Underuse of indicated medications among physically frail older US veterans at the time of hospital discharge: results of a cross-sectional analysis of data from the Geriatric Evaluation and Management Drug Study

Abstract

Background: Medication underutilization, or the omission of a potentially beneficial medication indicated for disease management, is common among older adults but poorly understood.

Objectives: The aims of this work were to assess the prevalence of medication underuse and to determine whether polypharmacy or comorbidity was associated with medication underuse among physically frail older veterans transitioning from the hospital to the community.

Methods: This was a cross-sectional analysis of patients who were discharged from 11 US veterans' hospitals to outpatient care, based on data from the Geriatric Evaluation and Management Drug Study, a substudy of the Veterans Affairs Cooperative Study of geriatric evaluation and management. Patients were enrolled between August 31, 1995, and January 31, 1999. To qualify for the study, patients had to be aged > or =65 years, hospitalized in a medical or surgical ward for >48 hours, and meet > or =2 of the following criteria: moderate functional disability; recent cerebrovascular accident with residual neurological deficit; history of > or =1 fall in the previous 3 months; documented difficulty with walking (ie, requiring personal assistance or equipment), not including preadmission use of a wheelchair with ability to transfer to and from chair independently; malnutrition (admission serum albumin of 3.5 g/dL, <80% of ideal body weight, or recent > or =15-lb weight loss reported in admission history); dementia; depression; documented diagnosis of new fracture or revision needed of older fracture; unplanned admission within 3 months of previous admission; and prolonged bed rest. Clinical pharmacist/physician pairs reviewed medical records and medication lists and independently applied the Assessment of Underutilization (AOU) index to determine omissions of indicated medications. Discordances in index ratings were resolved during clinical consensus conferences. The primary outcome measure was the percentage of patients with > or =1 medication omission detected by the AOU. Multivariable logistic regression analyses identified factors associated with underuse.

Results: A total of 384 patients were included in the study. The majority (53.6%) were between the ages of 65 and 74 years, and the mean (SD) Charlson comorbidity index was 2.44 (1.93). Overall, 374 patients (97.4%) were men and 274 (71.4%) were white. Medication undertreatment occurred in 238 participants (62.0%). Diseases of the Accepted for publication October 26, 2009. circulatory, endocrine/nutritional, musculoskeletal, and respiratory systems were the most commonly undertreated conditions. The indicated medications most likely to be omitted were nitrates for those with a history of myocardial infarction, multivitamins in those with malnutrition, and inhaled anticholinergics for chronic obstructive airways disease. Statistically significant factors associated with medication underuse included limitations in activities of daily living (adjusted odds ratio [AOR], 2.17 [95% CI, 1.27-3.71]; P = 0.01), being white (AOR, 1.70 [95% CI, 1.06-2.71]; P = 0.03), and Charlson comorbidity index (AOR, 1.13 for each 1-point increase [95% CI, 1.00-1.27]; P = 0.04). Discharge from a general medicine service as opposed to a surgical service was associated with lower risk of medication underuse (AOR, 0.61 [95% CI, 0.38-0.98]; P = 0.04).

Conclusions: Medication underuse was relatively common in this study. Patients with greater comorbidity, but not polypharmacy, had increased odds of undertreatment.