Background: Numerous prescription products have becomeavailable over the counter (OTC) in recent years. Previous simulationmodels have shown the Rx-to-OTC switch of loratadine to becost effective.
Objective: To empirically assess the overall effect of the Rx-to-OTC switch of loratadine and the specific effect of different pharmacybenefit structures on prescription drug utilization and costamong different plan sponsors.
Methods: Data from a national pharmacy benefit managementorganization covering lives throughout the United States wereused. The analysis included a comparison of the before and afterchange in prescription utilization and cost for plan sponsors thatinstituted 1 of 3 second-generation antihistamine (SGA) benefitresponses: made no change, moved SGAs to the third tier, orrestricted SGA benefits through a requirement for prior authorization.Multivariate regression analysis was used to control for differencesacross the study groups.
Results: There was a substantial decrease in utilization and costof all prescription drugs and combinations of drug classes. Patientswith allergic rhinitis facing restricted prescription benefits for SGAsdid not appear to increase utilization of other allergic rhinitis medicationsor other medications used to treat comorbid conditionssuch as asthma, sinusitis, and otitis media.
Conclusions: Utilization and cost decreased substantially for alltypes of medications and all pharmacy benefit structures. Futurestudies need to examine the effect of the Rx-to-OTC switch ofloratadine and resultant prescription benefit policies on medicalutilization and OTC antihistamine utilization.
(Am J Manag Care. 2005;11:374-382)
Numerous prescription products have becomeavailable over the counter (OTC) in recentyears, and there are several reasons why thisnumber may increase in the future.1-3 After years of use,some prescription drugs have the proven safety recordneeded for OTC status.3,4 Patients are also becomingmore interested and involved in the management oftheir health. Survey estimates suggest that US adults arebecoming more likely to self-treat their medical conditionsthan in the past.5 In addition, the escalating economicburden of providing insurance coverage forpharmaceutical products has prompted payers to shiftcost to patients.6 For example, in 2001, BlueCross ofCalifornia, a healthcare insurer, initiated a citizens'petition to the Food and Drug Administration to requestthe OTC sale of second-generation antihistamines(SGAs). This was the first time that a health insurerinitiated a request to transfer prescription drugs toOTC status. Most payers do not provide coverage forOTC medications and see them as a means of shiftingmedication cost to the consumer. The cost shifting ofRx-to-OTC drugs typically takes the form of higher prescriptioncopayments for remaining prescription substitutes,prior authorization, or other restrictions.6 Payersmay increasingly encourage OTC conversions of popularmedications as they face pressure to shift the costburden of providing safe and effective pharmaceuticalproducts to patients.
Whether the Rx-to-OTC transition of a particulardrug is desirable, however, depends on an assessment ofthe costs and benefits from different perspectives,including consumers, payers, and society as a whole. Itis also important to examine the clinician's perspectiveon the effectiveness of the transition. Previous researchhas attempted to assess the costs and benefits of Rx-to-OTC transitions from different perspectives usingempirical data and simulation modeling approaches. Ingeneral, studies7-16 of the effect of Rx-to-OTC switcheshave reported cost savings to society or to payersdepending on the drug assessed. However, it has beenargued that the effect on patients is less clear, and someanalyses have argued that the costs outweigh the benefitsfor certain drugs.17-19
To date, there have been simulation models but noempirical assessments of the effect of the Rx-to-OTCswitch of loratadine. Sullivan et al15 used a simulationmodel to assess the cost effectiveness of the Rx-to-OTC switch of loratadine from the societal perspectivein the United States. They found that the Rx-to-OTCswitch of loratadine improved effectiveness and wascost saving for society as a whole. The authors alsoconducted a cost-effectiveness analysis of differentSGA benefit policies in response to the OTC availabilityof loratadine from a plan sponsor perspective(managed care, Medicaid, and employer).20 This analysisfound that more generous prescription benefits forSGAs were more expensive but were cost effective comparedwith more restrictive policies.
