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Biomedical subjects

J A Nyman

Publications and source records attributed to J A Nyman.

At least 19 recordsLinked to original sources
PubMed2006

Potential for bone turnover markers to cost-effectively identify and select post-menopausal osteopenic women at high risk of fracture for bisphosphonate therapy.

INTRODUCTION AND HYPOTHESIS: Over half of all fractures among post-menopausal women occur in those who do not have osteoporosis by bone density criteria. Measurement of bone turnover may cost-effectively identify a subset of women with T-score >-2.5 for whom anti-resorptive drug therapy is cost-effective. METHODS: Using a Markov model, we estimated the cost per quality adjusted life year (QALY) for five years of oral bisphosphonate compared to no drug therapy for osteopenic post-menopausal women aged 60 to 80 years with a high (top quartile) or low (bottom 3 quartiles) level of a bone turnover marker. RESULTS: For women with high bone turnover, the cost per QALY gained with alendronate compared to no drug therapy among women aged 70 years with T-scores of -2.0 or -1.5 were $58,000 and $80,000 (U.S. 2004 dollars), respectively. If bisphosphonates therapy also reduced the risk of non-vertebral fractures by 20% among osteopenic women with high bone turnover, then the costs per QALY gained were $34,000 and $50,000 for women age 70 with high bone turnover and T-scores of -2.0 and -1.5, respectively. CONCLUSION: Measurement of bone turnover markers has the potential to identify a subset of post-menopausal women without osteoporosis by bone density criteria for whom bisphosphonate therapy to prevent fracture is cost-effective. The size of that subset highly depends on the assumed efficacy of bisphosphonates for fracture risk reduction among women with both a T-score >-2.5 and high bone turnover and the cost of bisphosphonate treatment.

Administration, Oral↗
PubMed2003

Toxicity to freshwater organisms from oils and oil spill chemical treatments in laboratory microcosms.

Toxicity and temporal changes in toxicity of freshwater-marsh-microcosms containing South Louisiana Crude (SLC) or diesel fuel and treated with a cleaner or dispersant, were investigated using Chironomus tentans, Daphnia pulex, and Oryzias latipes. Bioassays used microcosm water (for D. pulex and O. latipes) or soil slurry (for C. tentans) taken 1,7, 31, and 186 days after treatment. SLC was less toxic than diesel, chemical additives enhanced oil toxicity, the dispersant was more toxic than the cleaner, and toxicities were greatly reduced by day 186. Toxicities were higher in the bioassay with the benthic species than in those with the two water-column species. A separate experiment showed that C. tentans' sensitivity was intermediate to that of Tubifex tubifex and Hyallela azteca. Freshwater organisms, especially benthic invertebrates, thus appear seriously effected by oil under the worst-case-scenario of our microcosms. Moreover, the cleaner and dispersant tested were poor response options under those conditions.

Analysis of Variance↗
PubMed2001

The welfare economics of moral hazard.

Pauly's analysis of the welfare effects of moral hazard assumes that consumption of health care does not increase with income, however, empirical evidence suggests it does. For health insurance contracts that pay off by reducing price, the income effect is represented by the additional health care consumed because of income transfers from those who remain healthy to those who become ill. This implies a different decomposition of demand than the standard Hicksian decomposition. When the effect of income transfers is removed, the price-related welfare loss is smaller than either the loss suggested by Pauly's analysis or a Hicksian decomposition.

Health Expenditures↗
PubMed2000

The effects of oil spill and clean-up on dominant US Gulf coast marsh macrophytes: a review.

The objective of this review was to synthesize existing information regarding the effects of petroleum hydrocarbons on marsh macrophytes in a manner that will help guide research and improve spill-response efficiency. Petroleum hydrocarbons affect plants chemically and physically. Although plants sometime survive fouling by producing new leaves, even relatively non-toxic oils can stress or kill plants if oil physically prevents plant gas-exchange. Plant sensitivity to fouling varies among species and among populations within a species, age of the plant, and season of spill. Physical disturbance and compaction of vegetation and soil associated with clean-up activities following an oil spill appear to have detrimental effects on the US Gulf coast marshes. Other techniques, including the use of chemicals such as cleaners or bioremediation, may be necessary to address the problem. Clean-up may also be beneficial when timely removal prevents oil from migrating to more sensitive habitats.

Journal Article↗
PubMed1999

The value of health insurance: the access motive.

Why do people purchase health insurance? Many economists would answer that it permits purchasers to avoid risk of financial loss. This note suggests that health insurance is also demanded because it represents a mechanism for gaining access to health care that would otherwise be unaffordable. For example, although a US$300,000 procedure is unaffordable to a person with US$50,000 in net worth, access is possible through insurance because the annual premium is only a fraction of the procedure's cost. The value of insurance for coverage of unaffordable care is derived from the value of the medical care that insurance makes accessible.

