Outpatient Drug Use among TRICARE Beneficiaries Aged 65 and OlderObjective: To quantify the prevalence of use of multiple medications among a sample of Department of Defense (DoD) health care beneficiaries, aged 65 or older, who used their TRICARE benefit to obtain prescription medication. Outpatient pharmacy fill records were analyzed for a 10% random sample of 1.27 million TRICARE beneficiaries, aged 65+, who filled one or more prescriptions in the 90-day period from December 1, 2004, through February 28, 2005. The First DataBank generic code number (GCN) was used to identify drugs and calculate the mean number of medications obtained and the mean, frequency, and type of American Hospital Formulary System (AHFS) drug therapy categories utilized. Statistical significance between gender and age subgroups was tested via independent t-tests.
Results: There were 1,268,162 users of the TRICARE pharmacy benefit in the 90-day study period from December 1, 2004 through February 28, 2005, approximately 72.7% of 1,744,072 eligible beneficiaries. The 10% sample of these users (N=126,682) accounted for 1,091,699 pharmacy fill records for 761,043 unique medications, or an average of 6.01 [SD,+4.01] unique medications per user, distributed across an average of 3.80 [± 2.08] therapeutic categories; 8.8% of users received 1 medication, 50.0% received 5 or more medications from an average of 3 therapeutic categories, and 2.8% obtained 16 or more medications from an average of 8 therapeutic categories. Prescription medication use was more prevalent among women relative to men, with an average of 6.28 [± 4.12] medications from 4.03 [±2.11] therapeutic categories for women versus an average of 5.69 [± 3.85] medications from an average of 3.80 [± 2.08] therapeutic categories for men (P< 0.001. Prescription medication use peaked among beneficiaries ages 80 ? 84 years. Cardiovascular drugs, central nervous system agents, and hormones and synthetic substitutes were the 3 most common therapeutic categories used by 77%, 48%, and 42% of beneficiaries, respectively. This baseline analysis documented the prevalence of multiple medication usage among TRICARE beneficiaries and suggests that some form of intervention may be warranted for a portion of the study population to mitigate the risk of an adverse drug event or other risks associated with simultaneous use of multiple medications among seniors. The geographically distributed nature of the study population and the providers who treat them further suggests the prescribing behavior implied by our findings may be generalizable to the other seniors nationwide. The Department faces a challenge similar to that of many Medicare Part D drug plans to cost-effectively monitor and optimize pharmacotherapy treatments for it’s senior beneficiaries