Does the quality of care in Medicaid MCOs vary with the form of physician compensation?

A growing fraction of Medicaid participants are enrolled in managed care organizations (MCOs). MCOs contract with primary care physicians (PCPs) to provide health-care services to Medicaid enrollees. The PCPs are generally compensated either via fee-for-service (FFS) or via capitated arrangements. This paper investigates whether the quality of care that Medicaid enrollees receive varies with the means by which PCPs are compensated. Using data for all Medicaid MCO enrollees in a large state, we find that enrollees in MCOs that pay their PCPs exclusively via FFS arrangements are more likely to receive services for which the PCPs receive additional compensation. These enrollees also are less likely to receive services for which the PCPs do not receive additional compensation. These findings suggest that financial incentives may influence the behavior of PCPs in Medicaid MCOs, and thus the quality of the health care received by Medicaid participants enrolled in MCOs.     

Assessment of Quality of Care for Managed Care and Fee-For-Service Patients Based on Analysis of Avoidable Hospitalizations

As managed care has grown to dominate the US health care delivery system, questions have been raised about the impact on the quality of care provided to its enrollees. Two important aspects of health care quality are access to care and the appropriateness of care. This analysis evaluated the occurrence of preventable hospitalizations among managed care (MCO) versus fee for service (FFS) populations to compare access to and appropriateness of preventive, primary, and surgical health care services. Rates of preventable hospitalizations associated with ambulatory sensitive conditions (ASCs) were calculated based on all discharges from Massachusetts hospitals in 1995, and categorized by population characteristics including: age, sex, ethnicity, and insurance status. Multivariate logistic regression models were employed to explain the likelihood of having a preventable hospitalization. Rates of preventable hospitalizations for two of the conditions evaluated (perforated appendix and diabetes complications) were lower for MCO enrollees. For two additional indicators (immunization preventable pneumonia and low birth weight), MCO rates were no different from FFS rates. Results for pediatric asthma were inconclusive. For four out of five quality indicators evaluated, individuals in Massachusetts MCOs are doing better or no worse than their counterparts in FFS plans. Until population-based data on managed care enrollees becomes available, and until such data can be linked to utilization and health outcomes information, investigations into the quality of services provided by MCOs compared to FFS plans cannot be definitive.     

Plan characteristics and SSI enrollees' access to and quality of care in four TennCare MCOs

OBJECTIVE: To assess hypotheses about which managed care organization (MCO) characteristics affect access to care and quality of care--including access to specialists, providers' knowledge about disability, and coordination of care--for people with disabilities. DATA SOURCES/STUDY SETTING: Survey of blind/disabled Supplemental Security Income (SSI) enrollees in four MCOs serving TennCare, Tennessee's Medicaid managed care program, in Memphis, conducted from 1998 through spring 1999. STUDY DESIGN: We compared enrollee reports of access and quality across the four MCOs using regression methods, and we use case study methods to assess whether patterns both within and across MCOs are consistent with the hypotheses. DATA COLLECTION: We conducted computer-assisted telephone surveys and used regression analysis to compare access and quality controlling for enrollee characteristics. PRINCIPAL FINDINGS: Although the four MCOs' characteristics varied, access to providers, coordination of care, and access to some services were generally similar across MCOs. Enrollees in one plan, the only MCO with a larger provider network and that paid physicians on a fee-for-service basis, reported their providers were more knowledgeable, and they had more secondary preventive care visits. Differences found in access to specialists and delays in approving care appear to be unrelated to characteristics reported by the MCOs, but instead may be related to how tightly utilization is reviewed. CONCLUSIONS: Plan networks, financial incentives, utilization management methods, and state requirements are important areas for further study, and, in the meantime, ongoing monitoring of SSI enrollees in each MCO may be important for detecting problems and successes.     

