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Biomedical subjects

B J O'Brien

Publications and source records attributed to B J O'Brien.

At least 37 records · Page 2Linked to original sources
PubMed2000

Will the use of low-molecular-weight heparin (enoxaparin) in patients with acute coronary syndrome save costs in Canada?

BACKGROUND: One-year follow-up data from the Efficacy and Safety of Subcutaneous Enoxaparin in Non-Q-Wave Coronary Events (ESSENCE) trial show that use of low-molecular-weight heparin (enoxaparin) compared with unfractionated heparin in patients hospitalized with unstable angina or non-Q-wave myocardial infarction is associated with a 10% reduction in the cumulative 1-year risk of death, myocardial infarction, or recurrent angina. Given the higher acquisition cost of enoxaparin relative to unfractionated heparin, we assessed whether the reduced use of revascularization procedures and related care makes enoxaparin a cost-saving therapy in Canada. METHODS AND RESULTS: We analyzed cumulative 1-year resource use data on the 1259 ESSENCE patients enrolled in Canadian centers (40% of the total ESSENCE sample). Patient-specific data on use of drugs, diagnostic cardiac catheterization, percutaneous transluminal coronary angioplasty, coronary artery bypass grafting, and hospital days were available from the initial hospital stay and cumulative to 1 year. Hospital resources were costed with the use of data from a teaching hospital in southern Ontario that is a participant in the Ontario Case Costing Project. During the initial hospital stay, use of enoxaparin was associated with reduced use of diagnostic catheterization and revascularization procedures, with the largest effect being reduced use of percutaneous transluminal coronary angioplasty (15.0% vs 10.6%; P =.03). At 1 year, the reduced risk and costs of revascularization more than offset increased drug costs for enoxaparin, producing a cost-saving per patient of $1485 (95% confidence interval $-93 to $3167; P =.06). Sensitivity analysis with lower hospital per diem costs from a community hospital in Ontario still predicts cost savings of $1075 per patient over a period of 1 year. CONCLUSIONS: The acquisition and administration cost of enoxaparin is higher than for unfractionated heparin ($101 vs $39), but in patients with acute coronary syndrome, the reduced need for hospitalization and revascularization over a period of 1 year more than offsets this initial difference in cost. Evidence from this Canadian substudy of ESSENCE supports the view that enoxaparin is less costly and more effective than unfractionated heparin in this indication.

Adult↗
PubMed2000

HLA-B*4012: a new allele with unique serological features.

We have defined the new allele HLA-B*4012, which had been isolated from a black individual. It was initially recognized as a serologically unique allele when typing her father for renal transplantation. The HLA class I phenotype was A*0201,*6602; B*4001,*4012; Bw6; Cw*0304,*1505. Sequencing from exon 1 through intron 3 of B*4012 was performed. B*4012 is identical to B*4001 and B*4010 in exon 3, and in the 3' part of exon 2, but it is unique in that exon 1 and the 5' part of exon 2 are identical to B*1503, B*1509, B*1510, B*1518, B*1523, and B*1529. The generation of this allele is best explained by a recombination event in exon 2 (break point between nucleotides 205 and 222 from the beginning of the coding region) of B*4001 or B*4010 with one of these B*15 variants as a donor allele. Its unique serological feature (B48, B60, B70, and B72 reactivity) is consistent with the sequence data of its donor alleles.

Alleles↗
PubMed2000

Tension pneumo-orbitus and pneumocephalus induced by a nasal oxygen cannula: report on two paediatric cases.

The present paper highlights the potential dangers of misplaced nasopharyngeal oxygen cannulae causing secondary pneumo-orbitus and pneumocephalus in two paediatric patients. While this complication is uncommon, early recognition allows prompt and appropriate intervention, with cessation of nasal oxygen, cannula removal, early investigation with computed tomography (CT) head/orbit scan and orbital or cranial decompression, if required. Early CT imaging identifies medial orbital or paranasal sinus fractures, the presence of sinusitis, associated intracranial air and assessment of the degree of orbital or intracranial tension. Antibiotics are not usually required for this type of clean injury unless pre-existing sinusitis is identified. In both cases, direct orbital decompression was performed with excellent results after identification of marked unilateral tense exophthalmos, delayed pupillary reactions to light and ophthalmopegia.

Catheterization↗
PubMed2000

Building uncertainty into cost-effectiveness rankings: portfolio risk-return tradeoffs and implications for decision rules.

