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Objective: In the United States, clear partisan differences in responses to COVID-19 have been shown in leadership and elite cueing at the state level as well as in perspectives and behaviours of the citizenry. This study probes differences in political values-particularly the prevalence of laissez-faire attitudes-that might explain the stronger social consensus on pandemic countermeasures seen in Canada., Methods: Data were obtained from temporally aligned waves of cross-sectional surveys of Canadian and US adults in the first year of the pandemic. Survey questions were used to construct an index of laissez-faire attitudes (LFA) which, along with demographic variables and measures of partisanship, was incorporated into regression models to predict three outcomes: practice of personal mitigation measures (e.g. mask wearing), level of worry about the pandemic, and likeliness to get a vaccine., Results: LFA scores had a strong negative relationship to all three outcomes for Canadians and Americans, albeit with larger effects among the Americans on two outcomes. Overall differences in LFA scores between Americans and Canadians were modest (0.04 on a 0-1 scale). However, Republican Party stalwarts had considerably higher LFA scores and were proportionally more numerous than Conservative loyalists in Canada. While there were partisan differences in LFA scores within Canada, the largest gap by far was between Republicans and Democrats in the USA. Respondents from Canada's Prairie provinces had slightly higher average LFA scores but there were no significant residence effects on outcomes., Conclusion: Laissez-faire attitudes that may conflict with public health values and measures are much more prevalent in the USA than in Canada. This difference underpins the limited effects of political partisanship and broad consensus in the Canadian public's responses to the pandemic., (© 2023. The Author(s) under exclusive license to The Canadian Public Health Association.)

Competing Interests: Competing interests: Fahad Razak is Scientific Director and Arthur Slutsky is a member of the Ontario COVID-19 Science Advisory Table. Fahad Razak reports holding a salary award as the Graham Farquharson Knowledge Translation Fellow from the PSI Foundation and is an employee of Ontario Health and Public Health Ontario. Dr. Razak has also received grants (outside the current article) to study COVID-19 from the Canadian Institute of Health Research, Canadian Frailty Network, the University of Toronto (including the Department of Medicine, St. Michael’s Hospital and the Sunnybrook Health Sciences Centre), the Digital Research Alliance of Canada (Data Champions Pilot Project) and the Royal College of Physicians and Surgeons of Canada. David Naylor is volunteer Co-Chair of Canada’s COVID-19 Immunity Task Force, a federally funded and mandated group. Dr. Naylor reports receiving salary support from the Department of Medicine, University of Toronto. Arthur Slutsky is Chair of the International ECMO Network. Dr. Slutsky reports receiving consulting fees regarding the development of drugs to treat COVID-19 from Altimmune, Apeiron, GSK, Cellenkos, Edesa, Exvastat and Translate Bio. Dr. Slutsky also reports membership of safety committees in relation to treatments for COVID-19, from Diffusion Pharmaceuticals and Faron. No other competing interests were declared.

Competing Interests: Intérêts concurrents: Aucun déclaré.

Competing Interests: Competing interests: None declared.

Competing Interests: Competing interests: None declared.

Background: Despite its widespread use, limited data on the validity of the Canadian Cardiovascular Society angina (CCSA) classification relative to other measures of functional status have been reported., Objective: To assess the validity of the CCSA classification by comparing it with the Duke Activity Status Index (DASI) and evaluate its prognostic significance with respect to long-term mortality., Methods: The study population consisted of 1407 patients who underwent cardiac catheterization between 1992 and 1996. The median follow-up period was 9.7 years (interquartile range 6.1 to 11.1 years) and the mortality status as of December 31, 2004 was available for all patients., Results: The first three CCSA classes were inversely related to the DASI. The mean (+/- SD) scores were as follows: class I, 31.4+/-16.7; class II, 22.5+/-15.4; class III, 14.7+/-14.3; and class IV, 15.5+/-14.9 (P<0.01). Increasing CCSA class was associated with increased long-term mortality, even after adjusting for baseline characteristics. Chest pain course was also an important modulator of mortality among class III and IV patients; one-year mortality rates were 8.1% among unstable patients compared with 4.8% among patients with stable or progressing course., Conclusion: CCSA classes I to III were inversely related to DASI scores and linearly associated with mortality. The similarity in outcomes among class III and IV patients is probably explained by the confounding effect of the stability of the patients' symptoms. The higher mortality risk among class III and IV patients with an unstable course provides impetus for a revised CCSA definition incorporating this information.

