Effect of increased copayments on pharmacy use in the Department of Veterans Affairs

OBJECTIVES: In February 2002, the Department of Veterans Affairs (VA) raised medication copayments from $2 to $7 per 30-day supply of medication for certain veteran groups. We examined the impact of the copayment increase on medication acquisition from VA. METHODS: This was a retrospective cohort study using data from national VA databases from February 2001 through February 2003. We took a random sample of over 5% of male VA users in 2001. Of 149,107 veterans sampled, 19,504 (13%) had copayments for no drugs, 101,410 (68%) had copayments for some drugs, and 28,193 (19%) had copayments for all drugs. We used multivariable count models to examine changes in the number of 30-day medication supplies after the increase. RESULTS: After the copayment increase, veterans subject to copayments for all drugs received 8% fewer 30-day supplies of medication annually relative to veterans with no copayments (P < 0.001). The effect of the copayment increased as the number of different medications veterans received increased. Among veterans subject to copayments for all drugs, acquisition of lower-cost drugs fell by 36%, higher-cost medications fell by 6%, over-the-counter medications fell by 40%, and prescription-only medications fell by 4% relative to veterans with no drug copayments. CONCLUSIONS: The number of medications veterans obtained from VA decreased after the copayment increase. There were relatively larger impacts on veterans with higher medication use and on lower-cost and over-the-counter medications.