Managed Care Organizational Characteristics and Health Care Use among Children with Special Health Care Needs

Objective. To examine the relationship between features of managed care organizations (MCOs) and health care use patterns by children.
Data Sources. Telephone survey data from 2,223 parents of children with special health care needs, MCO-administrator interview data, and health care claims data.
Study Design. Cross-sectional survey data from families about the number of consequences of their children's conditions and from MCO administrators about their plans' organizational features were used. Indices reflecting the MCO characteristics were developed using data reduction techniques. Hierarchical models were developed to examine the relationship between child sociodemographic and health characteristics and the MCO indices labeled: Pediatrician Focused (PF) Index, Specialist Focused (SF) Index, and Fee-for-Service (FFS) Index, and outpatient use rates and charges, inpatient admissions, emergency room (ER) visits, and specialty consultations.
Data Collection/Extraction Methods. The telephone and MCO-administrator survey data were linked to the enrollment and claims files.
Principal Findings. The child's age, gender, and condition consequences were consistent predictor variables related to health care use and charges. The PF Index was associated with decreased outpatient use rates and charges and decreased inpatient admissions. The SF Index was associated with increased ER visits and decreased specialty consultations, while the FFS Index was associated with increased outpatient use rates and charges.
Conclusion. After controlling for sociodemographic and health characteristics, the PF, SF, and FFS indices were significantly associated with children's health care use patterns.     

Variability in Asthma Care and Services for Low-Income Populations among Practice Sites in Managed Medicaid Systems

Objective. To characterize and describe variability in processes of asthma care and services tailored for low–income populations in practice sites participating in Medicaid managed care (MMC).
Study Setting. Eighty-five practice sites affiliated with five not-for-profit organizations participating in managed Medicaid (three group-model health maintenance organizations [HMOs] and two Medicaid managed care organizations [MCOs]).
Study Design/Data Collection. We conducted a mail survey of managed care practice site informants using a conceptual model that included chronic illness care and services targeting low-income populations. The survey asked how frequently a number of processes related to asthma care occurred at the practice sites (on a scale from "never" to "always"). We report mean and standard deviations of item scores and rankings relative to other items. We used within-MCO intraclass correlations to assess how consistent responses were among practice sites in the same MCO.
Principal Findings. Processes of care related to asthma varied greatly in how often practice sites reported doing them, with information systems and self-management support services ranking lowest. There was also significant variation in the availability of services targeting low-income populations, specifically relating to cultural diversity, communication, and enrollee empowerment. Very little of the site-to-site variation was attributable to the MCO.
Conclusions. Our conceptual framework provides a means of assessing the provision of chronic illness care for vulnerable populations. There is room for improvement in provision of chronic asthma care for children in managed Medicaid, particularly in the areas of self-management support and information systems. The lack of consistency within MCOs on many processes of care suggests that care may be driven more at the practice site level than the MCO level, which has implications for quality improvement efforts.     

Effects of Medicaid managed care programs on health services access and use

OBJECTIVE: To estimate the effects of Medicaid managed care (MMC) programs on Medicaid enrollees' access to and use of health care services at the national level. DATA SOURCES/STUDY SETTING: 1991-1995 National Health Interview Surveys (NHIS) and a 1998 Urban Institute survey on state Medicaid managed care programs. STUDY DESIGN: Using multivariate regression models, we estimated the effect of living in a county with an MMC program on several access and use measures for nonelderly women who receive Medicaid through AFDC and child Medicaid recipients. We focus on mandatory programs and estimate separate effects for primary care case management (PCCM) programs, health maintenance organization (HMO) programs, and mixed PCCM/HMO programs, relative to fee-for-service (FFS) Medicaid. We control for individual and county characteristics, and state and year effects. DATA COLLECTION/EXTRACTION METHOD: This study uses pooled individual-level data from up to five years of the NHIS (1991-1995), linked to information on Medicaid managed care characteristics at the county level from the 1998 MMC survey. PRINCIPAL FINDINGS: We find virtually no effects of mandatory PCCM programs. For women, mandatory HMO programs reduce some types of non-emergency room (ER) use, and increase reported unmet need for medical care. The PCCM/HMO programs increase access, but had no effects on use. For children, mandatory HMO programs reduce ER visits, and increase the use of specialists. The PCCM/HMO programs reduce ER visits, while increasing other types of use and access. CONCLUSIONS: Mandatory PCCM/HMO programs improved access and utilization relative to traditional FFS Medicaid, primarily for children. Mandatory HMO programs caused some access problems for women.     