Objectives: This study was designed to determine whether admission to a Canadian hospital with on-site revascularization (invasive hospital) affected revascularization choice, timing, and outcome compared with community (non-invasive) hospitals., Background: Health care systems in Canada are characterized by relative restraint in diffusion of tertiary cardiovascular services, with capacity for revascularization procedures concentrated in large regional referral centers., Methods: We used linked administrative data and a clinical registry to follow-up 15,166 Ontario patients who underwent revascularization within the year after their index acute myocardial infarction (MI). Outcomes included recurrent urgent cardiac hospitalization, hospital bed-days, and death within the same year after the index admission. We adjusted for age, gender, socioeconomic status, illness severity, attending physician specialty, and academic hospital affiliation., Results: After adjusting for baseline factors, patients admitted to invasive hospitals were more likely to receive angioplasty than bypass surgery (adjusted odd ratio: 1.85; 95% confidence interval: 1.68 to 2.04, p < 0.001). The converse pattern was seen for patients admitted to community hospitals. Median revascularization waiting times were significantly shorter at invasive hospitals (12 vs. 48 days, p < 0.001). Patients admitted to invasive hospitals had fewer cardiac re-admissions (41.5 vs. 68.9 events per 100 patients, p < 0.001) before their first revascularization and consumed fewer hospital bed-days (379 vs. 517 per 100 patients, p < 0.001). There were no differences in outcomes beyond revascularization., Conclusions: Outcome advantages associated with timely post-MI revascularization highlight the importance of organizing revascularization referral networks and facilitating access to revascularization for patients with acute coronary syndromes admitted to community hospitals in Canada.

Parkinson's disease (PD) is associated with a significant burden of illness and cost to society, which has been difficult to quantify. Our objective was to use linked administrative databases from the population of Ontario, Canada, to assess the prevalence of parkinsonism, physician- and drug-related costs, and hospital utilization for parkinsonian patients compared with age/sex matched controls. An inception cohort of parkinsonian cases from 1993/1994 was age and sex matched (1:2) to controls and followed for 6 years. Patients were identified by the diagnostic code for PD, the use of specific PD drugs, or a combination. The parkinsonian case cohort (15,304) was matched to (30,608) controls that did not have parkinsonism. The age-adjusted prevalence rates were 3.63 for men and for 3.24 women per 1,000 (increased by 5.4% for men and 9.8% for women). Physician costs were 1.4 times more, there were 1.44 times more hospital admissions, admissions were on average 1.19 times longer, and drug costs were 3.0 times more for parkinsonian cases. We conclude that the substantially higher physician and drug costs as well as hospitalization rates compared with controls clearly suggest that parkinsonism is associated with large direct costs to society., (Copyright 2002 Movement Disorder Society)

Background: Many older people do not receive beta-blocker therapy after myocardial infarction or receive doses lower than those tested in trials, perhaps because physicians fear that beta-blockers may precipitate heart failure. We examined the relation between use of beta-blockers, the dose used, and hospital admission for heart failure and 1-year survival in a cohort of all older patients surviving myocardial infarction in Ontario, Canada., Methods: We collected data on a cohort of 13,623 patients aged 66 years or older who were discharged from hospital after a myocardial infarction and who did not receive beta-blocker therapy or received low, standard, or high doses. We used Cox's proportional-hazards models to study the association of dose with admission for heart failure and survival with adjustment for factors including age, sex, and comorbidity., Findings: Among 8232 patients with no previous history of heart failure, dispensing of beta-blocker therapy was associated with a 43% reduction in subsequent admission for heart failure (adjusted risk ratio 0.57 [95% CI 0.48-0.69]) compared with patients not dispensed this therapy. Among the 4681 patients prescribed beta-blockers, the risk of admission was greater in the high-dose than in the low-dose group (1.53 [1.01-2.31]). Among all 13,623 patients in the cohort, 2326 (17.1%) died by 1 year. Compared with those not dispensed beta-blocker therapy, the adjusted risk ratio for mortality was lower for all three doses (low 0.40 [0.34-0.47], standard 0.36 [0.31-0.42], high 0.43 [0.33-0.56])., Interpretation: Compared with high-dose beta-blocker therapy, low-dose treatment is associated with a lower rate of hospital admission for heart failure and has a similar 1-year survival benefit. Our findings support the need for a randomised controlled trial comparing doses of beta-blocker therapy in elderly patients.