Because empirical data were not available, theauthors modeled the potential changes in utilization ofprescription SGAs and substitute medications based onassumptions about the elasticity of demand within specificpatient populations. Specifically, the authorshypothesized the following: (1) The overall demand forprescription SGAs would decrease and shift to OTCloratadine because of improved access, ease of purchase,and lower opportunity cost of OTC medications.(2) Managed care payers would benefit from reducedprescription utilization and cost. (3) Managed caremembers would benefit because of the lower cost ofOTC loratadine compared with the opportunity cost ofobtaining an SGA prescription. (4) Restrictive SGApolicies may encourage patients to seek substitutetherapies and increase utilization of intranasal corticosteroids(INS) and leukotriene receptor antagonistsafter the OTC switch. Although not assumed in eithersimulation model, it has been suggested that thepotential exists for exacerbation of comorbid illnessessuch as asthma, sinusitis, and otitis media if patients arenot capable of appropriately self-treating their allergicrhinitis (AR) with OTC loratadine.21
As is generally the case in simulated models, thesehypotheses were based on assumptions because actualestimates were not available. It is important to examinethe actual changes in utilization after the Rx-to-OTCswitch of loratadine to assess their accuracy and provideestimates for future simulation models in similardisease categories. In addition to assessing the generaleffect of the Rx-to-OTC switch of loratadine, it is alsoimportant to examine the effect of different pharmacybenefit structures instituted in response to the switch.Previous research has shown that increasing cost sharingcan have a negative effect on utilization of prescriptiondrugs,22 and any assessment of the costs andbenefits of an Rx-to-OTC switch needs to incorporatethese payer responses.20
Simulation models are helpful in the absence ofexisting data, but empirical evaluation is essential toinform policy decisions and provide actual estimates forfuture research. The objective of this research was toassess the effect of implementing different pharmacybenefit structures in response to the Rx-to-OTC switchof loratadine on prescription drug utilization and costusing empirical data.
The data source was MedImpact Healthcare Systems,Inc, a private, national pharmacy benefit managementorganization based in California. The organization coversmembers across the United States and coordinatespharmacy benefits and specialty pharmacy services.Plan sponsors include employers, unions, insurance andmanaged care organizations, third-party administrators,and state and federal employee programs. The plansused in this research were a subset of MedImpactHealthcare Systems, Inc, members in which clear SGAbenefit changes were initiated.
Sample Selection and Study Groups
The study sample consisted of individuals with ARwho were continuously enrolled from 2002 to the studyend. Allergic rhinitis was identified based on utilization ofat least 2 prescriptions in 2002 for INS or SGAs.Loratadine was available OTC starting in December2002, but most health plans did not change benefits forSGAs until months later. The study period spanned 12months before and after the index date, which was thedate of the change in SGA benefits. The index date wasdifferent for most plan sponsors, generally falling betweenJanuary and April of 2003. Although some plans in theUnited States instituted coverage of OTC loratadine, thepresent research did not examine this benefit change.The classification of study groups was based on 3 commonresponses to the OTC availability of loratadine:
Plan Sponsors That Made no Change in the Formulary
Status of Second-Generation Antihistamines (No-Change Group).
This group was the largest among the3 study groups and consisted of 7 plan sponsors thatwere a combination of 2-and 3-tier plans. Membershipin these plan sponsors ranged from 35 000 to 300 000covered lives, with a total plan membership of approximately1.2 million covered lives for all plans combined.Before 2003, all but 1 plan in this group had at least 1SGA available in the second tier.
Plan Sponsors in 3-
Tier Plans That Moved All
Second-Generation Antihistamines to the Third Tier
Seven plan sponsors were categorizedin the third-tier group, with sample sizes rangingfrom 8000 to 90 000 covered lives, with a total planmembership of approximately 260 000 covered lives forall plans combined. All but 1 plan sponsor were healthmaintenance organization-based plans. The remainingplan was a state-based plan sponsor. Before 2003, allplans in this group had at least 1 SGA available in thesecond tier. The change in formulary status of all SGAs(index date) typically occurred between January 1,2003, and February 28, 2003, while 1 plan made achange on April 1, 2003.
Plan Sponsors That Imposed a Prior Authorization
Restriction for Second-Generation Antihistamines
Three large Medicaid plan sponsors(2-tier plans with approximately 170 000 covered livescombined) and 1 small health maintenance organization-based plan sponsor (2-and 3-tier plans withapproximately 10 000 covered lives) represented therestricted group. The restricted group was unique incomparison with the others because of the high proportionof Medicaid plan sponsors. Before 2003, all plans inthis group had at least 1 SGA available on formularywithout restrictions. Prior authorization restrictionswent into effect between January and June of 2003.
