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Biomedical subjects

Braden Manns

Publications and source records attributed to Braden Manns.

At least 19 recordsLinked to original sources
PubMed2007

The quality of reports of critical care meta-analyses in the Cochrane Database of Systematic Reviews: an independent appraisal.

OBJECTIVE: To independently appraise the methodological quality of a sample of reports of meta-analyses that address critical care topics in the Cochrane Database of Systematic Reviews compared with the quality of reports published in regular journals, using a validated assessment instrument, the Overview Quality Assessment Questionnaire (OQAQ). DATA SOURCE: Studies were selected from a search of MEDLINE, EMBASE, and the Cochrane Database of Systematic Reviews from 1994 to 2003, using multiple search terms for critical care and sensitive filters to identify meta-analyses. STUDY SELECTION: Two authors independently selected meta-analyses that addressed topics pertinent to critical care medicine. DATA EXTRACTION: Two authors independently extracted the data. The proportion of reports that met each component of the OQAQ was determined, as was the overall quality score. Meta-analyses published in the Cochrane Database of Systematic Reviews were compared with those published in regular journals. DATA SYNTHESIS: There were 36 reports of meta-analyses in the Cochrane Database of Systematic Reviews and 103 reports of meta-analyses published in regular journals; 11 of these were reports of Cochrane reviews. The meta-analyses published in the Cochrane Database of Systematic Reviews were more likely to fulfill most components of the OQAQ. The median overall OQAQ scores indicated significant methodological problems in the reports regardless of the source of publication, although the reports in the Cochrane database scored higher than those in regular journals (five compared with two, p<.001). Major methodological flaws, notably failure to appropriately refer to the validity of included studies, were found in meta-analyses in both the Cochrane Database of Systematic Reviews and regular journals (44.4% and 79.3%, respectively). CONCLUSIONS: Although the quality of reports of meta-analyses published in the Cochrane Database of Systematic Reviews is superior to the quality of reports of meta-analyses published in regular journals, there is significant room for improvement. Clinicians should critically appraise all reports of meta-analyses before considering the results, regardless of the source of publication.

Critical Care↗
PubMed2006

Residence location and likelihood of kidney transplantation.

BACKGROUND: In a universal, public health care system, access to kidney transplantation should not be influenced by residence location. We determined the likelihood of kidney transplantation from deceased donors among Canadian dialysis patients living in 7 geographic regions. Within each region we also determined whether distance from the closest transplant centre was associated with the likelihood of transplantation. METHODS: A random sample of 7034 subjects initiating dialysis in Canada between 1996 and 2000 was studied. We used Cox proportional hazards models to examine the relation between residence location and the likelihood of kidney transplantation from deceased donors over a median period of 2.4 years. RESULTS: There were significant differences in the likelihood of kidney transplantation from deceased donors and predicted waiting times between the different geographic regions. For example, the adjusted relative likelihood of transplantation in Alberta was 3.74 (95% confidence interval [CI] 2.95-4.76) compared with the likelihood in Ontario (p < 0.001). These differences persisted after further adjustment for differences in the rate of deceased organ donation. Within regions, patients who resided 50.1-150 km, 150.1-300 km and more than 300 km from the closest transplant centre had a similar adjusted likelihood of receiving a kidney transplant as those who lived less than 50 km away. INTERPRETATION: The adjusted likelihood of undergoing a kidney transplant from a deceased donor varied substantially between geographic regions in Canada. In contrast, the likelihood of transplantation within regions was not affected by distance from the closest transplant centre.

Aged↗
PubMed2006

The routine use of high-resolution immunological screening of recipients of primary deceased donor kidney allografts is cost-effective.

BACKGROUND: The economic and health benefits of kidney transplantation are dependent on the length of allograft survival. High-resolution immunological screening can identify recipients at increased risk of early graft loss caused by acute rejection, but the use of these tests increases screening costs before transplantation. The objective of this study was to evaluate the cost-effectiveness of routine use of high-resolution flow-cytometry cross-matching and solid-phase screening for all recipients of primary deceased donor kidney transplants. METHODS: A Markov model was constructed to evaluate costs and effects of two different clinical strategies on a simulated cohort of 1,000 transplant recipients: serological screening (SS) only and flow screening (FS) only. Outcomes measures were total cost of patient care over 25 years, life expectancy, quality-adjusted life expectancy, and transplant life expectancy. RESULTS: In the base-case analysis, FS was associated with an average gain of 0.08 life years, 0.25 transplant life years, and 0.08 quality-adjusted life years per patient. SS was associated with a higher cost of CND$6,397 per patient, mostly because of increased use of dialysis in patients who suffered early graft loss under the SS strategy. The results were robust to uncertainty in the majority of variables, and a strategy using FS was cost-effective except under the unlikely scenario where the false-negative rate for SS was <or=2% or the early graft loss rate for flow-positive recipients was <or=7% (compared with 5% for flow-negative recipients). CONCLUSIONS: Routine use of FS in recipients of first-deceased donor kidney transplants is cost-effective.

