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Biomedical subjects

Paul Hebert

Publications and source records attributed to Paul Hebert.

13 recordsLinked to original sources
PubMed2006

Variant Creutzfeldt-Jakob disease and the Canadian blood system after the tainted blood tragedy.

The transfusion transmission of hepatitis C and HIV to thousands of Canadian blood recipients was one of this country's largest public health catastrophes. In response to this crisis, and in an effort to prevent such a tragedy from occurring again, the Canadian blood system has undergone substantial reform. Variant Creutzfeldt-Jakob (vCJD) disease was the first infectious threat faced by the blood system since undergoing reform. The response at the time to this risk provides insights into the Canadian blood system's new approach to infectious threats. Our analysis of the decision-making concerning vCJD identifies two dominant themes characterizing the new blood system's approach to safety: (1) the adoption of a precautionary approach to new risks which involves taking action in advance of definitive evidence, and (2) risk aversion amongst policy makers, which has contributed to the adoption of safety measures with comparatively high cost-effectiveness ratios. Overall the principles governing the new blood system have contributed to the system both providing protection against emerging infectious risks and regaining the confidence of the public and recipients. However, the current set of policy factors will likely contribute to increasingly risk-averse policy making that will contribute to continued increases in the cost of the blood system. The challenge the blood system now faces is to find the appropriate balance between maximizing safety and ensuring the system remains affordable.

Blood Banks↗
PubMed2006

Factors affecting perioperative transfusion decisions in patients with coronary artery disease undergoing coronary artery bypass surgery.

BACKGROUND: A high proportion of patients having cardiac bypass surgery receive erythrocyte transfusions. Decisions about when to transfuse patients having surgery for coronary artery disease may impact on erythrocyte utilization and patient morbidity and mortality. There are no published data about the factors that influence physicians' decisions to transfuse erythrocytes to these patients. The objectives of this study were to determine the hemoglobin concentration for transfusion and the factors that influence physicians' perioperative transfusion decisions for coronary artery bypass patients. METHODS: The authors conducted a cross-sectional study using pretested, self-administered, mailed questionnaires sent in 2004 to all cardiac surgeons and anesthesiologists in Canada who participate in coronary artery bypass surgery. The questionnaire included four intraoperative and four postoperative vignettes. Factors assessed included patient age, sex, cardiac index, and myocardial ischemia. RESULTS: The response rates were 70% (345 of 489) for the intraoperative and 61% (297 of 489) for the postoperative case scenarios. The mean hemoglobin concentrations for transfusion were 7.0 g/dl for the intraoperative case scenarios and 7.2 g/dl for the postoperative case scenarios. Older age, the presence of myocardial ischemia, and a low cardiac index were factors that increased the hemoglobin concentration for transfusion (P < 0.0001). Physicians ranked myocardial ischemia as the most significant factor affecting their transfusion decisions. CONCLUSIONS: Factors such as the presence of a low cardiac index, myocardial ischemia, and older age increase the hemoglobin concentrations at which physicians transfuse coronary bypass surgery patients. Future studies are required to elucidate whether transfusions based on these variables affect patient morbidity and mortality.

Adult↗
PubMed2005

Ethnic disparities in the treatment of stage I non-small cell lung cancer.

RATIONALE: Important variations exist in the treatment of non-small cell lung cancer. Because resection is the most effective treatment for patients with early disease, disparities in surgical rates can generate considerable differences in outcomes. OBJECTIVE: We analyzed data from a national population-based registry to evaluate disparities in the treatment of Hispanic and white patients with stage I lung cancer and to assess the extent to which these inequalities explain survival differences. METHODS: This study included 16,036 Hispanic and white patients with stage I lung cancer diagnosed between 1991 and 2000. Cases were identified from the Surveillance, Epidemiology, and End Results registry. Survival was compared among white and Hispanics using Kaplan-Meier curves. Stratified survival curves and Cox regression were used to evaluate whether inequalities in stage (IA vs. IB) and resection could explain survival differences. RESULTS: Hispanics had worse overall and lung cancer-specific survival compared with whites (p = 0.04 and 0.008, respectively). Five-year lung cancer survival was 54% for Hispanics versus 62% for whites. Hispanics were more frequently diagnosed with stage IB disease (p = 0.0002) and less likely to undergo resection (p = 0.03). Among resected patients, survival was similar for the two groups, as it was among those who did not undergo unresection. After adjusting for surgery and stage, there was no difference in survival between groups. CONCLUSIONS: Hispanics with stage I lung cancer had worse survival as compared with whites. These disparities are largely explained by lower rates of resection and higher probability of diagnosis at stage IB. Future work must delineate why Hispanics are receiving less surgery.

