Effects of Limiting Medicaid Drug-Reimbursement Benefits on the Use of Psychotropic Agents and Acute Mental Health Services by Patients with Schizophrenia
Stephen B. Soumerai, Thomas J. McLaughlin, Dennis Ross-Degnan, Christina S. Casteris, and Paola Bollini
Background We examined the effects of a three-prescription monthlypayment limit (cap) on the use of psychotropic drugs and acutemental health care by noninstitutionalized patients with schizophrenia.We hypothesized that reducing access to such drugs would increasethe use of emergency mental health services and the rate ofpartial hospitalizations (full-day or half-day treatment programs)and psychiatric-hospital admissions.
Methods We linked Medicaid claims data for a period of 42 monthswith clinical records from two community mental health centers(CMHCs) and the single state psychiatric hospital in New Hampshire,where Medicaid imposed a three-prescription limit on reimbursementfor drugs during 11 months (months 15 through 25) of the study.For comparison, we used Medicaid claims for a period of 42 monthsin New Jersey, which had no limit on drug reimbursement. Thestudy patients (n = 268) and the comparison patients (n = 1959)were permanently disabled, noninstitutionalized patients withschizophrenia, 19 through 60 years of age, who were insuredby Medicaid. We conducted interrupted time-series regressionanalyses to estimate the effects of the cap on the use of medicationsand mental health services.
Results The cap resulted in immediate reductions (range, 15to 49 percent) in the use of antipsychotic drugs, antidepressantsand lithium, and anxiolytic and hypnotic drugs (P<0.01).It also resulted in coincident increases of one to two visitsper patient per month to CMHCs (range of increase, 43 to 57percent; P<0.001) and sharp increases in the use of emergencymental health services and partial hospitalization (1.2 to 1.4episodes per patient per month), but no change in the frequencyof hospital admissions. After the cap was discontinued, theuse of medications and most mental health services revertedto base-line levels (measured in the first 14 months of thestudy). The estimated average increase in mental health carecosts per patient during the cap ($1,530) exceeded the savingsin drug costs to Medicaid by a factor of 17.
Conclusions Limits on coverage for the costs of prescriptiondrugs can increase the use of acute mental health services amonglow-income patients with chronic mental illnesses and increasecosts to the government, even aside from the increases causedin pain and suffering on the part of patients.
Requirements for cost sharing by patients and limitations oncoverage for primary medical care are popular cost-containmentstrategies in the United States and other countries1,2,3; theymay become more prevalent as a result of future health insurancereforms. Yet objective data on the effects of these measureson the use, costs, and outcomes of health care in vulnerablepopulations are limited4,5,6. We examined the effects of limitson Medicaid payments for drug treatment on access to effectivepharmacotherapy and on the use of acute mental health care servicesamong low-income, noninstitutionalized patients with schizophrenia.
The economic, clinical, and personal burdens associated withschizophrenia make it a leading public health problem. The lifetimeprevalence of schizophrenia is between 0.5 percent and 1.0 percent7,8,9;rates of mortality and somatic morbidity are much higher amongpatients with schizophrenia than in the general population10;and the total costs to society are estimated to equal half thetotal financial burden of myocardial infarction11. Patientswith schizophrenia are also highly likely to receive fragmentedand uncoordinated care12,13,14,15.
Antipsychotic drugs, the most effective treatment for acuteepisodes or exacerbations of schizophrenic illness,16,17 allowmany patients to leave institutions and live in the community18,19.Rates of relapse among patients with schizophrenia who receivemedication are two to three times lower than those among patientsreceiving placebo,16,20 and noncompliance increases the frequencyof acute psychotic episodes and psychiatric hospitalization16,17.Although antipsychotic drugs can have serious adverse effects,19,21many clinicians prescribe them at moderate doses for as longas possible to prevent relapse. In addition to antipsychoticagents, patients with schizophrenia may receive lithium, antidepressants,or benzodiazepines for concomitant psychiatric disorders16.
