Establishment, retention, and loss to follow-up in outpatient HIV care.

Background: For optimal clinical benefit, HIV-infected patients should receive periodic outpatient care indefinitely. However, initially establishing HIV care and subsequent retention in care are problematic. This study examines establishment, retention, and loss to follow-up (LTFU) in a large multi-site cohort over a 2-8 year period.

Deriving SF-12v2 physical and mental health summary scores: a comparison of different scoring algorithms.

Purpose: Summary scores for the SF-12, version 2 (SF-12v2) health status measure are based on scoring coefficients derived for version 1 of the SF-36, despite changes in item wording and response scales and despite the fact that SF-12 scales only contain a subset of SF-36 items. This study derives new summary scores based directly on SF-12v2 data from a recent U.S.

Associations between outpatient and inpatient service use among persons with HIV infection: a positive or negative relationship?

Objective: To examine the prospective association between frequency of outpatient visits and subsequent inpatient admissions.

Data Sources: Medical record data on 13,942 patients with HIV infection seen in 10 HIV speciality care sites across the United States.

Study Design: This observational study followed a cohort of HIV-infected patients who were in care in the first half of 2001.

Being uninsured in 1996 compared to 1987: how has the experience of the uninsured changed over time?

Objective: To explore trends in the nonelderly uninsured population between 1987 and 1996 and examine whether the broad disparities in medical care utilization and out-of -pocket spending between the privately insured and uninsured populations that existed in 1987 continued over the following decade.

Data Sources/study Design: Data are from the 1996 Medical Expenditure Panel Survey and the 1987 National Medical Expenditure Survey. We used survey data to create descriptive tables examining the characteristics of the uninsured population and the use of medical services, total and out-of -pocket expenditures, and the burden of out-of -pocket spending for the uninsured and the privately insured in 1987 and 1996.

Employer offers, private coverage, and the tax subsidy for health insurance: 1987 and 1996.

Economists have long been interested in the effect of tax-based subsidies on private health insurance coverage. We examine this relationship using pooled data from the 1987 National Medical Expenditure Survey and the 1996 Medical Expenditure Panel Survey. Our main tax price elasticity estimates for employer offers and for private coverage are near the mid-point of the existing literature.

Employer contribution methods and health insurance premiums: does managed competition work?

We derive a two-stage model in which health plans first compete to be selected by employers and subsequently compete to be chosen by employees. We identify the key determinants of competition and show that increasing competition at one stage often comes at the expense of competition at the other stage. Many economists and policymakers have argued that in order to increase competition among health plans, employers should offer multiple plans and structure premium contributions to make employees more price sensitive.

Recent trends in HIV-related inpatient admissions 1996-2000: a 7-state study.

Background And Objectives: HIV-related inpatient utilization declined immediately after the diffusion of highly active antiretroviral therapy (HAART), but some studies suggest that admission rates may have recently begun to increase. Using comprehensive hospital discharge data from 7 states, this study examines trends in HIV-related inpatient admissions and length of stay (LOS) from 1996 through 2000.

Methods: We identified HIV-related admissions by ICD-9-CM diagnosis codes in the range from 042 to 044.

Demographic variation in SF-12 scores: true differences or differential item functioning?

Background: Demographic differences have been reported in summary measures of physical and mental health based on the SF-12 instrument.

Objectives: This study examines the extent to which differential item functioning (DIF) contributes to observed subgroup differences in health status. DIF refers to situations in which the psychometric properties of items are not invariant across different groups.

Workers' decisions to take-up offered health insurance coverage: assessing the importance of out-of-pocket premium costs.

Background: Many proposed policy initiatives involve subsidies directed toward encouraging employers to offer coverage and toward workers to encourage enrollment in offered plans. Given that insurance coverage reflects employers' decisions to offer coverage, eligibility requirements for such coverage, and employees' take-up decisions, all three elements are important when considering mechanisms to decrease the number of uninsured individuals.

Research Design: In this study, we examine the relationship between workers' decisions to take-up offers of health insurance and annual out-of-pocket contributions, total premiums, and employer and workforce characteristics.

Has the increase in HMO enrollment within the Medicaid population changed the pattern of health service use and expenditures?

Objective: To describe changes in health services use and expenditures within the Medicaid population between 1987 and 1997 and to estimate the extent to which the increase in Health Maintenance Organization (HMO) enrollment has influenced these changes.

Subjects: Individuals under the age of 65 years in the 1987 National Medical Expenditure Survey and the 1997 Medical Expenditure Panel Survey enrolled in Medicaid the entire year.

Research Design: Using bivariate and multivariate techniques, we compared several measures of health services use and expenditures across three groups: (1) individuals enrolled in Medicaid for all of 1987; (2) individuals enrolled in Medicaid for all of 1997 but never enrolled in an HMO; and (3) individuals enrolled in Medicaid for all of 1997 and enrolled in an HMO for at least part of the year.

Health care expenditure burdens among elderly adults: 1987 and 1996.

Objectives: Concerns about the health care expenditure burdens of elderly adults underlie the ongoing debate over expanding Medicare benefits and strengthening Medicare+Choice. We examine burdens for this population using data from the 1987 National Medical Expenditure Survey (NMES) and the 1996 Medical Expenditure Panel Survey (MEPS).

Methods: We estimate how frequently elderly adults live in families whose health expenditures exceed 20% or 40% of their after-tax disposable incomes.

Design strategies and innovations in the medical expenditure panel survey.

Background: Recent efforts to provide an annual profile of the health care quality of the nation's health care delivery system and to identify health care disparities in the population's access to and use of health care services have served to stimulate design innovations and content enhancements to the Medical Expenditure Panel Survey (MEPS).