Age Distribution↗
PubMed2005

Association between suicide attempts and selective serotonin reuptake inhibitors: systematic review of randomised controlled trials.

OBJECTIVE: To establish whether an association exists between use of selective serotonin reuptake inhibitors (SSRIs) and suicide attempts. DESIGN: Systematic review of randomised controlled trials. DATA SOURCES: Medline and the Cochrane Collaboration's register of controlled trials (November 2004) for trials produced by the Cochrane depression, anxiety, and neurosis group. SELECTION OF STUDIES: Studies had to be randomised controlled trials comparing an SSRI with either placebo or an active non-SSRI control. We included clinical trials that evaluated SSRIs for any clinical condition. We excluded abstracts, crossover trials, and all trials whose follow up was less than one week. RESULTS: Seven hundred and two trials met our inclusion criteria. A significant increase in the odds of suicide attempts (odds ratio 2.28, 95% confidence 1.14 to 4.55, number needed to treat to harm 684) was observed for patients receiving SSRIs compared with placebo. An increase in the odds ratio of suicide attempts was also observed in comparing SSRIs with therapeutic interventions other than tricyclic antidepressants (1.94, 1.06 to 3.57, 239). In the pooled analysis of SSRIs versus tricyclic antidepressants, we did not detect a difference in the odds ratio of suicide attempts (0.88, 0.54 to 1.42). DISCUSSION: Our systematic review, which included a total of 87 650 patients, documented an association between suicide attempts and the use of SSRIs. We also observed several major methodological limitations in the published trials. A more accurate estimation of risks of suicide could be garnered from investigators fully disclosing all events.

Adult↗
PubMed2005

Prophylaxis of Thromboembolism in Critical Care (PROTECT) Trial: a pilot study.

PURPOSE: There is no randomized trial comparing low-molecular weight heparin (LMWH) and unfractionated heparin (UFH) for thromboprophylaxis in medical-surgical ICU patients. The primary objective of this randomized pilot study on LMWH vs UFH was to assess the feasibility of conducting a large randomized trial with respect to timely enrollment and blinded study drug administration, practicality of twice-weekly lower limb ultrasounds to screen for deep venous thrombosis, LMWH bioaccumulation and dose adjustment in renal insufficiency, and recruitment rates for a future trial in medical-surgical intensive care unit (ICU) patients. Its additional goals were to evaluate the suitability of the exclusion criteria and to document the range of research activities that precede accrual of patients into a trial to plan multisite management. MATERIALS AND METHODS: By computerized telephone randomization, we allocated 129 medical-surgical ICU patients to treatment with dalteparin 5,000 IU QD SC or that with UFH 5,000 IU BID SC. Within each clinical center, only the study pharmacist was not blinded. We performed bilateral lower limb compression ultrasounds within 48 hours of ICU admission, twice weekly, on suspicion of deep venous thrombosis, and 7 days after ICU discharge. Research coordinators and investigators at 7 centers reported the time they engaged in all research activities before the first patient was randomized. RESULTS: Timely complete study drug administration occurred after enrollment. More than 99% of scheduled doses were administered in a blinded fashion. Scheduled ultrasounds were performed without exception. No bioaccumulation of dalteparin was observed when creatinine clearance decreased to lower than 30 mL/min. Average recruitment was 2 patients/center per month before the study exclusion criteria were modified. Study startup activities required, on average, 65.5 hours of combined investigator and research coordinator time at each center. Careful examination of the accrual in the pilot study led to a reexamination of the Prophylaxis of Thromboembolism in Critical Care Trial (PROTECT) study exclusion criteria. CONCLUSIONS: This pilot study suggests that a multicenter randomized clinical trial comparing LMWH with UFH in critically ill medical-surgical patients is feasible. Pilot studies can improve the design of larger trials and may enhance successful timely completion.

