Biomedical subjects

Colleen M Norris

Publications and source records attributed to Colleen M Norris.

17 recordsLinked to original sources

PubMed2006

Depression symptoms have a greater impact on the 1-year health-related quality of life outcomes of women post-myocardial infarction compared to men.

OBJECTIVE: Several studies report that women with CAD have a poorer prognosis than men and suggest that depressive symptoms may be a contributing factor. The purpose of this study was to examine gender differences in depressive symptoms, as they relate to health-related quality of life outcomes following an AMI. METHODS: Patients with documented AMI completed a questionnaire including the Short Form 36 physical (PCS), and mental component summary (MCS) scores, and Beck Depression Inventory at baseline and at 1 year after AMI admission. RESULTS: 486 (82%) patients completed the follow-up questionnaire. Females had significantly worse PCS and MCS scores at baseline and 1-year follow-up compared to males The mean 1-year Beck scores were significantly higher (p=0.01) for females (10.02+/-8.23) compared to males (7.78+/-8.01) indicating more reported depressive symptomatology. Multivariate analyses showed significant gender-related differences in the PCS scores at 1 year, but no gender-related differences in the 1-year MCS scores. CONCLUSIONS: These results suggest that gender differences in mental health at 1 year relate to gender-related differences at 1-year depression levels. The higher level of depression in women may be a consequence of gender differences in recovery patterns from an AMI and requires further investigation.

Activities of Daily Living↗

PubMed2006

Quality of life after coronary revascularization in the elderly.

AIMS: To describe health status outcomes at 4 years for a cohort of elderly patients with cardiac disease. METHODS AND RESULTS: Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease, an outcomes initiative capturing all patients undergoing cardiac catheterization in Alberta, Canada, health status was measured using the Seattle Angina Questionnaire (SAQ) and crude and risk-adjusted outcomes were determined and compared for patients treated with percutaneous coronary intervention or coronary artery bypass surgery (CABG) vs. medical therapy. Response rates among surviving, consenting patients were 64.8% for patients <70 years (n=7883), 77.3% for patients aged 70-79 years (n=2940), and 77.7% for patients >or=80 years of age (n=439). For patients aged <70 years, and those aged 70-79 years, for all dimensions of the SAQ, scores were significantly better for patients treated with revascularization procedures than with medical therapy. For patients over the age of 80 years, scores for patients treated with CABG in particular were significantly better, with the exception of exertional capacity. At 3 years, all scores remained stable or improved, and continued to favour revascularization. CONCLUSION: Elderly patients undergoing revascularization have better health status at 4 years than do those in the same age group who do not undergo revascularization. These findings suggest that age should not deter against revascularization given the combined survival and quality-of-life benefits.

Aged↗

PubMed2006

Ordinal regression model and the linear regression model were superior to the logistic regression models.

OBJECTIVE: Ordinal scales often generate scores with skewed data distributions. The optimal method of analyzing such data is not entirely clear. The objective was to compare four statistical multivariable strategies for analyzing skewed health-related quality of life (HRQOL) outcome data. HRQOL data were collected at 1 year following catheterization using the Seattle Angina Questionnaire (SAQ), a disease-specific quality of life and symptom rating scale. STUDY DESIGN AND SETTING: In this methodological study, four regression models were constructed. The first model used linear regression. The second and third models used logistic regression with two different cutpoints and the fourth model used ordinal regression. To compare the results of these four models, odds ratios, 95% confidence intervals, and 95% confidence interval widths (i.e., ratios of upper to lower confidence interval endpoints) were assessed. RESULTS: Relative to the two logistic regression analysis, the linear regression model and the ordinal regression model produced more stable parameter estimates with smaller confidence interval widths. CONCLUSION: A combination of analysis results from both of these models (adjusted SAQ scores and odds ratios) provides the most comprehensive interpretation of the data.

Adolescent↗

PubMed2006

Kaplan-Meier methods yielded misleading results in competing risk scenarios.

