BACKGROUND: Whileincreasesinprescriptiondrugspending have moderated in recentyears,drugspending is still aconcern among managed careorganizations and healthplanadministrators .Inorder to minimize costincreasesfromyeartoyear, many healthcare plans have shiftedmoreofthe costofmedications to themember-consumer. Coinsurance,abenefitdesign in which thepatient pays apercentage of thecostofthe medication, is garnering more attentionasatypeof cost-sharing that differsfromthe traditionalcopaymentmodel.OBJECTIVE: To estimate theimpactonmedicationexpenditures and utilization of apharmacybenefit design changefrom3-tiercopaymentto coinsurance.METHODS:Drugexpenditures and utilization of beneficiaries aged ≥ 18 yearsand continuously enrolled in 2privately insured groupswere compared beforeand afterabenefit design changein1ofthe groups. For the12monthsbeforethe benefitdesign change, both groupshad a3-tier, fixed-dollarcopaymentstructurewithidentical cost-sharing per 30-day supply:$10 tier-1 copaymentfor genericdrugs,$25 tier-2 copaymentfor preferred branddrugs,and $40tier-3copaymentfor non-preferred brand drugs. On September 1, 2005,a4-tiercoinsurance benefitdesign (25% forall tiersexcepttier-3[non-preferred]drugs at 50%, with minimum and maximum patient out-of-pocket[OOP]costapplied to each tier)was implemented in theinterventiongroup (N=46,311). The3-tiercopayment design wasmaintainedinthe comparison group (N=7,916). Adifferencein-difference analysis wasusedtoestimate theeffectofthe benefitdesign changeonexpenditures and utilization,overall (for allprescriptiondrugs), and for3classes of essentialmedications:antihypertensives,antidepressants, andstatins.Analyses measured changes in outcomesfrom6months pre-change (October 1, 2004,through March31, 2005)through 6months post-change (October1,2005, throughMarch 31,2006. In theoverall (all drug)analyses,per memberper month (PMPM) outcome measures were totalpharmacyclaims and cost, beneficiary (patientOOP)cost, and employer(plan sponsor)cost. Analyses of the3essential drug classes were limited to members with at least 1claiminthe drug class in both the pre-changeand post-changeperiods (N=11,917, intervention group;1,792, comparison group), and assessedper patient per month (PPPM)dayssupply,beneficiary cost, employercost, and total cost. RESULTS:Beneficiaries in theinterventiongroup paid31.8% of total pharmacybenefit cost at thepoint of care versus 31.5%inthe comparison group in thepost-changeperiod. Theincreasesinbeneficiary costfromthe pre-changeperiodtothe post-changeperiodwerenot significantlydifferentfor theintervention(7.5%)and comparison (3.0%) groups(P =0.983). From thepre-changeperiodtothe post-changeperiod, total spending per memberincreased $4.57PMPM(6.3%), from$72.29to$76.87inthe intervention group versus a$5.87 PMPM increase (9.5%),from$61.54 to $67.41,inthe comparison group,arelativedifference of $1.30PMPM ( P =0.013). Theincreasesinutilization fromthe pre-changeperiodtothe post-changeperiodwerenot significantlydifferent in theintervention group (2.4%) versus the...

Among members denied coverage for a COX-2 inhibitor after implementation of a PA program, pharmacy costs declined without a medical cost increase associated with gastrointestinal diagnoses.