For all plan sponsors in each of the 3 study groups,the "after" period lasted for 12 months after the indexdate of formulary change for SGAs. (Plan sponsor confidentialitypolicies prevent us from revealing individualplans and the exact date of formulary changes for theSGA drug class.) Because there was no change in SGAbenefits for the no-change group, the index date used toseparate the before and after periods was based on themean index date for the third-tier and restricted groups.The number of days between January 1, 2003, and theindex date was calculated for each plan sponsor in thethird-tier and restricted groups. This number of dayswas averaged over all of the plans to derive the meanindex date and was applied to each of the plan sponsorsin the no-change group.
Outcome Measures and Statistical Analysis
The main dependent variables were pharmacy utilization(measured as the number of prescriptions filledper member per month [PMPM] and days suppliedPMPM), the cost of the prescription to the plan sponsorPMPM, and the member prescription copayment PMPM.Second-generation antihistamines, INS, montelukastsodium, all AR medications combined (SGAs, INS, andmontelukast), all asthma medications combined, allantibiotics, and all pharmaceutical products were analyzedseparately.
Comorbid conditions, including asthma, sinusitis,and otitis media, are prevalent among patients withAR.23 It has been suggested that reduced utilization ofprescription SGAs, if not offset by simultaneous andappropriate self-treatment with OTC antihistamines,could exacerbate existing comorbid conditions.21 Tomeasure this potential deleterious "spillover" effect ofreduced utilization of prescription SGAs, utilization andcost of asthma medications, antibiotics, and all pharmaceuticalproducts combined were examined. Asthmaclasses included β-adrenergic agents, β-adrenergic agentand glucocorticoid combinations, leukotriene receptorantagonists, mast cell stabilizers, oral inhaled corticosteroids,and xanthines. Antibiotic classes includedabsorbable sulfonamides, betalactams, carbapenems,first-through fourth-generation cephalosporins,macrolides, nitrofuran derivatives, oxazolidinones, penicillins,quinolones, and tetracyclines. The Kruskal-Wallis test was used to test for significant differencesbetween groups in the unadjusted analyses of demographiccharacteristics in Table 1. Ordinary leastsquares regression analysis was used for the multivariateanalyses of the before and after index date changein utilization and cost of prescriptions PMPM.
The independent variables of primary interest werethe plan sponsor policy as represented by 3 mutuallyexclusive dichotomous variables of the postindex pharmacybenefit structure for SGAs, including made nochange, moved SGAs to the third tier, or restricted SGAbenefits, as described previously (the no-change variablewas used as the reference category in the multivariateregression). To control for possibleconfounding differences across the 3 groups that couldaffect utilization and cost of prescriptions, severalcovariates were included in the multivariate analyses.Asthma, chronic AR, and severe AR were included asdichotomous indicator variables to control for thepresence of significant clinical differences in the 3groups at baseline. Individuals were defined as havingchronic AR based on more than 6 months' utilizationof at least 1 AR medication in 2002. Severe AR wasdefined by more than 60 days' simultaneous use of 2or more AR medications in 2002. The presence ofasthma in 2002 was captured by the RxRisk asthmacategory.24 Because the incentive structure (lowercopayments, etc) and patient type (more severe andlower income) are significantly different in Medicaidplans than in commercial managed care plans, receivinghealth insurance through Medicaid was included asa dichotomous variable. In addition, generic burden ofchronic disease in 2002 was measured by the RxRiskalgorithm to control for differences across groups inthe burden of chronic illness.24 Age and sex were alsoincluded as covariates.
Baseline Descriptive Statistics
The no-change group was the largest in size,accounting for more than 75% of the study population(Table 1). The mean ages ranged from 40 to 44 years,and the sample was predominantly female (range, 60%-66%). The restricted group had the oldest individualsand a higher proportion of women. The types of plansponsors represented in each group varied. While theno-change and third-tier groups primarily consisted ofcommercial plans, the restricted group was largelymade up of Medicaid managed care plans. Members ofthe restricted plans appeared to have a higher chronicdisease burden (highest RxRisk score) and greatercomorbid asthma, but fewer had chronic or severe AR.A greater percentage of the restricted group's memberstook INS, and fewer took SGAs.
