A Comparison of Management Patterns after Acute Myocardial Infarction in Canada and the United States
Jean L. Rouleau, Lemuel A. Moye, Marc A. Pfeffer, J. Malcolm O. Arnold, Victoria Bernstein, Thomas E. Cuddy, Gilles R. Dagenais, Edward M. Geltman, Steven Goldman, David Gordon, Peggy Hamm, Marc Klein, Gervasio A. Lamas, John McCans, Patricia McEwan, Francis J. Menapace, John O. Parker, Francois Sestier, Bruce Sussex, Eugene Braunwald, for The SAVE Investigators
Background There are major differences in the organization ofthe health care systems in Canada and the United States. Wehypothesized that these differences may be accompanied by differencesin patient care.
Methods To test our hypothesis, we compared the treatment patternsfor patients with acute myocardial infarction in 19 Canadianand 93 United States hospitals participating in the Survivaland Ventricular Enlargement (SAVE) study, which tested the effectivenessof captopril in this population of patients after a myocardialinfarction.
Results In Canada, 51 percent of the patients admitted to aparticipating coronary care unit had acute myocardial infarctions,as compared with only 35 percent in the United States (P<0.001).Despite the similar clinical characteristics of the 1573 U.S.patients and 658 Canadian patients participating in the study,coronary arteriography was more commonly performed in the UnitedStates than in Canada (in 68 percent vs. 35 percent, P<0.001),as were revascularization procedures before randomization (31percent vs. 12 percent, P<0.001). During an average follow-upof 42 months, these procedures were also performed more commonlyin the United States than in Canada. These differences werenot associated with any apparent difference in mortality (22percent in Canada and 23 percent in the United States) or rateof reinfarction (14 percent in Canada and 13 percent in theUnited States), but there was a higher incidence of activity-limitingangina in Canada than in the United States (33 percent vs. 27percent, P<0.007).
Conclusions The threshold for the admission of patients to acoronary care unit or for the use of invasive diagnostic andtherapeutic interventions in the early and late periods afteran infarction is higher in Canada than in the United States.This is not associated with any apparent difference in the rateof reinfarction or survival, but is associated with a higherfrequency of activity-limiting angina.
Medical training is very similar in Canada and the United States,in that undergraduate and postgraduate training are both organizedalong the same lines and are considered equivalent in the twocountries1,2,3. Not surprisingly, studies comparing the practicepatterns of physicians in Canada and the United States havefound only minor differences4,5.
Despite these similarities, however, there are important differencesin the financing of the two medical care systems, differencesthat have attracted considerable attention in recent years1,2,3,4,5,6,7,8,9,10.In Canada, expenditures for health care are controlled by thegovernment, whereas in the United States there is much lessgovernment control1,2,3. Because of these structural differences,a lower percentage of the gross national product has been spenton health care in Canada than in the United States (9 percentvs. 11.5 percent)5. Along with budgetary constraints have comelimitations on the availability of expensive procedures, suchas coronary arteriography and revascularization6,7,11,12,13.The effects of these constraints on patterns of clinical practicehave been difficult to document, as a recent analysis of thetwo health care systems indicated6. That analysis found littledifference in the frequency of diagnostic and therapeutic interventions.Perhaps the inability heretofore to document such differenceshas been a result of the type of analysis performed -- i.e.,one that does not compare specific situations requiring theready availability of certain services, in which differenceswould be highlighted. Or perhaps the differences are new andhave developed since the earlier analyses -- a change that couldhave accompanied the increasing budgetary constraints of recentyears.
We hypothesized that along with differences in the structureof the two health care systems and in the availability of someservices in these two countries, differences have developedin the patterns of care given to patients with acute myocardialinfarction. More specifically, we hypothesized that Canadianphysicians would have a higher threshold for admitting patientswith chest pain to an intensive care unit, for performing coronaryarteriography and revascularization procedures, and for usingcertain medications in the early and late periods after an infarction.The Survival and Ventricular Enlargement (SAVE) trial was acooperative study in Canada and the United States that presentedan excellent opportunity to test this hypothesis14.
Methods
Patient Selection
All patients admitted to the coronary care units of 112 participatinginstitutions -- 19 in Canada and 93 in the United States --between January 27, 1987, and January 28, 1990, were enrolledin a coronary care logbook as required by the study protocol.In the United States, 13 centers were administered by the Departmentof Veterans Affairs, and the other 80 were divided equally betweenuniversity and community hospitals. All the Canadian centerswere either university centers or affiliated with such centers.
To be eligible for the trial, patients had to be randomizedbetween 3 and 16 days after an acute myocardial infarction14.They had to have left ventricular dysfunction, defined as aradionuclide ejection fraction of 40 percent or less, measured3 to 16 days after infarction, but no overt heart failure14.The patients were also screened for ischemia. Those with chestpain or a positive exercise stress test were excluded unlesscoronary angiography was performed. If revascularization wasrecommended, it had to be performed before randomization. Othercriteria for exclusion included contraindications to the useof captopril and the presence of concurrent medical problems,such as renal insufficiency (defined as a serum creatinine concentrationgreater than 2.5 mg per deciliter), severe valvular heart disease,refractory hypertension, cancer, or other conditions thoughtto limit survival or disqualify the patient14. All patientsparticipating in the study gave informed consent, and the studydesign was reviewed and approved by the institutional reviewboards of the participating centers.
During the recruitment period of the study, 78,197 patientswere admitted to the coronary care units in the various participatinginstitutions in the United States, and 17,659 patients wereadmitted in Canada. Of these, 23,175 American and 7835 Canadianpatients (30 and 44 percent, respectively) had myocardial infarctionsmeeting the clinical criteria, survived for at least 72 hours,and were eligible with respect to age. Of these, 21,380 Americanand 7110 Canadian patients (92 and 91 percent, respectively)were excluded either because they did not satisfy the criteriafor inclusion or because they met the criteria for exclusion14.Sixty-nine American and 71 Canadian patients were excluded becausethere was clinical evidence of myocardial ischemia after infarctionbut no coronary arteriography was performed, and 83 Americanand 39 Canadian patients were excluded because the recommendedcoronary revascularization could not be done in the time allottedfor randomization. A further 1 percent of eligible patientswith myocardial infarction were excluded because they eitherdeclined to participate in the study or had clinical hypotensionwhen captopril was administered. Thus, 1573 American and 658Canadian patients (7 and 8 percent, respectively) were enrolledin the study14.