Community Participation↗
PubMed1999

The economics of moral hazard revisited.

Pauly's (1968) [Pauly, M., 1968. The economics of moral hazard, Comment, American Economic Review 58, 531-537.] analysis of the welfare loss from insurance assumes that medical care consumption is not determined by income, but recent studies suggest it is. This study argues that (1) Pauly's analysis overstates the welfare loss because it includes the effect of income on consumption, (2) the relevant income effect is derived from income transfer from the healthy to the ill that occur when the probability of illness is less than 1, and (3) the welfare loss can be considered the transaction cost of insurance.

Health Expenditures↗
PubMed1999

Prophylactic coronary artery revascularization for elective vascular surgery: study design. Veterans Affairs Cooperative Study Group on Coronary Artery Revascularization Prophylaxis for Elective Vascular Surgery.

This article describes the design of an ongoing randomized trial intended to test whether patients who require elective vascular surgery would benefit from preoperative coronary artery revascularization prior to the vascular procedure. The primary objective is to determine whether coronary artery revascularization reduces long-term mortality (mean 3.5 years) in patients undergoing vascular surgery. The study design calls for 620 patients to be randomized and followed for a mean of 3.5 years following vascular surgery. Secondary endpoints include measures of quality of life and cost-effectiveness. Patients with coronary artery disease in need of an elective vascular operation are considered candidates for the study. Anatomic exclusion criteria include ejection fraction <20%, severe aortic stenosis (valve area <1.0 cm2), left main stenosis > or =50%, nonobstructive coronary artery disease (stenosis <70%), and coronary arteries that are not amenable to revascularization. Prior to the vascular surgery, the trial randomizes eligible patients to coronary artery revascularization (either bypass surgery or angioplasty) versus medical therapy. The trial stratifies the randomization by hospital and type of vascular surgery (intraabdominal versus infrainguinal) because of differences in long-term prognosis in those patients. A 1-year feasibility trial involving five Veterans Affairs (VA) medical centers of variable vascular surgical loads has been completed. The results showed that over 90% of expected patients could be randomized. As a result, a larger VA Cooperative Study involving 18 centers will begin recruitment of patients. The findings should help determine the best strategy for managing patients with coronary artery disease in need of elective vascular surgery.

Algorithms↗
PubMed1999

The costs of recurrent syncope of unknown origin in elderly patients.

Although syncope has been shown to reduce quality-of-life, its impact on resource costs has not been documented. The objective of this study was to quantify the annual medical costs of caring for elderly patients with syncope, especially recurrent syncope of unknown origin. Administrative data from the Health Care Financing Administration were obtained on 7,959 Medicare patients who had at least one inpatient admission with a diagnosis of syncope in 1993. The costs of any inpatient admissions, outpatient procedures, or physician visits with an ICD-CM-9 diagnosis for syncope were summed for a 365-day period from the date of the initial hospitalization for syncope. Patients who had at least two hospitalizations with admission and discharge diagnosis of syncope were deemed to have recurrent syncope of uncertain origin. To better estimate syncope costs for those whose syncope costs could have been attributed to other diagnoses, a regression analysis was performed including variables representing the most frequent secondary diagnoses. The average annual costs of those who were admitted with syncope but who were discharged with another diagnosis was $4,942 in 1993. The average annual cost of patients with recurrent syncope deemed to be of unknown origin was $5,165. For those patients with secondary diagnoses of atherosclerosis, urinary tract infections, or hypokalemia, the annual costs of syncope averaged $6,820, $7,013, or $7,949, respectively.

Age Factors↗
PubMed1998

Theory of health insurance.

The conventional explanation for purchasing insurance is to transfer risk. Psychologists, however, have shown that this explanation does not match actual behavior. They find that people generally prefer the risk of no loss at all to the certainty of a smaller actuarially equivalent loss, a situation exactly opposite to the one represented by the purchase of insurance. Nevertheless, people do purchase insurance, so there must be an explanation other than risk transfer for purchasing it. Of the explanations so far advanced, however, none have yet developed a wide acceptance. Regardless of risk issues, people will be more likely to purchase insurance when the premium is low compared to the value of the coverage to the consumer. Moral hazard raises the premium, as does adverse selection. The presence of either makes the purchase of insurance less likely. With health insurance, the tax subsidy can reduce the effective premium to less than the actuarially fair cost of insurance. This would increase the likelihood that health insurance is purchased. Finally, because of the value we place on our health, we desire access to a full range of health care. Health insurance is often the only affordable way of gaining access to this care, given the high costs of many of these procedures.

