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Biomedical subjects

B O'Brien

Publications and source records attributed to B O'Brien.

At least 37 records · Page 2Linked to original sources
PubMed1999

Economic evaluation of outpatient treatment with low-molecular-weight heparin for proximal vein thrombosis.

BACKGROUND: The safety and efficacy of taking low-molecular-weight heparin at home was previously demonstrated in a clinical trial in which patients with acute proximal deep vein thrombosis were randomized to receive either intravenous standard heparin in the hospital or subcutaneous low-molecular-weight heparin administered primarily at home. Treatment in the home has the potential to substantially reduce the cost to the health care system. METHODS: To conduct an economic evaluation we prospectively collected data on resource use and health-related quality of life (Medical Outcomes Study Short-Form 36) on the 300 patients who formed the trial stratum presenting with proximal vein thrombosis as outpatients, of whom 151 received standard heparin and 149 received low-molecular-weight heparin. The primary viewpoint of the analysis was societal, and costs included health care costs, patient travel costs, and productivity costs as a result of time off work. Costs were assessed over a period of 3 months from randomization. Quality of life was assessed as the change in Short-Form 36 domain scores from baseline to day 7 for each treatment group. All costs are reported in 1997 Canadian dollars. RESULTS: There were 11 recurrent thromboembolic events and 1 bleed in the 151 patients who received standard heparin; the corresponding data for the 149 patients receiving low-molecular-weight heparin were 10 and 4, respectively. The mean cost per patient who received standard heparin was Can $5323 compared with Can $2278 for low-molecular-weight heparin, a total societal cost savings per patient using low-molecular-weight heparin of Can $3045 (95% confidence interval, Can $2012-$4050). There was no difference in quality of life between the 2 groups except for the domain of social functioning, where a greater improvement from baseline to day 7 was observed for the low-molecular-weight heparin group vs the standard heparin group (P =.005). CONCLUSIONS: For patients with acute proximal deep vein thrombosis, treatment at home with low-molecular-weight heparin is less costly than hospital-based treatment with standard heparin. The economic evidence in favor of outpatient treatment with low-molecular-weight heparin exhibits dominance; a situation of reduced cost is created with no compromise in clinical outcomes or patients' quality of life.

Adult↗
PubMed1999

Site-directed hydroxyl radical probing of 30S ribosomal subunits by using Fe(II) tethered to an interruption in the 16S rRNA chain.

Two in vitro transcripts, one corresponding to the 5' and central domains (residues 1-920) of 16S rRNA and the other corresponding to its 3' domain (residues 922-1542), assemble efficiently in trans with 30S ribosomal proteins to form a compact ribonucleoprotein particle that cosediments with natural 30S subunits. Isolated particles are similar in appearance to natural 30S subunits with electron microscopy and contain a full complement of the small subunit ribosomal proteins. The particles have a reduced ability to bind tRNA (attributable to the location of the discontinuity in a conserved region of the rRNA) near features that have been implicated in tRNA binding. Association of these two halves of 16S rRNA in trans must be stabilized by either previously unidentified RNA-RNA contacts or interactions mediated by ribosomal proteins because there are no known direct interactions between them. The trans construct was used to probe the three-dimensional RNA neighborhood around position 922 of 16S rRNA by generating hydroxyl radicals from Fe(II) tethered to the 5' end of the 3' transcript. Hydroxyl radical-induced cuts in the 16S rRNA chain were localized by primer extension to nucleotides 923-929 and 1192-1198, providing evidence for the mutual proximity of the 920 and 1192 regions.

Centrifugation, Density Gradient↗
PubMed1999

Salmonella tel-el-kebir and terrapins.