BACKGROUND AND OBJECTIVE: Time-to-event curves are routinely presented in the medical literature. The most widely used method is the Kaplan-Meier (K-M) method, but this analysis approach may not be appropriate when an analysis focuses on time-to-first event in scenarios where there are competing events. We compared K-M methods applying various censoring approaches with the lesser-known "cumulative incidence competing risks" (CICR) method in an analysis of competing events. METHODS: A registry containing data on 21,624 patients undergoing cardiac catheterization was analyzed. Time to coronary artery bypass grafting (CABG) was assessed in an analysis for which percutaneous coronary intervention and death were competing events. Time-to-CABG curves were calculated using the "K-M censor all method," "K-M censor death only method," "K-M ignore all method," and the CICR method. RESULTS: One-year CABG rates calculated for the K-M "censor all," "censor death only," and "ignore all" methods were 28.8%, 22.8%, and 22.4%, respectively compared to the "actual" rate of 20.8%. For the CICR method, the corresponding 1-year rate was identical to the "actual" rate. CONCLUSION: In situations with competing risks, and where an analysis focuses on first events, the CICR method is most appropriate, as K-M methods will tend to overestimate event rates.

Angioplasty, Balloon, Coronary↗

PubMed2005

Population rates of cardiac catheterization and yield of high-risk coronary artery disease.

BACKGROUND: The optimal population rate of cardiac catheterization is unknown. One potential way to determine it would be to examine whether there is a population rate beyond which the yield of high-risk coronary artery disease (CAD) does not rise. METHODS: Using a detailed clinical registry that captures all patients undergoing cardiac catheterization in Alberta, we determined annual population rates of cardiac catheterization and the corresponding yield of cases of high-risk CAD in each of Alberta's 17 health regions from 1995 to 2002. Least squares linear regression analysis and hierarchical modelling methods were then used to assess the linear relation between catheterization rates and rates of high-risk CAD. RESULTS: The age-adjusted average rate of cardiac catheterization among men ranged from 404.9 to 638.1 per 100,000 population aged over 20 years. Among women, the average rate ranged from 171.8 to 314.0 per 100,000. For both sexes, increased regional rates of catheterization were associated with a linearly increasing yield of high-risk CAD, with no evidence of a plateau in yield when more procedures were performed. One additional case of high-risk CAD was identified for every 2.5 additional cardiac catheterization procedures performed among men, and for every 3.7 additional procedures performed among women. INTERPRETATION: The increasing yield of patients with high-risk CAD associated with increased regional population rates of cardiac catheterization, together with the absence of a plateau in yield, suggests that Alberta's population rates of cardiac catheterization are suboptimal to detect people with high-risk CAD.

Adult↗

PubMed2005

Characteristics and outcomes of patients with acute myocardial infarction and angiographically normal coronary arteries.

This study on patients undergoing coronary angiography for acute myocardial infarction demonstrated that 2.8% of patients had angiographically normal coronary arteries and that these patients have a better prognosis than patients with angiographically verified coronary artery disease. The trend toward a higher prevalence of malignancy in this unique patient group raises the possibility of malignancy-induced hypercoagulability or inflammation as an underlying etiologic factor.

Aged↗

PubMed2004

The association among renal insufficiency, pharmacotherapy, and outcomes in 6,427 patients with heart failure and coronary artery disease.