The mean copayment per SGA prescription remainedunchanged for the no-change group, increased by $11.40for the third-tier group, and decreased by $1.70 for therestricted group (Table 2). Overall, there was a substantialdecrease in utilization and cost of all prescriptiondrugs and combinations of drug classes except montelukastin this AR patient population. Second-generationantihistamine use decreased in a similar manneracross all 3 groups by 3.4 to 4.8 days PMPM (range, 43%-50% reduction). The mean number of prescriptionsdecreased in a similar manner (range, 46%-51% reduction);however, cost to the plan sponsor was significantlylower for the third-tier and restricted groupscompared with the no-change group (68% and 69% reductions,respectively, compared with a 45% reduction). Themean prescription copayment PMPM for SGAs alsodecreased for all groups, but members of the third-tiergroup experienced the lowest decrease because of thehigher copayments per prescription (a 23% reduction vsa 46%-64% reduction). The decline and trends were similarfor INS, asthma, antibiotics, all AR medications, andall pharmaceutical products across all study groups. Thetotal cost of all pharmaceutical products to the plan sponsordecreased for all groups but was 2 times lower for thethird-tier and restricted groups compared with the no-changegroup (16% and 12% reductions, respectively,compared with a 7% reduction).
Multivariate Regression Analysis
Table 3 presents a summary derived from the fullregression results (utilization PMPM is shown in Table4). After controlling for all covariates in the multivariateregression analyses, there was a larger and statisticallysignificant decrease in mean prescription fills PMPMfor SGAs in all 3 groups compared with the results inTable 3. There was a decrease of -0.184 prescriptionsPMPM in the no-change group. To provide perspective,this would equate to a 65% reduction from the unadjustedbaseline mean of 0.281 for the no-change group.The changes in prescription fills PMPM for the third-tier(change, -0.197) and restricted (change, -0.217)groups were statistically significantly lower than for theno-change group and would equate to 65% and 88%reductions from the unadjusted baseline means of0.303 and 0.246 for the third-tier and the restrictedgroups, respectively. The trends were similar for thecost to the plan sponsor, but the magnitude percentagechange compared with the unadjusted baseline wassignificantly greater: the decrease in mean cost PMPMwas -$17.56 (-144%) for the no-change group, -$20.25(-136%) for the third-tier group, and -$21.57 (-147%)for the restricted group.
Contrary to expectations of "substitution" andspillover effects, there was a significant decrease in utilizationand cost for all other categories of prescriptiondrugs across all 3 groups (Table 3). There was a decreaseof -0.134 mean prescriptions PMPM for INS in the noc-hange(change, -122%) and third-tier (change, -103%)groups and a statistically significantly lower magnitudedecrease of -0.125 (-86%) for the restricted group.Similarly, there was a decrease in the cost of INS to theplan sponsor for the no-change (-$6.70 [-150%]), third-tier(-$6.90 [-127%]), and restricted (-$6.11 [-79%])groups. The number of prescription fills PMPM for all ARmedications combined decreased for the no-change (-0.367 [-88%]), third-tier (-0.377 [-82%]), and restricted(-0.392 [-95%]) groups. Likewise, there was a more significantdecrease in the cost to the plan sponsor for allAR medications for the no-change (-$26.65 [-146%]),third-tier (-$29.47 [-133%]), and restricted (-$30.19 [-125%]) groups. For all 3 groups, there was a decrease inthe number and the cost to the health plan PMPM formontelukast and all asthma prescriptions. Antibioticutilization decreased for all 3 groups, but there was nostatistically significant difference between the groupsand no significant change in cost. The number of prescriptionsPMPM of all pharmaceutical products combineddecreased for the no-change (-0.586 [-26%]),third-tier (-0.586 [-28%]), and restricted (-0.639 [-19%]) groups, and the cost to the health plan for all pharmaceuticalproducts declined in a similar fashion for all 3groups (-34%, -33%, and -20%, respectively).
The full regression results examining the change inthe number of prescriptions PMPM for the 7 differentdrug categories are displayed in Table 4. Controlling fordrug benefit design and other covariates, chronic ARpatients decreased utilization of SGAs by twice as muchas nonchronic AR patients, but there was no significantdifference for severe AR patients. Asthmatic patients andMedicaid enrollees had less decreased utilization ofSGAs compared with nonasthmatic patients andnon-Medicaid enrollees.
Compared with patients with nonchronic and nonsevereAR, patients with chronic and severe AR decreasedutilization of INS by less but had a statistically significantgreater decrease in utilization PMPM of AR medications,asthma medications, and all pharmaceuticalproducts combined (Table 4). Chronic AR patientsdecreased antibiotic utilization PMPM by less, butsevere AR patients decreased antibiotic utilizationPMPM by more thantheir counterparts.Utilization of asthmamedications and allpharmaceutical productscombined PMPMwas lower for patientswith comorbid asthma.The decrease in utilizationof SGAs, INS, allAR medications, and allpharmaceutical productsPMPM was lowerfor Medicaid enrollees.The trends in the fullregression results weresimilar for the cost tothe health plan and thedays supplied (resultsnot shown). For example,chronic and severeAR patients saved theplan sponsor more forSGAs (-$31.13 and -$18.86, respectively)than nonchronic andnonsevere AR patients,while Medicaid enrolleesand asthmaticpatients saved the plansponsor less for SGAs(-$16.40 and -$16.25,respectively) than theircomparators.
