Biomedical subjects

Louise Pilote

Publications and source records attributed to Louise Pilote.

68 records · Page 4Linked to original sources

PubMed2003

Cardiac procedure use and outcomes in elderly patients with acute myocardial infarction in the United States and Quebec, Canada, 1988 to 1994.

BACKGROUND: Studies from the early 1990s have documented greater intensity of treatment for patients with acute myocardial infarction (AMI) in the United States compared with Canada, with little difference in health outcomes. Little is known about whether treatments and outcomes are changing differently over time in the two countries, and whether the differences vary with patient age. METHODS: We conducted a retrospective cohort study of trends in cardiac procedure use, mortality, and recurrent AMI for patients 65 years or older hospitalized with AMI in the United States and Quebec. We examined Medicare claims and enrollment data from the United States (1.5 million) and provincial claims data from Quebec (35,000) between 1988 and 1994. RESULTS: Use of cardiac procedures grew more rapidly between 1988 and 1994 in the United States, particularly for patients 75 years or older; unlike in Quebec, these cardiac procedures were performed soon after AMI. Both countries experienced significant declines in 1-year mortality: the decline averaged 1.27% points per year in the United States and 1.05% points in Quebec (P = ns). For AMI patients 75 years or older, 30-day and 1-year mortality declined approximately twice as rapidly in the United States as in Quebec (P < 0.01). The decline in mortality in the United States relative to Canada was significantly greater among patients 75 years or older but not among those age 65 to 74 years. Readmission rates with recurrent AMI were almost unchanged. CONCLUSIONS: Over time, the use of cardiac procedures in elderly patients with AMI has risen more rapidly in the United States than in Quebec. These differences in procedure trends were associated with reductions in overall long-term AMI mortality in both countries.

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PubMed2003

Does aggressive care following acute myocardial infarction reduce mortality? Analysis with instrumental variables to compare effectiveness in Canadian and United States patient populations.

BACKGROUND: Previous U.S. studies suggest that the incremental ("marginal") use of the aggressive approach to care for acute myocardial infarction (AMI) in patients differing only in their distance to hospitals offering aggressive care may be associated with small mortality benefits. We hypothesized that the marginal benefits should be larger in Canada, as the country is operating on a lower margin because the approach to care is more conservative overall. METHODS: This retrospective study used administrative data of hospital admissions and health services for all patients admitted for a first AMI in Quebec in 1988 (n = 8,674). We used differential distances to hospitals offering aggressive care as instrumental variables when measuring mortality up to four years after AMI. RESULTS: Of the 4,422 subjects who were > or = 65 years old, 11 percent received cardiac catheterization within 90 days after admission. In a previous study that applied similar methodology to the 1987 U.S. Medicare population, 23 percent of subjects received catheterization within 90 days. As in the U.S. study, we found that subjects living closer to hospitals offering aggressive care were more likely to receive aggressive care than subjects living further away (26 percent versus 19 percent received cardiac catheterization within 90 days; 95 percent CI: 5 percent to 9 percent). Unlike the U.S. study, we found no differences in mortality across the "close" versus "far" differential distance groups (unadjusted differences at one year: 1 percent; 95 percent CI: -1 percent to 3 percent). This absence of association held in elderly (> or = 65 years) and younger age groups. Adjusted results also showed no differences between subjects receiving aggressive versus conservative care (at one year: 4 percent; 95 percent CI: -11 percent to 20 percent). CONCLUSIONS: Contrary to our hypothesis, but consistent with results from numerous randomized trials and observational studies, we cannot confirm that, on the margin, the aggressive approach to post-AMI care is associated with mortality benefits in Canada.

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PubMed2003

CCORT/CCS quality indicators for acute myocardial infarction care.