BACKGROUND: Current principles of cost-effectiveness analysis emphasize the rank ordering of programs by expected economic return (eg, quality-adjusted life-years gained per dollar expended). This criterion ignores the variance associated with the cost-effectiveness of a program, yet variance is a common measure of risk when financial investment options are appraised. Variation in health care program return is likely to be a criterion of program selection for health care managers with fixed budgets and outcome performance targets. METHODS: Characterizing health care resource allocation as a risky investment problem, we show how concepts of portfolio analysis from financial economics can be adopted as a conceptual framework for presenting cost-effectiveness data from multiple programs as mean-variance data. RESULTS: Two specific propositions emerge: (1) the current convention of ranking programs by expected return is a special case of the portfolio selection problem in which the decision maker is assumed to be indifferent to risk, and (2) for risk-averse decision makers, the degree of joint risk or covariation in cost-effectiveness between programs will create incentives to diversify an investment portfolio. CONCLUSIONS: The conventional normative assumption of risk neutrality for social-level public investment decisions does not apply to a large number of health care resource allocation decisions in which health care managers seek to maximize returns subject to budget constraints and performance targets. Portfolio theory offers a useful framework for studying mean-variance tradeoffs in cost-effectiveness and offers some positive predictions (and explanations) of actual decision making in the health care sector.

Cost-Benefit Analysis↗
PubMed2000

Test and treat strategies for Helicobacter pylori in uninvestigated dyspepsia: a Canadian economic analysis.

BACKGROUND: Recognition of the pivotal role of Helicobacter pylori in the pathogenesis of peptic ulcer disease has revolutionized primary care approaches to dyspepsia. Decision analysis was used to compare the cost effectiveness of empirical ranitidine with a test and treat strategy using either H pylori serology or the 13carbon-urea breath test (13C-UBT). PATIENTS AND METHODS: A cohort of patients under age 50 years presenting with uninvestigated dyspepsia was evaluated. Three initial strategies were compared with respect to direct medical costs and effectiveness in curing H pylori-related ulcers - empirical ranitidine, H pylori serology and UBT. A one-year time horizon and third-party payer perspective were adopted in a Canadian health care setting. RESULTS: UBT was more costly than either serology or ranitidine but was the most effective strategy and required the fewest endoscopies. No strategy demonstrated dominance over another in the base case. The incremental cost effectiveness ratio (ICER) of serology versus ranitidine was $118/cure, and sensitivity analysis induced dominance of serology in several plausible scenarios. The baseline ICER of UBT versus serology was $885/cure but showed substantial variation in sensitivity analysis. Each ICER was highly sensitive to variation in the cost of the tests themselves. At a serology cost of $25, UBT became dominant when its cost fell to $39. CONCLUSIONS: In low risk patients with uninvestigated dyspepsia, testing for H pylori using serology appears to be economically attractive. 13C-UBT may be a cost effective alternative to serology if local conditions closely approximate the model parameters. Future changes in the costs of serology and 13C-UBT may determine the optimal approach.

Anti-Ulcer Agents↗
PubMed1999

Sample size and power issues in estimating incremental cost-effectiveness ratios from clinical trials data.

It is becoming increasingly more common for a randomized controlled trial of a new therapy to include a prospective economic evaluation. The advantage of such trial-based cost-effectiveness is that conventional principles of statistical inference can be used to quantify uncertainty in the estimate of the incremental cost-effectiveness ratio (ICER). Numerous articles in the recent literature have outlined and compared various approaches for determining confidence intervals for the ICER. In this paper we address the issue of power and sample size in trial-based cost-effectiveness analysis. Our approach is to determine the required sample size to ensure that the resulting confidence interval is narrow enough to distinguish between two regions in the cost-effectiveness plane: one in which the new therapy is considered to be cost-effective and one in which it is not. As a result, for a given sample size, the cost-effectiveness plane is divided into two regions, separated by an ellipse centred at the origin, such that the sample size is adequate only if the truth lies on or outside the ellipse.

Antineoplastic Agents↗
PubMed1999

Are health states "timeless"? The case of the standard gamble method.

The standard gamble method, as currently recommended for use in health care program evaluation, provides an individual's preference score or "utility weight" for living in a given health state for the rest of the individual's life. Many researchers interpret this value as a time-independent or "timeless" one and order health states on a scale of zero (death) to one (full health), regardless of the time spent in the health state. This article examines whether preference scores for a severe pain health state are "timeless," or in other words whether the utility independence assumption is satisfied. Our study results suggest that for the majority of respondents, the preference scores are not independent of time.

