Table 1.

Criteria and relative weights for the MAI

MAI CRITERION	WEIGHT*	PROPORTION UNKNOWN†
1. Is there an indication for the drug?	3	3.0
2. Is the medication effective for the condition?	3	1.7
3. Is the dosage correct?	2	2.0
4. Are the directions correct?	2	0.7
5. Are the directions practical?	1	0.3
6. Are there clinically significant drug-drug interactions?	2	0.7
7. Are there clinically significant drug-disease interactions?	2	0.4
8. Is there unnecessary duplication with other drugs?	1	0.9
9. Is the duration of therapy acceptable?	1	4.7
10. Is this drug the least expensive alternative compared with others of equal utility?	1	46.5

MAI—medication appropriateness index.

^*Relative weight applied to inappropriate ratings in the calculation of the total MAI score. The maximum potential MAI score is 18; however, the cost component was not considered in this study, so the highest potential score was 17.

^†Proportion of medications coded as unknown at baseline.