Purpose: Along with evidence, clinical policies must take patients' values into account. Particularly where evidence is limited and where assumptions of utility-maximizing behavior may not be valid, new methods such as trade-off techniques (TOTs), which allow elicitation of patients' treatment alternatives, might be useful in policy formulation. We used TOTs to assess breast cancer patients' attitudes toward two clinical policies designed to ration adjuvant postlumpectomy breast radiation therapy., Methods: Cross-sectional interviews were performed in a tertiary cancer center. A total of 102 patients were presented with information about the side effects and benefits associated with two hypothetical decisions: (1) willingness to receive treatment elsewhere to shorten the wait for radiation therapy, and (2) foregoing radiation therapy in the face of small marginal benefits. For each scenario, a TOT was used to identify the maximal acceptable wait time (MAWT) for therapy and the benefit threshold at which the patient would forego therapy. Associations of clinical and demographic factors with these decisions were determined by regression analysis., Results: Patients would be willing to wait, on average, 7 weeks before wanting to leave their city for radiation therapy, less than the 13-week delay our patients actually faced. Older patients were less willing to wait (P = .013); 46% of patients would not give up radiation therapy, even in the face of no stated benefit. Willingness to give up radiation therapy was predicted by willingness to accept delay (odds ratio [OR], 1.84; 95% confidence interval [CI], 1.05 to 3.37) and being employed (OR, 2.61; 95% CI, 1.08 to 6.54). Patients with larger tumors were less willing to give up radiation therapy (OR, 0.57; 95% CI, 0.31 to 0.97)., Conclusion: Even in difficult decisions such as rationing postlumpectomy breast cancer radiation therapy, TOTs can inform policy formulation by indicating the distributions of patients' preferences.

In the 1990s every Canadian province is struggling to reduce health care expenditures without jeopardizing access to health care or quality of care. The authors propose a new model for health care delivery: the Canadian Integrated Delivery System (CIDS). A CIDS is a network of health care organizations; it would provide, or arrange to provide, a coordinated continuum of services to a defined population and would be held clinically and fiscally accountable for the outcomes in and health status of that population. A CIDS would serve 100,000 to 2 million people; the care it would provide would be funded on a capitation basis. For providers, there would be explicit financial incentives to minimize costs. At the same time, service quality and consumer choice of primary care practitioner would be maintained. Primary care physicians and specialists would work with other health care service providers to offer a full spectrum of care. CIDS providers would form strategic alliances with community agencies, hospitals, the private sector and other health care services not managed by the CIDS, as needed. For physicians, affiliation with a CIDS that provided strong clinical leadership could be beneficial to their income stability and autonomy. Pilot projects of this model in several communities would determine whether this concept is feasible in the Canadian health care context.

Objective: To examine the sex-specific prevalence of referral to a cardiologist for noninvasive ischemic testing (NIIT) or angiography among outpatients with clinical suspicion of new coronary artery disease (CAD)., Design: Retrospective records-based cohort study., Setting: Group cardiology referral practice in a tertiary care teaching hospital in Toronto., Patients: Of 1212 new patients referred between Mar. 1, 1991, and Mar. 31, 1993, 339 (232 men and 107 women) had symptoms of CAD and had initiation or modification of antianginal therapy, or were prescribed NIIT or angiography by their cardiologist., Outcome Measures: Rates of prior NIIT and of subsequent diagnostic procedures for women and men., Results: Women were less likely than men to have had prior NIIT (51 [47.7%] v. 162 [69.8%]) (p < 0.001). Women with class I or II angina were less likely than their male counterparts to have had prior NIIT (20/40 [50.0%] v. 84/109 [77.1%]) (p = 0.001); a similar difference was found between women and men with class III or IV angina (5/15 [33.3%] v. 43/60 [71.7%]) (p = 0.006). Men and women with atypical angina were equally likely to have had prior NIIT. Among patients with a positive initial NIIT result a higher proportion of women than of men did not have any further testing done by the cardiologist (53.5% v. 33.7%) (p = 0.02). Cardiologists referred a higher proportion of women (40.2%) than of men (25.4%) for NIIT (p = 0.006) and, for patients with a positive prior NIIT result, were also more likely to refer women (25.7% [9/43]) than men (12.0% [16/133]) for further NIIT (p = 0.04). Women with a positive prior NIIT result were more likely than their male counterparts to have a negative retest result (42.8% v. 18.2%). After adjustment for age, anginal class and overall result of NIIT, women were less likely than men to be referred for angiography (odds ratio 1.4), although the difference was not significant., Conclusions: In this exploratory study sex-related differences in patterns of use of NIIT by cardiologists seem largely based on differences in testing before referral by family physicians and general internists.

