provider continuity and outcomes of care for persons with schizophrenia

Mental Health Services Research, Vol. 2, No. 4, 2000

Provider Continuity and Outcomes of Care for Personswith Schizophrenia

Chang Fu Chien,1 Donald M. Steinwachs,2,4 Anthony Lehman,3 Maureen Fahey,2

and Elizabeth A. Skinner2

The study examines the relationship of provider continuity to outcomes of care (quality oflife, payments for services) for Medicaid beneficiaries with schizophrenia. Data sourcesincluded Maryland Medicaid claims and enrollment data and in-person interviews. Measuresof provider continuity over the year preceding the interview, calculated from claims formental health ambulatory visits, were usual provider continuity (UPC—fraction of visits tothe most frequently seen provider), sequential continuity (SECON—fraction of sequentialvisit pairs to the same provider), and continuity of care (COC—distribution of visits acrossdifferent providers). Higher provider continuity was found to be related to lower costs andto lower likelihood of mental illness hospitalization. Provider continuity was not significantlyrelated to general life satisfaction or to satisfaction with health. Persons with zero or onevisit in a year (and for whom provider continuity could not be measured) had more severedepressive symptoms and were more likely to abuse substances but reported comparablesatisfaction with health and overall quality of life while incurring lower Medicaid costs.

KEY WORDS: schizophrenia; provider continuity; medicaid; quality of life; utilization; costs.

Continuity of care, and specifically provider con-tinuity, is a hallmark of quality care for persons withchronic diseases. Greater provider continuity in pedi-atric practices has been shown to be related to fewerepisodes of illness and lower hospitalization rates(Heagarty, Robertson, Kosa, & Alpert, 1970) andto better compliance with instructions and keepingappointments (Becker, Drachman, & Krischt, 1974).However, research evidence demonstrating positiveeffects of provider continuity is relatively limited andgenerally absent for adults. In particular, for personswith mental illnesses there is little evidence that pro-vider continuity makes a difference in the cost, qual-

1National Center for Health Statistics.2Department of Health Policy and Management, The Johns Hop-kins School of Hygiene and Public Health.

3Department of Psychiatry, University of Maryland School of Med-icine.

4Correspondence should be directed to Donald M. Steinwachs,Ph.D., Health Services Research and Development Center, JohnsHopkins School of Public Health, 624 North Broadway, Balti-more, Maryland 21205. e-mail: [email protected].

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1522-3434/00/1200-0201$18.00/0 2000 Plenum Publishing Corporation

ity of care, or patient-reported outcomes (Sturm,Meredith, & Wells, 1996; Bachrach, 1993).

It is important to distinguish between continuityof care and provider continuity. Continuity of careimplies ongoing (longitudinal) care that is integratedand coordinated over time. It is often suggested thatthe best way to achieve this is through provider conti-nuity, namely, seeing the same provider for all care,or all mental health care, over time. Provider continu-ity is more readily measurable than continuity of care,yet there are subtleties to consider regarding howthe provider of services is defined (Steinwachs, 1979).The provider may be an individual physician, or theprovider may be an interdisciplinary team or a clinicthat shares a common medical record. In this study,provider was defined as the organized care setting,which is expected to have a common patient recordthat can support integrated and longitudinal care.From billing data it was possible to identify the pro-vider at the organizational level, while it was notconsistently possible to identify the specific personrendering care. The provider can be a private office-

202 Chien, Steinwachs, Lehman, Fahey, and Skinner

based physician, community clinic, hospital outpa-tient clinic, or emergency room.

In the present study, mental health provider con-tinuity was examined among Medicaid enrollees witha diagnosis of schizophrenia. Information obtainedthrough consumer in-person interviews in the com-munity was linked with claims data identifying theprovider and the use of services over a 1-year periodprior to the interview. Three theoretically comple-mentary measures of provider continuity for mentalhealth services were calculated and relationshipswere examined among the continuity measures andbetween continuity and quality of life outcomes andMedicaid payments.