Impact of Removing Medicaid Fee-for-Service Hepatitis C Virus (HCV) Treatment Restrictions on HCV Provider Experience with Medicaid Managed Care Organizations in New York City

Immediately after the approval of direct-acting antiviral medications for the treatment of hepatitis C virus (HCV) in 2013, state Medicaid programs limited access to these expensive treatments based on liver disease stage, absence of active alcohol or substance use, and prescriber limitations. New York State fee-for-service (FFS) Medicaid eliminated these requirements in May 2016, but the effect on providers and patients obtaining prior authorization (PA) from Medicaid managed care organizations (MCOs) was unknown. We used a mixed methods approach to assess whether the removal of HCV treatment restrictions was associated with changes in Medicaid MCOs’ PA approval processes and length of time to treatment initiation at two large urban New York City provider organizations participating in Project INSPIRE, an HCV care coordination demonstration project. At baseline, the top criteria for clinic care coordinators ranking MCOs as being “most difficult” were liver staging criteria, delayed treatment, and requiring a urine toxicology test. At follow-up, liver staging criteria were replaced by medication formulary limitations. Univariate analysis of the Project INSPIRE participant data suggests a decrease in the percentage of participants with insurance/PA-related treatment delays pre- versus post-policy change (23% versus 15%, p value = 0.02). Interrupted time series analysis found a 2 percentage point decrease (p value = 0.02) in the proportion of PAs each month with insurance-related treatment delays that was attributable to policy change. These results from two urban clinics indicate New York State FFS Medicaid’s policy change for HCV treatment may have been associated with some changes in Medicaid MCO PA decisions, but MCO PA denials and treatment delays were still observed “on the ground” by clinic staff.Electronic supplementary materialThe online version of this article (10.1007/s11524-020-00422-0) contains supplementary material, which is available to authorized users.     

Medicare Managed Care Spillovers and Treatment Intensity

Evidence suggests that the share of Medicare managed care enrollees in a region affects the costs of treating traditional fee‐for‐service (FFS) Medicare beneficiaries; however, little is known about the mechanisms through which these ‘spillover effects’ operate. This paper examines the relationship between Medicare managed care penetration and treatment intensity for FFS enrollees hospitalized with a primary diagnosis of AMI. I find that increased Medicare managed care penetration is associated with a reduction in both the costs and the treatment intensity of FFS AMI patients. Specifically, as Medicare managed care penetration increases, FFS AMI patients are less likely to receive surgical reperfusion and mechanical ventilation and to experience an overall reduction in the number of inpatient procedures. Copyright © 2015 John Wiley & Sons, Ltd.     

Satisfaction with health care of dually eligible older beneficiaries

Satisfaction with health care was compared for dually eligible older beneficiaries receiving care in three settings: a managed care organization (MCO) that is at risk for providing Medicare and Medicaid benefits (n = 200); the fee-for-service (FFS) sector in the same ZIP Code (n = 201); and respondents to the national Medicare Current Beneficiary Survey (MCBS) (n = 531). Patients in the MCO were more likely to be highly satisfied in three domains--global quality, access to care, and technical skills--compared with patients in the local and national FFS study groups but fewer were highly satisfied with the interpersonal manner of their providers.     

A randomized trial to evaluate the effectiveness of a Medicaid HMO

The value of health-care services used by AFDC Medicaid patients receiving care in a voluntary enrollment HMO is contrasted with that of health care services used by Medicaid patients receiving fee-for-service (FFS) care. The randomized assignment of Medicaid recipients to the HMO or to FFS allows the authors to conclude that the apparent lower use of HMO enrollees results from the HMO's selection of patients with lower needs for care rather than from technical efficiency. Patients had lower use while in the HMO, but disenrollees and those who refused enrollment had significantly higher use than FFS participants. In contrast to the effect of HMOs on non-Medicaid populations, the Medicaid HMO studied provided significantly fewer outpatient services, but the same level of inpatient services as the FFS sector. Overall, voluntary enrollment of Medicaid eligibles into the HMO resulted in higher state expenditures for Medicaid because of favorable selection.     

Managed care and preventable hospitalization among Medicaid adults

OBJECTIVE: The study examines the association between managed care enrollment and preventable hospitalization patterns of adult Medicaid enrollees hospitalized in four states. DATA SOURCES/STUDY SETTING: Hospital discharge data from the Healthcare Cost and Utilization Project (HCUP) database of the Agency for Healthcare Research and Quality (AHRQ) for New York (NY), Pennsylvania (PA), Wisconsin (WI), and Tennessee (TN) residents in the age group 20-64 hospitalized in those states, linked to the Area Resource File (ARF) and American Hospital Association (AHA) survey files for 1997. STUDY DESIGN: The study uses separate logistic models for each state comparing preventable admissions with marker admissions (urgent, insensitive to primary care). The model controls for socioeconomic and demographic variables, and severity of illness. PRINCIPAL FINDINGS: Consistently in different states, private health maintenance organization (HMO) enrollment was associated with fewer preventable admissions than marker admissions, compared to private fee-for-service (FFS). However, Medicaid managed care enrollment was not associated with a reduction in preventable admissions, compared to Medicaid FFS. CONCLUSIONS: Our analysis suggests that the preventable hospitalization pattern for private HMO enrollees differs significantly from that for commercial FFS enrollees. However, little difference is found between Medicaid HMO enrollees and Medicaid FFS patients. The findings did not vary by the level of Medicaid managed care penetration in the study states.     