Evaluation of Patients
The cardiac history and risk factors of the study patients wereevaluated. The clinical characteristics of the acute myocardialinfarctions and the diagnostic and therapeutic interventionsrequired between the onset of the infarctions and randomizationwere recorded. Medications taken within 24 hours of randomization(a mean of 11 days after the infarction) were also noted.
Follow-up
The patients were followed for a mean of 43 months in the UnitedStates (range, 24 to 60 months) and of 39 months in Canada (range,24 to 59). Follow-up data were obtained for all but six patients.In addition to vital status, records were kept during the follow-upperiod of the number of patients with angina or recurrent myocardialinfarction and the number of times coronary arteriography, percutaneoustransluminal coronary angioplasty, and aortocoronary bypasssurgery were performed. Activity-limiting angina was definedby a Goldman score of at least 2, with the stated reason forthe limitation of activity being angina15. A recurrent myocardialinfarction was defined as a myocardial infarction reported bythe clinical center or by the mortality committee of the study.Drug use at 12 and 24 months was also noted.
Statistical Analysis
The comparability of the two treatment groups with respect tobase-line characteristics was ascertained by chi-square testsfor categorical variables and standard normal (z) tests forcontinuous variables16. All P values were calculated for two-tailedtesting of the hypothesis. Prevalence ratios were used to assessdifferences between countries in the use of procedures and drugtherapy. Cox proportional-hazards regression was used to assessthe effect of the country where treatment was given on clinicaloutcome after adjustment for minor base-line differences betweencountries with respect to age, race, and educational level ofpatients, the number of days between index myocardial infarctionand randomization, diabetes, smoking status, hypertension, historyof myocardial infarction, clinical angina before randomization,and percutaneous transluminal coronary angioplasty before randomization17,18.
Results
Patients Admitted to Coronary Care Units
In the United States, 35 percent of the patients admitted toone of the coronary care units involved in the study (27,544patients) had clinical myocardial infarctions, as compared with51 percent in Canada (9086 patients; P<0.001).
The study population consisted of 2231 patients randomized anaverage of 11 days after infarction. Of these, 1573 patientswere randomized in the United States and 658 in Canada. In bothcountries the average age was 59 years, and 83 percent weremale. However, more nonwhites were randomized in the UnitedStates than in Canada (13.7 percent vs. 3.5 percent; P<0.001).In addition, the patients in the United States were randomizedsooner after their myocardial infarctions than the Canadianpatients (10.7 vs. 11.7 days; P<0.007).
Characteristics at Base Line
Before the index myocardial infarction, the patients in theUnited States had a higher incidence of diabetes (P = 0.006),hypertension (P<0.001), current smoking (P = 0.03), previouscatheterization (P = 0.006), and percutaneous transluminal coronaryangioplasty (P<0.001) than did the Canadian patients, butthe patients in the United States had a lower incidence of angina(P = 0.005) (Table 1). They were also more likely to receivecalcium-channel blockers (P = 0.003), anticoagulants (P = 0.02),cholesterol-lowering agents (P = 0.05), and insulin (P = 0.02)as long-term drug therapy in the 72 hours before the index infarctions(Table 1).
Table 1. Base-Line Characteristics of the Study Patients before the Index Infarction.
Characteristics of the Index Infarctions
All the clinical and laboratory characteristics of the indexinfarctions were similar in the two groups of patients (Table 2).These variables included the maximal increase in creatinekinase, the frequency of use of thrombolytic agents, the Killipclass (defined in the note to Table 2), the postinfarction leftventricular ejection fraction, and the percentage of patientsrequiring defibrillation. The percentage of patients with hypotensionwho required intervention was slightly higher in the UnitedStates than in Canada (P = 0.003).
Procedures after the Index Infarction but before Randomization
Twice as many patients had coronary arteriography in the UnitedStates as in Canada (Table 3). Angina pectoris was more oftenthe reason for the procedure in Canada (35 percent, vs. 27 percentin the United States; P<0.03), and myocardial infarctionitself was more frequent in the United States (73 percent, vs.65 percent in Canada). The extent of coronary artery diseasefound on coronary arteriography in Canada was similar to thatin the United States. Seventeen percent of the Canadian patientswere found to have single-vessel disease, as compared with 13percent of Americans; 70 percent of Canadian patients had double-vesseldisease, as compared with 77 percent of Americans; and 13 percentof Canadian patients had triple-vessel disease, as comparedwith 10 percent of Americans. Intra-aortic balloon pumping wasalso used more frequently in the United States (8 percent vs.2 percent; P<0.001). Although the patients in both countrieshad similar coronary anatomy, cardiac surgery and percutaneoustransluminal coronary angioplasty were used more commonly inthe United States. Finally, the patients who had coronary arteriographyin the United States were more likely to undergo a revascularizationprocedure than their Canadian counterparts (45 percent vs. 34percent; P = 0.002). This increased likelihood of undergoingrevascularization after cardiac catheterization resulted solelyfrom differences in the use of percutaneous transluminal coronaryangioplasty. Patients who had coronary arteriography in eithercountry had equal chances of having aortocoronary bypass surgery.
Table 3. Coronary Arteriography and Revascularization Procedures Performed after the Index Infarction.
When the patients were included who had been excluded from thestudy either because no coronary arteriography was performeddespite the presence of clinical ischemia after infarction orbecause coronary revascularization was recommended but not donewithin the period allowed for randomization, the findings werenot significantly altered. When the patients excluded for thesereasons were included in the analyses of the study patients,the frequency of coronary arteriography remained higher in theUnited States (69 percent vs. 42 percent; P<0.001).
