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Deborah J. Cook

Bio: Deborah J. Cook is an academic researcher from McMaster University. The author has contributed to research in topics: Intensive care & Intensive care unit. The author has an hindex of 173, co-authored 907 publications receiving 148928 citations. Previous affiliations of Deborah J. Cook include McMaster University Medical Centre & Queen's University.


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Journal ArticleDOI
TL;DR: Patients with asthma who were symptomatic or required treatment at least once a week, and had airway hyperresponsiveness to methacholine aerosol participated, showed systematically greater HRQL impairment.

136 citations

Journal ArticleDOI
TL;DR: QOL assessments occur infrequently in the ICU literature and are of limited methodologic quality, so more studies using valid and reliable instruments are necessary to document the long-term QOL of critically ill patients, especially those at risk of a "poor" outcome.
Abstract: Objectives To present a framework for describing/measuring quality of life (QOL) and health-related quality of life (HRQL), and to assess the frequency and methodologic rigor of QOL studies in the adult critical care literature. Data sources Computerized bibliographic search of published research, manual search of key intensive care unit (ICU) journals, and citation review of relevant articles. Study selection We manually searched Critical Care Medicine, American Journal of Respiratory and Critical Care Medicine, and Intensive Care Medicine for the period January 1992 to July 1995 to assess the frequency of published QOL studies. Combined with a computerized bibliographic search, we found 64 studies that met our criteria that reported on patient-related outcomes (other than mortality) after hospital discharge. Data extraction We abstracted data on the nature of each study, the instruments used to measure QOL, and the methodologic rigor of the QOL assessments. We evaluated each study using criteria we developed to assess the validity of HRQL measurements. Measurements and main results In our manual search, we found 1,073 articles relevant to the practice of adult critical care. Of these, 19 (1.7%)/1073 included QOL measurements. Combined with our comprehensive search strategy, we found 64 papers that evaluated QOL in ICU patients. These papers dealt primarily with issues of: prognosis (32 [50%]), resource allocation (23 [36%]), and clinical prediction (9 [14%]). We found no randomized trials that included post-ICU QOL as an outcome. With respect to the validity of the HRQL assessments, 63/64 (98%) studies evaluated aspects of patients' lives that we considered important. Thirty-three (52%) studies were limited in scope to specific aspects of HRQL, and 31 (48%) studies covered broad areas of HRQL. In these 64 studies, there were 108 different instruments used. The reliability and validity of the instruments used were reported in 7 (6%) and 15 (14%) cases, respectively. For 81 (75%) instruments, the investigators either explained the results or used informative, qualitative descriptors whose interpretation was self-evident. Overall, three (5%) of the included studies met all four methodologic criteria to assess the validity of HRQL assessments. Conclusions QOL assessments occur infrequently in the ICU literature and are of limited methodologic quality. More studies using valid and reliable instruments are necessary to document the long-term QOL of critically ill patients, especially those at risk of a "poor" outcome.

135 citations

Journal ArticleDOI
TL;DR: No significant differences were found in death or disability at 24 months, bronchopulmonary dysplasia, retinopathy of prematurity, neurodevelopmental outcomes, or hearing loss at24 months, and the quality of evidence for these outcomes was moderate to low.
Abstract: Importance The optimal oxygen saturation (SpO 2 ) target for extremely preterm infants is unknown. Objective To systematically review evidence evaluating the effect of restricted vs liberal oxygen exposure on morbidity and mortality in extremely preterm infants. Data Sources MEDLINE, PubMed, CENTRAL, and CINAHL databases from their inception to March 31, 2014, and abstracts submitted to Pediatric Academic Societies from 2000 to 2014. Study Selection All published randomized trials evaluating the effect of restricted (SpO 2 , 85%-89%) vs liberal (SpO 2 , 91%-95%) oxygen exposure in preterm infants ( Data Extraction and Synthesis All meta-analyses were performed using Review Manager 5.2. The Cochrane risk-of-bias tool was used to assess study quality. The summary of the findings and the level of confidence in the estimate of effect were assessed using GRADEpro. Treatment effect was analyzed using a random-effects model. Main Outcomes and Measures Death before hospital discharge, death or severe disability before 24 months, death before 24 months, neurodevelopmental outcomes, hearing loss, bronchopulmonary dysplasia, necrotizing enterocolitis, and severe retinopathy of prematurity. Results Five trials were included in the final synthesis. These studies had a similar design with a prespecified composite outcome of death/disability at 18 to 24 months corrected for prematurity; however, this outcome has not been reported for 2 of the 5 trials. There was no difference in the outcome of death/disability before 24 months (risk ratio [RR], 1.02 [95% CI, 0.92-1.14]). Mortality before 24 months was not different (RR, 1.13 [95% CI, 0.97-1.33]); however, a significant increase in mortality before hospital discharge was found in the restricted oxygen group (RR, 1.18 [95% CI, 1.03-1.36]). The rates of bronchopulmonary dysplasia, neurodevelopmental outcomes, hearing loss, and retinopathy of prematurity were similar between the 2 groups. Necrotizing enterocolitis occurred more frequently in infants on restricted oxygen (RR, 1.24 [95% CI, 1.05-1.47]). Using the Grades of Recommendation, Assessment, Development, and Evaluation (GRADE) criteria, we found that the quality of evidence for these outcomes was moderate to low. Conclusions and Relevance Although infants cared for with a liberal oxygen target had significantly lower mortality before hospital discharge than infants cared for with a restricted oxygen target, the quality of evidence for this estimate of effect is low. Necrotizing enterocolitis occurred less frequently in the liberal oxygen group. We found no significant differences in death or disability at 24 months, bronchopulmonary dysplasia, retinopathy of prematurity, neurodevelopmental outcomes, or hearing loss at 24 months.