This analysis was anempirical assessment ofthe effect of the Rx-to-OTC switch of loratadine amongdifferent plan sponsors for the 3 most common pharmacybenefit structures in the face of a new Rx-to-OTCswitch. The potential for substitution and spillovereffects resulting from restricted prescription benefitsfor loratadine was also examined.
The results suggest that there was a substantialdecrease in utilization and cost for prescription SGAsregardless of the pharmacy benefit change. Annual utilizationPMPM of prescription SGAs decreased by morethan 65%, and cost to the payer decreased by more than136% for all 3 groups. Although there was a statisticallysignificantly greater decrease in SGA utilization andcost for the third-tier and restricted groups comparedwith the no-change group, even individuals experiencingno change in SGA benefits after the Rx-to-OTCswitch of loratadine substantially reduced utilization(change, -65%) and cost to the plan sponsor (change,-144%) in the postindex period. Similarly, memberspaid less to the health plan for SGAs. The mean membercopayments PMPM for SGAs decreased by 23% to64%. These results are consistent with but show agreater decrease in utilization and cost compared withthe assumptions used in previous simulation models.15,20
The results presented in Tables 2, 3, and 4 may beused by researchers involved in assessing the costs andbenefits of an Rx-to-OTC switch. The percentages givenmay be helpful for analysts conducting simulation modelsto determine approximate changes in overall utilization,as well as those associated with differentprescription drug benefit designs implemented as aresult of a new OTC entrant.
Given the restriction on SGA benefits among someplan sponsors, it has been hypothesized that there maybe a substitution effect in the prescription market (ie,patients and providers would attempt to seek alternativesto prescription SGAs). The results did not supportthis hypothesis. On the contrary, there was a significantreduction in utilization and cost to the plan sponsorfor INS and montelukast for all groups. As ameasure of the overall outcome of the hypothesizedsubstitution effect, utilization and cost to the heathplan for all AR medications combined decreased substantiallyand mirrored those of the SGAs. In addition,overall utilization and cost for all AR medications combineddecreased more for chronic and severe ARpatients. It appears from these results that the Rx-to-OTC switch of loratadine resulted in a decrease of allAR-related prescription utilization and cost regardlessof the pharmacy benefit structure of prescription SGAsafter the OTC switch.
It has also been hypothesized that reduced utilizationof prescription SGAs may lead to exacerbations ofcomorbid conditions such as asthma, sinusitis, and otitismedia due to potential inappropriate self-treatment withOTC antihistamines.21 The results of this study suggestthat reduced utilization of prescription SGAs was notassociated with increases in utilization of prescriptiondrugs used to treat these comorbid conditions. On thecontrary, the results showed a significant reduction inutilization and cost for asthma, antibiotics, and all prescriptiondrugs combined (although the decrease in costPMPM to the health plan for antibiotics was not statisticallysignificant). However, the use of medications is notnecessarily a surrogate for episodes of exacerbation orworsening of symptoms. It is possible that the decreasedutilization of medications for comorbid conditions such asasthma is a marker for lower quality of care. However, inthis case, the study group experiencing the lowest qualityof care would be the no-change group (because they hadthe greatest decrease in utilization of asthma medications).In addition, the inclusion of "all antibiotics" as anoutcome may have low specificity for AR complications,given the other potential indications for their use.
Allergic rhinitis medications are likely the primaryand most significant source of utilization for this studypopulation. The sample is young and healthy and wasidentified based on prior utilization of SGAs or INS. Itappears that OTC availability of SGAs resulted in a significantdecrease in the utilization of all prescriptiondrugs in this AR sample. It is possible that AR patientswere able to obtain adequate treatment with OTCloratadine and had less need to contact the health planfor the treatment of their primary condition (AR) and,hence, were less likely to seek treatment for any reason.It is also possible, however, that secular trends such asweather and region of the country could have contributedto reduced postindex utilization for the classesof drugs examined.