BACKGROUND: Although quality indicators for the care of acute myocardial infarction (AMI) patients have been described for other countries, there are none specifically designed for the Canadian health care system. The authors' goal was to develop a set of Canadian quality indicators for AMI care. METHODS: A literature review identified existing quality indicators for AMI care. A list of potential indicators was assessed by a nine-member panel of clinicians from a variety of disciplines using a modified-Delphi panel process. After an initial round of rating the potential indicators, a series of indicators was identified for a second round of discussion at a national meeting. Further refinement of indicators occurred following a teleconference and review by external reviewers. RESULTS: To identify an AMI cohort, case definition criteria were developed, using a hospital discharge diagnosis for AMI of International Classification of Diseases-Ninth revision (ICD-9) code 410.x. Thirty-seven indicators for AMI care were established. Pharmacological process of care indicators included administration of acetylsalicylic acid, beta-blockers, angiotensin-converting enzyme inhibitors, thrombolytics and statins. Mortality and readmissions for AMI, unstable angina and congestive heart failure were recommended as outcome indicators. Nonpharmacological indicators included median length of stay in the emergency department, and median waiting times for cardiac catheterization, percutaneous coronary intervention and/or coronary artery bypass graft surgery. INTERPRETATION: A set of Canadian quality indicators for the care of AMI patients has been established. It is anticipated that these indicators will be useful to clinicians and researchers who want to measure and improve the quality of AMI patient care in Canada.

Ambulatory Care↗

PubMed2003

Quality of life after acute myocardial infarction: a systematic review.

BACKGROUND: Health-related quality of life (HRQoL) is an important measure of a patient's recovery after an illness. It has been suggested that different treatments may affect the HRQoL of patients with acute myocardial infarction (AMI). OBJECTIVE: To examine the effects of an AMI on HRQoL and identify common patterns in the HRQoL assessments of post-AMI patients. METHODS: Systematic review of published studies. RESULTS: The impact of AMI on HRQoL appears to be modest. Physical capacity, work status, symptoms, functional status and general health perceptions declined the most after AMI. However, the majority of these HRQoL domains improved to normal levels with time. The severity of AMI-related symptoms, timing of HRQoL measurements after AMI and patients' age have had the most important influence on patient HRQoL after AMI. CONCLUSIONS: The review suggests that HRQoL is minimally affected by AMI. However, current measurement tools may not be sensitive enough to detect changes in HRQoL after AMI.

Age Factors↗

PubMed2003

Outcomes of acute myocardial infarction in Canada.

BACKGROUND: Little information is available on recent population-based trends in the outcomes of patients who have had an acute myocardial infarction (AMI) in Canada. METHODS: Data were analyzed from the Discharge Abstract Database and Hospital Morbidity Database of the Canadian Institute for Health Information. All new cases of AMI in Canada between fiscal 1997/98 and fiscal 1999/2000 of patients at least 20 years old were examined. Data were also analyzed from these databases for hospital readmissions for a second AMI, angina and congestive heart failure (CHF). RESULTS: There were 139,523 new AMI cases. The overall crude in-hospital AMI mortality rate in Canada was 12.3%. In-hospital mortality rate after an AMI was worse for women than for men in Canada (16.7% and 9.9%, respectively). The age- and sex-standardized in-hospital mortality rate varied from a low of 10.5% (95% CI 8.4% to 12.6%) in Prince Edward Island to a high of 13.1% (95% CI 12.8% to 13.5%) in Quebec. Among AMI survivors, 12.5% were readmitted within one year for angina, 7.7% for a second AMI and 7.5% for CHF. There were wide interregional differences in age- and sex-standardized mortality rates and one-year readmission rates. CONCLUSIONS: AMI is associated with a substantial acute mortality rate in Canada, especially in the elderly and female patients. Identifying the causes of interregional differences in patient outcomes should be a priority for future research.

Adult↗

PubMed2003

Medical therapy in patients undergoing percutaneous coronary intervention: results from the ROSETTA registry.