Objective: The purpose of the study was to evaluate the impact of time since the last meal on the glucose challenge test and to find cut points that are most likely to predict the outcome of the oral glucose tolerance test in patients screened for gestational diabetes., Study Design: This prospective analytic cohort study was carried out at the University of Toronto Perinatal Complex. A 50 gm glucose load was given at 26 weeks' gestation and the time since previous meal ingestion was recorded. At 28 weeks' gestation a 100 gm oral glucose tolerance test was administered. A total of 4274 eligible patients were screened., Results: Time since the last meal had a marked effect on mean plasma glucose. Receiver-operator characteristic curve analysis with National Diabetes Data Group criteria to interpret the oral glucose tolerance allowed the selection of the most efficient cut points for the glucose challenge test on the basis of time since the last meal. These cut points were 8.2, 7.9, and 8.3 mmol/L for elapsed postprandial times of < 2, 2 to 3, and > 3 hours, respectively. With this change from the current threshold of 7.8 mmol/L the number of patients with a positive screening test dropped from 18.5% to 13.7%. There was an increase in positive predictive value from 14.4% to 18.7%. The rate of patient misclassification fell from 18.0% to 13.1%., Conclusion: We suggest that screening strategies for detection of gestational diabetes be reconsidered, to account for the impact of variable postprandial status on the test results.

Objectives: To analyse the extent of variation by county and hospital in the use of breast-conserving surgery in the initial management of breast cancer and to assess some factors that might explain the observed variation., Design: Population-based retrospective cohort study., Setting: Ontario., Patients: All women with breast cancer newly diagnosed from Jan. 1, 1989, to Dec. 31, 1991., Main Outcome Measure: Proportion of women undergoing unilateral breast cancer surgery who had breast-conserving surgery in each hospital and county., Results: Of the 14,570 women with newly diagnosed breast cancer 12,815 (88.0%) underwent unilateral breast cancer surgery. The mean proportion of breast-conserving procedures by county was 52% and ranged from 11% to 84%. The proportion of breast-conserving procedures in individual hospitals with one or more cases of breast cancer per month ranged from 6% to 84%. The variations in the rates between hospitals was greater than that expected by chance alone (p < 0.0001)., Conclusions: There was marked variation at the hospital and county level in the use of breast-conserving surgery in the initial management of breast cancer. This variation was strongly associated with the hospital where the surgery was performed.

Objective: To assess sex-related differences in coronary revascularization practices in a Canadian setting., Design: Prospective analytic cohort study., Setting: Regional referral office in Toronto., Patients: A selected but consecutive group of 131 women and 440 men referred by cardiologists for revascularization procedures between Jan. 3, 1989, and June 30, 1991., Interventions: Coronary artery bypass grafting (CABG) or percutaneous transluminal coronary angioplasty (PTCA). Nurse-coordinators placed the referral with a surgeon or interventional cardiologist at one of three hospitals, who then communicated directly with the referring cardiologist., Main Outcome Measures: Symptom status at referral, procedures requested and performed, and time from referral to procedure., Results: Although the women were more likely than the men to have unstable angina at the time of referral (odds ratio [OR] 2.28, 95% confidence interval [CI] 1.38 to 3.79, p = 0.0006), more women than men (16.8% v. 12.1%) were turned down for a procedure. Significant sex-related differences in practice patterns (p < 0.001) persisted after controlling for age or for the referring cardiologists' perception of expected procedural risk. A stepwise multivariate model showed that anatomy was the main determinant of case management; sex was the only other significant variable (p = 0.016). The referring physicians requested CABG more often for men than for women (p = 0.009), and the men accepted for a procedure were much more likely to undergo CABG than the women (OR 2.40, CI 1.47 to 3.93, p = 0.0002). Although the women undergoing CABG waited shorter periods than the men (p = 0.0035), this difference was attributable to their more severe symptoms., Conclusions: In this selected group women had more serious symptoms before referral but were turned down for revascularization more often than men. Reduced use of CABG rather than PTCA largely accounted for the sex-related differences in revascularization. Once accepted for a procedure women had shorter waiting times, which was appropriate given their more severe symptoms.