The scope of this analysis is limited to the utilizationof prescription drugs. It is unclear whether individualswho decreased their utilization of prescription SGAsself-treated appropriately with OTC loratadine.Previous research has documented the deleteriouseffects of first-generation antihistamine (FGA) use.25First-generation-associated sedation has been shown toresult in increased motor vehicle crashes and occupationalinjuries, reduced productivity and learning, anddeath. It is unclear whether patients who decreased utilizationof prescription SGAs simultaneously increaseduse of OTC FGAs. This effect would be detrimental tosociety and should be examined in future research.However, an examination of the price of OTC FGAs(diphenhydramine hydrocholoride [Rite Aid Corporation,Harrisburg, Pa], 50 mg, 4 times daily; cost,$15.60/mo) compared with OTC loratadine (loratadine[Rite Aid Corporation], 10 mg/d; cost, $8.50/mo) showsthat OTC SGAs may be less expensive now.26 This pricecomparison suggests that it is unlikely that utilization ofOTC FGAs increased because there is no longer an economicincentive to choose OTC FGAs over OTC loratadine.(However, because of generic competition, the priceof OTC loratadine has decreased from approximately$30/mo when it was first made available.)
In addition, it is unclear if the reduction in utilizationof prescription SGAs found in this study wasassociated with an increase in medical utilization.Although utilization of prescription drugs for commoncomorbid conditions and all pharmaceuticalproducts combined decreased substantially, theeffect of the Rx-to-OTC switch of loratadine on medicalutilization is uncertain. Future research needs toincorporate measures of medical utilization (such asphysician visits and asthma-related emergencydepartment visits).
Numerous economic studies7-14,18,27-29 of the effect ofRx-to-OTC switches have reported cost savings to society or payers. One study17 of consumer cost data andmedical service utilization argues that 4 recent Rx-to-OTC switches did not benefit patients financially ormedically. A microeconomic analysis30 argues that theeconomic effect of the OTC switch of SGAs may not becost saving because of the uncertain price and consumerdemand response. Sullivan et al15 and Sullivanand Nichol,20 however, suggested that the Rx-to-OTCswitch of loratadine was cost effective for consumers,payers, and society as a whole. The present studydemonstrates that the Rx-to-OTC switch of loratadineresulted in cost savings for payers (in terms of prescriptionutilization and cost only). In addition, giventhat mean copayments for prescription SGAs in commercialmanaged care before the OTC switch of loratadinewere substantially higher than the current price ofOTC loratadine, consumers appear to have benefited aswell. The results of the present study support thisnotion because consumers facing no change in theirprescription benefits significantly decreased utilizationof prescription SGAs after the OTC availability ofloratadine.
However, the effect of the Rx-to-OTC switch ofloratadine and concomitant pharmacy benefit changeson the effectiveness of treatment or health outcomes isunclear from the results of this pharmacy-based analysis.Although patients may have been able to sustain orimprove the effectiveness of treatment after the Rx-to-OTC switch, it is also possible that the reduced utilizationfound in this research was accompanied by worsehealth outcomes or lower quality of symptom relief.This is an important area of future research. It is likelythat the effect of an Rx-to-OTC switch on health outcomeswill differ depending on the disease associatedwith the switch (eg, AR vs hypercholesterolemia).
The results of this study show that utilization andcost to the plan sponsor decreased substantially for alltypes of medications after the OTC introduction ofloratadine, even when there were no pharmacy benefitchanges for SGAs. In addition, AR patients facingrestricted prescription benefits for SGAs did not appearto increase utilization of other AR medications.Increased utilization of medications for comorbid conditionssuch as asthma, sinusitis, and otitis media wasnot seen in this pharmacy claims analysis regardless ofthe type of prescription benefit change for SGAs. Thescope of the present analysis was limited to the utilizationand cost of prescription drugs. Future studies needto examine the effect of the Rx-to-OTC switch of loratadineand resultant prescription benefit policies on medicalutilization and OTC antihistamine utilization.
From the Pharmaceutical Outcomes Research Program, University of Colorado Schoolof Pharmacy, Department of Clinical Pharmacy, Denver (PWS, KVN); and MedImpactHealthcare Systems, Inc, San Diego, Calif (BVP).
This research was supported by a grant from Schering Plough, Inc, Kenilworth, NJ. Theauthors had unrestricted authority for publication of results.
Address correspondence to: Patrick W. Sullivan, PhD, Pharmaceutical OutcomesResearch Program, University of Colorado School of Pharmacy, Department ofClinical Pharmacy, 4200 East Ninth Avenue, Box C238, Denver, CO 80262. E-mail:email@example.com.
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