Cadaver↗
PubMed2006

Benchmarking performance in organ donation programs: dependence on demographics and mortality rates.

PURPOSE: Donors whose diagnosis of death is based upon neurologic criteria are the primary source of organs for human transplantation. The current measure of effectiveness of organ donation programs is the crude statistic, donors per million population (DPMP). This statistic represents the number of available donors, divided by the potential donor population. Comparisons between transplantation programs are done using the DPMP statistic. We sought to determine if variance in organ donation rates, reported as DPMP could be accounted for by differences in population demographics, specifically age and gender-specific mortality rates. METHODS: We obtained the population distribution and deaths for the year 2000 for the Calgary Health Region (CHR) and the country of Spain. Expected deaths were then calculated by standardizing the sample, based upon weighted averages of age, gender and cause-specific mortality rates. RESULTS: In 2000, Spain reported a crude organ donation rate of 33.9 DPMP. Standardizing the observed deaths in Spain using the CHR population distribution and calculating expected deaths based on the CHR rates, resulted in an adjusted rate of 19.2 DPMP (P < 0.05). CONCLUSIONS: These results bring into question the reliability of using crude DPMP as a measure of organ and tissue donation program performance. Alternative measures of benchmarking performance in organ donation programs should be considered.

Adolescent↗
PubMed2005

A systematic evaluation of the quality of meta-analyses in the critical care literature.

INTRODUCTION: Meta-analyses have been suggested to be the highest form of evidence available to clinicians to guide clinical practice in critical care. The purpose of this study was to systematically evaluate the quality of meta-analyses that address topics pertinent to critical care. METHODS: To identify potentially eligible meta-analyses for inclusion, a systematic search of Medline, EMBASE and the Cochrane Database of Systematic Reviews was undertaken, using broad search terms relevant to intensive care, including: intensive care, critical care, shock, resuscitation, inotropes and mechanical ventilation. Predetermined inclusion criteria were applied to each identified meta-analysis independently by two authors. To assess report quality, the included meta-analyses were assessed using the component and overall scores from the Overview Quality Assessment Questionnaire (OQAQ). The quality of reports published before and after the publication of the QUOROM statement was compared. RESULTS: A total of 139 reports of meta-analyses were included (kappa = 0.93). The overall quality of reports of meta-analyses was found to be poor, with an estimated mean overall OQAQ score of 3.3 (95% CI; 3.0-3.6). Only 43 (30.9%) were scored as having minimal or minor flaws (>5). We noted problems with the reporting of key characteristics of meta-analyses, such as performing a thorough literature search, avoidance of bias in the inclusion of studies and appropriately referring to the validity of the included studies. After the release of the QUOROM statement, however, an improvement in the overall quality of published meta-analyses was noted. CONCLUSION: The overall quality of the reports of meta-analyses available to critical care physicians is poor. Physicians should critically evaluate these studies prior to considering applying the results of these studies in their clinical practice.

Critical Care↗
PubMed2005

A systematic review of the effect of nocturnal hemodialysis on blood pressure, left ventricular hypertrophy, anemia, mineral metabolism, and health-related quality of life.

