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Biomedical subjects

A Leibowitz

Publications and source records attributed to A Leibowitz.

At least 19 recordsLinked to original sources
PubMed2000

Access of vulnerable groups to antiretroviral therapy among persons in care for HIV disease in the United States. HCSUS Consortium. HIV Cost and Services Utilization Study.

OBJECTIVE: To employ the behavioral model of health services use in examining the extent to which predisposing, enabling, and need factors explain the treatment of the HIV-positive population in the United States with highly active antiretroviral therapy (HAART). DATA SOURCE: A national probability sample of 2,776 adults under treatment for human immunodeficiency virus (HIV) infection. STUDY DESIGN: The article uses data from the baseline and six-month follow-up surveys. The key independent variables describe vulnerable population groups including women, drug users, ethnic minorities, and the less educated. The dependent variable is whether or not a respondent received HAART by December 1996. DATA COLLECTION: All interviews were conducted using computer-assisted personal interview instruments designed for this study. Ninety-two percent of the baseline interviews were conducted in person and the remainder over the telephone. PRINCIPAL FINDINGS: A multistage logit regression shows that the predisposing factors that have previously described vulnerable groups in the general population with limited access to medical care also define HIV-positive groups who are less likely to gain early access to HAART including women, injection drug users, African Americans, and the least educated (odds ratios, controlling for need, ranged from 0.35 to 0.59). CONCLUSIONS: Those HIV-positive persons with the greatest need (defined by a low CD4 count) are most likely to have early access to HAART, which suggests equitable access. However, some predisposing and enabling variables continue to be important as well, suggesting inequitable access, especially for African Americans and lower-income groups. Policymakers and clinicians need to be sensitized to the continued problems of African Americans and other vulnerable populations in gaining access to such potentially beneficial therapies. Higher income, anonymous test sites, and same-day appointments are important enabling resources.

Adult↗
PubMed1999

Variation in inpatient resource use in the treatment of HIV: do the privately insured receive more care?

OBJECTIVE: To estimate the impact of insurance status on inpatient resource use after adjusting for health upon admission and site of care. DESIGN: Detailed patient information linked to billing records from the AIDS Cost and Service Utilization Survey (ACSUS), a longitudinal analysis of inpatient and outpatient care between March 1991 and August 1992. SETTING: Hospitalizations of human immunodeficiency virus (HIV) patients from 10 US cities with high incidence of AIDS. PATIENTS: One thousand, nine hundred and forty nine adolescents and adults at various stages of HIV. MAIN OUTCOME MEASURES: We estimate inpatient charges, payments and length of stay as a function of patient, and provider and reimbursement characteristics for more than 1,500 hospitalizations to HIV patients. We control for patient characteristics and underlying risk factors including disease stage, CD4 percentage, mode of transmission, discharge status, type of admission, and region. We use hospital-fixed effects to control for unmeasured differences across facilities. RESULTS: Unadjusted means indicate that uninsured patients or patients covered by public insurance have significantly lower charges and payments than privately insured patients with similar medical conditions. We find that those differences are substantially reduced after controlling for the hospital in which care is received. Further, we find little evidence that "underinsured" patients are discharged sooner on average. CONCLUSIONS: Inpatient resource use is affected by both the hospital in which care is received and the type of patient admitted. Failure to control for unmeasured differences across hospitals is likely to overstate the impact of insurance substantially.

Adolescent↗
PubMed1999

Job continuity among new mothers.

In the early 1990s, both state and federal governments enacted maternity-leave legislation. The key provision of that legislation is that after a leave of a limited duration, the recent mother is guaranteed the right to return to her preleave employer at the same or equivalent position. Using data from the National Longitudinal Survey of Youth, we correlate work status after childbirth with work status before pregnancy to estimate the prevalence, before the legislation, of returns to the preleave employer. Among women working full-time before the pregnancy, return to the prepregnancy employer was quite common. Sixty percent of women who worked full-time before the birth of a child continued to work for the same employer after the child was born. Furthermore, the labor market behavior of most of the remaining 40% suggests that maternity-leave legislation is unlikely to have a major effect on job continuity. Compared with all demographically similar women, however, new mothers have an excess probability of leaving their jobs.

