Appropriateness of medication prescribing in ambulatory elderly patients.
OBJECTIVE
To assess the quality of medication prescribing in ambulatory elderly patients on multiple medications using the Medication Appropriateness Index (MAI).


METHODS
Cross-sectional study.


METHODS
General Medical Clinic of the Durham VA Medical Center.


METHODS
208 elderly outpatients on five or more regularly scheduled medications.


METHODS
Medication prescribing appropriateness was measured with the MAI, a reliable method that employs 10 implicit criteria. A weighted MAI score (range 0-18 per drug) served as a summary measure of appropriateness.


RESULTS
There were 1644 medications evaluated; 26% received no inappropriate ratings, 37% had one, 19% had two, and 18% had three or more. Of 16,440 ratings, 2295 (14%) were evaluated as inappropriate. The percentage of inappropriate ratings varied across prescribing dimensions: drug-drug interactions, 0%; drug-disease interactions, 1.4%; medication effectiveness, 4.7%; therapeutic duplication, 5.7%; indication, 11.5%; duration of treatment, 16.5%; dosage, 17.3%; practical directions, 20.3%; cost, 29.7%; and correct directions, 32.4%. The mean MAI score for all medications was 2.2 +/- 2.1 (range 0-10) and varied by therapeutic class. MAI scores were significantly lower for medications with a high potential for adverse effects compared with those with a low potential (MAI score of 1.8 vs 2.9, P < 0.001). Regression analysis revealed that no patient characteristics were associated with a higher likelihood of inappropriate prescribing.


CONCLUSIONS
Medication prescribing for elderly outpatients taking multiple medications was substantially appropriate. Prescribing dimensions with the most room for improvement were more exact directions, less expensive drugs, and practical directions. Drugs at high risk for adverse effects were prescribed more appropriately than those at low risk.
Schmader
K
K
Geriatric Research, Education and Clinical Center, Durham Veterans Affairs Medical Center, NC.
Hanlon
J T
JT
Weinberger
M
M
Landsman
P B
PB
Samsa
G P
GP
Lewis
I
I
Uttech
K
K
Cohen
H J
HJ
Feussner
J R
JR
D000367:Age Factors; D000368:Aged; D000553:Ambulatory Care / Q000191:economics / Q000592:standards*; D003430:Cross-Sectional Studies; D016527:Drug Costs; D004347:Drug Interactions; D011307:Drug Prescriptions; D004359:Drug Therapy, Combination; D004363:Drug Utilization / Q000191:economics / Q000592:standards*; D017723:Drug Utilization Review; D005260:Female; D006787:Hospitals, Veterans; D006801:Humans; D016013:Likelihood Functions; D008297:Male; D009657:North Carolina; D010353:Patient Education as Topic; D011787:Quality of Health Care; D012044:Regression Analysis