Nine states limit the number of prescriptions per patient permonth that are reimbursed by Medicaid, but there are no dataon the effects of such caps on people with chronic mental illnesses.In September 1981, the New Hampshire legislature limited Medicaidreimbursement to three prescriptions per month as a cost-cuttingmeasure during a budget crisis that was precipitated, in part,by reduced federal support for the Medicaid program5. Patientswho filled more than three prescriptions in any month were usuallyunable to pay for them out of pocket22; this policy thereforereduced the use of essential medications (such as insulin andcardiac drugs) among elderly patients with chronic diseasesand increased nursing home admissions5. Eleven months later,after litigation by New Hampshire Legal Assistance, a publiclegal-aid agency, the state replaced the cap with a $1-per-prescriptioncopayment.
We undertook this study to determine whether the limit on drugreimbursement was followed by reductions in the use of antipsychoticagents, drugs for mood disorders, and anxiolytic and hypnoticagents and by an increase in the use of mental health servicesamong low-income adults with schizophrenia. We hypothesizedthat financial restrictions on access to psychotropic drugswould adversely affect the mental health of these patients.The resulting increase in agitation and in the frequency ofpsychotic episodes would increase the need for emergency mentalhealth services and partial hospitalization (full-day or half-daytreatment programs) at community mental health centers (CMHCs)and the frequency of admissions to psychiatric hospitals, therebyshifting costs from the federal-state Medicaid program to statemental health programs.
Methods
In this study we evaluated the effects of the cap with use ofan interrupted time-series design (with and without comparisonseries), one of the strongest quasi-experimental designs23,24.We determined rates of medication use before the cap was implemented(for a period of 14 months), during its application (11 months),and after it was discontinued (17 months) in a cohort of adultpatients with schizophrenia in New Hampshire and in an identicallydefined comparison cohort in New Jersey, which had no restrictionson drug reimbursement. In New Hampshire, we also measured changesin the use of acute mental health care services in associationwith the implementation and discontinuation of the cap.
Sources of Data
We used data from three sources to measure effects of policychanges: Medicaid enrollment and claims data, data on dischargesfrom state psychiatric hospitals, and data on visits to CMHCs.Medicaid enrollment files in both states (covering July 1980through December 1983) included age, race, sex, and monthlycategory of enrollment (e.g., Aid to the Permanently and TotallyDisabled). Medicaid drug-claims files contained reliable datafor individual patients on the identity of each medication,the date it was dispensed, the number of units, and the dose22,25,26,27.
Virtually all psychiatric admissions of patients with schizophreniaduring the study period were to New Hampshire's single statepsychiatric hospital. Since Medicaid did not cover most of theseadmissions, we collected data from medical records on the datesof all hospitalizations of study patients during this period.
For a subgroup of the study cohort, we also obtained computerizeddata on all episodes of treatment at CMHCs. CMHC clinical dataare more complete than Medicaid data, since they include allmental health services whether or not they are covered by Medicaid.At two of the largest CMHCs (designated CMHC 1 and CMHC 2),which provided services to approximately one third of the studysample, we obtained data on the dates, charges, and categoryof service for routine visits as well as more intensive partialhospitalizations and emergency mental health services. At CMHC1, where complete data were available, we abstracted from medicalrecords the date, name, dose, and quantity of each antipsychoticdrug prescribed or administered to study patients (n = 29);we also determined whether the prescription was paid for byMedicaid or purchased by the CMHC.
Study Cohorts
The study cohorts in the two states were made up of patientswith schizophrenia who lived in the community and were enrolledin Medicaid. We used a previously validated algorithm28 to identifypatients who had been given a diagnosis of schizophrenia atleast once as inpatients or twice as outpatients, accordingto Medicaid claims records during the base-line year (July 1980through June 1981). To ensure that we studied patients who wereseverely disabled by schizophrenia and to increase homogeneitybetween the study group and the comparison group, we requiredstudy patients to be enrolled in Medicaid's Aid to the Permanentlyand Totally Disabled program, to have been enrolled for 10 ormore months and not to have been admitted to a nursing homeduring the base-line year (and thus to be exposed to the cap),to be 19 through 60 years of age, and to be white (to controlfor the virtual absence of nonwhite patients in New Hampshire).
