Comparing mortality and time until death for medicare HMO and FFS beneficiaries

OBJECTIVE: To compare adjusted mortality rates of TEFRA-risk HMO enrollees and disenrollees with rates of beneficiaries enrolled in the Medicare fee-for-service sector (FFS), and to compare the time until death for decedents in these three groups. DATA SOURCE: Data are from the 124 counties with the largest TEFRA-risk HMO enrollment using 1993-1994 Medicare Denominator files for beneficiaries enrolled in the FFS and TEFRA-risk HMO sectors. STUDY DESIGN: A retrospective study that tracks the mortality rates and time until death of a random sample of 1,240,120 Medicare beneficiaries in the FFS sector and 1,526,502 enrollees in HMOs between April 1, 1993 and April 1, 1994. A total of 58,201 beneficiaries switched from an HMO to the FFS sector and were analyzed separately. PRINCIPAL FINDINGS: HMO enrollees have lower relative odds of mortality than a comparable group of FFS beneficiaries. Conversely, HMO disenrollees have higher relative odds of mortality than comparable FFS beneficiaries. Among decedents in the three groups, HMO enrollees lived longer than FFS beneficiaries, who in turn lived longer than HMO disenrollees. CONCLUSIONS: Medicare TEFRA-risk HMO enrollees appear to be, on average, healthier than beneficiaries enrolled in the FFS sector, who appear to be in turn healthier than HMO disenrollees. These health status differences persist, even after controlling for beneficiary demographics and county-level variables that might confound the relationship between mortality and the insurance sector.     

Medigap premiums and Medicare HMO enrollment

OBJECTIVE: Markets for Medicare HMOs (health maintenance organizations) and supplemental Medicare coverage are often treated separately in existing literature. Yet because managed care plans and Medigap plans both cover services not covered by basic Medicare, these markets are clearly interrelated. We examine the extent to which Medigap premiums affect the likelihood of the elderly joining managed care plans. DATA SOURCES: The analysis is based on a sample of Medicare beneficiaries drawn from the 1996-1997 Community Tracking Study (CTS) Household Survey by the Center for Studying Health System Change. Respondents span 56 different CTS sites from 30 different states. Measures of premiums for privately-purchased Medigap policies were collected from a survey of large insurers serving this market. Data for individual, market, and HMO characteristics were collected from the CTS, InterStudy, and HCFA (Health Care Financing Administration). STUDY DESIGN: Our analysis uses a reduced-form logit model to estimate the probability of Medicare HMO participation as a function of Medigap premiums controlling for other market- and individual-level characteristics. The logit coefficients were then used to simulate changes in Medicare participation in response to changes in Medigap premiums. PRINCIPAL FINDINGS: We found that Medigap premiums vary considerably among the geographic markets included in our sample. Measures of premiums from different insurers and for different types of Medigap policies were generally highly correlated across markets. Our models consistently indicate a strong positive relationship between Medigap premiums and HMO participation. This result is robust across several specifications. Simulations suggest that a one standard deviation increase in Medigap premiums would increase HMO participation by more than 8 percentage points. CONCLUSIONS: This research provides strong evidence that Medigap premiums have a significant effect on seniors' participation in Medicare HMOs. Policy initiatives aimed at lowering Medigap premiums will likely discourage enrollment in Medicare HMOs, holding other factors constant. Although the Medigap premiums are just one factor affecting the future penetration rate of Medicare HMOs, they are an important driver of HMO enrollment and should be considered carefully when creating policy related to seniors' supplemental coverage. Similarly, our results imply that reforms to the Medicare HMO market would influence the demand for Medigap policies.     

Designing health insurance information for the Medicare beneficiary: a policy synthesis.

Can Medicare beneficiaries make rational and informed decisions about their coverage under the Medicare program? Recent policy developments in the Medicare program have been based on the theory of competition in medical care. One of the key assumptions of the competitive model is the free flow of adequate information, enabling the consumer to make an informed choice from among the various sellers of a particular product. Options for Medicare beneficiaries in supplementing their basic Medicare coverage include the purchase of private supplementary insurance policies or enrollment in a Medicare HMO. These consumers, in a complex health insurance market, have only limited information available to them because many health plans do not make adequate comparable product information available. Moreover, since the introduction of the Medicare HMO option, the long-range plan for management of the Medicare budget has become based on the large-scale voluntary enrollment of beneficiaries into capitated health plans. The policy instrument that has been used to improve beneficiary decisions on how to supplement Medicare coverage is the informational or educational program. This synthesis presents findings regarding the relative effectiveness of different types of health insurance information programs for the Medicare beneficiary in an effort to promote practical use of the most effective types of information.     

Issues regarding health plan payments under Medicare and recommendations for reform.