BACKGROUND: Previous studies have examined medication use among patients with coronary artery disease who have suffered an acute myocardial infarction (MI). However, little is known about medication use among patients with coronary artery disease who undergo percutaneous coronary intervention (PCI). OBJECTIVE: To examine the patterns of use of medical therapy among patients who undergo PCI; and to examine the determinants of medical therapy in these patients. METHODS: The Routine versus Selective Exercise Treadmill Testing after Angioplasty (ROSETTA) registry is a prospective multicentre study examining the use of functional testing after PCI. The medication use was examined among 787 patients who were enrolled in the ROSETTA registry at 13 clinical centres in five countries. RESULTS: Most patients were men (mean age 61+/-11 years, 76% male) who underwent single vessel PCI (85%) with stent implantation (58%). At admission, discharge and six months, rates of acetylsalicylic acid use were 77%, 96% and 93%, respectively (discharge versus six months, P<0.0001). Rates of use of other oral antiplatelet agents were 11%, 59% and 2% (P=0.02). For individual anti-ischemic medications, rates of use were as follows: beta-blockers 49%, 58% and 59% (P<0.0001); calcium antagonists 34%, 43% and 42% (P<0.0001); and nitrates 42%, 56% and 43% (P<0.0001). Rates of use of combination anti-ischemic medications were as follows: triple therapy 7%, 9% and 9% (P<0.0001); double therapy 34%, 47% and 38% (P<0.0001); monotherapy 36%, 36% and 41% (P<0.0001); and no anti-ischemic therapy 23%, 8% and 12% (P<0.0001). Rates of use of angiotensin-converting enzyme inhibitors were 25%, 33% and 32% (P<0.0001), and rates of use of lipid lowering agents were 41%, 52% and 61% (P<0.0001). CONCLUSIONS: Trials and guidelines statements have favourably affected the rates of use of acetylsalicylic acid and other antiplatelet agents after PCI. However, in spite of patients undergoing a successful revascularization procedure, physicians do not reduce the use of anti-ischemic medical therapy.

Adrenergic beta-Antagonists↗

PubMed2002

The effects of cost-sharing on essential drug prescriptions, utilization of medical care and outcomes after acute myocardial infarction in elderly patients.

BACKGROUND: After a change in Quebec's policy on drug coverage in August 1996, elderly patients' copayments for prescription drugs increased. We assessed the impact of this drug policy reform on prescribing patterns for essential cardiac medications, utilization of medical care and related health outcomes after acute myocardial infarction. METHODS: Patients at least 65 years of age who experienced acute myocardial infarction between 1994 and 1998 were identified through the Quebec discharge summary database. Drug claims databases were analyzed to determine rates of prescription of essential cardiac medications for cohorts of patients admitted before and after the policy reform. The impact on readmissions for cardiac-related complications, outpatient visits to physicians and emergency departments, and mortality rate was also assessed. RESULTS: The proportion of patients who received prescriptions for beta-blockers, angiotensin-converting enzyme inhibitors and lipid-lowering drugs increased over time and, more specifically, did not appear to decline with the change in the drug policy. In addition, the policy reform did not appear to affect persistence of drug therapy (the proportion of time for which patients were covered by prescriptions over the year after discharge). There was no within-class shift from more to less expensive drugs. Use of cardiac procedures increased over time, but this increase was unrelated to the date of the policy reform. Finally, rates of readmission for complications, visits to individual physicians and to emergency departments, and mortality rate were unchanged. The findings did not vary with sex or socioeconomic status. INTERPRETATION: Prescriptions for essential cardiac medications and care related to acute myocardial infarction in elderly patients did not change with increases in out-of-pocket copayment, regardless of sex or socioeconomic status.

Adrenergic beta-Antagonists↗

PubMed2002

Association between naproxen use and protection against acute myocardial infarction.