OBJECTIVES: An outbreak of Salmonella tel-el-kebir occurring over a 6-month period is described in this report. This is the first outbreak of S. tel-el-kebir in the reported literature. METHODS: S. tel-el-kebir was isolated from human faecal samples using conventional laboratory methods. RESULTS: Eight patients had S. tel-el-kebir isolated from faeces. All patients were owners of, or in close contact with, pet terrapins. The terrapins were purchased in the same pet shop, where they were imported from America. The epidemiological link with these pets was confirmed, as S. tel-el-kebir was isolated from cloacal swabs from the terrapins, and from terrapin water. Molecular biology studies using DNA amplification fingerprinting (DAF) gave identical fingerprint patterns for all human and terrapin isolates. CONCLUSIONS: Salmonellosis associated with exotic pets is a re-emerging disease in the 1990s, and measures to reduce this are discussed.

Adult↗
PubMed1999

The Ontario Prehospital Advanced Life Support (OPALS) study Part II: Rationale and methodology for trauma and respiratory distress patients. OPALS Study Group.

The Ontario Prehospital Advanced Life Support (OPALS) Study represents the largest prehospital study yet conducted, worldwide. This study will involve more than 25,000 cardiac arrest, trauma, and critically ill patients over an 8-year period (1994-2002). The current article, Part II, describes in detail the rationale and methodology for major trauma and respiratory distress patients and for an economic evaluation of Advanced Life Support (ALS) programs in the OPALS Study. The OPALS Study, using a rigorous controlled methodology and a large sample size, should clearly indicate the benefit in trauma and respiratory distress patient survival and morbidity that results from the widespread introduction of prehospital ALS programs to communities of many different sizes. [Stiell IG, Wells GA, Spaite DW, Nichol G, O'Brien B, Munkley DP, Field BJ, Lyver MB, Luinstra LG, Dagnone E, Campeau T, Ward R, Anderson S, for the OPALS Study Group: The Ontario Prehospital Advanced Life Support (OPALS) Study Part II: Rationale and methodology for trauma and respiratory distress patients.

Emergency Medical Services↗
PubMed1999

Effects of stocking density and concentrate supplementation of grazing dairy cows on milk production, composition and processing characteristics.

The effects on milk composition and processing characteristics of varying grass supply by changing stocking density and of offering a concentrate supplement were investigated. The experiment was conducted over 28 weeks of the lactation (April-October) using 48 spring-calved Friesian-Holstein cows. Three herds each of 16 cows were offered a restricted grass supply, a standard grass supply and a standard grass supply with a supplement of 3 kg concentrate/d. Treatment groups were grazed separately with a residence time of 3 d/paddock. Milk production, composition and processing characteristics such as renneting properties, ethanol stability and plasmin activity were measured weekly. Increasing stocking density above the standard system resulted in significant reductions in milk fat and protein yields, the concentrations of total protein, casein and whey proteins, and a deterioration in most processing characteristics. Imposing concentrate supplementation on the standard system increased total protein, casein and whey protein concentrations but generally did not improve processing characteristics except for ethanol stability. These results suggest that the standard grass supply in a rotational grazing paddock system can support efficient production of quality milk, and concentrate supplementation will not improve processing characteristics when an adequate supply of good quality herbage is available.

Animal Feed↗
PubMed1999

Severity of nausea and vomiting during pregnancy: what does it predict?

BACKGROUND: Relationships between the severity of nausea and vomiting during pregnancy and selected demographic (employment status, parity, age, smoking) and pregnancy outcome (birthweight, gender) variables are described. METHODS: Women who volunteered for a community-based clinical trial were eligible for inclusion in this study. On three occasions, 12 hours apart, during early pregnancy using a continuous measure of nausea, vomiting, and retching, women assessed the amount, duration, and severity of symptoms as they occurred. After the birth of their infants, they provided information about the duration of nausea, vomiting, and retching as well pregnancy outcome information by responding to a mailed questionnaire. Multivariate methods were used to analyze data. RESULTS: More severe vomiting in early pregnancy was likely to continue for a longer period of time and was related to decreased infant birthweight. Gestational age, parity status, and severity of vomiting were predictors of infant birthweight and together explained 22 percent of the variance in birthweight. A significant relationship between fetal gender and severity of nausea and vomiting was not found. CONCLUSIONS: It may be possible to identify women at risk for third trimester vomiting and to provide appropriate nutritional support and counseling so that their risk of having a low-birthweight infant is reduced. A larger sample would be required to assess the relationship between fetal gender and severity of nausea, vomiting, and retching.

