Prevalence of Diabetes Medication Intensifications in Older Adults Discharged From US Veterans Health Administration Hospitals

Abstract

Importance: Elevated blood glucose levels are common in hospitalized older adults and may lead clinicians to intensify outpatient diabetes medications at discharge, risking potential overtreatment when patients return home.

Objective: To assess how often hospitalized older adults are discharged with intensified diabetes medications and the likelihood of benefit associated with these intensifications.

Design, setting, and participants: This retrospective cohort study examined patients aged 65 years and older with diabetes not previously requiring insulin. The study included patients who were hospitalized in a Veterans Health Administration hospital for common medical conditions between 2011 and 2013.

Main outcomes and measures: Intensification of outpatient diabetes medications, defined as receiving a new or higher-dose medication at discharge than was being taken prior to hospitalization. Mixed-effect logistic regression models were used to control for patient and hospitalization characteristics.

Results: Of 16 178 patients (mean [SD] age, 73 [8] years; 15 895 [98%] men), 8535 (53%) had a preadmission hemoglobin A1c (HbA1c) level less than 7.0%, and 1044 (6%) had an HbA1c level greater than 9.0%. Overall, 1626 patients (10%) were discharged with intensified diabetes medications including 781 (5%) with new insulins and 557 (3%) with intensified sulfonylureas. Nearly half of patients receiving intensifications (49% [791 of 1626]) were classified as being unlikely to benefit owing to limited life expectancy or already being at goal HbA1c, while 20% (329 of 1626) were classified as having potential to benefit. Both preadmission HbA1c level and inpatient blood glucose recordings were associated with discharge with intensified diabetes medications. Among patients with a preadmission HbA1c level less than 7.0%, the predicted probability of receiving an intensification was 4% (95% CI, 3%-4%) for patients without elevated inpatient blood glucose levels and 21% (95% CI, 15%-26%) for patients with severely elevated inpatient blood glucose levels.

Conclusions and relevance: In this study, 1 in 10 older adults with diabetes hospitalized for common medical conditions was discharged with intensified diabetes medications. Nearly half of these individuals were unlikely to benefit owing to limited life expectancy or already being at their HbA1c goal.

Figure 1.. Association Between Inpatient Blood Glucose Recordings and Preadmission Outpatient Hemoglobin A_1c Level

Preadmission hemoglobin A_1c was measured using most recent hemoglobin A_1c laboratory value collected within 1 year preceding hospitalization. Inpatient blood glucose control was defined by the number of elevated blood glucose recordings as severely elevated (≥3 recordings of ≥300 mg/dL [to convert to millimoles per liter, multiply by 0.0555]), moderately elevated (≥3 recordings of ≥200 mg/dL without meeting criteria for severely elevated), or not elevated. Preadmission hemoglobin A_1c was found to be associated with inpatient blood glucose categories (P < .001 using a χ² test). To convert hemoglobin A_1c to proportion of total hemoglobin, multiply by 0.01.

Figure 2.. Intensification of Diabetes Medications by Estimated Likelihood to Benefit

High-risk intensifications included addition of insulin and/or addition or dose increase of sulfonylurea medications. Likelihood of benefit from diabetes medication intensification was estimated using preadmission hemoglobin A_1c and estimated life expectancy. Patients were categorized as having potential to benefit if their preadmission hemoglobin A_1c level was greater than 9.0% (to convert to proportion of total hemoglobin, multiply by 0.01). Patients were categorized as unlikely to benefit if their preadmission hemoglobin A_1c level was less than 7.5% regardless of life expectancy or if their preadmission hemoglobin A_1c level was less than 9.0% and their estimated life expectancy was less than 5 years. All others were classified as having indeterminate benefit (eTable 1 in the Supplement). Estimated likelihood of benefit was found to be associated with intensification category (P < .001 using a χ² test).

Figure 3.. Predicted Probability of Receiving a Diabetes Medication Intensification at Discharge, by Inpatient and Outpatient Glucose Control

Preadmission hemoglobin A_1c was measured using the most recent laboratory value collected within 1 year preceding hospitalization. Inpatient blood glucose control was defined by the number of elevated blood glucose recordings as severely elevated (≥3 recordings of ≥300 mg/dL [to convert to millimoles per liter, multiply by 0.0555]), moderately elevated (≥3 recordings of ≥200 mg/dL without meeting criteria for severely elevated), or not elevated. Predicted probabilities were estimated following mixed-effect logistic regression accounting for age, sex, race/ethnicity, income, Charlson Comorbidity Index score, length of stay, primary discharge diagnosis, year, hospital training status, receipt of steroids during hospitalization, preadmission hemoglobin A_1c, inpatient blood glucose level, an interaction term for preadmission hemoglobin A_1c and inpatient blood glucose level, and random effects to account for clustering by Veterans Health Administration hospital. Error bars indicate 95% CIs. To convert hemoglobin A_1c to proportion of total hemoglobin, multiply by 0.01.