Adult↗
PubMed1998

The policy implications of better structure and process on birth outcomes in Jamaica.

BACKGROUND: We investigated if better structural and process elements of prenatal care relate to higher birth weights in the Jamaican population. METHODS: We used data from two surveys: (1) a national sample of randomly selected households; and (2) a concurrent facility survey of the public health clinics in Jamaica. In the household survey, all women aged 14-50, who had a pregnancy lasting 7 months during the previous 5 years (n = 913) were interviewed. From the household survey, we gathered information on the maternal, clinical and socioeconomic risk factors and on the newborns birth weight (the outcome measure). The facility survey collected data from all public primary care clinics in the country (n = 366). This gave us information on the quality of care (structure and process measures) provided in the clinics. FINDINGS: Prenatal care in Jamaica, while generally available, provides care to many women who are at particular risk because of parity, age and poverty. Structural measures of the facilities show that clinics are in general disrepair, have only 70% of the basic equipment and are insufficiently stocked with supplies or medication. Many facilities had poor process of care, as measured by assessing the clinical examination and counseling. The average birth weight was 3232 g and 9.8% weighed < 2500 g. The relationships between birth weight and the quality of care were estimated using multiple regression. The biologic and socioeconomic risk factors related to birth weight in the expected direction. None of the structural quality measures were statistically significant. Among the process measures, women who had access to a more complete examination, had infants that weighed an average of 128 g more at birth. INTERPRETATION: Better quality of care, provided by a more thorough clinical evaluation, has a more powerful effect on birth weight in the population than upgraded facilities or equipment. In developed or developing countries, where resources are limited, policy should focus on education and training to improve birth outcomes.

Adolescent↗
PubMed1997

Effects of the stable prostacyclin analogue iloprost on mesenteric blood flow in porcine endotoxic shock.

OBJECTIVE: To determine the effects of the stable prostacyclin analog, iloprost, in a porcine model of endotoxin-induced mesenteric ischemia. DESIGN: Prospective, experimental, randomized, controlled study. SETTING: Animal research laboratory at a university medical center. INTERVENTIONS: Pigs were randomized to receive a constant infusion of iloprost (0.18 microg/kg/min) or an equivalent amount of carrier solution (normal saline) 30 mins before being infused with endotoxin (100 microg/kg over 1 hr). The infusion with iloprost or carrier solution was continued for the duration of the experiment. MEASUREMENTS AND MAIN RESULTS: Twelve pigs (six per group), weighing between 20 and 22 kg, underwent laparotomy during which a magnetic flowprobe was placed around the superior mesenteric artery and an ileal tonometer was inserted. Thirty minutes before they were infused with endotoxin, the animals were randomized to receive intravenous iloprost or normal saline. Endotoxin was infused centrally over a 60-min period. Animals received normal saline at a rate of 1.2 mL/kg/min which was begun at the start of the endotoxin infusion. Data were measured at the end of the endotoxin infusion (E60) and 1 hr later (E120). Mean arterial pressure was not affected by the dosage of iloprost used in this experiment. After resuscitation, the cardiac output returned to baseline in the iloprost-treated group but remained decreased in the control group (2.6 +/- 0.5 vs. 1.6 +/- 0.4 L/min). Superior mesenteric blood flow increased 34% above baseline levels in animals pretreated with iloprost (from 363 +/- 85 to 485 +/- 81 mL/min). The superior mesenteric PCO2 was significantly higher (53 +/- 9 vs. 40 +/- 5 torr; 7.1 +/- 1.2 vs. 5.3 +/- 0.7 kPa) and the ileal intramucosal pH was significantly lower (7.07 +/- .28 vs. 7.44 +/- .23) in the control group than in the iloprost-treated group. CONCLUSIONS: Pretreatment with intravenous iloprost effectively increased intestinal blood flow in this model of endotoxin-induced mesenteric ischemia. This action of the drug resulted in an attenuation of ileal intracellular acidosis. Since low-dose iloprost had no effect on mean arterial pressure, it may be a useful adjunct in the treatment of sepsis and septic shock.