BACKGROUND: Nocturnal hemodialysis is a novel form of dialysis where patients perform dialysis 6 nights per week while they sleep. Multiple publications report significant improvements in selected clinical outcomes, although the strength of these results is limited by shortcomings in study design. A systematic review of the current available literature was undertaken to examine the effect of nocturnal hemodialysis on key health outcomes. METHODS: An inclusive search of medical databases was undertaken to identify all nocturnal hemodialysis studies. These results were manually reviewed for relevance to nocturnal hemodialysis and its impact on the following predefined health outcomes: blood pressure control, left ventricular hypertrophy, anemia, mineral metabolism, and health related quality of life. Case reports, short-term studies (<4 weeks), studies without comparator groups, and studies not reporting data in a quantitative fashion were excluded. The results of the remaining studies were reported in tabular format. RESULTS: Of the initial 270 studies identified, only 14 met inclusion/exclusion criteria. No studies examining the impact of nocturnal hemodialysis on mortality were identified. All studies reported improved blood pressure control after conversion to nocturnal hemodialysis. Data regarding the other health outcomes of interest revealed mixed results. CONCLUSION: Nocturnal hemodialysis is a potential alternative to conventional intermittent hemodialysis. Before significant resources are invested in initiating nocturnal hemodialysis programs, further data on mortality and cardiovascular morbidity, preferably from randomized clinical trials, are required.

Anemia↗
PubMed2004

Use and outcomes of peritoneal dialysis among Aboriginal people in Canada.

There has been a dramatic increase in the incidence of ESRD among Aboriginal people in North America. Although peritoneal dialysis (PD) seems to be the dialysis modality of choice for this often rural-dwelling population, few data exist to confirm this. This study was conducted to evaluate rates of PD use, technique failure, and mortality among incident Aboriginal dialysis patients. Adults of white or Aboriginal race who initiated dialysis in three Canadian provinces between January 1, 1990, and December 31, 2000, were included and followed until December 31, 2001. Logistic regression and Cox proportional hazards models were used to examine adjusted associations between Aboriginal race and PD use, technique failure, and mortality. Among the 3823 patients of white (n = 3138; 82.1%) or Aboriginal (n = 685; 17.9%) race, 835 (21.8%) initiated dialysis on PD. After adjustment for age and comorbidity and comparison with white patients, Aboriginal patients were significantly less likely to initiate therapy on PD compared with white patients (odds ratio, 0.51; 95% confidence interval, 0.40 to 0.65), with a nonsignificant trend toward a higher risk for technique failure (hazards ratio, 1.46; 95% confidence interval, 0.95 to 2.23). Adjusted survival among Aboriginal PD patients seemed similar to both white PD patients and Aboriginal patients who were treated with hemodialysis. In summary, among people who were treated with dialysis in Canada, PD was used less frequently in Aboriginal patients than in those of white race. Although Aboriginal patients who initiate dialysis on PD seemed more likely to experience technique failure, their adjusted risk for death was similar to that of white patients. Future studies should address barriers to the initiation and maintenance of PD in the Aboriginal population, especially those who reside in rural locations.

Adult↗
PubMed2004

Establishment and maintenance of vascular access in incident hemodialysis patients: a prospective cost analysis.

Despite the importance of hemodialysis vascular access, the cost of vascular access care has not been studied in detail. A prospective cost analysis was performed among incident hemodialysis patients to determine the cost of vascular access care overall and on the basis of access type. Detailed clinical and demographic information, as well as data on access type, was collected for all local incident hemodialysis patients between July 1, 1999, and November 1, 2001. A comprehensive measure of total vascular access costs, including surgery, radiology, hospitalization for access complications, physician costs, costs for management of outpatient bacteremia, and vascular access monitoring costs, was obtained. Costs are reported in 2002 Canadian dollars (1 CAN dollar = 0.69 US dollar). A total of 239 consecutive incident hemodialysis patients were identified, 49, 157, and 33 of whom were dialyzed exclusively with a catheter or had a native arteriovenous fistula or synthetic graft attempted, respectively. In year 1, 18.4% of all hospital admissions were for vascular access-related complications. The mean cost of all vascular access care in year 1 was 6890 CAN dollars(median 4020 dollars; interquartile range [IQR] 2440 dollars to 7540 dollars). The mean cost of access care per patient-year at risk for maintaining a catheter exclusively, attempting an arteriovenous fistula, or attempting a graft was 9180 dollars (median 3812 dollars; IQR 2250 dollars to 7762 dollars), 7989 dollars (median 4641 dollars ; IQR 3035 dollars to 8832 dollars), and 11,685 dollars (median 8152 dollars; IQR 3395 dollars to 12,908 dollars), respectively (P = 0.01). Vascular access care is responsible for a significant proportion of health care costs in the first year of hemodialysis. These results support clinical practice guidelines that recommend preferential placement of a native fistula.

Aged↗
PubMed2004

Death and renal transplantation among Aboriginal people undergoing dialysis.