OBJECTIVES: This study was designed to examine the use of cardiovascular medications and outcomes in patients with heart failure (HF) and renal dysfunction. BACKGROUND: Renal insufficiency is associated with poorer outcomes in patients with HF, but the mechanisms are uncertain. In particular, the degree of therapeutic nihilism in these patients, and whether it is appropriate, is unclear. METHODS: This was a prospective cohort study with a one-year follow-up. RESULTS: In 6,427 patients with cardiologist-diagnosed HF and angiographically proven coronary artery disease (mean age 69 years; 65% men; one-year mortality, 10%), 39% had creatinine clearances <60 ml/min. Patients with renal insufficiency were less likely to be prescribed angiotensin-converting enzyme (ACE) inhibitors, beta-blockers, statins, or aspirin (all p < 0.001). However, users of aspirin (odds ratio [OR] 0.69, 95% confidence interval [CI] 0.57 to 0.85), statins (OR 0.79, 95% CI 0.64 to 0.97), and beta-blockers (OR 0.75, 95% CI 0.62 to 0.90) were less likely to die in the subsequent 12 months than nonusers, irrespective of renal function (all OR adjusted for covariates including atherosclerotic burden and ejection fraction). Although ACE inhibitor users with creatinine clearances > or =60 ml/min had lower 12-month mortality (OR 0.72, 95% CI 0.48 to 0.99), ACE inhibitor users with clearances <60 ml/min did not (OR 1.21, 95% CI 0.97 to 1.51). CONCLUSIONS: Renal insufficiency is common in patients with HF and coronary artery disease, and these patients have more advanced coronary atherosclerosis. Patients with renal insufficiency are less likely to be prescribed efficacious therapies, but have better outcomes if they receive these medications.

Adrenergic beta-Antagonists↗

PubMed2004

Women with coronary artery disease report worse health-related quality of life outcomes compared to men.

BACKGROUND: Although there have been substantial medical advances that improve the outcomes following cardiac ischemic events, gender differences in the treatment and course of recovery for patients with coronary artery disease (CAD) continue to exist. There is a general paucity of data comparing the health related quality of life (HRQOL) in men and women undergoing treatment for CAD. The purpose of this study was to compare HRQOL outcomes of men and women in Alberta, at one-year following initial catheterization, after adjustment for known demographic, co-morbid, and disease severity predictors of outcome. METHOD: The HRQOL outcome data were collected by means of a self-reported questionnaire mailed to patients on or near the one-year anniversary of their initial cardiac catheterization. Using the Seattle Angina Questionnaire (SAQ), 5 dimensions of HRQOL were measured: exertional capacity, anginal stability, anginal frequency, quality of life and treatment satisfaction. Data from the APPROACH registry were used to risk-adjust the SAQ scale scores. Two analytical strategies were used including general least squares linear modeling, and proportional odds modeling sometimes referred to as the "ordinal logistic modeling". RESULTS: 3392 (78.1%) patients responded to the follow-up survey. The adjusted proportional odds ratios for men relative to women (PORs > 1 = better) indicated that men reported significantly better HRQOL on all 5 SAQ dimensions as compared to women. (PORs: Exertional Capacity 3.38 (2.75-4.15), Anginal Stability 1.23 (1.03-1.47), Anginal Frequency 1.70 (1.43-2.01), Treatment Satisfaction 1.27 (1.07-1.50), and QOL 1.74 (1.48-2.04). CONCLUSIONS: Women with CAD consistently reported worse HRQOL at one year follow-up compared to men. These findings underline the fact that conclusions based on research performed on men with CAD may not be valid for women and that more gender-related research is needed. Future studies are needed to further examine gender differences in psychosocial adjustment following treatment for CAD, as adjustment for traditional clinical variables fails to explain sex differences in health related quality of life outcomes.

Aged↗

PubMed2004

Systematic review of statistical methods used to analyze Seattle Angina Questionnaire scores.