Adult↗
PubMed1999

The relationship between method of pain management during labor and birth outcomes.

This study examined the relationship between method of pain management during labor and birth outcomes. A retrospective comparative chart review of 233 primiparous deliveries was conducted and group assignment was based on method of pain control (nonnarcotic, narcotic, or epidural). Epidural analgesia or anesthesia was associated with increased rates of instrumental and cesarean delivery. Augmentation of labor using a synthetic oxytocin was reported in more charts than expected, and the length of the second stage of labor was longer in those who received epidural analgesia or anesthesia. Apgar scores for those who received early epidural analgesia or anesthesia were lower than for those who received late or no epidural analgesia or anesthesia, although Apgar scores were satisfactory across all groups. Between-groups differences were unrelated to time of epidural placement or maternal temperature. Findings are relevant for maternal child nurses who serve as a resource for families wishing to make informed decisions about pain management in labor.

Adult↗
PubMed1999

Willingness to pay and the valuation of programmes for the prevention and control of influenza.

In this paper, we consider the role of willingness to pay (WTP) as a method for measuring the impact of healthcare programmes on population well-being. Alternative methods of outcome valuation, such as quality-adjusted life-years (QALYs), measure values through individuals' willingness to trade off a particular commodity, future life. Moreover, the method of valuation fails to incorporate several dimensions of benefit relevant to measuring well-being that are particularly important in programmes aimed at the prevention and control of influenza. In contrast, WTP provides a broad method of valuation based on individuals' willingness to trade off a much wider range of commodities. In addition, WTP incorporates externalities and uncertainty within individual valuations. We show that the main limitations of the WTP approach are not avoided by adoption of the QALY approach.

Attitude to Health↗
PubMed1999

Economic evaluation of long-term management strategies for erosive oesophagitis.

OBJECTIVE: To compare the expected costs and outcomes of alternative strategies for the management of patients with erosive oesophagitis. DESIGN: There were 3 components to the overall analytic approach. First, a decision model was constructed to compare expected costs and outcomes of 6 management strategies. Second, principles of quantitative literature review and meta-analysis were used to determine probabilities of clinical events (i.e. oesophagitis healing and recurrence). Finally, principles of cost-effectiveness analysis were used to compare treatment alternatives in terms of dominance and incremental cost effectiveness. The viewpoint for the study was that of a provincial government payer for healthcare over a 1-year period. MAIN OUTCOME MEASURES AND RESULTS: Healing rates were significantly higher for proton pump inhibitors (PPI) [p < 0.001]. Recurrence rates were significantly higher for intermittent therapy (placebo) and lower for regular dose PPI (p < 0.001). Maintenance prokinetic agent (PA) is dominated (i.e. more costly and less effective) and step-down maintenance PPI is dominated through principles of extended dominance. The 'efficient frontier' is represented by: maintenance H2-receptor antagonist (H2RA), intermittent PPI, step-down maintenance H2RA and maintenance PPI. CONCLUSIONS: The price of H2RA is a key factor influencing whether step-down maintenance PPI forms part of, or is contained within, the 'efficient frontier' of long term management for erosive oesophagitis.

Costs and Cost Analysis↗
PubMed1999

G-tube site care: a practical guide.

Effective care of your patient's gastrostomy site is key to her recovery--even after she's been discharged. Here we'll zero in on the prevention and treatment of skin problems and tube dislodgement, and review which anchoring device best suits your particular patient's needs.

Enteral Nutrition↗
PubMed1999

Venous thromboembolism prophylaxis after total hip or knee arthroplasty: a survey of Canadian orthopedic surgeons.

