Mean age was 74.6, and patients used a mean+/-standard deviation of 8.1+/-2.5 medications (range 5-17). Use of one or more inappropriate medications was documented in 128 patients (65%), including 73 (37%) taking a medication in violation of the Beers drugs-to-avoid criteria and 112 (57%) taking a medication that was ineffective, not indicated, or duplicative. Medication underuse was observed in 125 patients (64%). Together, inappropriate use and underuse were simultaneously present in 82 patients (42%), whereas 25 (13%) had neither inappropriate use nor underuse. When assessed by the total number of medications taken, the frequency of inappropriate medication use rose sharply from a mean of 0.4 inappropriate medications in patients taking five to six drugs, to 1.1 inappropriate medications in patients taking seven to nine drugs, to 1.9 inappropriate medications in patients taking 10 or more drugs (P