Classification and Standardization of Use of Study Drugs
We measured the rates of use of three types of psychotropicmedication: antipsychotic agents, anxiolytic and hypnotic agents,and medications used to treat affective disorders (lithium andantidepressants). As previously reported,5 we created a standardizedmeasure of use for each medication, the standard monthly dose(SMD); for each study drug, one SMD equaled the median monthlydose received by each Medicaid patient during the base-lineyear.
Statistical Analysis
We used segmented linear-regression analysis5,22,26 to estimatesudden changes in levels or trends in the time series of medicationuse (the number of SMDs per enrolled patient in each month)and use of mental health services associated with the cap. Wecontrolled for loss to follow-up (<8 percent during the 42months of the study) by including only the number of patientsstill enrolled in Medicaid in the denominators for each monthlyrate. Regression models included a constant term, a term forlinear time trend, and terms to estimate changes in the levelor trend of service use that coincided with the introductionand discontinuation of the payment limit29. We controlled forautocorrelation by assuming a first-order autoregressive process(correlation between two consecutive observations), and we usedresidual analysis to test the adequacy of the resulting models5,22,26.We determined the statistical significance of regression coefficientsby means of two-tailed t-tests, and we estimated percent changesin the use of services during the period when the cap was inplace as the observed use minus the expected use (on the basisof base-line trends) divided by the expected use.
Results
Characteristics of the Patients
The base-line characteristics of the patients in the study cohortand the comparison cohort were similar (Table 1). Forty-fourpercent of the study cohort and 46 percent of the comparisoncohort received antipsychotic agents regularly ( 1 prescriptionper quarter). About 30 percent of the patients in both cohortsreceived one or more prescriptions for drugs to treat affectivedisorders; 70 percent of these prescriptions were for antidepressants,and 30 percent were for lithium. About 75 percent of the patientsin both cohorts received drugs from more than one category.
Table 1. Base-Line Characteristics of the Study and Comparison Cohorts.
Changes in Medication Use
After the introduction of the Medicaid cap in New Hampshire,there was a sudden drop in the level of reimbursed use of allthree categories of psychoactive medications (Figure 1). Nochanges in the level of use of the medications occurred in theNew Jersey (comparison) cohort, which received somewhat highernumbers of SMDs of antipsychotic drugs and anxiolytic and hypnoticagents. Before the cap was implemented, the use of antipsychoticagents was stable at approximately 1.4 SMDs per patient permonth in New Hampshire; the level of use dropped abruptly bya mean (±SE) 0.23 ±0.08 SMD during the cap (adecrease of 15.4 percent, P = 0.003) but rose to a level slightlyabove pre-cap rates after the discontinuation of the policy.We also observed statistically significant reductions in theuse of anxiolytic and hypnotic agents (a decrease of 0.07 ±0.02SMD per patient per month [37.3 percent], P = 0.001) and ofantidepressants and lithium (0.13 ±0.02 SMD [49.1 percent],P<0.001). The use of these drugs returned nearly to base-linelevels after the discontinuation of the cap.
Figure 1. Standard Monthly Doses (SMDs) per Patient of Antipsychotic Agents, Drugs for Affective Disorders, and Anxiolytic and Hypnotic Agents Whose Cost Was Reimbursed by Medicaid in the Study Cohort (New Hampshire; N = 268) and the Comparison Cohort (New Jersey; N = 1959).
The fitted trend lines for the study cohort show predicted values for segmented time-series regressions. After the cap was discontinued, a copayment of $1 per prescription was instituted.