134 citations

Journal Article
TL;DR: It is recommended all CEAs in the critically ill include a PCEHM reference case, where the cost-effectiveness ratio is calculated by adopting a societal perspective, estimating long-term costs and quality of life after ICU care, applying a 3% annual discount rate to costs and effects, and conducting multiway sensitivity analyses.
Abstract: Economic evaluations are increasingly common in the critical care literature, although approaches to their conduct are not standardized. The American Thoracic Society convened a workshop to address methodologic and reporting issues for economic analyses in critical care and to determine how guidelines from the U.S. Public Health Service Panel on Cost-effectiveness in Health and Medicine (PCEHM) were applicable to critical care. We identified several issues that hamper cost-effectiveness analyses (CEAs) in the critically ill. Data on the effectiveness of intensive care unit (ICU) interventions are often lacking; ICU patients are complex, with multiple concurrent problems and interventions; most ICU therapies are only supportive, and therefore may not individually result in improved outcome; accurate cost data are not commonly available and are difficult to obtain; there is no standardized approach for measuring or valuing costs across countries; typical outcomes in ICU studies (e.g., short-term mortality) are not ideal for CEAs while preferred outcomes for CEAs (e.g., long-term quality-adjusted survival) are rarely collected; valuing the importance of appropriate end-of-life care, an important aspect of ICU care, is difficult, and the burden of critical illness on family members is not easily captured in a CEA. Nevertheless, many of these problems are not unique to critical care, and we believe the PCEHM guidelines can be adapted to the critical care setting. We recommend all CEAs in the critically ill include a PCEHM reference case, where the cost-effectiveness ratio is calculated by adopting a societal perspective, estimating long-term costs and quality of life after ICU care, applying a 3% annual discount rate to costs and effects, and conducting multiway sensitivity analyses. Because elements of the reference case, such as long-term costs and quality of life, may only be estimated using modeling and assumptions, we also recommend inclusion of a "data-rich" case, where the cost-effectiveness ratio is generated as closely as possible from data on actual patient outcomes and costs (e.g., hospital costs per hospital survivor). We recommend that investigators conducting a CEA concurrently with a randomized trial make the proposed model available (e.g., via the Internet) before unblinding of trial data to minimize bias. Adopting a standard approach to CEAs of ICU therapies will provide a valid and more transparent evidence base for health care policy with regard to care of the critically ill.

134 citations

Journal ArticleDOI
TL;DR: Although patterns vary by system, daily MODS component scores provide additional prognostic value over baseline MODS, which varied significantly over time and among organ systems.
Abstract: Objective The multiple organ dysfunction score (MODS) describes and quantifies organ-specific physiology The objective of this study was to examine the relation between six components of MODS (cardiovascular, respiratory, renal, central nervous system, hepatic, and hematologic) measured at admission to the intensive care unit (ICU) and during the ICU stay, with time to death in the ICU Design Prospective observational cohort study Setting Sixteen Canadian ICUs Patients A total of 1,200 patients were mechanically ventilated for >48 hrs Measurements and Main Results The six organ systems comprising MODS were measured at ICU admission (baseline scores) and daily thereafter The change in organ dysfunction each day (serial scores) were calculated as daily component scores minus the corresponding baseline component scores In Cox regression analyses, the independent explanatory variables were the MODS components measured at baseline and serially, and the dependent variable was the time from admission to ICU mortality When each organ system was analyzed individually, both the baseline and serial MODS for the cardiovascular, respiratory, renal, central nervous system, and hematologic components were significantly associated with ICU mortality After adjusting for the serial hepatic score, the baseline hepatic score was unrelated to mortality After adjusting for all baseline and serial MODS components in aggregate, four organ systems were significantly associated with ICU mortality: cardiovascular (baseline relative risk [RR], 15; serial RR, 14); respiratory (baseline RR, 14; serial RR, 14); renal (baseline RR, 13; serial RR, 15); and central nervous system (baseline RR, 16; serial RR, 17) We found that the relative risk of mortality related to organ dysfunction varied significantly over time and among organ systems Baseline respiratory function was not associated with mortality until the second ICU week (week 1: RR, 11 [09–14]; week 2 onward: RR, 19 [15–24]); the same was true for the change in respiratory function as measured by the serial respiratory score (week 1: RR, 12 [10–15]; week 2 onward: RR, 17 [14–21]) The serial hepatic score was not associated with mortality until the fourth ICU week (weeks 1–3: RR, 09 [07–11]; week 4 onward: RR, 14 [10–20]) Conclusions Organ dysfunction scores describe physiology at ICU admission and during ICU stay Although patterns vary by system, daily MODS component scores provide additional prognostic value over baseline MODS