Actuarial Analysis↗
PubMed1998

Can specialists reduce costs? The case of referrals to orthopaedic surgeons.

This study investigates whether timely referral to specialists, in this case orthopaedic surgeons, potentially can reduce the costs of a health care episode. Five musculoskeletal diagnoses were chosen, and the diagnostic and treatment history of approximately 2500 persons with these five diagnoses was traced to determine when in the course of their treatment episode they were referred from nonorthopaedist to orthopaedist care and how much their episode of care cost. It was found that the average episodic costs for those who were referred earlier in the episode of care was lower than for those referred later. The implication is that there are likely to be numerous identifiable health conditions that should be flagged for early referral to specialists to reduce costs. It also questions the validity of the presumption that specialist care is necessarily more expensive.

Cost Savings↗
PubMed1997

Do specialists order too many tests? The case of allergists and pediatric asthma.

BACKGROUND: Is the practice style of specialists overly reliant on diagnostic tests? Health maintenance organization managers and other clinicians have been critical of the high cost practice styles of specialists, but if the specialists' practice style ultimately results in similar or lower total costs because of better outcomes in the treatment of exceptional cases, then such practice styles are cost-effective and should be encouraged. Indeed, if this is the case, not employing a test-intensive practice style could be considered negligent under a legal criterion. OBJECTIVE: We attempted to determine whether the care of pediatric asthmatic patients by allergists is characterized by more testing, but by better, less costly outcomes than care by non-allergists. METHODS: We used administrative data on pediatric asthmatic cases from a large health care plan from 1992 to determine whether patients treated by allergists received more tests, cost more, and had fewer asthmatic management breakdowns than patients treated by non-allergists. We used regression analysis to hold constant aspects of the patient's case mix. RESULTS: Although allergists ordered significantly more tests than non-allergists, their overall treatment costs were similar. Patients treated by allergists had fewer management breakdowns. CONCLUSIONS: These results suggest that the allergists' test-intensive practice style is cost-effective.

Allergy and Immunology↗
PubMed1997

The effect of certificate of need and moratoria policy on change in nursing home beds in the United States.

OBJECTIVES: This study examined the effects of state certificate of need and/or moratorium requirements on the change in nursing home bed growth in states over a 13-year period. METHODS: Data were collected from five telephone surveys of state officials about state certificate of need and moratorium policies, state Medicaid nursing home reimbursement rates, and the licensed nursing home beds in each state for the 1979 through 1993 period. Two-stage least squares regression analysis treated certificate of need and/or moratorium and Medicaid reimbursement rates as endogenous variables in predicting the change in nursing home beds per aged population in states. RESULTS: States that had a certificate of need and/or moratorium did have significant reductions in the growth in nursing home beds but Medicaid nursing home reimbursement rates were not related to change in bed stock. The percentage of the population living in a metropolitan area, the personal income per 1,000 population, the percent unemployed, a state's tax effort, and time were positively associated with change in nursing home beds. The ratio of nursing home beds per 1,000 aged population in the previous year was a negative predictor of change in bed stock in a given year. CONCLUSIONS: State regulatory policies have an effect on bed growth in contrast to reimbursement policies.

Certificate of Need↗
PubMed1997

The substitutability of adult foster care for nursing home care in Oregon.

OBJECTIVES: This study investigates the degree of substitutability of adult foster care for nursing home care in Oregon. METHODS: Using three tests, the authors determined (1) the extent to which an additional adult foster care resident in a county reduces the number of nursing home residents in that county, (2) which characteristics of residents and facilities are important in sorting residents into either nursing homes or adult foster care facilities, and (3) the price elasticity of demand for adult foster care, using the county as the unit of observation. RESULTS: It was found that for every additional foster care resident in a county, a nursing home loses 0.85 residents-almost a one-to-one substitution ratio. CONCLUSIONS: Despite the high degree of substitutability, residents perceive important differences in the characteristics of the two forms of care. Indeed, private residents are, on average, willing to pay twice as much for nursing home care as for adult foster care, suggesting that these differences are important. Finally, private consumers are sensitive to price differences among adult foster care facilities. The implications for policy are discussed.

Adult↗
PubMed1995

Does publishing the parameters that trigger review of Medicare claims change provider behavior? Results of the parameter release study.

In April 1989, the Health Care Financing Administration stopped publishing the parameters that trigger review of Medicare claims because they thought that knowledge of the parameters would permit providers to schedule visits to avoid review. In this article, the authors report the results of an experimental study where previously unrevealed parameters were revealed to some providers of Medicare services and not to others. The authors find little evidence to suggest that providers schedule procedures to avoid review when they know the parameters. There is some evidence, however, that providers may be responding to the release of the parameters in other ways.

Centers for Medicare and Medicaid Services, U.S.↗