BACKGROUND: Despite the increase in the number of Aboriginal people with end-stage renal disease around the world, little is known about their health outcomes when undergoing renal replacement therapy. We evaluated differences in survival and rate of renal transplantation among Aboriginal and white patients after initiation of dialysis. METHODS: Adult patients who were Aboriginal or white and who commenced dialysis in Alberta, Saskatchewan or Manitoba between Jan. 1, 1990, and Dec. 31, 2000, were recruited for the study and were followed until death, transplantation, loss to follow-up or the end of the study (Dec. 31, 2001). We used Cox proportional hazards models to examine the effect of race on patient survival and likelihood of transplant, with adjustment for potential confounders. RESULTS: Of the 4333 adults who commenced dialysis during the study period, 15.8% were Aboriginal and 72.4% were white. Unadjusted rates of death per 1000 patient-years during the study period were 158 (95% confidence interval [CI] 144-176) for Aboriginal patients and 146 (95% CI 139-153) for white patients. When follow-up was censored at the time of transplantation, the age-adjusted risk of death after initiation of dialysis was significantly higher among Aboriginal patients than among white patients (hazard ratio [HR] 1.15, 95% CI 1.02-1.30). The greater risk of death associated with Aboriginal race was no longer observed after adjustment for diabetes mellitus and other comorbid conditions (adjusted HR 0.89, 95% CI 0.77-1.02) and did not appear to be associated with socioeconomic status. During the study period, unadjusted transplantation rates per 1000 patient-years were 62 (95% CI 52-75) for Aboriginal patients and 133 (95% CI 125-142) for white patients. Aboriginal patients were significantly less likely to receive a renal transplant after commencing dialysis, even after adjustment for potential confounders (HR 0.43, 95% CI 0.35-0.53). In an additional analysis that included follow-up after transplantation for those who received renal allografts, the age-adjusted risk of death associated with Aboriginal race (HR 1.36, 95% CI 1.21-1.52) was higher than when follow-up after transplantation was not considered, perhaps because of the lower rate of transplantation among Aboriginals. INTERPRETATION: Survival among dialysis patients was similar for Aboriginal and white patients after adjustment for comorbidity. However, despite universal access to health care, Aboriginal people had a significantly lower rate of renal transplantation, which might have adversely affected their survival when receiving renal replacement therapy.

Canada↗
PubMed2004

Detailed cost analysis of care for survivors of severe sepsis.

OBJECTIVES: The objectives of our study were to accurately describe the costs and resources required to treat survivors of severe sepsis subsequent to hospital discharge and to determine what factors influenced these costs. DESIGN: Observational cohort study. SETTING: Three regional intensive care units. PATIENTS: Patients with severe sepsis admitted to one of three regional intensive care units in southern Alberta between April 1, 1996, and March 31, 1999. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients were identified using an intensive care unit research database; all survivors were followed prospectively for 3 yrs. Information on baseline patient characteristics, including acuity of illness (Acute Physiology and Chronic Health Evaluation II scores) and Charlson comorbidity scores, was collected. Costs considered included all episodes of inpatient and outpatient care and all physician claims. Of 787 patients who were admitted with severe sepsis, 502 survived to hospital discharge and were followed. Subsequent mean cost of care for years 1, 2, and 3 was CAN$20,855, $7,139 and $7,091, respectively. Using various regression models, the Acute Physiology and Chronic Health Evaluation II score and the Charlson comorbidity score were the only factors that consistently predicted higher healthcare costs in the first year after hospital discharge. Diabetes was the comorbid condition that best predicted subsequent cost. CONCLUSIONS: Cost of care for survivors of severe sepsis was highest in the first year after hospital discharge. Acuity of illness and patient comorbidity were the main determinants of cost. In assessing whether new therapeutic innovations for intensive care unit patients with severe sepsis are cost-effective, an accurate estimate of the cost of subsequent health care for survivors treated with and without the new intervention will be important.

APACHE↗
PubMed2004

Systematic review of the impact of N-acetylcysteine on contrast nephropathy.