The failures of the market for current Medicare health plans include poor information and price distortions and can be attributed to government policy. Reforms that could improve its structure are annual open enrollment periods, premium rebates from health management organizations (HMOs) to members, and termination of the federal government's subsidy of Medicare supplementary insurance. However, the price for a basic Medicare benefits package would still be distorted because Medicare bases its contribution on the cost of a comparable package in the fee-for-service (FFS) sector rather than on the cost of the most efficient plan available to beneficiaries in each market area. The present Medicare HMO program almost certainly increases total Medicare costs and actually discourages HMO growth by shielding beneficiaries from the true price difference between basic benefits in the HMO and FFS sectors. Lacking payment reforms, the Medicare HMO program should be terminated.     

Enrollee health status under Medicare risk contracts: an analysis of mortality rates.

Previous studies comparing the health status of Medicare beneficiaries enrolled under HMO risk contracts to that of Medicare beneficiaries in fee-for-service (FFS) have generally focused on demonstration projects conducted before 1985. This study examines mortality rates in 1987 for approximately 1 million aged Medicare beneficiaries enrolled in 108 HMOs. We estimated adjusted mortality ratios (AMR) for each HMO and across all HMOs, by dividing the actual number of deaths among HMO enrollees by the "expected" number of deaths. The expected number of deaths was based on death rates among local FFS populations, adjusting for age, sex, Medicaid buy-in status, and institutional status. The AMR for all HMO enrollees pooled together was 0.80. For persons newly enrolled in 1987, the AMR was 0.69; in general, AMRs were higher for beneficiaries who had been enrolled for longer periods of time. Among individual HMOs, none exhibited an AMR substantially above 1.00. Regression analysis indicated lower AMRs for staff model HMOs than for either IPA or group models. Low mortality among Medicare HMO enrollees is consistent with favorable selection or with improvements in the health status of enrollees due to better access or quality of care in HMOs. In either case, health status differences between HMO enrollees and FFS beneficiaries have implications for the appropriateness of Medicare's Adjusted Average Per Capita Cost (AAPCC) payment formula for HMOs.     

Do health maintenance organizations work for Medicare?

Since 1985, the Health Care Financing Administration (HCFA) has encouraged health maintenance organizations (HMOs) to provide Medicare coverage to enrolled beneficiaries for fixed prepaid premiums. Our evaluation shows that the risk program achieves some of its goals while not fulfilling others. We find that HMOs provide care of comparable quality to that delivered by free-for-service (FFS) providers using fewer health care resources. Enrollees experience substantially reduced out-of-pocket costs and greater coverage. However, because the capitation system does not account for the better health of those who enroll, the program does not save money for Medicare.     

How the elderly fare in HMOs: outcomes from the Medicare competition demonstrations.

Because of concern about the effects of prepaid care on outcomes for elderly enrollees in health maintenance organizations (HMOs), a prospective study of access to care and functional outcomes was performed. HMOs with Medicare risk contracts in January 1985 (N = 17) were selected from ten communities and were matched for comparison with ten similar communities where no Medicare HMOs were in operation. Random samples of HMO enrollees (N = 2,098) and fee-for-service (FFS) nonenrollees (N = 1,059) were assessed at baseline and at follow-up one year later (HMO = 1,873, FFS = 916) to observe access to care and functional outcomes. At baseline, nonenrollees had more bed days and poorer functional status than HMO enrollees. While fewer HMO enrollees experienced declines in functional status between baseline and follow-up (e.g., patient's ability to function declined in one or more activities of daily living: HMOs at 5.3 percent versus FFS at 8.5 percent, p < .01), after controlling for other factors with logistic regression, enrollment status was not significantly associated with functional decline. Self-rated health, history of hospitalization, age of 80 or older and baseline functional status were predictive of decline in function. After controlling for baseline differences, HMO disenrollees also experienced similar functional declines at follow-up compared to continuously enrolled beneficiaries. These findings suggest that Medicare beneficiaries who belong to HMOs experience comparable rates of functional decline to those experienced by beneficiaries in the FFS sector with similar initial levels of function and health status. Together with results showing no significant difference in medical visits according to various symptoms, we conclude that access and quality of care delivered by HMOs is comparable to that provided in FFS settings.     

Service-level selection by HMOs in Medicare

In the federal Medicare program, contracting health maintenance organizations (HMOs) are paid on a capitated basis. There has long been concern that an "adverse selection" of risks remain in the traditional fee-for-service (FFS) sector, since beneficiaries with low costs may leave the FFS sector and join the HMOs. The distortion associated with this form of selection is that health plans may design their mix of health care services in order to effectuate favorable selection. This paper scrutinizes patterns of HMO membership and costs by service in the FFS sector for evidence consistent with the hypothesis that HMOs engage in service-level product distortion. We develop a multi-service model of choice between FFS and HMOs and show that if the HMO sector is underproviding (overproviding) a service relative to the FFS sector, we should observe a positive (negative) correlation between the HMO market share and average costs of those remaining in the FFS sector. We estimate the correlation between the HMO market share and the average FFS costs for different health care services using Medicare data for 1996. We find evidence indicating that there exists significant service-level selection by HMOs.     