In general, studies of treatment effectiveness inmental health have not measured the impact of varia-tions in continuity of care on outcomes. As a result,the relationship between continuity and outcomes ofcare is not well documented. Although it is generallyagreed that provider continuity is a potentially effec-tive means for assuring continuity of care, there isno consensus regarding what are acceptable or unac-ceptable levels of provider continuity, even thoughit might be argued that perfect continuity is clearlydesirable and random care seeking is undesirable(Bachrach, 1993).

The study hypothesis was that greater providercontinuity would be associated with better outcomesof care, including quality of life, and lower costs oftotal health care. One study summarizing evidenceon relapse rates for schizophrenia found rates of 70%under placebo treatment, 30% in randomized con-trolled trials with antipsychotic medications, and 50%in community samples receiving usual care (Kissling,1992). To the extent provider continuity enhancesthe likelihood of better than usual care, reductionsin the likelihood of relapse, hospitalization, and costsof mental health care would be expected. This wasour second hypothesis.

The broader conceptual framework guiding thisstudy recognizes that provider continuity may be in-fluenced by a range of factors, including personal andsociodemographic characteristics, disease and co-morbidity, usual provider access and organizationalcharacteristics, access controls imposed by insuranceand managed care, and geographic access/availabilityto alternative sources of care (Chien, 1997). Thesecharacteristics also might be expected to influenceutilization, costs, and quality of life outcomes.

Evidence regarding the value of provider conti-nuity may be particularly timely. As mental healthservices are being organized into managed behavioral

health systems, there is the potential to influencedirectly provider continuity by organizational design,incentives, and control of access arrangements. Atthe same time, there are other opportunities to en-hance the patient’s continuity experience through theuse of managed care information systems to monitorprovider continuity, identify when consumers switchproviders and determine why, and intervene withpersons who do not return for follow-up care.

METHODS

This study includes Medicaid recipients in theState of Maryland who participated in a study exam-ining the relationship of patterns of treatment forsevere and persistent mental illness (SPMI) to out-comes, including quality of life, symptoms, and costsof care. Using Medicaid enrollment and claims data, astratified sample was selected from among all personswith 2 years of continuous Medicaid enrollmentthrough the end of FY94 and with a mental illnessdiagnosis and/or a specialty mental health serviceoccurring between July 1, 1992, and June 30, 1993(FY93). Sampling was stratified by geographic areaof residence (80% in six Baltimore metropolitan areacounties and 20% in six rural Eastern Shore counties).Another eligibility criterion was age 21 to 64 at thetime of the survey.

Among the 1069 people sampled, 762 (71%)completed interviews between July 1994 and March1995, including 105 interviews conducted with proxyrespondents because of cognitive or emotional im-pairment of the sampled individual. Fourteen percentof the full target sample could not be located, 3%had moved out of the study area, 5% refused, and theremainder were incomplete for a variety of differentreasons. The interviews were completed in person(after obtaining informed consent) by trained surveyinterviewers during home visits lasting approximately1.5 hr. The questionnaire covered a wide variety oftopics, including demographic information, living ar-rangements, social and family relationships, daily ac-tivities and functioning, quality of life, employmentand job training, financial resources, physical healthstatus, mental health conditions, substance use, andmental health services utilization.

The present analysis included those individualswho had schizophrenia as a diagnosis, from either aninpatient or an outpatient Medicaid service claim,or responding to the interview question concerningwhether or not they had ever been told by a physician

Continuity and Outcomes of Care 203

that they had schizophrenia. Those with schizophre-nia totaled 351 (46%) of the 762 respondents. On arandom subsample of 100 cases, the Structured Clini-cal Interview for DSM-III-R (SCID) was used tovalidate diagnosis (Spitzer, Williams, Gibbon, &First, 1990). Agreement between the SCID and self-reported schizophrenia was 85% and between SCIDand claims data was 89%. Among the 351 completedinterviews, 41 (12%) were proxy interviews.

Independent and Dependent Variables

The independent variables included socioeco-nomic and demographic characteristics, illness char-acteristics, usual sources of medical and mentalhealth care, and provider continuity. The dependentvariables included Medicaid payments for mental ill-ness care and total payments. Two of the 10 LehmanQuality of Life domains were used as outcome mea-sures, general life satisfaction, and satisfaction withhealth (Lehman, 1988).