BACKGROUND: The Seattle Angina Questionnaire (SAQ) is being used with increasing frequency in clinical research to address the health-related quality of life (HRQOL) outcomes of patients with coronary artery disease. The reliability and validity of the SAQ as a disease-specific HRQOL questionnaire has been established. The purpose of this paper was to systematically identify all studies analyzing SAQ scores, and to review the suitability of the statistical methods used. METHODS: The literature search included all years from the development of the SAQ (1994) to December 2001. Electronic databases were searched using 'Seattle angina questionnaire' as a key word, text word or medical subject heading, as well as combinations of Seattle, angina and questionnaire. The Scientific Citation Index was searched to identify any manuscripts that cited the developmental articles of the SAQ. Relevant manuscripts were identified as studies that used the SAQ as a measurement tool for HRQOL outcome data. RESULTS: Of the 62 studies identified, 14 articles used the SAQ as an outcome measurement tool. The statistical validity of all but one of the 14 studies was doubtful because assumptions required for the use of parametric tests were not addressed and there was no mention of the distributions of the SAQ scores. Based on the designs of the studies, unsuitable analysis methods were used. CONCLUSIONS: Our results demonstrate that investigators may need to increase their attention to the distributional characteristics of their HRQOL data and the design of the study before applying statistical tests to appropriately analyze SAQ HRQOL data.

Angina Pectoris↗

PubMed2004

Health-related quality of life outcomes of patients with coronary artery disease treated with cardiac surgery, percutaneous coronary intervention or medical management.

BACKGROUND: Given the repeated findings of little or no difference in mortality outcomes between percutaneous coronary intervention (PCI) with or without stent and coronary artery bypass graft surgery (CABG), there is a need to assess the health-related quality of life (HRQOL) outcomes associated with revascularization decisions. OBJECTIVE: To compare risk-adjusted HRQOL outcomes by treatment strategy one year following cardiac catheterization. METHODS: Using an inception cohort study design, the sample included all Alberta residents, 18 years of age or older, referred for cardiac catheterization, from January 1, 1996, to December 31, 1998, with two or more diseased coronary vessels at catheterization. Patients received a follow-up questionnaire including the Seattle Angina Questionnaire (SAQ), one year following their index catheterization. The SAQ comprises five dimensional scales measuring exertional capacity, anginal stability, anginal frequency, treatment satisfaction and quality of life. RESULTS: Three thousand three hundred ninety-two (78.1%) patients responded to the follow-up survey. Responders who were revascularized consistently reported significantly better HRQOL compared with responders treated with medical management. Responders undergoing CABG reported significantly better HRQOL in all but one SAQ dimension compared with responders who had either a PCI with or without stent. Responders who had a PCI with stent reported better HRQOL compared with responders who underwent a PCI without a stent. CONCLUSION: The treatment decision to revascularize the coronary vessels, whether with PCI with or without a stent or with CABG, was consistently associated with significantly better HRQOL at one-year follow-up compared with patients treated with medical therapy.

Adult↗

PubMed2003

Sex differences in the prognostic importance of diabetes in patients with ischemic heart disease undergoing coronary angiography.

OBJECTIVE: Women with ischemic heart disease have poorer outcomes than men and are suggested to have greater risk associated with diabetes. We evaluated the prognosis associated with diabetes, in analyses stratified by sex, to determine whether similar differences are seen in a large unselected cohort of patients. RESEARCH DESIGN AND METHODS: Using the Alberta Provincial Project for Outcomes Assessment in Coronary Heart Disease (APPROACH), a clinical data collection and follow-up initiative capturing all patients undergoing cardiac catheterization in Alberta, Canada, the relative significance of diabetes on long-term survival in 13152 men and 4249 women was evaluated in patients presenting with or without myocardial infarction and according to first treatment received. RESULTS: The 1-year mortality rates were 4.7% and 6.8% in men and women (P < 0.001), 4.1% and 7.4% in nondiabetic and diabetic men (P < 0.001), and 5.8% and 9.6% in nondiabetic and diabetic women, respectively (P < 0.001). The risk-adjusted Cox proportional hazard ratios associated with diabetes in myocardial infarction were 1.03 in men and 1.20 in women. The diabetes hazard ratios for percutaneous coronary intervention were 1.28 in men and 1.40 in women, 1.23 in men and 1.32 in women for bypass surgery, and 1.26 in men and 1.31 in women for medical therapy (P = NS for all diabetes hazard ratio comparisons between men and women). CONCLUSIONS: Hazard ratios quantifying the adverse prognosis associated with diabetes in patients undergoing angiography are consistently higher among women than men, but the differences across sexes are not statistically significant. These slight sex differences noted in the APPROACH registry are similar to previously reported findings and may be clinically important.