BACKGROUND: The efficacy of N-acetylcysteine (NAC) for preventing contrast nephropathy is uncertain. We performed a systematic review and meta-analysis to assess the efficacy of NAC for preventing contrast nephropathy after administration of intravenous contrast media. METHODS: Data were obtained from searching MEDLINE (1969-2003) and EMBASE (1988-2003), Cochrane Controlled Clinical Trial Registry (2002, Volume 3), and conference proceedings. We considered all randomized studies that compared changes in renal function between groups that received and did not receive NAC. Studies in which the control group also received active therapy were excluded, although co-intervention directed at both groups was permitted. Two reviewers independently extracted quantitative and qualitative data. Disagreements were resolved by consensus with the aid of a third party. RESULTS: Fifteen studies with a total of 1776 patients satisfied inclusion and exclusion criteria. Contrast nephropathy was typically defined by an increase in serum creatinine of 0.5 mg/dL within 24 to 48 hours of contrast administration. The pooled random effect relative risk was 0.65 (0.43-1.00, P= 0.049), indicating that NAC significantly reduced the incidence of contrast nephropathy. However, the effect of NAC was not statistically significant in several prespecified subgroup analyses, and the results were not robust to the addition of hypothetical new or unidentified randomized trials. There was evidence of significant heterogeneity in NAC effect across studies (Q = 26.3, P= 0.02). Random effects meta-regression did not implicate identified differences in participant or study characteristics as responsible for the observed heterogeneity. CONCLUSION: NAC may reduce the incidence of acutely increased serum creatinine after administration of intravenous contrast, but this finding was of borderline statistical significance, and there was significant heterogeneity between trials. Before NAC becomes the standard of care for all patients receiving intravenous contrast, new randomized trials evaluating its effect on clinically relevant outcomes are required.

Acetylcysteine↗
PubMed2004

A systematic review of sevelamer in ESRD and an analysis of its potential economic impact in Canada and the United States.

BACKGROUND: The Kidney Disease Outcomes Quality Initiatives (K/DOQI) guidelines on bone metabolism and disease in chronic kidney disease were recently published. Despite limited evidence of clinical effectiveness and without detailed consideration of cost, these guidelines recommend the use of a nonmineral-containing phosphate binder (i.e., sevelamer) in several common clinical situations. The objective of this study is to use the example of sevelamer to outline the information that is needed to assist health care payers with the decision to fund a new and expensive therapy. METHODS: We assessed the clinical benefit of sevelamer by performing a systematic review of all randomized trials evaluating its use. To estimate the direct budget impact associated with implementation of the K/DOQI bone disease guidelines, we used laboratory and medication data available from two cohorts of dialysis patients (one treated in Canada and one in the United States) to determine the proportion of patients who meet the criteria for the use of sevelamer as described in the K/DOQI bone disease guidelines. RESULTS: No randomized trials document the impact of sevelamer on survival, hospitalization, or quality of life. However, at least 51% and 64% of dialysis patients in the Canadian and American cohorts, respectively, would meet K/DOQI criteria for use of sevelamer. Extrapolating to the United States dialysis population, adoption of the K/DOQI bone guidelines would result in expenditures of approximately 781 million dollars annually on sevelamer alone. CONCLUSION: Given their potential budgetary impact, future nephrology clinical practice guidelines should consider resource use, in addition to clinical data.

Canada↗
PubMed2003

Illustrating the impact of including future costs in economic evaluations: an application to end-stage renal disease care.

There are strong theoretical arguments for including future costs for related and unrelated medical care and non-medical expenditures within economic evaluations. Nevertheless, there is limited data on how inclusion of such costs affects the cost effectiveness of medical interventions in practice. For a low-cost intervention that improves survival in end-stage renal disease (ESRD) patients, we sought to determine how the inclusion of future costs for related medical care (i.e. dialysis and transplantation) and for unrelated medical care and non-medical expenditure would affect the magnitude of the cost per QALY ratio. We performed a cost-utility analysis comparing hemodialysis using a synthetic dialyser (the current treatment of choice in Canada) with the historical gold-standard treatment (use of a cellulose dialyser). We contrasted the results of the analysis including and excluding various measures of future costs. While the inclusion of future costs for unrelated medical care and non-medical expenditures had a significant impact on the cost per QALY ratio, the size of the cost per QALY ratio was most sensitive to inclusion of future costs for related medical care. Our analysis shows that even relatively inexpensive interventions that extend survival of dialysis patients may not be cost-effective since, by extending survival, the extra outpatient dialysis costs that are incurred are large. Inclusion of such costs (which, in and of itself, is methodologically correct) in economic evaluations in this area may mitigate against the acceptance of interventions that are relatively inexpensive themselves but which improve patient survival.

Adult↗