Acidosis↗
PubMed1997

Redistributional consequences of community rating.

OBJECTIVE: To predict the geographical effects of community rating of health insurance premiums on the amount individuals pay for insurance. DATA SOURCES: We estimate premiums and health expenditures for a 5 percent sample of Californians from the 1990 U.S. Census (the Public Use Microdata Sample) and use data from Blue Cross of California to adjust for regional price differences in services. STUDY DESIGN: We use an episodic health simulation model to estimate health expenditures for 975,074 Californians. Because the simulations do not reflect expenditure differences due to price variation in cost of services, we adjust these data for relative price differences by county. This leaves us with a sample of Californians for whom we have estimated health expenditures. We then compute average expenditures within areas of different sizes (all California, two regions, within counties) to estimate community-rated premiums. We then compare these premiums with actual expenditures on a county-by-county basis. PRINCIPAL FINDINGS: With a single California-wide premium, rural residents pay premiums that exceed their use of care, while urban residents pay premiums that are less than their use of care. These transfers are substantial. Dividing California into regional risk pools at the county level still results in poorer communities providing substantial subsidies to their more wealthy counterparts. CONCLUSIONS: Mandated community rating of premiums in a heterogeneous state such as California results in large unintended transfers of wealth from poorer, rural communities to urban, wealthier communities. Allowing premiums to vary with the regional cost of medical care would eliminate some of the transfers without sacrificing the benefits of community rating. Subsidies to low-income families could also effectively mitigate this redistribution. UTILITY: This article points out some potentially regressive consequences of geographic community rating and suggests ways to mitigate them.

California↗
PubMed1996

Medicaid health maintenance organizations. Can they reduce program spending?

A randomized trial to evaluate the Florida site of the Program for Prepaid Managed Care showed that the plan, a staff model health maintenance organization, was successful in attracting Medicaid enrollees. The evaluation established that the health maintenance organization was able to limit members' utilization. The savings were in the form of lower likelihood of using care. The amount of services received, once care was initiated, was the same in both fee-for service Medicaid and health maintenance organizations. The authors detected no differences in inpatient use or costs. Additionally, they found evidence that the plan attracted sicker than average enrollees, so this reduced utilization translates into Medicaid program savings.

Adolescent↗
PubMed1996

Comparison of access and costs of Medicaid dental services in a hospital clinic and community practices.

OBJECTIVES: This paper reports the results of a three-year evaluation of access to dental care and its associated costs for Aid to Families with Dependent Children (AFDC) beneficiaries enrolled in a hospital-based health maintenance organization (HMO) or a fee-for-service (FFS) option. METHODS: Medicaid enrollees (n = 3, l655) having a year of eligibility were assigned to either the hospital HMO or FFS care, and their use of dental care and its costs compared. RESULTS: A higher percent of those beneficiaries enrolled in the FFS option used dental care than those in the HMO plan. FFS enrollees also had more annual visits per person than those in the randomly assigned HMO group. FFS dental patients treated in the hospital had the highest costs of any payment-provider combination studied. CONCLUSIONS: To understand the mix of utilization rates, visits, and costs, one must take into account the way in which the HMO hospital plan is reimbursed, the way in which the dental department is reimbursed, and the way in which the dental provider is reimbursed.

Adolescent↗
PubMed1996

Continuous fiberoptic arterial and venous blood gas monitoring in hemorrhagic shock.