BACKGROUND: The association between the use of nonsteroidal anti-inflammatory drugs (NSAIDs) and acute myocardial infarction (AMI) is unclear. Nonsteroidal anti-inflammatory drugs vary in their antithrombotic properties, with naproxen having a particularly effective antithrombotic potential. OBJECTIVE: To compare the effect of naproxen vs other NSAIDs in the prevention of AMI in an older population. METHODS: Population-based, matched case-control study. Patients (aged > or =65 years) in Quebec had been hospitalized for AMI between January 1, 1992, and December 31, 1994. The admission date for AMI was considered the index date. Control subjects were randomly selected from a Quebec drug and physician claims database. For each case, a control was matched with the same index date, age (within 2 years), and sex. Cases and controls were required to have at least 1 year of pharmaceutical and medical records before the index date to identify risk factors for AMI and exposure to naproxen or other nonaspirin NSAIDs. Concurrent exposure to a medication was defined as exposure to that medication at the index date. Logistic regression analyses were used to evaluate the association between the use of naproxen and other NSAIDs in the prevention of AMI, adjusting for potential confounders. RESULTS: Included in the study were 4163 cases and 14 160 controls. Determinants (adjusted odds ratios [95% confidence intervals]) of AMI included use in the prior year of anticoagulants (0.76 [0.64-0.90]), nitrates (2.01 [1.86-2.17]), antidiabetic agents (1.72 [1.56-1.90]), antihypertensive agents (1.36 [1.28-1.45]), and lipid-lowering agents (0.83 [0.75-0.91]), as well as concurrent exposure to naproxen vs other NSAIDs (0.79 [0.63-0.99]). CONCLUSION: Compared with other NSAIDs, concurrent exposure to naproxen has a protective effect against AMI.

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PubMed2002

Outcomes research in the development and evaluation of practice guidelines.

BACKGROUND: Practice guidelines have been developed in response to the observation that variations exist in clinical medicine that are not related to variations in the clinical presentation and severity of the disease. Despite their widespread use, however, practice guideline evaluation lacks a rigorous scientific methodology to support its development and application. DISCUSSION: Firstly, we review the major epidemiological foundations of practice guideline development. Secondly, we propose a chronic disease epidemiological model in which practice patterns are viewed as the exposure and outcomes of interest such as quality or cost are viewed as the disease. Sources of selection, information, confounding and temporal trend bias are identified and discussed. SUMMARY: The proposed methodological framework for outcomes research to evaluate practice guidelines reflects the selection, information and confounding biases inherent in its observational nature which must be accounted for in both the design and the analysis phases of any outcomes research study.

Biomedical Research↗

PubMed2002

Quality of life after acute myocardial infarction among patients treated at sites with and without on-site availability of angiography.

BACKGROUND: Previous studies have compared the treatment and outcome of patients with acute myocardial infarction (AMI) admitted at sites with and without availability of angiography. Although mortality rates do not differ, it is unknown if quality of life (QOL) and functional status differ. METHODS: We measured QOL and functional status in patients with AMI treated within Québec at 5 sites with (n = 253) and 5 sites without (n = 334) angiography. RESULTS: At admission, clinical characteristics, complication rates, and baseline measures of QOL and functional status were similar at sites with and without angiography. During hospitalization, patients treated at sites with angiography were more likely to undergo an invasive cardiac procedure than patients admitted at sites without angiography (angiography, 63% vs 26%; percutaneous transluminal coronary angioplasty, 33% vs 13%; and coronary artery bypass graft, 12% vs 5%). At 30 days and 6 months after AMI, QOL was slightly superior at sites with angiography, but by 1 year, most measures of QOL were back to baseline at both types of sites and were similar between the 2 groups. At 6 months, most standard health-related QOL components were similar; only physical and emotional role limitations were higher at sites with angiography. Return to work occurred earlier (at 30 days, 23% vs 12%), and a lower proportion of patients was readmitted for angina (within 1 year after AMI, 12% vs 18%) at sites with angiography. CONCLUSIONS: In the early post-AMI period, the QOL of patients admitted at sites with angiography was higher than that of patients admitted at sites without angiography. However, by 1 year, the QOL and functional status of patients was similar in both groups. Differences in QOL were greatest when differences in treatment were greatest, lending support to a positive albeit small association between an early invasive approach to post-AMI care and improved QOL.