The impact of Medicaid managed care on hospitalizations for ambulatory care sensitive conditions

OBJECTIVE: To determine whether Medicaid managed care is associated with lower hospitalization rates for ambulatory care sensitive conditions than Medicaid fee-for-service. We also explored whether there was a differential effect of Medicaid managed care by patient's race or ethnicity on the hospitalization rates for ambulatory care sensitive conditions. DATA SOURCES/STUDY SETTING: Electronic hospital discharge abstracts for all California temporary assistance to needy families (TANF)-eligible Medicaid beneficiaries less than age 65 who were admitted to acute care hospitals in California between 1994 and 1999. STUDY DESIGN: We performed a cross-sectional comparison of average monthly rates of admission for ambulatory care-sensitive conditions among TANF-eligible Medicaid beneficiaries in fee-for-service, voluntary managed care, and mandatory managed care. DATA COLLECTION/EXTRACTION METHODS: We calculated monthly rates of ambulatory care-sensitive condition admission rates by counting admissions for specified conditions in hospital discharge files and dividing the monthly count of admissions by the size of the at-risk population derived from a separate monthly Medicaid eligibility file. We used multivariate Poisson regression to model monthly hospital admission rates for ambulatory care-sensitive conditions as a function of the Medicaid delivery model controlling for admission month, admission year, patient age, sex, race/ethnicity, and county of residence. PRINCIPAL FINDINGS: The adjusted average monthly hospitalization rate for ambulatory care-sensitive conditions per 10,000 was 9.36 in fee-for-service, 6.40 in mandatory managed care, and 5.25 in voluntary managed care (p<.0001 for all pairwise comparisons). The difference in hospitalization rates for ambulatory care sensitive conditions in Medicaid fee-for-service versus managed care was significantly larger for patients from minority groups than for whites. CONCLUSIONS: Selection bias in voluntary Medicaid managed care programs exaggerates the differences between managed care and fee-for-service, but the 33 percent lower rate of hospitalizations for ambulatory care sensitive conditions found in mandatory managed care compared with fee-for-service suggests that Medicaid managed care is associated with a large reduction in hospital utilization, which likely reflects health benefits. The greater effect of Medicaid managed care for minority compared with white beneficiaries is consistent with other findings that suggest that managed care is associated with improvements in access to ambulatory care for those patients who have traditionally faced the greatest barriers to health care.     

Access and use of health services by chronically mentally ill Medicaid beneficiaries

This article has two objectives: to quantify the access and utilization of services received by chronically mentally ill Medicaid recipients, and to compare service utilization and access under prepayment and fee-for-service (FFS) payment. The study setting is Hennepin County (Minneapolis), Minnesota, where 35 percent of Medicaid recipients were randomly assigned to receive services from prepaid plans. An algorithm was developed to identify recipients with chronic mental illness, resulting in 739 study participants, split approximately evenly between prepayment and FFS Medicaid. Data were collected through in-person surveys at baseline, and after 1 year. We found slight improvements in the majority of access measures studied and no significant decreases in the use of inpatient or outpatient services for enrollees in prepaid health plans. The results support efforts to expand the use of prepaid health plans to meet the needs of non-institutionalized chronically mentally ill Medicaid beneficiaries.     