Sociodemographic and Comorbidity Characteristics

The respondents were adults in their middleyears, about equally distributed by gender and race(Table 1). As might be expected in a sample of peopleenrolled in Medicaid, the educational attainment wasrelatively low, most resided in an urban–suburbanarea, and the average monthly income was low. Indi-viduals had a range of living arrangements and mosthad regular contact with family and friends. Self-reported coexisting mental and somatic disorderswere common among those in the study.

Substance abuse was defined as a positive re-sponse to two or more items on the CAGE (Mayfield,McLeod, & Hall, 1974) or by responding positivelyto any of the following: taking Antabuse, participat-ing in a Methadone maintenance program, used ille-gal drugs, attended AA or NA meeting, talked witha therapist about this problem, and attended detoxor group therapy for substance abuse problems in thepast year. Overall, 36% screened positive on having asubstance abuse problem.

Hospitalization for a mental disorder in the13–24 months preceding the interview was used as aproxy for severity of mental illness. The source ofprior hospitalization information is Medicaid serviceclaims, with 38% having a hospitalization in the yearbefore the study year.

As part of the interview, respondents completedthe Colorado Symptom Index for psychotic and de-pressive symptoms (Shern, Wilson, & Coen, 1994).The average score for psychotic symptoms is 4.01 andfor depression is 3.57; possible scores range from 1(symptoms every day) to 5 (not at all in the pastmonth).

Sources of Care and Medicaid Program

In this study population, 95% reported having ausual source for medical care and 96% reported hav-ing a usual source for mental health care. Amongthose with a usual source for medical care, a hospitalor clinic was cited as the usual source by 53%, aprivate MD by 40%, and 2% cited other sources.For mental health care, 84% reported the hospital orclinic to be their usual source of mental health care,13% identified a private MD, and 3% identifiedother sources.

The Maryland Medicaid Access to Care (MAC)program was designed to assure all recipients had aregular provider and the provider received supple-mental payments to serve as a gatekeeper. Individu-als could either chose their own MAC provider fromamong those participating in the program or be as-signed to one by the program. Over half the respon-dents identified their MAC provider of record as theirusual source of medical care (59%) and over a thirdnamed it as the usual source of mental health care(35%). Approximately a quarter responded that theMAC provider was the usual source of care for bothmedical and mental health care (26%).

Provider Continuity

Three measures of provider continuity were usedin this study, each of which emphasized a differentaspect of continuity. Continuity was measured acrossall outpatient visits during the year for mental healthcare. Only visits in which a health professional wasseen for evaluation, treatment, or rehabilitative ser-vices for a mental health problem were included,based on information available in billing codes andICD-9 diagnosis. All three measures had a value ofone if there was perfect provider continuity and ap-proached zero at the other extreme. The index, conti-nuity of care (COC), measured the distribution ofvisits across different providers (Shortell, 1976). Forexample, when two providers were seen for a total


Table 1. Demographic Characteristics

N(�351) Percentage

Age18–25 10 2.826–35 118 33.636–45 105 29.946–55 69 19.755–64 49 14.0

Percentage female 181 51.6Race

White 176 50.1Black 172 49.0Other 3 0.9

EducationLess than high school 167 47.6High school graduate 125 35.6Some college or more 59 16.8

LocationUrban 271 76.9Rural 80 23.1

Average monthly income (all sources) $491Living arrangements

Independently 122 34.8With family 118 33.6Supervised settings 73 20.8Homeless, shelter, jail 38 10.8

Percentage reporting at least weekly family contactsBy phone 208 59.2In person 118 48.6Less than weekly or no family contacts reported 106 30.6

Mean family contactsa 3.17Percentage reporting social activities at least weekly

Doing things with close friend 147 41.9Visiting someone 148 42.2Writing a letter 17 4.8Telephoning someone 173 49.3Doing something planned ahead with friend 89 25.4Spending time with boyfriend/girlfriend 118 33.6Less than weekly or no social activities reported 73 21.9