Drug Therapy before Randomization
During the 24 hours before randomization, the patients in theUnited States were more likely to receive nitrates, beta-blockers,calcium-channel blockers, non-aspirin antiplatelet drugs, antiarrhythmicagents, and cholesterol-lowering agents, whereas diuretic agentswere used more frequently in Canada (Table 4). Digitalis, anticoagulantagents, and aspirin were used to similar extents in the twocountries.
Table 4. Drug Therapy within the 24 Hours before Randomization.
Follow-up
After randomization, more invasive diagnostic and therapeuticinterventions continued to be used in the United States thanin Canada (Table 3). This difference was not as great, however,as that in the early postinfarction period. Also, if coronaryarteriography was performed, the likelihood of having a revascularizationprocedure (either coronary-artery bypass grafting or percutaneoustransluminal coronary angioplasty) was similar in both countries.The greater use of drugs before randomization in the UnitedStates persisted throughout the study, although in some casesthese differences tended to decrease over time (Table 5). Theonly exception was that of cholesterol-lowering agents, whichwere used equally during follow-up. Diuretic agents continuedto be used more frequently in Canada, whereas anticoagulantsand digoxin were used with similar frequency in both countries.There was a transiently greater use of aspirin in Canada duringthe first year after randomization.
Table 5. Drug Therapy 12 and 24 Months after Randomization.
Outcome
The greater use of invasive diagnostic and revascularizationprocedures in the United States, as well as the greater useof medications in both the early and late periods after an infarction,was not associated with either survival or the rate of recurrentmyocardial infarction. The increased use of these interventionswas, however, associated with a lower risk of having activity-limitingangina in the United States and a lower risk of having at leastone of the following: activity-limiting angina, recurrent myocardialinfarction, or death. These findings were observed after oneyear, after two years, and over the entire follow-up period(Table 6). It is noteworthy, however, that our study had limitedpower to detect differences between the two countries in mortalityand recurrent myocardial infarction, as reflected by the relativelywide confidence intervals around the relative risks.
Table 6. Relative Risk of Death, Recurrent Myocardial Infarction, or Activity-Limiting Angina.
Discussion
Invasive diagnostic and therapeutic interventions were performedmore frequently and cardiovascular drugs were prescribed moreoften during the early and late periods after an infarctionin the study population in the United States than in Canada.However, this greater use of therapeutic interventions was notassociated with significant differences in the rate of recurrentmyocardial infarction or death between the two countries, althoughthe power of our study to detect differences in these outcomeswas limited. These findings are consistent with those of phaseIIB of the Thrombolysis in Myocardial Infarction trial,19 whichsuggest that a conservative strategy for the diagnosis and careof patients without overt myocardial ischemia after an infarctiondoes not significantly modify rates of reinfarction or mortality.These results appear to favor the more conservative Canadianapproach, even in patients with left ventricular dysfunctionafter infarction. This approach was associated, however, witha higher frequency of activity-limiting angina throughout thestudy -- an indication that a price must be paid for using thismore conservative strategy. Thus, it would appear that the thresholdfor performing invasive diagnostic and therapeutic interventionsand for using antianginal medications is higher in Canada thanin the United States.
Just over half the patients (51 percent) admitted to the Canadiancoronary care units involved in our study had clinical myocardialinfarctions -- a significantly higher percentage than in theU.S. units (35 percent). The figure of 35 percent in the UnitedStates is similar to the percentages found in the literature20,21,22,23,24,25,26.This difference may reflect a response to more stringent limitationson the use of resources in Canada. In a study of the allocationof beds in intensive care units during a massive shortage, Singeret al.27 found that the percentage of patients admitted forchest pain who had myocardial infarctions was proportional tothe extent to which the bed supply was restricted. In the presentstudy, the percentage of patients admitted to Canadian coronarycare units who had clinical myocardial infarctions was evenhigher, and it approached the proportion expected with markedbed restriction when only patients at high risk (those witha clinical probability of myocardial infarction greater than75 percent) are admitted to the coronary care unit20,25,27.Whether this policy also led to the admission of high-risk patientsto beds in other units and to extra deaths cannot be evaluatedin this study. From the study of Singer et al.,27 however, andfrom studies of computer-derived protocols26,28 to aid in thediagnosis of emergency room patients with acute chest pain,it appears that the threshold for the admission of patientswith chest pain in the United States can safely be raised, leadingto a more cost-effective use of intensive care beds26.
Despite having similar clinical and laboratory profiles at aboutthe time of the infarction, the patients in the United Statesreceived more invasive diagnostic and therapeutic interventionsthan the patients in Canada, suggesting that there is a higherthreshold for the use of these procedures in Canada. One couldinterpret this finding as indicating a more careful selectionof patients in Canada. However, since the rate of revascularization(by percutaneous transluminal coronary angioplasty or aortocoronarybypass surgery) for each coronary arteriography was higher inthe United States, it is more likely that this difference reflectsa more aggressive approach to the investigation and treatmentof coronary artery disease in the United States. Since the rateof aortocoronary bypass surgery per coronary arteriography wassimilar in the two countries, it would appear that physiciansin both countries approach the treatment of more severe coronaryartery disease similarly and that differences are mostly limitedto situations in which coronary artery disease is less severe.
The more conservative approach of Canadian physicians as comparedwith their American counterparts was also reflected in the smallernumber of medications given at the time of randomization. Theuse of medications in the United States was greater for medicationsknown to improve,29 not change, or possibly even decrease30,31survival in this population. It persisted throughout the studyand may at least partly explain why activity-limiting anginawas reported less often in patients in the United States.
