Colleen M. Norris

Dr. Colleen M. Norris

orcid

Research Focus & Metrics

Academic Career Length

34Years (1993-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 July 2008 in American Heart Journal
Verified
Journal Article
Open access
AOAntigone Oreopoulos
Antigone Oreopoulos
RPRaj Padwal
Raj Padwal
Kamyar Kalantar-ZadehKamyar Kalantar-Zadeh
Kamyar Kalantar-Zadeh
GFGregg C. Fonarow
Gregg C. Fonarow
CNColleen M. Norris
Colleen M. Norris
FMFinlay A. McAlister
Finlay A. McAlister
In patients with chronic heart failure (CHF), previous studies have reported reduced mortality rates in patients with increased body mass index (BMI). The potentially protective effect of increased BMI in CHF has been termed the obesity paradox or reverse epidemiology. This meta-analysis was conducted to examine the relationship between increased BMI and mortality in patients with CHF. We searched the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, Scopus, and Web of Science to identify studies with contemporaneous control groups (cohort, case-control, or randomized controlled trials) that examined the effect of obesity on all-cause and cardiovascular mortality. Two reviewers independently assessed studies for inclusion and performed data extraction. Nine observational studies met final inclusion criteria (total n = 28,209). Mean length of follow-up was 2.7 years. Compared to individuals without elevated BMI levels, both overweight (BMI approximately 25.0-29.9 kg/m(2), RR 0.84, 95% CI 0.79-0.90) and obesity (BMI approximately > or =30 kg/m(2), RR 0.67, 95% CI 0.62-0.73) were associated with lower all-cause mortality. Overweight (RR 0.81, 95% CI 0.72-0.92) and obesity (RR 0.60, 95% CI 0.53-0.69) were also associated with lower cardiovascular mortality. In a risk-adjusted sensitivity analysis, both obesity (adjusted HR 0.88, 95% CI 0.83-0.93) and overweight (adjusted HR 0.93, 95% CI 0.89-0.97) remained protective against mortality. Overweight and obesity were associated with lower all-cause and cardiovascular mortality rates in patients with CHF and were not associated with increased mortality in any study. There is a need for prospective studies to elucidate mechanisms for this relationship.

23 January 2008 in BMC Medical Research Methodology
Verified
Journal Article
Open access
PDF file
DSDanielle A Southern
Danielle A Southern
CNColleen M. Norris
Colleen M. Norris
HQHude Quan
Hude Quan
FSFiona M Shrive
Fiona M Shrive
PGP Diane Galbraith
P Diane Galbraith
TIthe APPROACH Investigators
the APPROACH Investigators
Background: We have previously described a method for dealing with missing data in a prospective cardiac registry initiative. The method involves merging registry data to corresponding ICD-9-CM administrative data to fill in missing data 'holes'. Here, we describe the process of translating our data merging solution to ICD-10, and then validating its performance. Methods: A multi-step translation process was undertaken to produce an ICD-10 algorithm, and merging was then implemented to produce complete datasets for 1995–2001 based on the ICD-9-CM coding algorithm, and for 2002–2005 based on the ICD-10 algorithm. We used cardiac registry data for patients undergoing cardiac catheterization in fiscal years 1995–2005. The corresponding administrative data records were coded in ICD-9-CM for 1995–2001 and in ICD-10 for 2002–2005. The resulting datasets were then evaluated for their ability to predict death at one year. Results: The prevalence of the individual clinical risk factors increased gradually across years. There was, however, no evidence of either an abrupt drop or rise in prevalence of any of the risk factors. The performance of the new data merging model was comparable to that of our previously reported methodology: c-statistic = 0.788 (95% CI 0.775, 0.802) for the ICD-10 model versus c-statistic = 0.784 (95% CI 0.780, 0.790) for the ICD-9-CM model. The two models also exhibited similar goodness-of-fit. Conclusion: The ICD-10 implementation of our data merging method performs as well as the previously-validated ICD-9-CM method. Such methodological research is an essential prerequisite for research with administrative data now that most health systems are transitioning to ICD-10.