Objective: To assess the internal logic (content validity) of the Canadian Cardiovascular Society (CCS) scale for grading angina pectoris., Patients: Forty-one consenting patients with stable angina of at least two months duration, admitted to a tertiary centre for coronary angiography., Methods: Patients completed a supervised questionnaire with closed-ended questions. Key questions included: usual numbers of blocks walked on the level or flights of stairs climbed before onset of chest pain; frequency with which chest pain occurred at the usual threshold distance; presence of rest pain; and influence of modifiers suggested for class II of the scale such as walking uphill and into the wind., Results: Agreement of four questionnaire-defined 'stair-climbing grades' and 'walking grades' was statistically significant (P < 0.001) but only 37% better than expected by chance alone (weighted kappa). Frequency of angina at a patient's self-defined exercise threshold varied; only 22 of 41 patients (54%) had symptoms always or often. Higher classes of angina were more likely to be associated with frequent symptoms at threshold, eg, class I/II, six of 23 versus class III/IV, 16 of 17; 2P = 0.00002). Pain at rest was reported as 'definitely' present by 23 of 41 patients, and was similar in incidence across angina classes. All suggested modifiers reduced distances walked in a significant majority of patients (P values uniformly < 0.01) except for walking in the first few hours after awakening. However, the proportions of subjects for whom these factors were relevant were statistically similar for all angina grades, rather than for class II patients alone., Conclusions: These findings suggest that internal inconsistencies in the CCS scale are identifiable with simple validity checks. Further research appears warranted to improve this popular and useful clinical tool.

Objective: To appraise the measurement properties of the Canadian Cardiovascular Society (CCS) classification of stable angina pectoris., Data Sources: Relevant articles were identified through a MEDLINE search (1976 to November 1991). Bibliographies of retrieved articles were also reviewed., Study Selection: Studies chosen directly addressed the validity and reliability of the CCS scale. Recent studies and reviews of related topics (for example, silent ischemia) are selectively cited., Data Synthesis: No data address the scale's applicability, that is, how clinicians typically assign angina grades in practice. Comprehensiveness would be improved by coverage of the patient's perceptions of symptom burden; mixed exertional and rest symptoms; episodic or changing symptoms; and modifying factors. Reliability was assessed in one study with two clinicians; the interobserver, chance-corrected agreement on patient grading was 60%. Content validity (the ability of the scale to measure what it claims) is threatened by the unproven assumption of symptomatic or physiologic equivalence among diverse levels of different activities within any given grade of angina. Construct validity is uncertain, given weak relations between angina grade and noninvasive markers of ischemia, anatomical disease, or prognosis. The scale's responsiveness (the ability to detect the smallest clinically important changes) is limited by the reliance on four coarse gradations based on only ambulation or stair-climbing., Conclusions: The CCS scale for stable angina might be made more useful by developing measurements for patients' self-rated symptom burden and the changes they deem important; by adding items on clinical instability (that is, progressive symptoms or pain at rest); and by empirically testing the current scale to eliminate redundant or inconsistent elements.

The American health care system has the world's highest per capita costs and over 30 million citizens uninsured. The neighbouring Canadian system provides coverage for all basic medical and hospital services, at costs per capita that are about US$700 lower. Single-agency public funding allows tighter control of Canadian expenditures, and reduces administrative overheads. Hospitals are run as non-profit private corporations, funded primarily by a fixed annual allocation for operating costs. Most physicians are in private fee-for-service practice, but cannot charge more than the insured tariff negotiated between their provincial government and medical association. This approach, while attractive in its decentralization, tends to separate the funding and management of clinical services. Thus, hospital information systems lag a decade behind the USA, managed care initiatives are few, health maintenance organisations do not exist, and experimentation with alternative funding or delivery systems has been sporadic. Strengths of the system compared to the USA include: higher patient satisfaction, universal coverage, slightly better cost containment, higher hospital occupancy rates, and reduction in income-related rationing with more equitable distribution of services. Weaknesses in common with the United States are: cost escalation consistently outstripping the consumer price index with costs per capita second highest in the world, ever rising consumption of services per capita, inadequate manpower planning and physician maldistribution, poor regional co-ordination of services, inadequate quality assurance and provider frustration. Additional weaknesses include: an emerging funding crisis caused by the massive federal deficit, less innovation in management and delivery of care as compared to the USA, implicit rationing with long waiting lists for some services, and recurrent provider-government conflicts that have reduced goodwill among stakeholders. Thus, while the Canadian model has important advantages, it does not offer a panacea for American health care woes.