Why such differences occurred despite so many similarities betweenthese two countries remains unresolved. Certainly, faced withlong waiting lists for elective cardiac catheterization, percutaneoustransluminal coronary angioplasty, and surgery,12,13 it wouldnot be surprising if Canadian physicians had a higher thresholdfor performing these procedures than their counterparts in theUnited States11. The recent publication of a consensus reporton the assignment of priorities to patients requiring revascularizationin Canada supports this possibility13. This cannot be the entireanswer, however, because Canadian physicians prescribed medicationsless often an average of 11 days after infarction -- behaviorunrelated to limitation of resources and more likely to reflectan inherently more conservative attitude. A third possible explanationis the difference in the structure of medical financing betweenthe two countries. In Canada all procedures are revenue-consumingand a drain on the hospital budget, whereas in the United Statesthe use of most procedures generates revenue and helps balancethe hospital budget1,2,3,4,5,6. Also, there is a disparity inthe fee scale for invasive procedures, these fees being twoto five times higher in the United States6.
Another possible explanation for the differences in proceduresbetween the countries could be selection bias. Only 7 percentof the American and 8 percent of the Canadian patients who hadclinical myocardial infarctions, survived 72 hours, and wereeligible with respect to age were finally admitted to the study.Of the various steps at which patients were excluded duringscreening, the one most likely to cause a selection bias wasthe stage at which patients were excluded because of ischemia-relatedevents that could not be addressed in the randomization periodduring their postinfarction clinical course. The inclusion ofthese patients in the analyses of events before randomizationdid not modify the results substantially, however, suggestingthat these patterns of treatment after an infarction are theresult of different approaches rather than of a selection bias.
Supported by a grant from the Bristol-Myers Squibb Institutefor Pharmaceutical Research.
We are indebted to Marguerite Cloutier for assistance in thepreparation of the manuscript, to the reviewers for their helpfulcomments, and to the SAVE investigators and coordinators.
Source Information
From the Universite de Sherbrooke, Sherbrooke, Que. (J.L.R.); Victoria Hospital, London, Ont. (J.M.O.A.); University of British Columbia, Vancouver (V.B.); University of Manitoba, Winnipeg (T.E.C.); Institut de Cardiologie de Quebec, Quebec City (G.R.D.); Hopital du Sacre-Coeur de Montreal, Montreal (M.K.); Jewish General Hospital, Montreal (J.M.); the Wellesley Hospital, Toronto (P.M.); Kingston General Hospital, Kingston, Ont. (J.O.P.); Hopital Notre-Dame de Montreal, Montreal (F.S.); and Memorial University of St. John's, Newf. (B.S.) -- all in Canada; and the University of Texas Health Science Center at Houston (L.A.M., P.H.); Harvard Medical School and Brigham and Women's Hospital, Boston (M.A.P., G.A.L., E.B.); Washington University School of Medicine, St. Louis (E.M.G.); Veterans Affairs Medical Center, Tucson, Ariz. (S.G.); Cardiology Associates, Des Moines, Iowa (D.G.); and the Geisinger Medical Center, Danville, Pa. (F.J.M.).
Address reprint requests to Dr. Rouleau at the Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, QC J1H 5N4, Canada.
References
Iglehart JK. Canada's health care system. N Engl J Med 1986;315:202-8, 778. [Medline]
Evans RG, Lomas J, Barer ML, et al. Controlling health expenditures -- the Canadian reality. N Engl J Med 1989;320:571-577. [Abstract]
Relman AS. The United States and Canada: different approaches to health care. N Engl J Med 1986;315:1608-1610. [Medline]
Anderson GM, Newhouse JP, Roos LL. Hospital care for elderly patients with diseases of the circulatory system: a comparison of hospital use in the United States and Canada. N Engl J Med 1989;321:1443-1448. [Abstract]
Fuchs VR, Hahn JS. How does Canada do it? A comparison of expenditures for physicians' services in the United States and Canada. N Engl J Med 1990;323:884-890. [Abstract]
Iglehart JK. Canada's health care system faces its problems. N Engl J Med 1990;322:562-568. [Medline]
Doherty K. Is the Canadian system as good as it looks for employers? Bus Health 1989;7:31-34.
Moloney TW, Paul B. A new financial framework: lessons from Canada. Health Aff (Millwood) 1989;8:148-159. [CrossRef][Medline]
Detsky AS, Stacey SR, Bombardier C. The effectiveness of a regulatory strategy in containing hospital costs: the Ontario experience, 1967-1981. N Engl J Med 1983;309:151-159. [Abstract]
Detsky AS, Abrams HB, Ladha L, Stacey SR. Global budgeting and the teaching hospital in Ontario. Med Care 1986;24:89-94. [Medline]
Morin JE, Symes JF, Guerraty AJ, Poirier NL, Sampalis J. Coronary artery bypass profile in Canada and the United States. Can J Cardiol 1990;6:319-322. [Medline]
Katz SJ, Mizgala HF, Welch HG. British Columbia sends patients to Seattle for coronary artery surgery: bypassing the queue in Canada. JAMA 1991;266:1108-1111. [Free Full Text]
Naylor CD, Baigrie RS, Goldman BS, et al. Assigning priority to patients requiring coronary revascularization: consensus principles from a panel of cardiologists and cardiac surgeons. Can J Cardiol 1991;7:207-213. [Medline]
Pfeffer MA, Braunwald E, Moye LA, et al. Effect of captopril on mortality and morbidity in patients with left ventricular dysfunction after myocardial infarction -- results of the Survival and Ventricular Enlargement trial. N Engl J Med 1992;327:669-677. [Abstract]
Goldman L, Hashimoto B, Cook EF, Loscalzo A. Comparative reproducibility and validity of systems for assessing cardiovascular functional class: advantages of a new specific activity scale. Circulation 1981;64:1227-1234. [Free Full Text]
Woolson RF. Statistical methods for the analysis of biomedical data. New York: John Wiley, 1987.
Mantel N. Evaluation of survival data and two new rank order statistics arising in its consideration. Cancer Chemother Rep 1966;50:163-170. [Medline]
Cox DR. Regression models and life-tables. J R Stat Soc [B] 1972;34:187-202.