Among regular recipients of antipsychotic drugs, the level ofuse of these medications dropped by 0.64 ±0.15 SMD perpatient per month after the cap was instituted (a decrease inthe level of 21.2 percent, P<0.001). The average monthlydose of antipsychotic drugs among regular recipients beforethe cap was 2.85 SMDs (415 mg of chlorpromazine or the equivalentper day),30 well within the accepted range of maintenance doses22.
Provision of Medications in CMHCs
Figure 2 shows a substantial increase in the amount of antipsychoticdrugs administered to members of the study cohort at CMHC 1after the cap was instituted. This change shifted costs formedications to the state mental health system. When both Medicaid-reimbursedand CMHC-provided antipsychotic agents were included, the averageuse per patient per month was 0.91 SMD before the cap was instituted,1.24 SMDs while it was in effect, and 0.80 SMD after it wasdiscontinued.
Figure 2. Standard Monthly Doses (SMDs) of Antipsychotic Agents Administered per Patient at CMHC 1 to Members of the Study Cohort (N = 29).
The average amount of antipsychotic agents administered at and paid for by the CMHC was equivalent to 0.18 SMD per patient per month before the cap was instituted; this increased by a mean (±SE) of 0.93 ±0.33 SMD while the cap was in effect (P = 0.008) and declined gradually to base-line levels after the cap was discontinued.
Use of CMHCs and Admissions to State Psychiatric Hospitals
As illustrated in Figure 3, after a moderate decline at CMHC1 from 7.6 to 4.3 visits to the center per patient per month,the number of visits increased abruptly when the cap was putinto effect, reaching 7.5 visits by the end of the cap period(increase in trend, 0.6 ±0.1 visit per patient per month[57 percent]; P<0.001). When the cap was withdrawn, the numberof visits declined to 6.4 per patient per month by the end ofthe 17-month follow-up period (P<0.001). At CMHC 2, the institutionof the cap was associated with an immediate increase in thenumber of visits (increase in level, 1.0 ±0.4 visits,P = 0.01) and an increase in slope (0.2 ±0.04 visit perpatient per month [43 percent], P<0.001), which continuedto the end of the study period.
Figure 3. Visits to CMHC 1 and CMHC 2 per Patient per Month in the Study Cohort.
A total of 29 patients received services at CMHC 1, and 49 received services at CMHC 2. The fitted trend lines show predicted values for segmented time-series regressions.
We hypothesized that exacerbations of schizophrenic symptomswould result in an increased use of emergency mental healthservices and in more partial hospitalizations. Before the capwent into effect, study patients used no emergency servicesat CMHC 1; while the cap was in place, there was 0.03 serviceper patient per month (P = 0.002 for the change in level) (Figure 4);by three months after the cap was discontinued, the useof emergency services had returned to zero. Similarly, the trendin the use of emergency services increased markedly at CMHC2, from 0.002 per patient per month at base line to 0.26 atthe end of the cap period (Figure 4) (increase in trend, 0.02service per patient per month; P<0.001). The use of emergencyservices declined after discontinuation of the policy.
Figure 4. Emergency Mental Health Services per Patient per Month at CMHC 1 (N = 29) and CMHC 2 (N = 49).
At CMHC 1, the number of days of partial hospitalization increasedsubstantially, from 3.4 per patient per month before the capwas imposed to 4.6 at the end of the period during which thecap was in effect, falling again to 2.3 after the copaymentwas introduced (no time-series analysis was carried out becauseof a statistically unstable pre-cap series). At CMHC 2, thenumber of days of partial hospitalization increased from 1.5at base line to 2.9 at the end of the cap (increase in trend,0.17 ±0.04 per patient per month; P<0.001); no furtherchange was observed during the copayment period that followedthe discontinuation of the cap.
Analyses of all study patients in New Hampshire (n = 268) detectedno change in the rate of admission to the state psychiatrichospital. Before the cap was implemented, the admission ratewas 0.38 per patient-year; while the cap was in effect, it was0.41; and after the cap was discontinued, it was 0.38 (P notsignificant for any of the three comparisons).
