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BACKGROUND: Drugs can improve quality of life for many older people, but they may cause adverse health outcomes (eg, drug—disease interactions) if used inappropriately. OBJECTIVE: To determine the prevalence of potential drug—disease interactions as defined by explicit criteria and examine associations between sociodemographic and health status variables and potential drug—disease interactions. METHODS: The study design was cross-sectional. We evaluated 397 frail elderly inpatients from the Geriatric Evaluation and Management trial conducted at 11 Veterans Affairs Medical Centers. Drug—disease interactions were defined using explicit criteria from consensus expert panels of geriatricians from the US and Canada. RESULTS: Overall, 159 (40.1%) patients had one or more potential drug—disease interaction. The most common potential interactions were calcium-channel blockers and heart failure (12.3%) and β-blockers and diabetes (6.8%). Multivariable logistic regression analyses revealed that age ⩾75 years (adjusted OR 2.43; 95% CI 1.52 to 3.88), being married (adjusted OR 1.77; 95% CI 1.11 to 2.82), comorbidity index defined by Charlson method (adjusted OR 1.19; 95% CI 1.05 to 1.34), and use of multiple prescription drugs (5–8: adjusted OR 4.17; 95% CI 1.96 to 8.88, ⩾9: adjusted OR 9.22; 95% CI 4.26 to 19.95), were significantly (p < 0.05) associated with having one or more potential drug—disease interaction. CONCLUSIONS: Potential drug—disease interactions are common in hospitalized elderly patients and are related to specific sociodemographic and health status factors. Further research is needed to examine the relationship between health outcomes and drug—disease interactions.

OBJECTIVE: To determine the relationship of inappropriate prescribing in the elderly to health outcomes. SETTING: General Medical Clinic of the Durham Veterans Affairs Medical Center. PATIENTS: A total of 208 veterans more than 65 years old who were each taking five or more drugs and participated in a pharmacist intervention trial. MEASUREMENTS: Prescribing appropriateness was assessed by a clinical pharmacist using the medication appropriateness index (MAI). A summed MAI score was calculated, with higher scores indicating less appropriate prescribing. The health outcomes were hospitalization, unscheduled ambulatory or emergency care visits, and blood pressure control. RESULTS: Bivariate analyses revealed that mean MAI scores at baseline were higher for those with hospital admissions (18.9 vs. 16.9, p = 0.07) and unscheduled ambulatory or emergency care visits (18.8 vs. 16.3, p = 0.05) over the subsequent 12 months than for those without admissions and emergency care visits. MAI scores for antihypertensive medications were higher for patients with inadequate blood pressure control (> 160/90 mm Hg) than for those whose blood pressure was controlled (4.7 vs. 3.1, p = 0.02). CONCLUSIONS: Inappropriate prescribing appeared to be associated with adverse health outcomes. This finding needs to be confirmed in future studies that have larger samples and control for potential confounders.

OBJECTIVE: To test the reliability of drug utilization evaluation (DUE) applied to medications commonly used by the ambulatory elderly. METHODS: A DUE model was developed for four domains: (1) justification for use, (2) critical process indicators, (3) complications, and (4) clinical outcomes. DUE criteria specific to use in the elderly were developed for angiotensin-converting enzyme (ACE) inhibitors and histamine2 (H2)-antagonists, and consensus was reached by an external expert panel. After pilot testing, two clinical pharmacists independently evaluated these medications, applying the DUE criteria and rating each item as appropriate or inappropriate. Interrater and intrarater reliability was assessed by using κ statistics. RESULTS: In a sample of 208 ambulatory elderly veterans, 42 (20.2%) were taking an ACE inhibitor and 56 (26.9%) an H2-antagonist. The interrater agreement for individual domains, represented by κ statistics, were 0.10–0.58 and 0–0.83 for ACE inhibitors and H2-antagonists, respectively. The κ statistic for overall agreement, which considered ratings from all criteria across all domains, was 0.24 for ACE inhibitors and 0.18 for H2-antagonists. Intrarater reliability was assessed 3 months later, and κ statistics were 0.61–0.65 (0.49 overall) and 0–0.96 (0.81 overall) for ACE inhibitors and H2-antagonists, respectively. CONCLUSIONS: Intrarater reliability for DUE was good to excellent. However, interrater reliability exhibited only marginal reproducibility, particularly where evaluators were required to use subjective judgment (i.e., complications, clinical outcomes). DUE may not be a suitable standard for assessing medication appropriateness in ambulatory elderly patients.

OBJECTIVE: To evaluate the reliability of a medication appropriateness index (MAI) modified for elderly outpatients in a non-Veterans Affairs setting. DESIGN: Reliability study. SETTING: General community. PARTICIPANTS: Ten community-dwelling elderly (> 65 y) taking five or more regularly scheduled medications and participating in a university-based health service intervention study. MAIN OUTCOME MEASURES: Interrater reliability of MAI ratings of 65 medications made by two clinical pharmacists for individual items and for an overall summed score was calculated by use of κ statistics and intraclass correlation coefficient. RESULTS: The interrater agreement for each of the individual MAI items was high for both appropriate and inappropriate ratings and ranged from 80% to 100% (overall κ = 0.64). Overall agreement for the summed score was good (intraclass correlation = 0.80). CONCLUSIONS: The modified MAI is a reliable instrument for evaluation of medication appropriateness in a non-Veterans Affairs, ambulatory, elderly population and may provide pharmacists with a practical and standard method to evaluate patients' drug regimens and identify some potential drug-related problems.

Adverse drug events happen all too often in older adults, but we still do not have a clear understanding of potentially modifiable risk factors, with the exception of polypharmacy. This paper critiques the article in this issue of The Annals entitled, "Inappropriate Prescribing Predicts Adverse Drug Events in Older Adults." A validated measure for self-reported adverse drug events was used, along with a modified measure for inappropriate prescribing that we developed nearly 2 decades ago (ie, Medication Appropriateness Index). Besides discussing the strengths and weaknesses of this article, we also recommend future research directions in this area.