Anticoagulants↗
PubMed2005

Disparities in indigenous health: a cross-country comparison between New Zealand and the United States.

OBJECTIVES: We compared the health statuses of the indigenous populations of New Zealand and the United States with those of the numerically dominant populations of these countries. METHODS: Health indicators compared included health outcome measures, preventive care measures, modifiable risk factor prevalence, and treatment measures. RESULTS: In the case of nearly every health status indicator assessed, disparities (both absolute and relative) were more pronounced for Maoris than for American Indians/Alaska Natives. Both indigenous populations suffered from disparities across a range of health indicators. However, no disparities were observed for American Indians/Alaska Natives in regard to immunization coverage. CONCLUSIONS: Ethnic health disparities appear to be more pronounced in New Zealand than in the United States. These disparities are not necessarily intractable. Although differences in national health sector responses exist, New Zealand may be well placed in the future to evaluate the effectiveness of new strategies to reduce these disparities given the extent and quality of Maori-specific health information available.

Adult↗
PubMed2004

Indigenous disparities in disease-specific mortality, a cross-country comparison: New Zealand, Australia, Canada, and the United States.

AIMS: To compare the disease-specific mortality rates of the indigenous populations of New Zealand, Australia, Canada, and the United States with the non-indigenous populations in each country. METHODS: For New Zealand, Australia, Canada, and the United States, we compiled and calculated (from crude data) ethnic-specific mortality rates by primary cause of death in 1999 for the indigenous and non-indigenous populations in each country. We calculated age-adjusted mortality rates, using direct standardisation and weights based on the World Health Organization world population. RESULTS: Australia experienced the largest relative and absolute disparities in life expectancy between indigenous and non-indigenous populations. For specific causes of death, New Zealand Maori, and Australian Aboriginals and Torres Strait Islanders experienced the highest levels of disparities when compared to their respective non-indigenous population group. Large disparities exist for indigenous peoples in all four countries for diabetes mortality. CONCLUSION The indigenous peoples of New Zealand and Australia suffer from high disease-specific mortality rates. The relative size of indigenous/non-indigenous mortality disparities are highest in New Zealand and Australia. There appears to be a number of common issues that adversely affect the quality of the mortality data that is available in the four countries. Action is required to address indigenous health disparities and to improve the quality of indigenous mortality data.

Australia↗
PubMed2003

Outpatient oral prednisone after emergency treatment of chronic obstructive pulmonary disease.

BACKGROUND: In this randomized, double-blind, placebo-controlled trial, we studied the effectiveness of prednisone in reducing the risk of relapse after outpatient exacerbations of chronic obstructive pulmonary disease (COPD). METHODS: We enrolled 147 patients who were being discharged from the emergency department after an exacerbation of COPD and randomly assigned them to 10 days of treatment with 40 mg of oral prednisone once daily or identical-appearing placebo. All patients received oral antibiotics for 10 days, plus inhaled bronchodilators. The primary end point was relapse, defined as an unscheduled visit to a physician's office or a return to the emergency department because of worsening dyspnea, within 30 days after randomization. RESULTS: The overall rate of relapse at 30 days was lower in the prednisone group than in the placebo group (27 percent vs. 43 percent, P=0.05), and the time to relapse was prolonged in those taking prednisone (P=0.04). After 10 days of therapy, patients in the prednisone group had greater improvements in forced expiratory volume in one second than did patients in the placebo group (mean [+/-SD] increase from base line, 34+/-42 percent vs. 15+/-31 percent; P=0.007). Patients in the prednisone group also had significant improvements in dyspnea, as measured by the transitional dyspnea index (P=0.04) and by the dyspnea domain of the Chronic Respiratory Disease Index Questionnaire (P=0.02), but not in health-related quality of life (P=0.14). CONCLUSIONS: Outpatient treatment with oral prednisone offers a small advantage over placebo in treating patients who are discharged from the emergency department with an exacerbation of COPD.

Acute Disease↗
PubMed2003

A qualitative study of physicians' perceptions of three decision aids.

