of consistency of medication use may identify opportunities to improve diabetes care. Objective: To evaluate trends in longitudinal use of glucose-, blood pressure-, and lipid-lowering medications by adults with diabetes. Design, Setting, and Participants: This serial cross-sectional study assessed trends in longitudinal use of glucose-, blood pressure-, and lipid-lowering medications by adults with diagnosed diabetes participating in the Medical Expenditure Panel Survey (MEPS), which allows serial cross-sections and 2-year longitudinal follow-up, between the 2005 to 2006 panel and 2018 to 2019 panel. Population-weighted, nationally representative estimates for the US were reported. Included individuals were adult MEPS participants with diagnosed diabetes during both years (ie, during 2005 and 2006 or during 2018 and 2019) who participated in all survey rounds. Data were analyzed from August 2021 to November 2022. Main Outcomes and Measures: Longitudinal use over the 2 years was categorized as continued use (at least 1 fill per year), no use, inconsistent use, and new use by medication type (glucose-, blood pressure-, and lipid-lowering medications). New medications were defined as prescription fills for a medication type first prescribed and filled in year 2 of MEPS participation. Results: A total of 15 237 participants with diabetes (7222 individuals aged 45-64 years 47.4%; 8258 54.2% female participants; 3851 Latino 25.3%; 3619 non-Latino Black (23.8%), and 6487 non-Latino White 42.6%) were included in the analytical sample. A mean of 19.5% (95% CI, 18.6%-20.3%), 17.1% (95% CI, 16.2%-18.1%), and 43.3% (95% CI, 42.2%-44.3%) of participants did not maintain continuity in use of glucose-, blood pressure-, or lipid-lowering medications, respectively, during both years of follow-up. The proportion of participants who continued use of glucose-lowering medication in both years trended down from 84.5% (95% CI, 81.8%-87.3%) in 2005 to 2006 to 77.4% (95% CI, 74.8%-80.1%) in 2018 to 2019; this decrease coincided with rate increases in inconsistent use (3.3% 95% CI, 1.9%-4.7% in 2005-2006 to 7.1% 95% CI, 5.6%-8.6% in 2018-2019) and no use (8.1% 95% CI, 6.0%-10.1% in 2005-2006 to 12.9% 95% CI, 10.9%-14.9% in 2018-2019). Inconsistent use of blood pressure-lowering medications trended upward from 3.9% (95% CI, 1.8%-6.0%) in 2005 to 2006 to 9.0% (95% CI, 7.0%-11.0%) in 2016 to 2017. Inconsistent use of lipid-lowering medication trended up to a high of 9.9% (95% CI, 7.0%-12.7%) in 2017 to 2018. Conclusions and Relevance: This study found that a mean of 19.5% of participants did not maintain continuity in use of glucose-lowering medication, with recent decreases, while a mean of 17.1% and 43.2% of participants did not maintain continuity of use of blood pressure- or lipid-lowering medications, respectively.