Aged↗
PubMed1999

Economic evaluation of donepezil for the treatment of Alzheimer's disease in Canada.

BACKGROUND: Donepezil is a new drug recently approved in the United States and Canada for the treatment of Alzheimer's disease (AD). We estimated the cost-effectiveness of donepezil 5 mg daily as an adjunct to usual care in the management of persons with mild-to-moderate AD defined as a Mini-Mental Health State Examination (MMSE) score in the range 10 to 26. METHODS: Treatment effect data as MMSE change-over-baseline scores were obtained from a 30-week placebo-controlled trial of donepezil. MMSE scores beyond observed trial data were estimated using a Markov model with 10 cycles of 24 weeks based on the placebo MMSE progression observed in the trial. Data from AD subjects in the Canadian Study of Health and Aging were used to estimate costs of nursing home care, community services, medications, and caregiver time as a function of MMSE score. A clinic-based cohort study from Alberta was used to estimate the distribution of AD patients by MMSE score presenting for treatment. The effectiveness measure for the economic model was expected time (over 5 years) spent with nonsevere AD (MMSE > or = 10). RESULTS: Over 5 years of treatment, donepezil is predicted to reduce health care costs by CA$929 per patient but increase caregiver time costs by CA$48 per patient for an overall cost saving to society of CA$882 per patient. Patients not receiving donepezil are predicted to spend 2.21 years of the 5 years in nonsevere AD compared with 2.41 years for treated patients (a gain of just over 2 months). Sensitivity analysis reveals that cost savings per patient increase if more AD patients are assumed to survive to 5 years; however, if donepezil treatment continues when patients' MMSE score falls below 10, the incremental cost is higher for treatment at CA$1554 per patient. CONCLUSION: Based on the limited available data, our model predicts that the use of donepezil for mild-to-moderate AD in Canada is associated with lower 5-year costs and less time spent with severe AD when compared with the alternative of usual care with no donepezil therapy. As more reliable long-term data become available, these predictions should be confirmed and/or updated.

Aged↗
PubMed1999

The valuation of productivity costs due to premature mortality: a comparison of the human-capital and friction-cost methods for schizophrenia.

OBJECTIVE: To compare productivity-cost estimates for schizophrenia-related premature mortality in Canada in 1996 using the human-capital (HC) approach and friction-cost (FC) method. METHODS: The number of deaths directly attributed to schizophrenia was combined with the estimated number of deaths attributable to schizophrenia from suicide. These premature deaths were valued using 2 methods: 1) the traditional HC approach, based on "potential" lost output to normal age of retirement, and 2) the FC method, based on finding a replacement worker. RESULTS: In 1996, there were 342 male and female preretirement deaths attributed to schizophrenia, directly or indirectly by suicide, in Canada. Most deaths were in males (78%) and by suicide (97%). The productivity cost of these deaths was estimated to be $105 million using the HC approach but only $1.53 million using the FC method. CONCLUSIONS: Productivity-cost estimates from the HC approach are substantially higher than those obtained from the FC method (69 times higher). In circumstances of unemployment, the HC approach is an overestimate of future productivity losses for premature mortality.

Adolescent↗
PubMed1999

The economic burden of schizophrenia in Canada.

OBJECTIVE: To estimate the financial burden of schizophrenia in Canada in 1996. METHOD: Using a prevalence-based approach, all direct health care costs, administrative costs of income assistance plans, and costs of incarceration attributable to schizophrenia were determined. Also included was the value of lost productivity associated with premature mortality and morbidity. In addition to using published papers and documents, direct contact was made with representatives from various provincial and federal programs for estimates of the direct health care and non-health care costs. RESULTS: The estimated number of persons with schizophrenia in Canada in 1996 was 221,000, with equal distribution between males and females. The direct health care and non-health care cost was estimated to be $1.12 billion in 1996. In addition, another $1.23 billion in lost productivity associated with morbidity and premature mortality was attributable to schizophrenia. CONCLUSIONS: The total financial burden of schizophrenia in Canada was estimated to be $2.35 billion in 1996. The largest category of cost was morbidity (52%), followed by acute care and psychiatric hospital admissions (14% and 10% respectively). Given the magnitude of these cost estimates, there are large potential cost savings with more effective management and control of this debilitating disease.

Adolescent↗
PubMed1998

Relation between severity of Alzheimer's disease and costs of caring.