Mean social contactsa 2.88Cooccurring mental disorders 216 61.5

Major depression 134 38.2Bipolar disorder 126 37.0Anxiety disorder 80 23.4Personality disorder 75 21.8Other 279 80.0

One or more cooccurring mental disordersMedical comorbidities (selected)

High blood pressure 120 34.2Diabetes 50 14.2Cancer 26 7.4Lung problems 99 28.2Heart disease 67 19.1

One or more medical comorbidities 197 56.1

aAverage of responses (1 � not at all, 5 � every day).


of four visits, a higher COC continuity score wasachieved if three of the visits were to one providerversus two visits to each provider. Usual providercontinuity (UPC) measured the proportion of totalmental health visits to the solo physician or clinic, orhospital outpatient department that was the usualcare source (Breslau & Reeb, 1975). In this study, itwas assumed that the mental health provider withthe largest number of visits in the past year was theusual source of mental health care. Alternatively, theusual source reported on the interview could havebeen matched with the provider identity on the billingrecords. We conducted a preliminary test and con-cluded matching could not be reliably completed forall providers. Another perspective on continuity ex-perience was sequential continuity (SECON), whichmeasured the extent to which sequential pairs of visitswere made to the same provider (Steinwachs, 1979).A person seeing two providers for three visits eachduring the year would have a SECON value of 0.8if the sequence of visits was three to provider A andthen three to provider B, compared to a value ofzero if visits to providers A and B alternated overthe year.

Dependent Variables

The study examined the relationship of providercontinuity to total Medicaid payments, mental illnesspayments, and consumer-reported quality of life asoutcomes of care. The respondent rated quality oflife dimensions on a scale from 1 (terrible) to 7 (de-lighted). General life satisfaction was based on a sin-gle question asked twice, at the beginning and endof the interview, with the two ratings then averaged.Satisfaction with health was based on six questionswhose responses were averaged to obtain an overallscore: satisfaction with health, medical care availabil-ity, frequency of seeing a doctor, chances to talkwith a therapist, physical condition, and emotionalwell-being.

Total Medicaid payments averaged $11,444(range, $0 to $81,258) for the year prior to the inter-view. These payments included inpatient, outpatient,physician, long-term care, home health, pharmacy,equipment, and rehabilitation services, among oth-ers. Mental illness payments averaged $6,142 (range,$0 to $53,631) and included those services that hada mental disorder diagnosis or for which the providerwas a mental health specialist, including hospitaliza-tions with a principal discharge diagnosis of a mental

disorder, physician services, and clinic visits. All sub-stance abuse diagnoses were excluded from the men-tal illness computations.

The calculation of mental illness payments wasbased on diagnosis and the specialty of the provider.The calculation is expected to understate total pay-ments for mental health services because it excludedany mental illness service that did not have a diagno-sis or specialty code on the service claim. An impor-tant category of service excluded is outpatient pre-scriptions.

RESULTS

Differences between those persons who wereexcluded from the measurement of provider continu-ity due to having zero or one visit in the prior yearand those with two or more visits are presented. Thisis followed by a discussion of the distribution andrelationships among the three continuity measuresand the relationship of continuity to quality of lifeand Medicaid payments.

Persons Excluded from ProviderContinuity Calculation

A limitation of provider continuity measures isthat they can be applied only to those persons withtwo or more mental health visits during the year.Among persons with a schizophrenia diagnosis in thestudy, 30% had no visits or only one for mental healthcare in the year preceding the interview and had to beexcluded from the calculation of provider continuity.The excluded group did not differ significantly indemographic characteristics from those with two ormore mental health visits, except for race, where theproportion of blacks was higher in the excluded group(59% versus 45%).

Those with zero or one visit scored significantlyworse on the Colorado Symptom Index’s depressivesymptom scale (3.30 versus 3.67; p � .0032) but werenot significantly different on the psychotic symptomscale (3.84 versus 4.08; p � .083). Persons in theexcluded group having zero or one visit were morelikely to screen positive for substance abuse problems(45% versus 31%; p � .018), were less likely to havea hospital or clinic as their usual source for mentalhealth care (71% versus 84%; p � .002), and wereless likely to live in supervised residences (9% versus26%; p � .001).