STUDY OBJECTIVE: To compare the performance of continuous fiberoptic blood gas monitoring with standard, intermittent blood gas sampling in the measurement of arterial and central venous blood gases during marked hemodynamic changes. DESIGN: Prospective, consecutive, enrollment, experimental study. SETTING: Research laboratory at a university medical center. PARTICIPANTS: Seven anesthetized, mechanically ventilated pigs. INTERVENTIONS: Severe shock was induced by hemorrhage in pigs monitored by a pulmonary artery catheter, an arterial line, and two fiberoptic blood gas sensors: one intra-arterial, and the other inserted into the superior vena cava via right internal jugular vein cutdown. Fiberoptic blood gas monitor measurements were compared with standard intermittent blood gas sampling. MEASUREMENTS AND RESULTS: A total of 184 blood gas samples were compared in seven animals at baseline, during shock, and after resuscitation. The baseline mean (+/- 1 SD) cardiac output decreased from 4.0 +/- 0.9 to 1.2 +/- 0.6 L/min during shock and returned to baseline after retransfusion (3.9 +/- 1.3 L/min). The comparison of continuous fiberoptic blood gas monitoring with intermittent blood gas sampling showed a bias+/-precision of 0.035 +/- 0.047 for arterial pH, 0.021 +/- 0.031 for central venous pH, -4.09 +/- 2.96 mm Hg (-0.55 +/- 0.39 kPa) for arterial Pco2, -3.67 +/- 2.44 mm Hg (-0.49 +/- 0.3 3 kPa) for central venous Pco2, -5.79 +/- 9.64 mm Hg (-0.77 +/- 1.29 kPa) for arterial Po2, and -7.85 +/- 8.52 mm Hg (-1.05 +/- 1.14 kPa) for central venous Po2. CONCLUSIONS: Continuous fiberoptic blood gas monitoring agrees closely with standard intermittent blood gas sampling during severe hemodynamic shifts and has a comparable accuracy for both arterial and venous blood gas measurements. Changes in venous Pco2 have recently been shown to correlate with changes in global tissue perfusion (eg, changes in cardiac output). Such data, available immediately via continuous venous blood gas monitoring, may be useful for monitoring shock and the response to resuscitation.

Animals↗
PubMed1995

Assessing the quality of care for children. Prospects under health reform.

The failure to pass federal health reform legislation this year does not mean that the health care crisis has been solved. As we look forward to predictably more incremental efforts to reduce costs, increase access, and improve quality, key issues from the most recent round of deliberations will undoubtedly reemerge. In the last session of Congress, private and public policymakers sent a clear signal that the era of accountability had arrived. In the health reform bills that Congress considered last year, a range of "measurement" strategies were put forth as essential elements for achieving accountability in a reformed health care system. For example, routine monitoring of the quality of care delivered by health plans and health providers was viewed as necessary to balance the impact of policies to control the cost of health care. Each of the major bills that were introduced this past year--Gephardt/Mitchell (S 1757/HR 3600), Cooper/Grandy (HR 3222), Breaux/Durenburger (S 1579), Nickles (S 1743), Chafee/Thomas (S 1770/HR 3704), and Wellstone/McDermott (S 491/HR 1200)--and the mark-up bills that have emerged from Senate and House committees have placed considerable emphasis on evaluating changes in access to health care and quality of care. Although the bills addressed issues related to financing, coverage, and the structure of the delivery system quite differently, they demonstrated much more consensus with regard to quality monitoring.

Child↗
PubMed1995

Heritability and selection on body size in a natural population of Drosophila buzzatii.

An attempt was made to assess whether the phenotypic differences in body size (as measured by wing length) between wild-caught mating and single Drosophila buzzatii males could be attributed to genetic differences between the samples. Mating males were found to be larger and less variable than a random sample of the population. The progeny of the mating males (produced by crossing to a random female from a stock derived from the same population) were on average larger than those of the single males, but not significantly so (P = 0.063), and less phenotypically variable. This difference in variance between the samples suggests that there are indeed genetic differences between the paternal samples but tests for significant differences in the additive genetic component of variance proved inconclusive. For both samples it was found that while the ratio of additive genetic variation in the laboratory to phenotypic variation in the field yielded estimates of ĥs2(N) congruent to 10% the regression of offspring reared in the laboratory on parents from the wild was not significantly different from zero. In addition, it was found that the average development time of the progeny of the mating males is shorter than that of the random sample.