The effect of HMOs on the inpatient utilization of medicare beneficiaries

OBJECTIVE: To determine the effect of joining HMOs (health maintenance organizations) on the inpatient utilization of Medicare beneficiaries. DATA SOURCES: We linked enrollment data on Medicare beneficiaries to patient discharge data from the California Office of Statewide Health Planning and Development (OSHPD) for 1991-1995. DESIGN AND SAMPLE: A quasi-experimental design comparing inpatient utilization before and after switching from fee-for-service (FFS) to Medicare HMOs; with comparison groups of continuous FFS and HMO beneficiaries to adjust for aging and secular trends. The sample consisted of 124,111 Medicare beneficiaries who switched from FFS to HMOs in 1992 and 1993, and random samples of 108,966 continuous FFS beneficiaries and 18,276 continuous HMO enrollees yielding 1,227,105 person-year observations over five years. MAIN OUTCOMES MEASURE: Total inpatient days per thousand per year. PRINCIPAL FINDINGS: When beneficiaries joined a group/staff HMO, their total days per year were 18 percent lower (95 percent confidence interval, 15-22 percent) than if the beneficiaries had remained in FFS. Total days per year were reduced less for beneficiaries joining an IPA (independent practice association) HMO (11 percent; 95 percent confidence interval, 4-19 percent). Medicare group/staff and IPA-model HMO enrollees had roughly 60 percent of the inpatient days per thousand beneficiaries in 1995 as did FFS beneficiaries (976 and 928 versus 1,679 days per thousand, respectively). In the group/staff model HMOs, our analysis suggests that managed care practices accounted for 214 days of this difference, and the remaining 489 days (70 percent) were due to favorable selection. In IPA HMOs, managed care practices appear to account for only 115 days, with 636 days (85 percent) due to selection. CONCLUSIONS: Through the mid-nineties, Medicare HMOs in California were able to reduce inpatient utilization beyond that attributable to the high level of favorable selection, but the reduction varied by type of HMO.     

Selection experiences in Medicare HMOs: pre-enrollment expenditures

Using 1993 and 1994 data, the authors examine whether beneficiaries who enroll in a Medicare health maintenance organization (HMO), including those enrolling for only a short period of time, have lower expenditures than continuous fee-for-service (FFS) beneficiaries the year prior to enrollment. We also test whether biased selection varies by the level of HMO market penetration and the rate of market-share growth. We find favorable selection associated with enrollment into Medicare HMOs, which declines as market share increases but does not disappear. Among short-term enrollees, we find unfavorable selection, however, selection bias was not sensitive to market characteristics.     

Patient selection in the ESRD managed care demonstration

The Centers for Medicare & Medicaid Service's (CMS') end stage renal disease (ESRD) managed care demonstration offered an opportunity to assess patient selection among a chronically ill and inherently costly population. Patient selection refers to the phenomenon whereby those Medicare beneficiaries who choose to enroll or stay in health maintenance organizations (HMOs) are, on average, younger, healthier, and less costly to treat than beneficiaries who remain in the traditional Medicare fee-for-service (FFS) sector. The results presented in this article show that enrollees into the demonstration were generally younger and healthier than a representative group of comparison patients from the same geographic areas.     

An Analysis of Unobserved Selection in an Inpatient Diagnostic Cost Group Model

The study assesses unobserved selection bias in an inpatient diagnostic cost group (DCG) model similar to Medicare's Principal Inpatient Diagnostic Cost Group (PIP-DCG) risk adjustment model using a unique data set that contains hospital discharge records for both FFS and HMO Medicare beneficiaries in California from 1994 to 1996. We use a simultaneous equations model that jointly estimates HMO enrollment and subsequent hospital use to test the existence of unobserved selection and estimate the true HMO effect. It is found that the inpatient DCG model does not adequately adjust for biased selection into Medicare HMOs. New HMO enrollees are healthier than FFS beneficiaries even after adjustment for the included PIP-DCG risk factors. A model developed over an FFS sample ignoring unobserved selection overestimates hospital use of new HMO enrollees by 28 percent compared to their use if they had remained in FFS. Models that better captures selection bias are needed to reduce overestimation of Medicare HMO enrollees' resource use.     