The TIMI Study Group. Comparison of invasive and conservative strategies after treatment with intravenous tissue plasminogen activator in acute myocardial infarction: results of the Thrombolysis in Myocardial Infarction (TIMI) phase II trial. N Engl J Med 1989;320:618-627. [Abstract]
Fuchs R, Scheidt S. Improved criteria for admission to cardiac care units. JAMA 1981;246:2037-2041. [Free Full Text]
Williams B. Admissions to a coronary-care unit over the past seven years (1973-79). N Z Med J 1981;93:158-160. [Medline]
Tierney WM, Roth BJ, Psaty B, et al. Predictors of myocardial infarction in emergency room patients. Crit Care Med 1985;13:526-531. [Medline]
Selker HP, Griffith JL, Dorey FJ, D'Agostino RB. How do physicians adapt when the coronary care unit is full? A prospective multicenter study. JAMA 1987;257:1181-1185. [Free Full Text]
Slater DK, Hlatky MA, Mark DB, Harrell FE Jr, Pryor DB, Califf RM. Outcome in suspected acute myocardial infarction with normal or minimally abnormal admission electrocardiographic findings. Am J Cardiol 1987;60:766-770. [CrossRef][Medline]
Gheorghiade M, Anderson J, Rosman H, et al. Risk identification at the time of admission to coronary care unit in patients with suspected myocardial infarction. Am Heart J 1988;116:1212-1217. [CrossRef][Medline]
Lee TH, Goldman L. The coronary care unit turns 25: historical trends and future directions. Ann Intern Med 1988;108:887-894.
Singer DE, Carr PL, Mulley AG, Thibault GE. Rationing intensive care -- physician responses to a resource shortage. N Engl J Med 1983;309:1155-1160. [Abstract]
Goldman L, Weinberg M, Weisberg M, et al. A computer-derived protocol to aid in the diagnosis of emergency room patients with acute chest pain. N Engl J Med 1982;307:588-596. [Abstract]
Chadda K, Goldstein S, Byington R, Curb JD. Effect of propranolol after acute myocardial infarction in patients with congestive heart failure. Circulation 1986;73:503-510. [Free Full Text]
The Multicenter Diltiazem Postinfarction Trial Research Group. The effect of diltiazem on mortality and reinfarction after myocardial infarction. N Engl J Med 1988;319:385-392. [Abstract]
The Cardiac Arrhythmia Suppression Trial (CAST) Investigators. Preliminary report: effect of encainide and flecainide on mortality in a randomized trial of arrhythmia suppression after myocardial infarction. N Engl J Med 1989;321:406-412. [Abstract]
Tu, J. V., Ko, D. T.
(2008). Ecological Studies and Cardiovascular Outcomes Research. Circulation
118: 2588-2593
[Full Text]
Jackevicius, C. A., Tu, J. V., Ross, J. S., Ko, D. T., Krumholz, H. M.
(2008). Use of Ezetimibe in the United States and Canada. NEJM
358: 1819-1828
[Abstract][Full Text]
Birnie, D. H. MB ChB MD, Sambell, C. BSc, Johansen, H. PhD, Williams, K. MS, Lemery, R. MD, Green, M. S. MD, Gollob, M. H. MD, Lee, D. S. MD PhD, Tang, A. S.L. MD
(2007). Use of implantable cardioverter defibrillators in Canadian and US survivors of out-of-hospital cardiac arrest. CMAJ
177: 41-46
[Abstract][Full Text]
Merhige, M. E., Breen, W. J., Shelton, V., Houston, T., D'Arcy, B. J., Perna, A. F.
(2007). Impact of Myocardial Perfusion Imaging with PET and 82Rb on Downstream Invasive Procedure Utilization, Costs, and Outcomes in Coronary Disease Management. JNM
48: 1069-1076
[Abstract][Full Text]
Ko, D. T., Krumholz, H. M., Wang, Y., Foody, J. M., Masoudi, F. A., Havranek, E. P., You, J. J., Alter, D. A., Stukel, T. A., Newman, A. M., Tu, J. V.
(2007). Regional Differences in Process of Care and Outcomes for Older Acute Myocardial Infarction Patients in the United States and Ontario, Canada. Circulation
115: 196-203
[Abstract][Full Text]
Alexander, K. P., Newby, L. K., Bhapkar, M. V., White, H. D., Hochman, J. S., Pfisterer, M. E., Moliterno, D. J., Peterson, E. D., Van de Werf, F., Armstrong, P. W., Califf, R. M., for the SYMPHONY and 2nd SYMPHONY Investigators,
(2006). International variation in invasive care of the elderly with acute coronary syndromes. Eur Heart J
27: 1558-1564
[Abstract][Full Text]
Kaul, P., Chang, W.-C., Lincoff, A. M., Aylward, P., Betriu, A., Bode, C., Califf, R. M., Ohman, E. M., Guetta, V., Steg, P. G., Van de Werf, F., Armstrong, P. W.
(2006). Optimizing use of revascularization and clinical outcomes in ST-elevation myocardial infarction: insights from the GUSTO-V trial. Eur Heart J
27: 1198-1206
[Abstract][Full Text]
Ko, D. T., Tu, J. V., Masoudi, F. A., Wang, Y., Havranek, E. P., Rathore, S. S., Newman, A. M., Donovan, L. R., Lee, D. S., Foody, J. M., Krumholz, H. M.
(2005). Quality of Care and Outcomes of Older Patients With Heart Failure Hospitalized in the United States and Canada. Arch Intern Med
165: 2486-2492
[Abstract][Full Text]
Chang, W.-C., Midodzi, W. K, Westerhout, C. M, Boersma, E., Cooper, J., Barnathan, E. S, Simoons, M. L, Wallentin, L., Ohman, E M., Armstrong, P. W, for the GUSTO-IV ACS Investigators,
(2005). Are international differences in the outcomes of acute coronary syndromes apparent or real? A multilevel analysis. J. Epidemiol. Community Health
59: 427-433
[Abstract][Full Text]
Kaul, P., Armstrong, P. W., Chang, W.-C., Naylor, C. D., Granger, C. B., Lee, K. L., Peterson, E. D., Califf, R. M., Topol, E. J., Mark, D. B.