Activities of Daily Living↗

PubMed2002

Antibiotics against Chlamydia pneumoniae and prognosis after acute myocardial infarction.

BACKGROUND: There is mounting pathologic and immunologic evidence that Chlamydia pneumoniae plays a role in the atherogenic pathway. However, very few clinical studies have supported these findings. METHODS: Using the administrative data of all patients > or =65 years of age who had an acute myocardial infarction (AMI) in Quebec between 1991 and 1995 (n = 26,195), we studied the relationship between the intake of antichlamydial antibiotics and post-AMI prognosis. Three groups were compared: patients exposed to (1) antichlamydial antibiotics, (2) sulfa-derivative antibiotics, to which C pneumoniae is not sensitive, and (3) neither of the above classes of antibiotics. Two periods of antibiotic exposure were explored: (1) during the first 3 months after AMI and (2) during the 6 months before AMI. RESULTS: Patients in the 3 exposure groups were similar except for a slightly lower proportion of men in the sulfa-derivative antibiotics group. Among all patients who were exposed during the 3 months after AMI and who survived at least 3 months, the 1-year mortality rate was similar across the 3 groups (10.1%, 11.1%, and 10.4% for the antichlamydial, sulfa-derivative, and nonexposed group, respectively) but favored the antichlamydial group at 2 years (15.9%, 23.0%, and 20.0%). In adjusted survival analysis, patients in the sulfa-derivative and nonexposed groups were slightly more likely to die than patients in the antichlamydial group (relative risk [RR], 1.38; 95% confidence interval [CI], 1.04 to 1.82 and 1.29; 95% CI, 1.05 to 1.59, respectively). Among individuals treated during the 6 months before AMI, the adjusted risk of dying was similar in the sulfa-derivative and nonexposed groups compared with the antichlamydial group (RR 1.03, 95% CI 0.90 to 1.18 and 1.08, 95% CI 0.99 to 1.19, respectively). CONCLUSIONS: Exposure to antichlamydial antibiotics during the 3 months after AMI is associated with a small survival benefit, whereas exposure during the 6 months before AMI does not affect survival.

4-Quinolones↗

PubMed2002

Effects of hospital volume on long-term outcomes after percutaneous transluminal coronary angioplasty after acute myocardial infarction.

BACKGROUND: Volume of procedures has been associated with short-term outcome after percutaneous transluminal coronary angioplasty. However, the effect of hospital procedural volume on long-term outcome after PTCA is unknown. METHODS AND RESULTS: We analyzed the physician claims and discharge data of 6635 patients who underwent PTCA after acute myocardial infarction (AMI) between 1991 and 1995 in the province of Quebec, Canada. For each administrative year, hospitals in which PTCA was performed were classified into 3 groups: low-volume, <200 procedures per year; medium-volume, 200 to 399 procedures per year; and high-volume, > or =400 procedures per year. Compared with patients in medium-volume and high-volume hospitals, patients in low-volume hospitals were older, had more recent AMI, and were less likely to have been transferred for PTCA. After adjustment for baseline differences, patients in the low-volume and medium-volume groups were more likely to undergo CABG within 6 months compared with patients in the high-volume group (odds ratio [OR] 2.1, 95% CI 1.3-3.3, and OR 1.5, 95% CI 1.2-1.9, respectively). In contrast, patients in the low-volume and medium-volume groups were less likely than patients in the high-volume group to undergo repeat PTCA within 6 months (OR 0.37, 95% CI 0.24-0.58, and OR 0.8, 95% CI 0.70-0.92, respectively). At 6 months, adjusted rates of repeat revascularization, recurrent AMI, or death did not differ between the 3 groups. CONCLUSION: Overall adverse event rates at 6 months after PTCA do not differ between hospital volume groups. The higher rate of CABG in low-volume hospitals and the higher rate of repeat PTCA in high-volume hospitals may represent different physician preferences for the treatment of failed PTCA rather than higher complication rates.

Age Factors↗

PubMed2002

Regional variation in the management of acute myocardial infarction in the province of Quebec.