Use of preventive care services,beneficiary characteristics,and Medicare HMO performance

Medicare health maintenance organization (HMO) enrollees use more preventive care services than their fee-for-service (FFS) counterparts. This may be because those who enroll in HMOs have characteristics that make them more disposed to use preventive care. To investigate this possibility, we examined the use of four preventive care services by respondents to the 1996 Medicare Current Beneficiary Survey (MCBS). Unadjusted preventive care use rates for HMO enrollees were slightly higher than rates for non-HMO enrollees with private supplemental insurance. However, after adjusting for enrollee characteristics (sociodemographics, health behaviors, health status, and functioning) we found that preventive care use rates for HMO enrollees were substantially higher--consistent with HMO enrollees being less disposed to use preventive care. In comparing preventive care service rates across groups, managers and policymakers may want to consider taking into account beneficiary characteristics that are correlated with the disposition to use preventive care.     

Do determinants of medicare supplemental coverage choice vary by income

Using data from the Community Tracking Study Household Survey (1998-99), we estimate the relationship between Medigap premiums and senior Medicare beneficiaries' supplemental coverage decisions. All seniors are more likely to be enrolled in an HMO in markets with higher Medigap prices. Lower income seniors are particularly sensitive to Medigap premiums and are more likely to have no supplemental coverage when faced with higher Medigap premiums. As Medicare supplemental options evolve in response to the 2003 Medicare Modernization Act, it is important to consider that lower income beneficiaries may respond to price changes and other factors differently than their higher income counterparts.     

The effect of HMOs on premiums in employment-based health plans.

This study documents the effect of HMOs on premiums in employment-based health plans. We analyzed a survey of Minnesota employers conducted in 1986. Among 922 usable observations, 239 firms offered HMOs in addition to fee-for-service (FFS) health plans. We estimated an equation for the probability of offering an HMO, followed by equations for HMO enrollment share, and HMO and FFS premiums. The weighted average HMO and FFS premium in firms that offer HMOs was compared to the premium of FFS-only firms. We found that offering an HMO raises the average premium for family coverage health insurance by $25.14 per month and for single coverage by $3.68 per month. This effect was smaller for firms in the Twin Cities metropolitan area. HMOs may be viewed as a progressive and innovative health care benefit, but they are likely to increase firms' health insurance premiums.     

A comparison of inpatient severity, average length of stay, and cost for traditional fee-for-service medicare and medicare HMOs in Florida

This research compares the mean severity level, length of stay, and cost of Medicare health maintenance organization (HMO) and Medicare fee-for-service (FFS) inpatients. The results suggest Medicare HMOs have healthier inpatients and shorter lengths of stay, but more costly per-day utilization. These findings are contrary to the assumption that HMOs reduce daily utilization.     

Including hospice in Medicare capitation payments: would it save money?

Hospice services received by Medicare risk-based health maintenance organization (HMO) enrollees are paid on a non-capitated basis, creating financial incentives for HMOs to encourage their terminally ill patients to elect hospice. Using Medicare administrative records for 1998, we found that hospice enrollment in the last month of life was significantly higher among HMO enrollees than among beneficiaries in fee-for-service (FFS). However, low mortality rates among HMO enrollees produced similar population-based rates of hospice use in the HMO and FFS sectors. Simulations showed that including hospice care under capitation payments in July 1998 would have produced very small savings for Medicare.     

A comparison of satisfaction levels between traditional and managed care Medicare recipients

The Spokane County health department conducted a survey of randomly selected households in the county. The survey combined several previously validated instruments. Since the purpose of this study was to compare satisfaction levels and access and communication issues of Medicare recipients in Health Maintenance Organizations (HMOs) to Medicare recipients using the traditional fee-for-service (FFS), a subpopulation was used. The results of this study did not support the findings of previous studies; HMO members were older and had no differences in health status from traditional FFS members. HMO members were more educated, had higher incomes, and were more satisfied with their care than the FFS group. The authors suggest that these differences from previous studies may be due to the fact that the majority of HMO respondents are in not-for-profit HMOs which return a fairly high proportion of the insurance premium to the patients in the form of medical care. They also suggest that not-for-profit HMOs may be different than for-profits due to the lack of pressure to return profits to the stockholders.     

Medigap coverage and Medicare spending: a second look

Medicare supplemental insurance (Medigap) provides important financial protections for many low- and moderate-income beneficiaries in Medicare's traditional fee-for-service program. However, conventional wisdom among policymakers holds that Medigap coverage substantially raises Medicare claims costs. This report uses detailed diagnosis data provided by three large Medigap insurers, information from the Medicare Current Beneficiary Survey, and the Medicare 5 percent sample file to reexamine the impact of Medigap coverage on Medicare spending. We conclude that previous studies might have overestimated the impact of Medigap coverage on Medicare costs and that past projections of potential Medicare cost savings from restrictions on Medigap coverage probably are overstated.