OBJECTIVE: To determine the pharmacologic and physical modalities used by orthopedic surgeons in Canada to prevent venous thromboembolism (deep venous thrombosis and pulmonary embolism) after total hip or knee arthroplasty. DESIGN: Mail survey sent to all members of the Canadian Orthopaedic Association. SETTING: A nation-wide study. METHODS: A total of 828 questionnaires, designed to identify the type and frequency of prophylaxis against venous thromboembolism that were used after hip and knee arthroplasty were mailed to orthopedic surgeons. OUTCOME MEASURES: Demographic data and the frequency and type of thromboprophylaxis. RESULTS: Of the 828 surveys mailed 445 (54%) were returned, and 397 were included in this analysis. Of the respondents, 97% used prophylaxis routinely for patients who undergo total hip or knee arthroplasty. Three of the 397 (0.8%) did not use any method ofprophylaxis. Warfarin was the most common agent used (46%), followed by low-molecular-weight heparin (LMWH) (36%). Combination therapy with both mechanical and pharmacologic methods were used in 39% of patients. Objective screening tests were not frequently performed before discharge. Extended prophylaxis beyond the duration of hospitalization was used by 36% of physicians. CONCLUSION: Prophylaxis for venous thromboembolism with warfarin or LMWH has become standard care after total hip or knee arthroplasty in Canada.

Anticoagulants↗
PubMed1998

Health care contingent valuation studies: a review and classification of the literature.

PURPOSE: The contingent valuation method (CVM) is a survey-based approach for eliciting consumer's monetary valuations for programme benefits for use in cost-benefit analysis (CBA). We used the conceptual framework of O'Brien and Gafni (1996) to classify and critically appraise health care CVM studies. METHODS: Search of computerized health care and economic citation databases (e.g. MEDLINE, ECONLIT) and manual search for papers published between 1984 1996 reporting primary data valuing health programme benefits in monetary units by CVM using willingness-to-pay (WTP) or accept (WTA). We classified studies using both empirical (i.e. who was surveyed and how) and conceptual criteria (i.e. which measure of consumer utility was measured and why). RESULTS: 48 CVM studies were retrieved; the majority (42) undertook money valuation in the context of cost benefit analysis (CBA), with the remainder being pricing/demand studies. Among the 42 CBA studies, the consumer utility being measured (i.e. compensating (CV) vs. equivalent variation (EV) was explicitly stated in only three (7%) studies). WTP was measured in 95% of studies and WTA in 5%. By cross-tabulation, 42 (91%) studies were designed as WTP/CV, two (4%) were WTP/EV, two (4%) were WTA/CV and no studies used WTA/EV. Most studies were administered by mail (52%) with 38% being in-person interviews. Value elicitation techniques included open-ended questions (38%), payment cards (19%) discrete choice questions (26%) or bidding games (29%). Some form of construct validation tests, particularly associations between WTP and income, were done in 21 studies (50%). CONCLUSIONS: (i) The number of health care CVM studies is growing rapidly and the majority are done in the context of CBA; (ii) there is wide variation among health care CVM studies in terms of the types of questions being posed and the elicitation formats being used; (iii) classification and appraisal of the literature is difficult because reporting of methods and their relationship with the conceptual framework of CBA is poor; (iii) the applicability to health care of the CVM guidelines issued by the National Oceanic and Atmospheric Administration (NOAA) panel for environmental economics is unclear.

Attitude to Health↗
PubMed1998

Valuing outcomes in health care: a comparison of willingness to pay and quality-adjusted life-years.

Quality-adjusted life-years (QALYs) and willingness to pay (WTP) are two preference-based measures of health-related outcomes. In this article, we compare these two measures in eliciting individuals' preferences for health outcomes associated with shingles. To collect the necessary preference data, we administered computer-interactive interviews to a sample of 65- to 70-year-olds. We found no significant correlation between QALYs and WTP across individuals. We discuss our findings and argue that our results raise questions about whether QALYs and WTP are equivalent preference-based measures of health outcomes.

Aged↗