Aged↗

PubMed2002

Survival after coronary revascularization in the elderly.

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 > or =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 > or = 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 > or =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.

Aged↗

PubMed2002

Sex differences in access to coronary revascularization after cardiac catheterization: importance of detailed clinical data.

BACKGROUND: Although some studies suggest that access to cardiac procedures may differ by sex, others have found no evidence of gender bias in cardiac care. OBJECTIVE: To study rates of percutaneous coronary intervention (PCI) or coronary artery bypass graft (CABG) surgery in men and women after cardiac catheterization. DESIGN: Cohort study with prospective data collection. SETTING: Alberta, Canada. PATIENTS: Persons undergoing cardiac catheterization between 1 January 1995 and 31 December 1998 (n = 21 816). MEASUREMENTS: The occurrence of revascularization procedures (PCI or CABG) in the year after cardiac catheterization was measured. Unadjusted revascularization rates, partially adjusted rates (adjusted for clinical variables available in most databases, including administrative databases), and fully adjusted rates (additionally adjusted for extent of coronary artery disease and ejection fraction) were also evaluated. RESULTS: The unadjusted relative risk was 0.67 (95% CI, 0.65 to 0.71) for the end point of any revascularization in women relative to men. The relative risk increased to 0.69 (CI, 0.66 to 0.72) with partial adjustment and to 0.98 (CI, 0.94 to 1.03) with full adjustment, indicating equivalent access to revascularization for men and women. For PCI, the corresponding relative risks were 0.77 (CI, 0.73 to 0.82), 0.84 (CI, 0.80 to 0.89), and 1.02 (CI, 0.96 to 1.08). For CABG surgery, the relative risks were 0.54 (CI, 0.51 to 0.58), 0.51 (CI, 0.48 to 0.55), and 0.93 (CI, 0.87 to 1.01). CONCLUSIONS: In Alberta, Canada, clinical variables fully explain sex differences in rates of revascularization after cardiac catheterization, and misleading conclusions would arise without full adjustment for clinical differences between men and women. Extreme caution is needed in interpreting reports on access to care that use sparsely detailed clinical data sources.

Alberta↗

PubMed2002

Multiple imputation versus data enhancement for dealing with missing data in observational health care outcome analyses.

The problem of missing data is frequently encountered in observational studies. We compared approaches to dealing with missing data. Three multiple imputation methods were compared with a method of enhancing a clinical database through merging with administrative data. The clinical database used for comparison contained information collected from 6,065 cardiac care patients in 1995 in the province of Alberta, Canada. The effectiveness of the different strategies was evaluated using measures of discrimination and goodness of fit for the 1995 data. The strategies were further evaluated by examining how well the models predicted outcomes in data collected from patients in 1996. In general, the different methods produced similar results, with one of the multiple imputation methods demonstrating a slight advantage. It is concluded that the choice of missing data strategy should be guided by statistical expertise and data resources.

Alberta↗

PubMedDate not supplied

Referral rate and outcomes of cardiac rehabilitation after cardiac catheterization in a large Canadian city.