Comparisons between the two groups on thedependent measures showed the excluded group tohave significantly lower mental health costs ($1,183versus $8,287; p � .0001) and significantly lower totalhealth costs ($6,653 versus $13,517; p � .001). Thedifference in total costs approximately equals the dif-ference in mental health costs; substance abuse treat-ment costs were aggregated with somatic and generalpreventive care. Even though individuals had noneor one ambulatory mental health visit, they couldincur substantial mental health costs by being hospi-talized for a mental illness. General life satisfactionwas not significantly different, nor was satisfactionwith health. In summary, the group excluded fromthe analysis having none or one mental health visitin the year preceding the interview included a higherproportion of blacks and persons with more severedepressive symptoms, who were more likely to screenpositive for substance abuse problems, with a differ-ent mix of usual sources of care and living arrange-ments, and with lower total Medicaid payments thanthose with two or more visits.

Provider Continuity

The extent of provider continuity during the yearprior to the interview was highly variable. Visits in-cluded in the measurement of continuity were allambulatory and emergency room visits (dischargedto community) where a provider was seen; excludedwere all inpatient visits and emergency room visitsoccurring as part of a hospital admission. In Fig. 1,the distribution of provider continuity scores for thethree measures is shown. Sequential continuity(SECON) showed 44% of the study group having90% or more of their next visits to the same provider.Even so, there were about 12% who saw a different

Fig. 1. Percentage distribution of provider continuity measures (n � 245).

provider at the next visit a majority of the time. Aboutone-quarter of the sample saw their usual provider90% or more of the time (UPC), while almost 20%saw the usual provider less than half the time. Thethird continuity measure, COC, measured the extentof dispersion in visits across providers and looks moresimilar to UPC than SECON. Overall, a substantialproportion of persons with two or more visits in theyear experienced moderate to high levels of providercontinuity. A small but potentially important grouphad low levels of provider continuity.

While each measure provides a somewhat differ-ent insight into the provider continuity experience,even so they would be expected to be correlatedsignificantly with each other. Pearson correlations forthese measures were as follows: COC–UPC, .949;COC–SECON, .655; and UPC–SECON, .519. Twoof the measures were highly correlated (COC andUPC), while SECON had a strong association withbut varied to some degree from the other two mea-sures. Due to the almost-perfect correlation of COCand UPC, the subsequent analysis used the UPC andSECON measures only. Total number of mentalhealth visits was significantly correlated with each ofthe continuity measures; more visits was associatedwith lower provider continuity.

Few statistically significant bivariate relation-ships were found between provider continuity andthe dependent and independent variables. Socioeco-nomic and demographic characteristics (age, gender,race, marital status, monthly income, living arrange-ments, and urban/rural) were not associated withcontinuity, with the exception of living arrange-ments.

Persons residing in supervised housing experi-enced significantly lower UPC continuity than didpersons living independently or with family. Fre-quency of family contact was not related to continu-


ity, but frequency of social contact was. Higher socialcontact was related to lower levels of provider conti-nuity for SECON (p � .010).

UPC showed significantly lower provider conti-nuity among those with a claims diagnosis of schizo-phrenia compared to those without a claims diagno-sis, who self-reported having schizophrenia. Psy-chotic symptoms, depressive symptoms, medicalcomorbidity, mental illness comorbidity, and thepresence of a substance abuse disorder were not re-lated to provider continuity experience. Almost allof this sample had received disability coverage underSSI or SSDI, and compared to those not receivingdisability, there were no differences in continuity ex-perience.

The Maryland Medicaid Access to Care (MAC)program assures that all recipients have a providerwho functions as a gatekeeper to specialty services.No relationship to provider continuity was found be-tween persons whose MAC provider was their usualsource of mental health care, or if the MAC providerwas their usual source of medical care. Organiza-tional type of usual care source for medical care ap-proached standard levels of significance for UPC(p � .052). Persons reporting private physicians asthe usual source of medical care, compared to hospi-tals or clinics, experienced lower provider continuity.No relationship was found between continuity andthe type of usual care source for mental health care.Persons hospitalized for any mental illness in the yearprior to the study year (a proxy measure for severityof illness) experienced lower sequential continuity(SECON).