(2004). Long-Term Mortality of Patients With Acute Myocardial Infarction in the United States and Canada: Comparison of Patients Enrolled in Global Utilization of Streptokinase and t-PA for Occluded Coronary Arteries (GUSTO)-I. Circulation
110: 1754-1760
[Abstract][Full Text]
Brophy, J. M., Bourgault, C., Brassard, P.
(2003). The use of cholesterol-lowering medications after coronary revascularization. CMAJ
169: 1153-1157
[Abstract][Full Text]
Gupta, M., Chang, W.-C., Van de Werf, F., Granger, C. B., Midodzi, W., Barbash, G., Pehrson, K., Oto, A., Toutouzas, P., Jansky, P., Armstrong, P. W., for the ASSENT II Investigators,
(2003). International differences in in-hospital revascularization and outcomes following acute myocardial infarction: A multilevel analysis of patients in ASSENT-2. Eur Heart J
24: 1640-1650
[Abstract][Full Text]
Klarenbach, S. W., Jacobs, P.
(2003). International Comparison of Health Resource Utilization in Subjects With Diabetes: An analysis of Canadian and American national health surveys. Diabetes Care
26: 1116-1122
[Abstract][Full Text]
Khaykin, Y, Austin, P C, Tu, J V, Alter, D A
(2002). Utilisation of coronary angiography after acute myocardial infarction in Ontario over time: have referral patterns changed?. Heart
88: 460-466
[Abstract][Full Text]
Mehta, R. H., Criger, D. A., Granger, C. B., Pieper, K. K., Califf, R. M., Topol, E. J., Bates, E. R.
(2002). Patient outcomes after fibrinolytic therapy for acute myocardial infarction at hospitals with and without coronary revascularization capability. J Am Coll Cardiol
40: 1034-1040
[Abstract][Full Text]
Dzavik, V., Rouleau, J.-L. u.
(2002). Should all patients with an acute myocardial infarction present to a hospital with revascularization capabilities?: The evidence is mounting that they need not. J Am Coll Cardiol
40: 1041-1043
[Full Text]
Lumer, G.B, Roy, D, Talajic, M, Couturier, A, Lambert, J, Frasure-Smith, N, Thibault, B, Dubuc, M, Gagne, P, Nattel, S
(2002). Amiodarone reduces procedures and costs related to atrial fibrillation in a controlled clinical trial. Eur Heart J
23: 1050-1056
[Abstract][Full Text]
Booth, G. L., Zinman, B., Redelmeier, D. A.
(2002). Diabetes Care in the U.S. and Canada. Diabetes Care
25: 1149-1153
[Abstract][Full Text]
Pilote, L., Lauzon, C., Huynh, T., Dion, D., Roux, R., Racine, N., Carignan, S., Diodati, J. G., Levesque, C., Charbonneau, F., Pouliot, J., Joseph, L., Eisenberg, M. J.
(2002). Quality of Life After Acute Myocardial Infarction Among Patients Treated at Sites With and Without On-site Availability of Angiography. Arch Intern Med
162: 553-559
[Abstract][Full Text]
Llevadot, J, Giugliano, R.P, Antman, E.M, Wilcox, R.G, Gurfinkel, E.P, Henry, T, McCabe, C.H, Charlesworth, A, Thompson, S, Nicolau, J.C, Tebbe, U, Sadowski, Z, Braunwald, E, for the InTIME II Invatigators,
(2001). Availability of on-site catheterization and clinical outcomes in patients receiving fibrinolysis for ST-elevation myocardial infarction. Eur Heart J
22: 2104-2115
[Abstract]
Giugliano, R.P, Llevadot, J, Wilcox, R.G, Gurfinkel, E.P, McCabe, C.H, Charlesworth, A, Thompson, S.L, Antman, E.M, Braunwald, E, for the In TIME II Investigators,
(2001). Geographic variation in patient and hospital characteristics, management, and clinical outcomes in ST-elevation myocardial infarction treated with fibrinolysis. Results from InTIME-II. Eur Heart J
22: 1702-1715
[Abstract]
Boucher, J.-M., Racine, N., Thanh, T. H., Rahme, E., Brophy, J., LeLorier, J., Theroux, P.
(2001). Age-related differences in in-hospital mortality and the use of thrombolytic therapy for acute myocardial infarction. CMAJ
164: 1285-1290
[Abstract][Full Text]
Alter, D. A., Naylor, C. D., Austin, P. C., Tu, J. V.
(2001). Long-term MI Outcomes at Hospitals With or Without On-site Revascularization. JAMA
285: 2101-2108
[Abstract][Full Text]
Kovac, J.D., Gershlick, A.H.
(2001). How should we detect and manage failed thrombolysis?. Eur Heart J
22: 450-457
Caro, J. J., Huybrechts, K. F., Kelley, H. E.
(2001). Predicting Treatment Costs After Acute Ischemic Stroke on the Basis of Patient Characteristics at Presentation and Early Dysfunction. Stroke
32: 100-106
[Abstract][Full Text]
Heggunje, P.S, Wade, M.J, O'Rourke, R.A, Kleiger, R.E, Deedwania, P.C, Lavori, P.W, Boden, W.E, Veterans Affairs Non-Q-Wave Infarction Strategies,
(2000). Early invasive versus ischaemia-guided strategies in the management of non-Q wave myocardial infarction patients with and without prior myocardial infarction. Results of Veterans Affairs Non-Q Wave Infarction Strategies In Hospital (VANQWISH) trial. Eur Heart J
21: 2014-2025
[Abstract]
Fu, Y., Chang, W.-C., Mark, D., Califf, R. M., Mackenzie, B., Granger, C. B., Topol, E. J., Hlatky, M., Armstrong, P. W.