BACKGROUND: Data from the Canadian Study of Health and Aging (CSHA) were used to examine the relation between severity of Alzheimer's disease, as measured by the Mini-Mental State Examination (MMSE), and costs of caring. METHODS: The CSHA was a community-based survey of the prevalence of dementia, including subtypes such as Alzheimer's disease, among elderly Canadians. Survey subjects with a diagnosis of possible or probable Alzheimer's disease were grouped into disease severity levels of mild (MMSE score 21-26), mild to moderate (MMSE score 15-20), moderate (MMSE score 10-14) and severe (MMSE score below 10). Components of care available from the CSHA were use of nursing home care, use of medications, use of community support services by caregivers and unpaid caregiver time. Costs were calculated from a societal perspective and are expressed in 1996 Canadian dollars. RESULTS: The annual societal cost of care per patient increased significantly with severity of Alzheimer's disease. The cost per patient was estimated to be $9451 for mild disease, $16,054 for mild to moderate disease, $25,724 for moderate disease and $36,794 for severe disease. Institutionalization was the largest component of cost, accounting for as much as 84% of the cost for people with severe disease. For subjects living in the community, unpaid caregiver time and use of community services were the greatest components of cost and increased with disease severity. INTERPRETATION: The societal cost of care of Alzheimer's disease increases drastically with increasing disease severity. Institutionalization is responsible for the largest cost component.

Alzheimer Disease↗
PubMed1998

Effect of altering the daily herbage allowance to cows in mid lactation on the composition, ripening and functionality of low-moisture, part-skim Mozzarella cheese.

Milk was collected from three spring-calving herds, on different daily herbage allowances (DHA) of perennial rye-grass (16, 20 or 24 kg dry matter (DM)/cow for a 17 week period. On five occasions, at weekly intervals in the middle of the period, the three different milks were converted into low-moisture part-skim Mozzarella cheese. Increasing the DHA resulted in significant increases in the concentrations of protein in the cheesemilk (P < 0.05) and cheese whey (P < 0.02). The moisture-adjusted cheese yield increased significantly (P < 0.01) on raising the DHA from 16 to 24 kg grass DM/cow. DHA had no significant effects on any of the gross compositional values of the cheese (although moisture and fat-in-DM levels tended to decrease and increase respectively with increasing DHA). The hardness of the uncooked cheese and functionality of cooked cheese (i.e. melt time, flowability, stretch and viscosity) were not significantly influenced by DHA over the 115 d ripening period at 4 degrees C.

Animals↗
PubMed1998

Assessing the value of a new pharmaceutical. A feasibility study of contingent valuation in managed care.

OBJECTIVES: The authors assessed the feasibility and construct validity of the contingent valuation method for measuring the monetary value to healthy enrollees in a health maintenance organization of a new drug, filgrastim, as prophylaxis against febrile neutropenia after chemotherapy treatment for cancer. METHODS: A random sample of 220 enrollees from a closed-panel staff-model health maintenance organization who did not have cancer were interviewed. Chemotherapy, febrile neutropenia and filgrastim were described by video and decision board. Questions were asked in two different scenarios: (1) User-based: Assuming they were at the point of consumption and about to receive chemotherapy, what is the maximum they would be willing to pay to receive filgrastim? and (2) Insurance-based: Given they were at risk of cancer in the future, what is the maximum they would be willing to pay in additional monthly insurance premiums to add filgrastim to the plan? In a second insurance scenario where respondents were told that filgrastim was covered, what is the minimum reduction in premium that persons were willing to accept to relinquish coverage of the drug? A 2 x 2 factorial design was used to contrast two bidding algorithms to test for starting point bias and two 5-yearly prior risks of cancer, 1/200 versus 1/100. Main effects were tested by ANCOVA controlling for age, sex, health, and income. RESULTS: Demographics of experimental cells were similar. No evidence was found of significant starting point bias. For user-based questions, as expected, willingness-to-pay increases with febrile neutropenia risk reduction, but at a declining marginal rate. Despite careful presentation of information to respondents, willingness-to-pay for insurance was higher in the lower prior risk group. Consistent with previous contingent valuation studies, the authors of the present study found evidence that willingness-to-accept exceeds willingness-to-pay for coverage of the same benefit. CONCLUSIONS: An insurance-based contingent valuation study is feasible in a health maintenance organization. Construct validation evidence was encouraging, with the exception of the test for prior risk of cancer; however, this was a between-person contrast and may have been confounded by other factors.

Adult↗