Economic Effects
The base-line Medicaid drug expenditure was $21.97 per studypatient per month in the 14 months before the cap was imposed;expenditures decreased abruptly by $5.14 ±0.67 per patientper month during the period of the cap (a decrease in levelof 23 percent, P<0.001). The increase in costs associatedwith the cap was about $139 per patient per month at the twoCMHCs we studied ($1,530 per patient during the 11-month capperiod), based on a weighted average of estimated increasesin the use of mental health services at the study CMHCs (1.5visits per patient per month) and the average unit charge forthese services to third-party payers at the time ($92). Claimsdata showed that an estimated 95 percent of study patients (n= 255) had at least one visit to a CMHC. The estimated increasein the statewide cost of mental health services while the capwas in effect was $390,000, based on figures extrapolated fromthe sampled CMHCs. Assuming conservatively that the increasedstatewide costs were one third lower than those observed inthe two CMHCs we studied, the increases in the costs of mentalhealth services exceeded the savings in drug expenditures bya factor of more than 17. Moreover, we probably underestimatedthese costs because of the lack of data on administrative costsand the costs of the psychoactive drugs provided free at CMHCs,other unobserved expenditures (for example, cost shifting toMedicare, the criminal-justice system, family efforts to compensatefor disruptions in care, and possibly increased cost of treatingthe approximately 30 percent of patients with schizophrenianot identified by our algorithm),31 and intangible costs, suchas increases in pain, suffering, and the risk of suicide amongpatients, that were associated with exacerbations of schizophrenicillness.
Discussion
We previously reported a direct relation between the New HampshireMedicaid drug-payment cap and both the reduced use of essentialtherapies and increased institutionalization of frail elderlypersons5. In the present study, we examined the effects of thispolicy on another vulnerable population: low-income adult patientswith schizophrenia who were living in the community. Our resultsstrongly suggest that the restriction on payment for psychoactivemedication caused immediate and sustained reductions in theuse of antipsychotic drugs, antidepressants and lithium, andanxiolytic and hypnotic agents. The lower base-line use of antipsychoticagents among New Hampshire patients, as compared with patientsin New Jersey, suggests that psychiatrists in New Hampshirewere already reducing doses to minimize adverse effects, a findingthat is consistent with recent positive evaluations of New Hampshire'spublic mental health system32.
We detected no changes related to the cap in the rates of admissionto the state psychiatric hospital. However, there was a significantincrease in visits to CMHCs; an increase in the administrationof antipsychotic agents at the CMHCs that were paid for by thestate mental health system; and increases in the use of emergencymental health services, partial hospitalizations, and dosesof antipsychotic agents given at the CMHCs. The sudden declinein the number of patients given psychoactive medications atthe CMHCs and the downward trends in the use of most acute mentalhealth services after the cap was discontinued further supportthe hypothesis that the limit on drug benefits increased patients'agitation or exacerbated schizophrenic symptoms, thereby increasingthe use of expensive acute care services. Continued higher ratesof partial hospitalization and increased numbers of outpatientvisits at CMHC 2 suggest that some local effects of the capcontinued even after its withdrawal. These consequences maybe due to the need for continued surveillance to stabilize thecondition of patients after relapse, the difficulty of changingadministrative mechanisms once they are in place, and the effectsof the newly required copayment.
Could some other factor have caused the increased use of acutemental health care services? This is unlikely, since such aconfounder would have had both to increase use after the 14-monthbase-line period and to reduce it again 11 months later. Inaddition, none of the directors and staff members of New HampshireCMHCs could suggest alternative explanations. The fact thatadmissions to the state psychiatric hospital did not increaseis consistent with state mental health policies that stronglydiscouraged such admissions.