Medicaid Managed Care and Health Care for Children

Objective. Many states expanded their Medicaid managed care programs during the 1990s, causing concern about impacts on health care for affected populations. We investigate the relationship between Medicaid managed care enrollment and health care for children.
Data Sources and Measures. Repeated cross-sections of Medicaid-covered children under 18 years of age from the 1996/1997 and 1998/1999 Community Tracking Study Household Surveys ( n =2,602) matched to state-year CMS Medicaid managed care enrollment data. For each individual, we constructed measures of health care utilization (provider and emergency department visits, hospitalizations, surgeries); health care access (usual source of care, unmet medical needs, put-off needed care); and satisfaction (satisfaction overall, with doctor choice, and with last visit).
Study Design. Regression analysis of the relationship between within-state changes in Medicaid managed care enrollment rates and changes in mean utilization, access, and satisfaction measures for children covered by Medicaid, controlling for a range of potentially confounding factors.
Principal Findings. Increases in Medicaid health maintenance organization (HMO) enrollment are associated with less emergency room use, more outpatient visits, fewer hospitalizations, higher rates of reporting having put off care, and lower satisfaction with the most recent visit. Medicaid primary care case management (PCCM) plans are associated with increases in outpatient visits, but also with higher rates of reporting unmet medical needs, putting off care, and having no usual source of care.
Conclusions. Both Medicaid HMO and PCCM plans can have important impacts on health care utilization, access, and satisfaction. Some impacts may be positive (e.g., less ED use and more outpatient provider use), although concern about increasing challenges in access to care and satisfaction is also warranted.     

Medicaid managed care in New York City: recent performance and coming challenges

OBJECTIVES: This study evaluated New York City's voluntary Medicaid managed care program in terms of health care use and access. METHODS: A survey of adults in Medicaid managed care and fee-for-service programs during 1996-1997 was analyzed. RESULTS: Responses showed significant favorable risk selection into managed care but little difference in use of health care services. Although some measures of access favored managed care, many others showed no difference between the study groups. CONCLUSIONS: The early impact of mandatory enrollment will probably include an increase in the average risk of managed care enrollees with little change in beneficiary use and access to care.     

The Effect of Capitation on Switching Primary Care Physicians

Objective.  To examine the relationship between patient case-mix, utilization, primary care physician (PCP) payment method, and the probability that patients switch their PCPs.
Data Sources/Study Setting.  Administrative enrollment and claims/encounter data for 1994–1995 from four physician organizations.
Study Design.  We developed a conceptual model of patient switching behavior, which we used to guide the specification of multivariate logistic analyses focusing on interactions between patient case-mix, utilization, and PCP reimbursement methods.
Data Collection/Extraction Methods.  Claims data were aggregated to the encounter level; a switch was defined as a change in PCP since the previous encounter. The PCPs were reimbursed on either a capitated or fee-for-service (FFS) basis.
Principal Findings.  Patients with stable chronic conditions (Ambulatory Diagnostic Groups [ADG] 10) and capitated PCPs were 36 percent more likely to switch PCPs than similar patients with FFS PCPs, controlling for patient age and sex and physician fixed effects. When the number of previous encounters was included in the model, this relationship was no longer significant. Instead high utilizers with capitated PCPs were significantly more likely to switch PCPs than were similar patients with FFS PCPs.
Conclusions.  A patient's demographics and utilization are associated with the probability that the patient will switch PCPs. Capitated PCP payment was associated with higher rates of switching among high utilizers of health care resources. These findings raise concerns about the continuity and quality of care experienced by vulnerable patients in an era of changing financial incentives.     

Medicaid prenatal care: a comparison of use and outcomes in fee-for-service and managed care.

BACKGROUND. To control rising costs, state Medicaid agencies are enrolling recipients in managed care health plans (MCPs). We performed this study to assess this policy's impact on accessibility and outcomes of Medicaid-funded prenatal care. METHODS. We performed a retrospective, controlled study with three cohorts: a study group of 1106 Medicaid recipients enrolled in three MCPs, a matched comparison group of 4830 recipients receiving care in the fee-for-service (FFS) system, and a second matched comparison group of 4434 non-Medicaid enrollees of the same MCPs. Data on prenatal care use and birth outcomes were obtained through linkage of claims and discharge files with birth certificate files. RESULTS. Medicaid recipients enrolled in MCPs used prenatal care similarly to those in the FFS system and showed equal or modestly improved birth-weight distributions. However, Medicaid MCP enrollees showed poorer use of prenatal care and birth outcomes compared with non-Medicaid enrollees of the same plans. CONCLUSIONS. Enrollment in MCPs has a neutral or small beneficial effect on the prenatal care received by the Medicaid population. However, providing financial access and modifying the system of care for this population did not result in parity with the general population.     

