Assessing the appropriateness of physician prescribing for geriatric outpatients. Development and testing of an instrument

Abstract

Objective: In a randomized, controlled trial evaluating the impact of clinical pharmacists' consultations on physicians' prescribing decisions, a seven-member physician/pharmacist panel developed an instrument to characterize and quantify the full range of drug-prescribing problems. The instrument was tested for validity and reliability.

Sample: The instrument was applied in reviewing prescribing for 236 geriatric outpatients.

Methods: To ensure internal validity of the instrument, five panel meetings were devoted to reaching a consensus on procedures, categories, criteria, and scoring. Each case was evaluated independently by two reviewers and each drug in the regimen was evaluated for drug-drug interactions, dosage, schedule, allergic reactions, therapeutic duplication, use of drugs without established diagnoses, and inappropriate drugs for the patient's clinical conditions; discrepancies were adjudicated by the panel chairperson. Self-reported adverse effects of 60 study patients who were interviewed, and hospital readmissions of all study patients were used to test the external validity of the instrument.

Results: Inter-rater reliability improved over time, reaching a high of 97.1 percent after six months. A positive association was determined between the prescribing scores and the number of reported adverse effects (rho = 0.28, p = 0.02). Although the number of patients with drug-related hospital readmissions was too few to establish a significant association between the prescribing scores and readmissions, the findings were expected.

Conclusions: Given current requirements for drug utilization reviews in hospitals, health maintenance organizations, and Medicaid programs, this instrument may prove to be very useful.