Could the observed changes merely reflect patients' effortsto gain access to medications rather than changes in their mentalhealth status? This explanation is unlikely, because most patientsreceived one-month supplies of medications and were alreadyvisiting the CMHCs about once a week before the cap was imposed(Figure 3). Thus, additional visits were not needed to obtainmedications. It is more likely that the increased use of services,especially the higher rate of use of partial hospitalizationand emergency mental health services, represents a responseto acute exacerbation of illness, although the exact reasonsfor the increases in acute care services remain unknown.
Case reports obtained from state mental health records corroboratethese impressions. For example, during the period when the capwas in effect a middle-aged woman with schizophrenia was admittedto the New Hampshire Hospital on an emergency basis becauseof extreme agitation. At admission, her medication regimen includedan antipsychotic agent, an antiparkinsonian drug, insulin, anda cardiac medication. The reasons for admission included diabeticketoacidosis precipitated by her discontinuation of insulinin favor of continuing her other three medications.
What are the policy implications of these findings? First, ourstudy suggests that even small reductions in reimbursement foreffective medications (e.g., $5 per month) can have substantialunintended effects on low-income people with chronic mentalillnesses. Medications are frequent targets for cost-containmentprograms. However, the literature does not support the viewthat cost sharing or arbitrary limits on drug-reimbursementbenefits reduce overall costs while maintaining essential carefor low-income, chronically ill populations1.
Second, our results challenge once again the assumption thatchanges in one sector of care can have simple and isolated effects5,6.Vulnerable patients have sustained needs in a system of carethat is in fragile equilibrium. Even slight perturbations intheir support system can have direct consequences and also secondaryor compensatory effects. In this study, the new equilibriumincluded costly increases in the use of acute services.
Third, our data suggest that important changes in health policiesaffecting vulnerable populations should be implemented underclose scientific scrutiny. At the very least, policy changesthat pose substantial risks should undergo careful evaluationbefore their widespread adoption. Because policy changes oftenoccur rapidly, faster funding mechanisms are needed to allowprospective studies and direct measures of health outcomes.
The results of this study illustrate the need for a mechanismto disseminate timely, objective, and concise information onthe positive and negative effects of cost-containment policiesto state legislators and administrators when decisions are beingmade. Political factors often predominate at such times, butscientific data also have an important role. For example, areport in the Wall Street Journal on the effects of the NewHampshire cap on the institutionalization of frail elderly patients4was successfully used to prevent the reintroduction of the policyby the legislature in 1990. As the quality of health policystudies increases, attention should focus on disseminating relevantfindings to organizations whose decisions affect the stabilityof vulnerable patients and the costs and outcomes of their care.
Supported by a grant (R01MH44881) from the National Instituteof Mental Health and by the Agency for Health Care Policy andResearch, the Robert Wood Johnson Foundation, and the HarvardCommunity Health Plan Foundation.
We are indebted to the Medicaid programs of New Hampshire andNew Jersey for facilitating our access to the Medicaid claimsdata; to the New Hampshire Department of Mental Health, theCommunity Mental Health Centers, and the New Hampshire Hospitalfor providing and helping to interpret the data on mental healthtreatment episodes; to Sharon Hawley for abstracting clinicaldata; to Dan Gilden of Jen Associates for statistical and data-processingsupport; to Leon Eisenberg, Thomas Inui, Helene Lipton, HaroldSchwartz, Gordon Schiff, Jonathan Lomas, and Paul Widem fortheir helpful comments on an earlier version of this paper;and to Ann Payson and Laura Goldberg for assisting in the preparationof the figures and the manuscript.
Source Information
From the Departments of Ambulatory Care (S.B.S., T.J.M., D.R.-D., C.S.C.) and Prevention and Social Medicine (D.R.-D.), Harvard Medical School and Harvard Community Health Plan, Boston; and the International Organization for Migration, Geneva (P.B.).
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1 prescription per quarter). About 30 percent of the patients in both cohorts received one or more prescriptions for drugs to treat affective disorders; 70 percent of these prescriptions were for antidepressants, and 30 percent were for lithium. About 75 percent of the patients in both cohorts received drugs from more than one category. 
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