Objectives: To present a summary of the analytical objectives, design, and core content of the MEPS, and to provide an overview of the new and innovative design features that add capacity for health status and quality of care measurement and improve data quality.

Summary: The MEPS questionnaire has been expanded to include content taken from the Consumer Assessment of Health Plans Study (CAHPS) to facilitate assessments of patient experiences with health care at the national level.

SSI enrollees' health care in TennCare.

How well does TennCare, Tennessee's Medicaid managed care program, meet the needs of blind/disabled Supplemental Security Income (SSI) enrollees? People with disabilities have extensive health care needs and greater barriers to accessing care, so efforts to reduce service use may decrease their health and independence. On the other hand, managed care plans may better coordinate care. Computer-assisted telephone surveys of urban SSI and other urban TennCare enrollees were conducted to assess these issues.

Pathways to access: health insurance, the health care delivery system, and racial/ethnic disparities, 1996-1999.

We examine the roles that insurance coverage, the delivery system, and external factors play in explaining persistent disparities in access among racial and ethnic groups of all ages. Using data from the 1996-1999 Medical Expenditure Panel Surveys and regression-based decomposition methods, we find that our measures of health care system capacity explain little and that while insurance clearly matters, external factors are equally important. Employment, job characteristics, and marital status are key determinants of disparities in access to insurance but are difficult for health policy to affect directly.

Spending and service use among people with the fifteen most costly medical conditions, 1997.

This study addresses the Institute of Medicine's recommendation that AHRQ use MEPS data to identify a set of priority conditions to inform efforts at improving quality of care. Using MEPS data we identify the fifteen most expensive conditions in the U.S.

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.

Individual and contextual risks of death among race and ethnic groups in the United States.

An emerging area of social science research focuses on individual-level and contextual-level determinants of black-white adult mortality differentials in the United States. However, no research on adult mortality differentials has distinguished multiple Hispanic subgroups and explored the role of nativity at both the individual and contextual levels for small geographic areas. Using the 1986-1997 National Health Interview Survey-National Death Index linked file, we examine the effects of individual and contextual factors on black-white and multiple Hispanic subgroups (Mexican Americans, Puerto Ricans, and "other" Hispanic) differentials in adult mortality.

Risk selection among SSI enrollees in TennCare.

The issue of risk selection is especially important for states that enroll blind and disabled beneficiaries of Supplemental Security Income (SSI) in Medicaid managed care. SSI beneficiaries have persistent needs for care, have a wide variety of chronic conditions, and often need atypical and complex services. Risk selection occurs when the health care needs of beneficiaries enrolled in a specific plan differ systematically from the needs of the overall beneficiary population and payments do not reflect those needs.

Impact of differential item functioning on age and gender differences in functional disability.

Objectives: Estimates of group differences in functional disability may be biased if items exhibit differential item functioning (DIF). For a given item, DIF exists if persons in different groups do not have the same probability of responding, given their level of disability. This study examines the extent to which DIF affects estimates of age and gender group differences in disability severity among adults with some functional disability.

A guide to comparing health care expenditures in the 1996 MEPS to the 1987 NMES.

Substantial changes in the organization, delivery, and financing of health care over the last decade, combined with data collection and methodological improvements in the 1996 Medical Expenditure Panel Survey (MEPS), pose special challenges in comparing expenditure estimates in MEPS with those in the 1987 National Medical Expenditure Survey (NMES). The 1987 NMES used charges as its fundamental expenditure concept, whereas the 1996 MEPS used actual payments as its expenditure measure. In spite of these differences, researchers and policymakers will want to be able to analyze trends in health care expenditures using these two surveys.

The impacts of mental health parity and managed care in one large employer group.

We examine the impacts of a state mental health parity mandate on a large employer group, which simultaneously introduced a managed behavioral health care carve-out. Overall, we find that mental health/substance abuse (MH/SA) costs dropped 39 percent from the year prior to three years after parity, with managed care offsetting increases in demand induced by parity coverage. Managed care was most effective in reducing very high inpatient use among adolescents and children.

Mental health parity: what are the gaps in coverage?

BACKGROUND: Mental health benefits in private health insurance plans in the United States are typically less generous than benefits for physical health care services, driving reform efforts to achieve parity in coverage. While there is growing evidence about the effects such legislation would have on the utilization and cost of mental health services, less is known about the impact parity would have on reducing the risk of large out-of-pocket expenses that families would face in the event of mental illness. AIMS OF THE STUDY: We seek to understand the impact that mental health parity would have on the out-of-pocket burden that families would face in the event of mental illness.

Assessing state parity legislation*.

The temptation is great, but premature, to conclude from the Sturm study that parity mandates had no effect on access and insurance coverage for the mentally ill. The study lacks statistical power for those directly covered by the mandates, and it is unlikely adequate power exists for those only indirectly affected. The inclusion of the uninsured, Medicaid enrollees, and privately covered individuals not subject to the mandates, and the imprecise outcome measures, increase the likelihood that other factors dominate parity.

Trends and outcomes in the hospitalization of older Americans for cardiac conduction disorders or arrhythmias, 1991-1998.

Objective: To identify epidemiological trends and measure outcomes in elderly patients hospitalized for cardiac conduction disorders or arrhythmias.

Design: Review of the standard 5% samples of the Medicare Provider Analysis and Review Files to characterize 144,512 discharges from 1991 through 1998 in which the principal diagnosis was a conduction disorder or arrhythmia, using the corresponding Enrollment Databases for denominator data.

Setting: Short-stay hospitals in the United States.