Table 2. Regression Results for Quality of Life and Medicaid Payment Outcomes with Provider Continuitya

Usual provider continuity Sequential continuity(UPC) (SECON)

Dependent variable b SD R 2 b SD R 2

General life satisfaction .171 .509 .442 .367 .420 .436Satisfaction with health .208 .399 .462 .236 .329 .442Total Medicaid payments (year) — 4,127.19 .440 — 3,252.56 .477

8,909.83* 12,959.00*— 3,317.37 .471 �9,240.11* 2,601.76 .496

Mental health payments (year) 7,248.12*

aLinear regression models included the following independent variables in addition to provider continuity: gender,age (continuous), race, education, monthly income (continuous), living arrangements, location (Baltimore or EasternShore), marital status, contact with family, social contact, SPMI category 1, disability entitlement, mental illnesshospitalization in previous year, Colorado Symptom Scale for depressive symptoms and for psychotic symptoms,presence of medical comorbidities, presence of mental comorbidities, screen for substance abuse problems, organiza-tional type of usual source for medical care, organizational type of care source for mental health, MAC providerused for medical, and MAC provider used for mental health. In the Medicaid cost regressions, Medicaid costs fromprior year included as covariate.

*p � .05.

In summary, few correlates of provider continu-ity were found, with one or both measures. Correlatesof lower provider continuity were living in a super-vised residence, more frequent social contacts, havinga private physician as a usual source of medical care,and hospitalization for mental illness in the year priorto the study year.

Quality of Life Outcomes

In Table 2, multivariate models of two quality oflife outcomes are examined. The findings were thatprovider continuity was not related to general life sat-isfaction or satisfaction with health. General life satis-faction showed arelationship to depressive symptoms,but none of the other independent variables achievedstatistical significance across the two models.

In a bivariate analysis of general life satisfactionwith the independent variables, the following werefound to be statistically significant: being on disabilitywas associated with higher life satisfaction (4.84 versus4.00; p � .017), hospitalization for a mental disorderin the year previous was associated with lower life sat-isfaction (4.33 versus 5.02; p � .002), presence of men-tal comorbidity was associated with lower satisfaction(4.64 versus 5.56; p � .0001), and the depression andpsychotic symptom scales of the Colorado SymptomIndex were both significantly related—fewer symp-toms related to higher general life satisfaction.

Greater satisfaction with health was related tohigher income and to fewer depressive symptomsacross the two models, but not to provider continuity.


In a bivariate analysis, greater satisfaction with healthwas related to not being hospitalized for a mentalillness in the prior year (5.13 versus 4.78; p � .035),not having a mental comorbidity (5.33 versus 4.95;p � .018), having a higher monthly income, and hav-ing fewer depressive and psychotic symptoms.

Medicaid Payments

Table 2 also shows multivariate regression mod-els of total Medicaid and mental health paymentsduring the year. Two alternative specifications of themodels were estimated, one with all the independentvariables described previously and one with thesevariables plus Medicaid payments 2 years previously(13–24 months prior to interview). Including pay-ments 2 years previously as an additional controlfor historical intensity of service use increased theexplanatory power of the models but did not substan-tially change the findings. To test the sensitivity ofthe results, alternative model specifications were esti-mated, including regression models of log Medicaidpayments and models controlling for numbers of am-bulatory mental health visits during the year. Thesignificance of provider continuity and the directionof effect was consistent across all these specifications.

In Fig. 2, the relationship of continuity to hospi-

Fig. 2. Relationship of usual provider continuity (UPC), hospitalization for mental illness, and medicaid payments.

talization is shown. For lower levels of continuity (lessthan .50), the proportion and costs of hospitalizationdecreased substantially as provider continuity in-creased. Not shown in the figure are people for whoma UPC score could not be calculated because theyhad no or only one visit. Among these, only 9% hada mental illness hospitalization in the past year, andMedicaid payments were low, $1,183 for mentalhealth services and $6,653 overall.