(2000). Canadian-American Differences in the Management of Acute Coronary Syndromes in the GUSTO IIb Trial : One-Year Follow-Up of Patients Without ST-Segment Elevation. Circulation
102: 1375-1381
[Abstract][Full Text]
Bucher, H. C, Hengstler, P., Schindler, C., Guyatt, G. H
(2000). Percutaneous transluminal coronary angioplasty versus medical treatment for non-acute coronary heart disease: meta-analysis of randomised controlled trials. BMJ
321: 73-77
[Abstract][Full Text]
Pilote, L., Lavoie, F., Ho, V., Eisenberg, M. J.
(2000). Changes in the treatment and outcomes of acute myocardial infarction in Quebec, 1988-1995. CMAJ
163: 31-36
[Abstract][Full Text]
Dodek, A.
(2000). Acute myocardial infarction in Canada: improvement with time. CMAJ
163: 41-42
[Full Text]
Marrugat, J, Ferrieres, J, Masia, R, Ruidavets, J, Sala, J
(2000). Differences in use of coronary angiography and outcome of myocardial infarction in Toulouse (France) and Gerona (Spain). Eur Heart J
21: 740-746
[Abstract]
White, H.D.
(2000). International differences: selection, noise, or real?. Eur Heart J
21: 339-342
Akkerhuis, K.M, Deckers, J.W, Boersma, E, Harrington, R.A, Stepinska, J, Mahaffey, K.W, Wilcox, R.G, Lincoff, A.M, Keltai, M, Topol, E.J, Califf, R.M, Simoons, M.L
(2000). Geographic variability in outcomes within an international trial of glycoprotein IIb/IIIa inhibition in patients with acute coronary syndromes. Results from PURSUIT. Eur Heart J
21: 371-381
[Abstract]
Lupon, J., Valle, V., Marrugat, J., Elosua, R., Seres, L., Pavesi, M., Freixa, R., Sanz, G., Masia, R., Molina, L., Sala, J., Serra, J., for the R.E.S.C.A.T.E. Investigators,
(1999). Six-month outcome in unstable angina patients without previous myocardial infarction according to the use of tertiary cardiologic resources. J Am Coll Cardiol
34: 1947-1953
[Abstract][Full Text]
Batchelor, W. B., Peterson, E. D., Mark, D. B., Knight, J. D., Granger, C. B., Armstrong, P. W., Califf, R. M.
(1999). A comparison of U.S. and Canadian cardiac catheterization practices in detecting severe coronary artery disease after myocardial infarction: efficiency, yield and long-term implications. J Am Coll Cardiol
34: 12-19
[Abstract][Full Text]
Gottlieb, S., Boyko, V., Harpaz, D., Hod, H., Cohen, M., Mandelzweig, L., Khoury, Z., Stern, S., Behar, S., for the Israeli Thrombolytic Survey Group,
(1999). Long-term (three-year) prognosis of patients treated with reperfusion or conservatively after acute myocardial infarction. J Am Coll Cardiol
34: 70-82
[Abstract][Full Text]
Scanlon, P. J., Faxon, D. P., Audet, A.-M., Carabello, B., Dehmer, G. J., Eagle, K. A., Legako, R. D., Leon, D. F., Murray, J. A., Nissen, S. E., Pepine, C. J., Watson, R. M., Ritchie, J. L., Gibbons, R. J., Cheitlin, M. D., Eagle, K. A., Gardner, T. J., Garson, A. Jr, Russell, R. O. Jr, Ryan, T. J., Smith, S. C. Jr
(1999). ACC/AHA guidelines for coronary angiography: A report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (Committee on Coronary Angiography) developed in collaboration with the Society for Cardiac Angiography and Interventions. J Am Coll Cardiol
33: 1756-1824
[Full Text]
Mahon, N G, O'Rorke, C, Codd, M B, McCann, H A, McGarry, K, Sugrue, D D
(1999). Hospital mortality of acute myocardial infarction in the thrombolytic era. Heart
81: 478-482
[Abstract][Full Text]
Grover, S. A., Coupal, L., Paquet, S., Zowall, H.
(1999). Cost-effectiveness of 3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Inhibitors in the Secondary Prevention of Cardiovascular Disease: Forecasting the Incremental Benefits of Preventing Coronary and Cerebrovascular Events. Arch Intern Med
159: 593-600
[Abstract][Full Text]
O'Connor, G. T., Quinton, H. B., Traven, N. D., Ramunno, L. D., Dodds, T. A., Marciniak, T. A., Wennberg, J. E.
(1999). Geographic Variation in the Treatment of Acute Myocardial Infarction: The Cooperative Cardiovascular Project. JAMA
281: 627-633
[Abstract][Full Text]
Dakik, H. A., Kleiman, N. S., Farmer, J. A., He, Z.-X., Wendt, J. A., Pratt, C. M., Verani, M. S., Mahmarian, J. J.
(1998). Intensive Medical Therapy Versus Coronary Angioplasty for Suppression of Myocardial Ischemia in Survivors of Acute Myocardial Infarction : A Prospective, Randomized Pilot Study. Circulation
98: 2017-2023
[Abstract][Full Text]
Donohoe, M. T.
(1998). Comparing Generalist and Specialty Care: Discrepancies, Deficiencies, and Excesses. Arch Intern Med
158: 1596-1608
[Abstract][Full Text]
Boden, W. E., O'Rourke, R. A., Crawford, M. H., Blaustein, A. S., Deedwania, P. C., Zoble, R. G., Wexler, L. F., Kleiger, R. E., Pepine, C. J., Ferry, D. R., Chow, B. K., Lavori, P. W., The Veterans Affairs Non-Q-Wave Infarction Strateg,
(1998). Outcomes in Patients with Acute Non-Q-Wave Myocardial Infarction Randomly Assigned to an Invasive as Compared with a Conservative Management Strategy. NEJM
338: 1785-1792
[Abstract][Full Text]
Giugliano, R. P., Camargo, C. A. Jr, Lloyd-Jones, D. M., Zagrodsky, J. D., Alexis, J. D., Eagle, K. A., Fuster, V., O'Donnell, C. J.