BACKGROUND: Previous studies have shown that there are differences in acute myocardial infarction (AMI) management in Canada and in the United States. However, there has been little research to evaluate regional variations in AMI treatment and outcomes for Canadian patients. OBJECTIVE: To determine whether regional variation in the management of AMI in Quebec has an impact on patient mortality and morbidity. PATIENTS AND METHODS: Discharge summary and physician claims databases for 76,012 patients with AMI were used between January 1, 1988 and December 31, 1995 to build 16 cohorts for the administrative regions of the province of Quebec. The clinical characteristics, prescription medications, cardiac procedure use, readmissions for cardiac complications and mortality across the different regions were compared. RESULTS: After adjusting for age and sex, discharge prescriptions resulted in the following ranges: angiotensin-converting enzyme inhibitors 34% to 46% of patients, acetylsalicylic acid 49% to 77%, beta-blockers 32% to 54%, calcium channel blockers 25% to 48%, lipid-lowering drugs 4% to 16% and nitrates 76% to 86%. Procedure use varied considerably across the province during the initial 10 days post-AMI (catheterization 3% to 28%; percutaneous coronary intervention 1% to 8%, and coronary artery bypass surgery 0 to 2%), as well as one year after discharge (27% to 47%, 8% to 17%, and 6% to 12%, respectively). Some variation was observed for cardiac complications after one year (unstable angina 9% to 21%; congestive heart failure and recurrent myocardial infarction, no major variation). However, there was no significant regional variation observed for one-year and three-year mortality rates (19% to 22% and 27% to 31%, respectively). CONCLUSIONS: There was marked regional variation in the rates of discharge prescriptions for cardiac medications and cardiac procedures in patients who have had an AMI in Quebec. These results suggest that the type of treatment received for an AMI depends on the region in which the patient lives. This variation appeared to affect readmission rates for unstable angina, but had no impact on mortality or other cardiac complications post-AMI.

Adult↗

PubMedDate not supplied

A cost analysis of nonelective coronary artery bypass graft surgery.

BACKGROUND: Previous studies suggest that nonelective coronary artery bypass graft surgery (CABG) is more costly than elective CABG. The goal of this study was to examine why cost differences exist between patients undergoing nonelective and elective CABG. METHODS: We compared the outcomes and costs of treating 1613 consecutive patients undergoing nonelective (N = 1071) and elective (N = 542) CABG at three U.S. hospitals. Participating centers each used the same cost accounting system to provide patient-level clinical and cost data. Total, direct, and overhead costs were examined as were department-level costs. RESULTS: Compared to elective patients, nonelective patients were of similar age (66.4 years vs 67.0 years, respectively, p = NS), but were more likely to be female (32.7% vs 24.0%, p = 0.0003). Nonelective patients had longer lengths of stay (LOS) than elective patients (9.7 +/- 0.2 days vs 6.6 +/- 0.3 days, p < 0.0001). The longer LOS among nonelective patients was primarily due to a longer preoperative LOS (2.6 +/- 0.08 days vs 0.4 +/- 0.05 days). Unadjusted in-hospital costs of treatment were 38% higher among nonelective patients ($25,111 +/-$550 vs $18,445 +/-$752, p < 0.0001). After controlling for baseline demographic and clinical differences, the increase in cost among nonelective patients was reduced to 33% (cost ratio = 1.33, 95% confidence interval = 1.27 to 1.39, p < 0.0001). The difference in cost among nonelective patients was further reduced to 16% after controlling for rates of preoperative angiography and percutaneous coronary intervention (PCI), 14% after adjusting for the use of a pacemaker or a balloon pump, and 7% after adjusting for preoperative LOS. CONCLUSIONS: Patients undergoing nonelective CABG have longer LOS and higher costs than patients undergoing elective CABG. The increased cost among nonelective patients is largely due to differences in rates of preoperative LOS, angiography, and PCI. This differential reflects increased nonsurgical costs among patients undergoing nonelective CABG rather than surgical costs.

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