Objective: To determine the point at which adverse quality-of-life effects engendered by an aggressive cholesterol-lowering strategy dictate the use of a less aggressive approach., Design: Decision analysis was used to compare the effects of the National Cholesterol Education Program (NCEP) guidelines, an aggressive program, with those of the Canadian Task Force on the Periodic Health Examination (CTF) guidelines, a more conservative program. Quality-adjusted life expectancy was calculated for a theoretical cohort of middle-aged men treated according to each program using Markov cohort analysis., Measurements: Guidelines were applied to the population of the Lipid Research Clinics Coronary Primary Prevention Trial (LRC-CPPT), under the assumption that cholesterol levels had the distribution of the age- and sex-matched general population. Outcomes were calculated using a three-state (health, coronary heart disease, and death) Markov model. State transition probabilities were calculated using bivariate (age and cholesterol) proportional hazards and logistic regression functions., Main Results: The result was a "toss-up"; the number of expected quality-adjusted life years was similar for both programs at all time intervals, although the conservative program was consistently slightly favored. The result was very sensitive to the disutility of dietary therapy (threshold value, 0.0014 compared with the baseline estimate of 0.02) but was also affected by the time frame of the analysis and the rate at which adverse effects of treatment decline., Conclusions: Even small disutilities associated with treatment may outweight the benefits of aggressive cholesterol-lowering strategies. Research should be directed toward measuring these disutilities and finding ways to reduce their size. Incorporation of the disutility of treatment into policy formulation may result in less interventionist and less costly policies.

In light of lengthy waiting lists for coronary surgery in Canada, a panel of 16 cardiologists and cardiac surgeons was convened to derive guiding principles for ranking how urgently diverse patients with angiographically proven coronary disease require revascularization. Factors likely to affect urgency were agreed upon by the panelists and incorporated into a case scenario questionnaire. Each panelist then rated 438 case scenarios with respect to maximum acceptable waiting time on a scale with seven time frames ranging from emergency surgery ('level 1') to delays of up to six months ('level 7'). The scenario rating process facilitated attainment of a panel consensus. The purpose of the principles is to assist in assigning priorities to patients according to both symptoms and risk of death or additional morbidity from ischemic events. The pattern or severity of the patient's anginal symptoms and the response of those symptoms to medical therapy emerged as the single most important determinant of the level of urgency. Anatomy and noninvasive tests of ischemic risk were the other key determinants of priority. All other factors were less important, and operated largely within a given level of urgency on the seven-point scale. The principles, including explicit ranking criteria divided according to angina class, are outlined in this final report. The panel specifically cautioned that adoption of such principles is not designed to countenance delays in treatment, but if necessary, should help form more rational queues for coronary revascularization.

Hospital medical records staff enter diagnostic codes on charts using the International Classification of Diseases (Clinically Modified), Ninth Revision (ICD-9-CM). In a downtown Toronto tertiary hospital, 209 consecutive charts coded for acute myocardial infarction as the primary diagnosis in 1987-88 were reviewed. Criteria for documentation of acute myocardial infarction included symptomatic, electrocardiographic and enzymatic elements. Forty-three (21%) false-positives, ie, charts coded acute myocardial infarction where criteria were not fulfilled, were found (95% confidence interval 15 to 26%). Physician diagnosis of acute myocardial infarction appeared on the face sheet of 30 of the false-positive cases. Common reasons for false-positive face sheet entries and chart coding were acute myocardial infarction within the previous eight weeks with transfer or readmission for coronary angiography and other procedures; and presumed acute myocardial infarction on admission subsequently unproven or disproved. The false-positive proportion was similar to a Canadian study drawing on charts from hospitals of various sizes in 1977, lower than in recent reports from various American tertiary teaching hospitals (P less than 0.0001), and higher than in five Boston area community hospitals (P = 0.0005) where procedure-related transfers or readmissions of previous acute myocardial infarction patients were less likely. This audit lends credence to arguments that changes are needed in ICD-9-CM codes for acute myocardial infarction and in the assignation of reasons for hospitalization.