In summary, total Medicaid payments (mean �$11,444) and mental health payments (mean �$6,142) were significantly lower for persons withgreater continuity experience during the year, forboth UPC and SECON. A 10% increase in UPCwas associated with $891 lower total Medicaid annualpayments per person-year and $725 lower mentalhealth payments. For SECON the estimated effectswere larger. A 10% increase in follow-up visits to thesame provider was associated with a decrease in totalMedicaid payments of $1,296 and in mental healthpayments of $924.

DISCUSSION

The findings regarding the contribution of pro-vider continuity to Medicaid payments were gener-


ally positive: better continuity was related to lowerpayments. No evidence was found of a relationshipbetween better provider continuity and general lifesatisfaction or satisfaction with health. To the extentthat treatment is appropriate and ongoing, betterquality of life would be expected compared to treat-ment that is inadequate and discontinuous in compa-rable patients. The expected results for quality of lifeoutcomes were not observed in this cross-sectionalanalysis.

Persons Excluded from ProviderContinuity Analysis

The findings related to those individuals whohad zero or one visit for mental health care in theyear prior to the interview are important. These indi-viduals accounted for 30% of the study group andcould not be included in the analysis of providercontinuity due to having one or no visit in the preced-ing year. Their apparent lack of any continuity ofcare could be related to greater access barriers orless motivation to seek professional care. It is notablethat this group included a higher proportion of blacksand a lower proportion of persons relying on hospi-tals and clinics as their usual source of mental healthcare. Both race and source of care could be indicatorsof poorer access to mental health services. While thisgroup reported more severe symptoms of depressionand was more likely to screen positive for substanceabuse problems, they did not significantly differ onpsychotic symptoms. Even so, the combination oflittle or no care for schizophrenia and the likely pres-ence of substance use problems places this group atrisk of poor long-term outcomes for schizophrenia.The capacity to identify this group from administra-tive data suggests the feasibility of outreach and inter-vention. Such efforts would exemplify the principlesof population-based mental health care, namely, thetargeting of interventions based on risk and the useof population-based monitoring to assess impact.

Impact of Provider Continuity

The findings related to total Medicaid paymentsand mental health payments suggest that providercontinuity, as one descriptor of the care process, isrelated to lower overall costs to Medicaid. The pri-mary source of these cost reductions is a lower rate ofhospitalization for mental illnesses and lower mental

health costs. Research has shown that hospitalizationis lower for those treated than for untreated controlsand lower in clinical trials than in community popula-tions receiving treatment (Kissling, 1992). The ques-tion is why provider continuity is associated with lesslikelihood of hospitalization. One hypothesis is thatprovider continuity is associated with a more success-ful patient–provider relationship and, as a result, withbetter quality of care over time.

This study does not address specifically what fac-tors influence the achievement of provider continuity.These may include patient preferences, provider or-ganization, incentives, and arrangements for accessand continuity. The interview did ask for providercontinuity preferences. Among those who used men-tal health services in the previous year, 73% reportedprovider continuity to be very important, 16% some-what important, and 12% not important. The pro-vider is defined here as the organization billing Med-icaid for mental health services rendered, whichranges from a private physician, to a community men-tal health center, to a hospital clinic or a hospitalemergency department. The expectations associatedwith provider continuity at the organizational levelmay vary from those associated with seeing an indi-vidual practitioner over time. At a minimum, it wouldbe expected that organizational provider continuityfacilitates sharing of a patient’s medical record.

The potential for achieving provider continuityover time likely depends on the scope of prescribedservices in the treatment plan, the capacity of theusual mental health provider to provide the full rangeof services needed, and the organizational arrange-ments for crisis and urgent care. Thus, poorer pro-vider continuity could be an artifact of seeing provid-ers who each specialize in a narrow scope of services.Even so, the need to go to multiple providers toreceive the full range of services needed may be diffi-cult for some persons with schizophrenia. Also, pa-tients may be switching providers and seeking betteror more acceptable care. It is likely that there aremultiple contributing factors to lower levels of pro-vider continuity, yet the net effect is a strong associa-tion with higher rates of mental illness hospitalizationand higher mental health care costs.