Analysis of Variance↗
PubMed1995

Explaining changes in married mothers' employment over time.

Employment of married mothers with preschool children rose dramatically between 1971 and 1990. Using CPS data, we find that about one-fifth of the increase in labor supply can be attributed to changes in mothers' demographic characteristics (age, education, and number of children). Changes in the earnings opportunities of new mothers and their husbands explain another one-fifth of the growth in employment. Over the two decades, infants up to three months old became less of a barrier to employment, while women's labor supply became more sensitive to their own earnings opportunities and less sensitive to those of their husbands.

Adult↗
PubMed1994

Adiposis dolorosa (Dercum's disease): 10-year follow-up.

Adiposis dolorosa is a disease characterized by painful, subcutaneous fatty tumors. This disorder usually occurs in obese, postmenopausal women and is associated with weakness and mental disturbances such as depression, confusion, lethargy, and dementia. The cause is unknown, and there is no specific treatment. Pain may be relieved by steroids, intravenous lidocaine, or analgesics. Surgical treatment consists of excision or liposuction of the painful masses. We present two cases of adiposis dolorosa in men, with a follow-up of more than 10 years.

Adiposis Dolorosa↗
PubMed1994

Rationing or rationalizing children's medical care: comparison of a Medicaid HMO with fee-for-service care.

OBJECTIVES: This paper examines how medical care obtained by children enrolled in a Medicaid health maintenance organization (HMO) differs from that obtained by similar children who receive care from fee-for-service Medicaid providers. METHODS: In a randomized trial, some Medicaid households were assigned to remain in a traditional fee-for-service arrangement and others were randomly selected to join a Medicaid prepaid plan (an HMO). Participating households recorded data on children's health status and use of medical care. RESULTS: The prepaid plan members and the fee-for-service recipients received equivalent numbers of checkup visits, but the children in the prepaid plan made significantly fewer acute care visits. This plan appeared to target its services to children with the greatest health care needs. However, the content of health visits in the two systems did not differ, nor did prepaid and fee-for-service enrollees use the emergency room differently. CONCLUSIONS: It is possible to design a Medicaid HMO that achieves financial savings without reducing services to the most vulnerable patients. However, these findings alone do not provide a basis for widespread policy change in the direction of Medicaid HMOs. Further research is needed to establish whether the children treated in the HMO differed in health outcomes from those treated by fee-for-service care.

Child↗
PubMed1992

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.

Ambulatory Care↗
PubMed1992

HMOs for Medicaid: the road to financial independence is often poorly paved.

During the 1980s both the federal government and the private sector articulated policies to encourage the development and participation of health maintenance organizations (HMOs) in the Medicaid program. However, the policies, intended to save costs, limited the ability of new HMOs to achieve financial independence. New plans that emphasize Medicaid participation have few, if any, options on benefit design or in setting capitation rates. Relative to fee-for-service Medicaid programs, their costs to provide services may be quite high, as they have neither the buying power not the ability to impose discounts. As a consequence, plans must focus their financial planning efforts on targeting and attaining a stable enrollment base and on controlling the amount of services provided, tasks that are difficult for all HMOs. Achieving a stable enrollment base is particularly hard because Medicaid eligibles have few incentives to enroll and once enrolled often lose their Medicaid eligibility. Traditional HMOs control the amount of services provided through physician selection, financial incentives on physicians, and monitoring and utilization review. Lack of information and the difficulty inherent in attracting sufficient provider participation limit the first two strategies, so new plans often adopt organization structures that rely heavily on monitoring activities. Unfortunately, management information systems for HMOs are often the weakest link. We discuss the tasks and present data on financial planning, on putting financial plans into operation, and on monitoring progress toward financial independence for a set of ten demonstration projects sponsored by the Robert Wood Johnson Foundation.

Cost Control↗