131 citations


Cited by
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Journal ArticleDOI
TL;DR: Moher et al. as mentioned in this paper introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses, which is used in this paper.
Abstract: David Moher and colleagues introduce PRISMA, an update of the QUOROM guidelines for reporting systematic reviews and meta-analyses

62,157 citations

Journal Article
TL;DR: The QUOROM Statement (QUality Of Reporting Of Meta-analyses) as mentioned in this paper was developed to address the suboptimal reporting of systematic reviews and meta-analysis of randomized controlled trials.
Abstract: Systematic reviews and meta-analyses have become increasingly important in health care. Clinicians read them to keep up to date with their field,1,2 and they are often used as a starting point for developing clinical practice guidelines. Granting agencies may require a systematic review to ensure there is justification for further research,3 and some health care journals are moving in this direction.4 As with all research, the value of a systematic review depends on what was done, what was found, and the clarity of reporting. As with other publications, the reporting quality of systematic reviews varies, limiting readers' ability to assess the strengths and weaknesses of those reviews. Several early studies evaluated the quality of review reports. In 1987, Mulrow examined 50 review articles published in 4 leading medical journals in 1985 and 1986 and found that none met all 8 explicit scientific criteria, such as a quality assessment of included studies.5 In 1987, Sacks and colleagues6 evaluated the adequacy of reporting of 83 meta-analyses on 23 characteristics in 6 domains. Reporting was generally poor; between 1 and 14 characteristics were adequately reported (mean = 7.7; standard deviation = 2.7). A 1996 update of this study found little improvement.7 In 1996, to address the suboptimal reporting of meta-analyses, an international group developed a guidance called the QUOROM Statement (QUality Of Reporting Of Meta-analyses), which focused on the reporting of meta-analyses of randomized controlled trials.8 In this article, we summarize a revision of these guidelines, renamed PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), which have been updated to address several conceptual and practical advances in the science of systematic reviews (Box 1). Box 1 Conceptual issues in the evolution from QUOROM to PRISMA

46,935 citations

Journal ArticleDOI
04 Sep 2003-BMJ
TL;DR: A new quantity is developed, I 2, which the authors believe gives a better measure of the consistency between trials in a meta-analysis, which is susceptible to the number of trials included in the meta- analysis.
Abstract: Cochrane Reviews have recently started including the quantity I 2 to help readers assess the consistency of the results of studies in meta-analyses. What does this new quantity mean, and why is assessment of heterogeneity so important to clinical practice? Systematic reviews and meta-analyses can provide convincing and reliable evidence relevant to many aspects of medicine and health care.1 Their value is especially clear when the results of the studies they include show clinically important effects of similar magnitude. However, the conclusions are less clear when the included studies have differing results. In an attempt to establish whether studies are consistent, reports of meta-analyses commonly present a statistical test of heterogeneity. The test seeks to determine whether there are genuine differences underlying the results of the studies (heterogeneity), or whether the variation in findings is compatible with chance alone (homogeneity). However, the test is susceptible to the number of trials included in the meta-analysis. We have developed a new quantity, I 2, which we believe gives a better measure of the consistency between trials in a meta-analysis. Assessment of the consistency of effects across studies is an essential part of meta-analysis. Unless we know how consistent the results of studies are, we cannot determine the generalisability of the findings of the meta-analysis. Indeed, several hierarchical systems for grading evidence state that the results of studies must be consistent or homogeneous to obtain the highest grading.2–4 Tests for heterogeneity are commonly used to decide on methods for combining studies and for concluding consistency or inconsistency of findings.5 6 But what does the test achieve in practice, and how should the resulting P values be interpreted? A test for heterogeneity examines the null hypothesis that all studies are evaluating the same effect. The usual test statistic …

45,105 citations

Journal ArticleDOI
TL;DR: A structured summary is provided including, as applicable, background, objectives, data sources, study eligibility criteria, participants, interventions, study appraisal and synthesis methods, results, limitations, conclusions and implications of key findings.

31,379 citations