13 March 2007 in Canadian Medical Association Journal
Verified
Journal Article
Open access
PDF file
LPLouise Pilote
Louise Pilote
KDKaberi Dasgupta
Kaberi Dasgupta
VGVeena Guru
Veena Guru
KHKarin H. Humphries
Karin H. Humphries
JMJennifer McGrath
Jennifer McGrath
VTVicky Tagalakis
Vicky Tagalakis
Cardiovascular disease (CVD) is the leading cause of mortality in women. In fact, CVD is responsible for a third of all deaths of women worldwide and half of all deaths of women over 50 years of age in developing countries. The prevalence of CVD risk factor precursors is increasing in children. Retrospective analyses suggest that there are some clinically relevant differences between women and men in terms of prevalence, presentation, management and outcomes of the disease, but little is known about why CVD affects women and men differently. For instance, women with diabetes have a significantly higher CVD mortality rate than men with diabetes. Similarly, women with atrial fibrillation are at greater risk of stroke than men with atrial fibrillation. Historically, women have been underrepresented in clinical trials. The lack of good trial evidence concerning sex-specific outcomes has led to assumptions about CVD treatment in women, which in turn may have resulted in inadequate diagnoses and suboptimal management, greatly affecting outcomes. This knowledge gap may also explain why cardiovascular health in women is not improving as fast as that of men. Over the last decades, mortality rates in men have steadily declined, while those in women remained stable. It is also becoming increasingly evident that gender differences in cultural, behavioural, psychosocial and socioeconomic status are responsible, to various degrees, for the observed differences between women and men. However, the interaction between sex-and gender-related factors and CVD outcomes in women remains largely unknown.

1 October 2004 in JACC
Verified
Journal Article
Closed access
JEJustin Ezekowitz
Justin Ezekowitz
FMFinlay A. McAlister
Finlay A. McAlister
KHKarin H. Humphries
Karin H. Humphries
CNColleen M. Norris
Colleen M. Norris
MTMarcello Tonelli
Marcello Tonelli
MKMerril L. Knudtson
Merril L. Knudtson

21 May 2002 in Circulation
Verified
Journal Article
Closed access
MGMichelle M. Graham
Michelle M. Graham
WGWilliam A. Ghali
William A. Ghali
PFPeter D. Faris
Peter D. Faris
PGP. Diane Galbraith
P. Diane Galbraith
CNColleen M. Norris
Colleen M. Norris
MKMerril L. Knudtson
Merril L. Knudtson
Background — Elderly patients with ischemic heart disease are increasingly referred for coronary artery bypass grafting (CABG) or percutaneous coronary intervention (PCI). However, reports of poor outcomes in the elderly have led to questions about the benefit of these strategies. We studied survival by prescribed treatment (CABG, PCI, or medical therapy) for patients in 3 age categories: <70 years, 70 to 79 years, and ≥80 years of age. Methods and Results — The Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH) is a clinical data collection and outcome monitoring initiative capturing all patients undergoing cardiac catheterization and revascularization in the province of Alberta, Canada, since 1995. Characteristics and long-term outcomes of a cohort of >6000 elderly patients with ischemic heart disease were compared with younger patients. In 15 392 patients >70 years of age, 4-year adjusted actuarial survival rates for CABG, PCI, and medical therapy were 95.0%, 93.8%, and 90.5%, respectively. In 5198 patients 70 to 79 years of age, survival rates were 87.3%, 83.9%, and 79.1%, respectively. In 983 patients ≥80 years of age, survival was 77.4% for CABG, 71.6% for PCI, and 60.3% for medical therapy. Absolute risk differences in comparison to medical therapy for CABG (17.0%) and PCI (11.3%) were greater for patients ≥80 years of age than for younger patients. Conclusions — Elderly patients paradoxically have greater absolute risk reductions associated with surgical or percutaneous revascularization than do younger patients. The combination of these results with a recent randomized trial suggests that the benefits of aggressive revascularization therapies may extend to subsets of patients in older age groups.

1 January 2016 in JACC
Verified
Journal Article
Closed access
RPRoxanne Pelletier
Roxanne Pelletier
NKNadia A. Khan
Nadia A. Khan
JCJafna Cox
Jafna Cox
SDStella S. Daskalopoulou
Stella S. Daskalopoulou
MEMark J. Eisenberg
Mark J. Eisenberg
LPLouise Pilote
Louise Pilote