Limitations

There are limitations to inferences that can bedrawn from a cross-sectional examination of providercontinuity and outcomes. Although the continuity


experience preceded in time the quality of life out-comes measured, many of the independent variablesare based on recall at the same time that the qualityof life outcomes are also being measured. The effectof this potential measurement bias is uncertain. Thecosts paid by Medicaid include the visits which arepart of the continuity measures. Another potentialsource of bias would be a strong relationship betweenprovider continuity and the numbers of mental healthvisits during the year. It was found that the number ofmental visits in the year did not explain the observeddifferences in the relationship of continuity to totalMedicaid payments and mental health payments.

The continuity measures are applied across allvisits, independent of the type of service, e.g., medica-tions check, psychosocial rehabilitation, and outpa-tient crisis intervention. We do not know what therelationship might be between the numbers of servicetypes received and overall visit continuity. More visittypes could contribute to lower continuity if differentorganizations provide the different types of services.

Interpretation of these findings is dependent onthe adequacy of statistical controls for severity ofillness. One might expect persons who are more se-verely ill to have a greater attachment to one pro-vider, higher utilization of services, higher costs, andpotentially poorer outcomes than persons whose ill-ness is less severe. The proxies for severity incorpo-rated in the analysis included hospitalization in theprior year for a mental illness, mental and medicalcomorbidity, age, sex, disability status, and psychoticand depressive symptoms. Other variables, includingliving arrangements, marital status, family and socialcontacts, may further adjust for some of the disablingaspects of schizophrenia. Even so, it is uncertain howadequate these adjustments are in assuring fair statis-tical comparisons across levels of provider continuity.An additional limitation in the measures used in thisanalysis is that some are expected to change in re-sponse to treatment, including depressive and psy-chotic symptoms. However, due to the cross-sectionaldesign, these indicators of severity were measured atthe same time as the quality of life outcomes.

SUMMARY

This study found that provider continuity wasassociated with lower Medicaid costs among thosewith two or more mental health visits in the year.The attractiveness of these results in an era of man-aged care and cost controls is evident, and therefore,

caution is important due to the limitations of thestudy design.

A significant service delivery challenge is to ad-dress the inverted-U relationship between continuityof care/provider continuity and the cost of care. Per-sons with little or no continuity of care (one or lessmental health visits in the year) incurred low averagecosts, even though most providers would assert thatthere should have been more active clinical manage-ment of their mental illness. Among those with twoor more mental health visits, those with high providercontinuity had lower costs, while those with low pro-vider continuity incurred the highest costs and highesthospitalization rates. Targeting this small but high-cost group for clinical and case management inter-ventions may have benefits for improving quality ofcare and patient outcomes, as well as potentially con-taining costs of care by reducing hospitalization rates.Targeting the zero- to one-visit group may increasethe short-term costs for more mental health visitsand medications, with the potential of longer-termbenefits.

ACKNOWLEDGMENTS

The authors gratefully acknowledge fundingfrom Grant R01 MH49250 from the National Insti-tute of Mental Health (Drs. Steinwachs and Lehman,Principal Investigators), which supported data collec-tion and the overall study. This paper comes fromDr. Chien’s doctoral dissertation and his interest inprovider continuity and outcomes of care; the contri-butions of Faye E. Malitz, M.P.A., in the preparationof the dissertation are noted with thanks. This re-search would not have been possible without the sup-port of the Maryland Department of Health andMental Hygiene and, in particular, the Directors ofthe Maryland Medical Assistance Program. The de-sign and conduct of the NIMH study benefited fromthe input and dedication of a multidisciplinary re-search team including C. Alan Lyles, Sc.D., MaryStuart, Sc.D., Michael Fox, Sc.D., and Deanie Leo-nard, M.B.A. Interviews and fieldwork were per-formed under contract by the Battelle Centers forPublic Health Research and Evaluation.

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