Increased Children's Access to Fluoride Varnish Treatment by Involving Medical Care Providers: Effect of a Medicaid Policy Change

Background. In 2004, the State of Wisconsin introduced a change to their Medicaid Policy allowing medical care providers to be reimbursed for fluoride varnish treatment provided to Medicaid enrolled children.
Objective. To determine the extent by which a state-level policy change impacted access to fluoride varnish treatment (FVT) for Medicaid enrolled children.
Data Source. The Electronic Data Systems of Medicaid Evaluation and Decision Support database for Wisconsin from 2002 to 2006.
Study Design. We analyzed Wisconsin Medicaid claims for FVT for children between the ages of 1 and 6 years, comparing rates in the prepolicy period (2002–2003) to the period (2004–2006) following the policy change.
Principal Findings. Medicaid claims for FVT in 2002–2003 totaled 3,631. Following the policy change, claims for FVT increased to 28,303, with 38.0 percent submitted by medical care providers. FVT rates increased for children of both sexes and all ages, rising from 1.4 per 1,000 person-years of enrollment in 2002–2003 to 6.6 per 1,000 person-years in 2004–2006. Overall, 48.6 percent of the increase in FVT was attributable to medical care providers. The largest increase was seen in children 1–2 years of age, among whom medical care providers were responsible for 83.5 percent of the increase.
Conclusions. A state-level Medicaid policy change was followed by both a significant involvement of medical care providers and an overall increase in FVT. Children between the ages of 1 and 2 years appear to benefit the most from the involvement of medical care providers.     

Children's health services in a "system of care": patterns of mental health, primary and specialty use

OBJECTIVES: This study was designed to investigate demonstrable impacts of the Mental Health Services Program for Youth (MHSPY), a highly coordinated, intentionally integrated "system of care," on patterns of health service utilization for youth with multiple needs. METHODS: The MHSPY intervention is available to a target population of urban youth who face barriers to health care and are at risk for out-of-home placement. These youth are enrolled in a non-profit managed care organization (MCO). Patterns of medical, pharmacy, and mental health and substance abuse service use were compared for children aged 3 to 19 across insurance categories. RESULTS: Despite risks for access and engagement barriers to care, and for greater medical expense due to greater morbidity, MHSPY enrollees received significantly more ambulatory care per person-year than either the privately insured population or the Medicaid Standard population, and medical expense for MHSPY members was significantly lower than expected. During the four years studied, individuals in the privately insured and Medicaid Standard populations were less likely than MHSPY enrollees to have had an ambulatory pediatric visit (odds ratio [OR] 0.833, 95% confidence interval [CI] 0.765, 0.908 and OR 0.823, 95% CI 0.775, 0.897, respectively). Medical expenses per member per month for MHSPY enrollees were significantly less than that for the similarly impaired Medicaid Disabled population with any medical claim (p < 0.001) or with any outpatient mental health claim (p < 0.01). CONCLUSIONS: Patterns of health care for subpopulations with known risk are important to identify to evaluate system-of-care effectiveness. The service utilization patterns for youth enrolled in the MHSYP system of care vs. those for similar MCO youth suggest health care access for individuals can be affected by delivery system design variables.     

The Impact of Private Insurance Coverage on Veterans' Use of VA Care: Insurance and Selection Effects

Objective. To examine private insurance coverage and its impact on use of Veterans Health Administration (VA) care among VA enrollees without Medicare coverage.
Data Sources. The 1999 National Health Survey of Veteran Enrollees merged with VA administrative data, with other information drawn from American Hospital Association data and the Area Resource File.
Study Design. We modeled VA enrollees' decision of having private insurance coverage and its impact on use of VA care controlling for sociodemographic information, patients' health status, VA priority status and access to VA and non-VA alternatives. We estimated the true impact of insurance on the use of VA care by teasing out potential selection bias. Bias came from two sources: a security selection effect (sicker enrollees purchase private insurance for extra security and use more VA and non-VA care) and a preference selection effect (VA enrollees who prefer non-VA care may purchase private insurance and use less VA care).
Principal Findings. VA enrollees with private insurance coverage were less likely to use VA care. Security selection dominated preference selection and naïve models that did not control for selection effects consistently underestimated the insurance effect.
Conclusions. Our results indicate that prior research, which has not controlled for insurance selection effects, may have underestimated the potential impact of any private insurance policy change, which may in turn affect VA enrollees' private insurance coverage and consequently their use of VA care. From the decline in private insurance coverage from 1999 to 2002, we projected an increase of 29,400 patients and 158 million dollars for VA health care services.