The study objective was to investigate physicians' perceptions of three patient decision aids (DA). Semi-structured telephone interviews were conducted with 20 family physicians and 12 gynecologists about a DA for women considering long-term hormone replacement therapy; with 16 respirologists about a DA for the use of intubation and mechanical ventilation for patients with severe chronic obstructive pulmonary disease; and with 19 physicians (geriatricians, gastroenterologists, internists) about a DA for long-term placement of feeding tubes in the elderly. Participants were identified by a snowball sampling technique. The interviews were analyzed using standard qualitative methods. Most participants (81%) indicated some willingness to use the DAs. The characteristics of the DA viewed positively included it being: balanced, well organized, a useful tool, evidence-based, improves decision making process and multimedia. Some of the negative characteristics were stated as: too complex, the cost, the availability, only appropriate for certain groups of patients, and time consuming. The DAs were acceptable to most participants. Perceived positive and negative factors were similar for all DAs. Uptake of decision aids may be facilitated if physicians have an opportunity to examine and try them, and if they can have unfettered access to them for distribution purposes.

Attitude of Health Personnel↗
PubMed2002

The before/after study design in transfusion medicine: methodologic considerations.

To ascertain the effectiveness of an intervention, a randomized controlled trial (RCT) is considered the gold standard. An obstacle to conducting an RCT only rarely discussed is the universal implementation of an intervention. Universal implementation clearly precludes the feasibility of conducting an RCT. Thus, the most attractive alternative study design in such instances becomes the before/after study. This article describes important methodologic considerations in undertaking a before/after evaluation. The methodologic considerations to be discussed are (1) threats to internal validity, (2) precision and (3) generalizability. Two before/after studies evaluating the potential effectiveness of universal leukoreduction serve as examples. Because of the universal application of many transfusion interventions, one has to consider carefully the methodologic rigor as to which of these interventions are evaluated. We have outlined the major methodologic issues one must consider when undertaking a before/after study design. When properly conceived, conducted, and analyzed, such a before/after study design can yield informative associations.

Adult↗
PubMed2002

Common methodological terms in health services research and their synonyms [correction of symptoms].

OBJECTIVE: Health services researchers use methods and terminology from a variety of disciplines to understand individual and organizational behavior related to health, health care, and health insurance. Although this diversity benefits the process of research, the resulting differences in terminology can occasionally lead to confusion among even the most experienced researchers. The purpose of this paper is to clarify different methodological terms used to represent common study designs and statistical concepts in health services research. METHOD: Faculty from the departments of Health Services, Biostatistics and Epidemiology at the University of Washington were asked to provide a list of terms commonly used in health services research that had one or more methodological terms with the same or similar meaning. Consistent with the Delphi method, the initial list was then circulated to internal and external methodologists and additional terms were added for completeness. Terms related to study designs, equation specification, and estimation problems with synonymous terminology were included. RESULTS: A "methodological thesaurus" is developed and described in this paper. Many terms were found which described essentially identical concepts. In other cases, terms had slight but important differences in meaning across disciplines, leading to potential confusion in their use. CONCLUSION: In light of these differences in terminology, it is not surprising that health services researchers with a particular disciplinary orientation currently find literature within their own discipline entirely readable and literature from another discipline considerably less accessible. The "methodological thesaurus" presented in this paper should be of value to health services researchers who are interested in exploring the full array of methods developed to address a particular problem. Teachers and students of health services research should also find this article of use in relating similar concepts across disciplines in quantitative health services research publications.

Bias↗
PubMedDate not supplied

Reducing excessive medication administration in hospitalized adults with renal dysfunction.

Medication errors are common and harm hospitalized patients. The authors designed and implemented an automated system to complement an existing computerized order entry system by detecting the administration of excessive doses of medication to adult in-patients with renal insufficiency. Its impact, in combination with feedback to prescribers, was evaluated in 3 participating nursing units and compared with the remainder of a tertiary care academic medical center. The baseline rate of excessive dosing was 23.2% of administered medications requiring adjustment for renal insufficiency given to patients with renal impairment on the participating units and 23.6% in the rest of the hospital. The rate fell to 17.3% with nurse feedback and 16.8% with pharmacist feedback in the participating units (P<.05 for each, relative to baseline). The rates of excessive dosing for the same time periods were 26.1% and 24.8% in the rest of the hospital. Automated detection and routine feedback can reduce the rate of excessive administration of medication in hospitalized adults with renal insufficiency.

Academic Medical Centers↗