PURPOSE: The benefits of cardiac rehabilitation (CR) for patients with coronary artery disease are extensive and compelling, demonstrating reductions in mortality. However, some reports suggest that only 10% to 20% of eligible patients currently participate in formal CR programs. The purpose of this study was to identify the proportion of patients referred to CR in a large Canadian city, and to determine their statistically adjusted survival rates relative to patients not referred to CR. METHODS: Subjects eligible for this study included all adult residents with coronary artery disease from 1995 to 1999 in the Alberta Provincial Project for Outcome Assessment in Coronary Heart Disease registry. All 5,081 patients who survived 6 months or more after catheterization were included in the analysis. Survival data were adjusted using a Cox proportional hazards model. RESULTS: Referral to a CR program (28.9% of patients) was significantly more likely for young male patients who had undergone a prior revascularization procedure, presented with an ejection fraction exceeding 50%, and did not report cerebrovascular, peripheral vascular, or renal disease. Crude hazard ratios indicated that referral to a CR program remained significantly associated with lower mortality after control was used for clinical, anatomic, treatment and comorbid conditions recorded at catheterization (hazard ratio, 0.68; 95% confidence interval, 0.51-0.90; P = .005). CONCLUSIONS: Despite the proven efficacy of CR in clinical trials, fewer than one third of the patients undergoing cardiac catheterization are referred to a CR program. The better survival outcomes noted for patients referred to CR suggests that there is an opportunity to improve care and outcomes through increased referral of patients to such programs.

Alberta↗

PubMedDate not supplied

Pretransplant diabetes, not donor age, predicts long-term outcomes in cardiac transplantation.

BACKGROUND AND AIM: Accepting donors of advanced age may increase the number of hearts available for transplantation. Objectives were to review the outcomes of using cardiac donors 50 years of age and older and to identify predictors of outcome at a single institution. METHODS: A retrospective analysis of all adult cardiac transplants (n = 338) performed at our institution between 1988 and 2002 was conducted. RESULTS: Of these, 284 patients received hearts from donors <50 years old and 54 received hearts from donors > or =50 years old. Recipients of hearts from older donors had a greater frequency of pretransplant diabetes (19% vs 33%), renal failure (16% vs 30%), and dialysis (3% vs 9%). There were no differences in ICU or postoperative length of stay, days ventilated, or early rejection episodes. Recipients of older donor hearts, however, had increased perioperative mortality (7% vs 17%; p = 0.03). Multivariate analysis identified older donors (OR 2.599; p = 0.03) and donor ischemia time (OR 1.006; p = 0.002) as significant predictors of perioperative mortality. Actuarial survival at 1 (87% vs 74%), 5 (76% vs 69%), and 10 (59% vs 58%) years was similar (p = 0.08) for the two groups. Separate multivariate analyses identified pretransplant diabetes as the sole predictor of long-term survival (HR 1.659; p = 0.02) and transplant coronary disease (HR 2.486; p = 0.003). CONCLUSIONS: Despite increased perioperative mortality, donors > or =50 years old may be used with long-term outcomes similar to those of younger donor hearts. This has potential to expand the donor pool. Pretransplant diabetes has a significant impact on long-term outcomes in cardiac transplantation and requires further investigation.

Adolescent↗

PubMedDate not supplied

Misclassification of income quintiles derived from area-based measures. A comparison of enumeration area and forward sortation area.

BACKGROUND: Census-based methods are often used to estimate socioeconomic status. We assessed the agreement between Forward Sortation Area (FSA) and Enumeration Area (EA) derived income levels for all patients undergoing cardiac catheterization in Alberta, Canada, from 1995-1998. METHODS: Income quintiles were calculated from census data for FSA and EA level. FSA- and EA-derived income measures were compared for misclassification. Both methods were then applied to the data to determine 4-year survival by income grouping in 21,446 patients following catheterization. RESULTS: The variability in EA-derived incomes for any given FSA-derived income is large. Only 40% of income quintiles are in agreement between the methods. For EA-based analyses, there is a linear relationship between higher income and lower mortality across all quintiles, while for FSA-based analyses, only the lowest income quintile had significantly higher mortality. DISCUSSION: Assuming that FSA-based methods are more likely to misclassify income compared to EA-based measures, the results for the FSA-based analyses are more likely to be erroneous. EA-derived measures should therefore be used when individual data are not available.

Alberta↗