(1998). Elderly Patients Receive Less Aggressive Medical and Invasive Management of Unstable Angina: Potential Impact of Practice Guidelines. Arch Intern Med
158: 1113-1120
[Abstract][Full Text]
Bell, C. M., Crystal, M., Detsky, A. S., Redelmeier, D. A.
(1998). Shopping Around for Hospital Services: A Comparison of the United States and Canada. JAMA
279: 1015-1017
[Abstract][Full Text]
Glick, H. A., Polsky, D., Willke, R. J., Alves, W. M., Kassell, N., Schulman, K.
(1998). Comparison of the Use of Medical Resources and Outcomes in the Treatment of Aneurysmal Subarachnoid Hemorrhage Between Canada and the United States. Stroke
29: 351-358
[Abstract][Full Text]
BROPHY, J M, SLEIGHT, P
(1998). Enthusiasm, reality, and cost-effectiveness analysis. Heart
79: 9-10
[Full Text]
Every, N. R., Parsons, L. S., Fihn, S. D., Larson, E. B., Maynard, C., Hallstrom, A. P., Martin, J. S., Weaver, W. D., Investigators, f. t. M.
(1997). Long-term Outcome in Acute Myocardial Infarction Patients Admitted to Hospitals With and Without On-site Cardiac Catheterization Facilities. Circulation
96: 1770-1775
[Abstract][Full Text]
Tu, J. V., Pashos, C. L., Naylor, C. D., Chen, E., Normand, S.-L., Newhouse, J. P., McNeil, B. J.
(1997). Use of Cardiac Procedures and Outcomes in Elderly Patients with Myocardial Infarction in the United States and Canada. NEJM
336: 1500-1505
[Abstract][Full Text]
Krumholz, H. M.
(1997). Cardiac Procedures, Outcomes, and Accountability. NEJM
336: 1521-1523
[Full Text]
Quinones, M. A.
(1997). Risk Stratification After Myocardial Infarction: Clinical Science Versus Practice Behavior. Circulation
95: 1352-1354
[Full Text]
Tavazzi, L., Volpi, A.
(1997). Remarks About Postinfarction Prognosis in Light of the Experience With the Gruppo Italiano per lo Studio della Sopravvivenza nell' Infarto Miocardico (GISSI) Trials. Circulation
95: 1341-1345
[Full Text]
Selby, J. V., Fireman, B. H., Lundstrom, R. J., Swain, B. E., Truman, A. F., Wong, C. C., Froelicher, E. S., Barron, H. V., Hlatky, M. A.
(1996). Variation among Hospitals in Coronary-Angiography Practices and Outcomes after Myocardial Infarction in a Large Health Maintenance Organization. NEJM
335: 1888-1896
[Abstract][Full Text]
Gorlin, R.
(1996). Cardiologist Adapts to Healthcare Change for the Year 2000: The Herrick Lecture. Circulation
94: 1781-1785
[Full Text]
Hand, R., Klemka-Walden, L., Inczauskis, D.
(1996). Rural Hospital Mortality for Myocardial Infarction in Medicare Patients in Illinois. American Journal of Medical Quality
11: 135-141
[Abstract]
Welch, W. P., Verrilli, D., Katz, S. J., Latimer, E.
(1996). A Detailed Comparison of Physician Services for the Elderly in the United States and Canada. JAMA
275: 1410-1416
[Abstract]
Evans, J. G.
(1996). Health Care for Older People: A Look Across a Frontier. JAMA
275: 1449-1450
[Abstract]
Wennberg, D. E., Kellett, M. A., Dickens, J. D. Jr, Malenka, D. J., Keilson, L. M., Keller, R. B.
(1996). The Association Between Local Diagnostic Testing Intensity and Invasive Cardiac Procedures. JAMA
275: 1161-1164
[Abstract]
Col, N. F., McLaughlin, T. J., Soumerai, S. B., Hosmer, D. W. Jr, Yarzebski, J., Gurwitz, J. H., Gore, J. M., Goldberg, R. J.
(1996). The Impact of Clinical Trials on the Use of Medications for Acute Myocardial Infarction: Results of a Community-Based Study. Arch Intern Med
156: 54-60
[Abstract]
Pilote, L., Califf, R. M., Sapp, S., Miller, D. P., Mark, D. B., Weaver, W. D., Gore, J. M., Armstrong, P. W., Ohman, E. M., Topol, E. J., The GUSTO-1 Investigators,
(1995). Regional Variation across the United States in the Management of Acute Myocardial Infarction. NEJM
333: 565-572
[Abstract][Full Text]
Guadagnoli, E., Hauptman, P. J., Ayanian, J. Z., Pashos, C. L., McNeil, B. J., Cleary, P. D.
(1995). Variation in the Use of Cardiac Procedures after Acute Myocardial Infarction. NEJM
333: 573-578
[Abstract][Full Text]
Detsky, A. S.
(1995). Regional Variation in Medical Care. NEJM
333: 589-590
[Full Text]
Van de Werf, F., Topol, E. J., Lee, K. L., Woodlief, L. H., Granger, C. B., Armstrong, P. W., Barbash, G. I., Hampton, J. R., Guerci, A., Simes, R. J., Ross, A. M., Califf, R. M., the GUSTO Investigators,
(1995). Variations in Patient Management and Outcomes for Acute Myocardial Infarction in the United States and Other Countries: Results From the GUSTO Trial. JAMA
273: 1586-1591
[Abstract]
Rasell, M. E.
(1995). Cost Sharing in Health Insurance -- A Reexamination. NEJM
332: 1164-1168
[Full Text]
Behar, S., Hod, H., Benari, B., Narinsky, R., Pauzner, H., Rechavia, E., Faibel, H. E., Katz, A., Roth, A., Goldhammer, E., Freedberg, N. A., Rougin, N., Kracoff, O., Shapira, C., Jafari, J., Lotan, C., Daka, F., Gottlieb, S., Weiss, T., Kanetti, M., Klutstein, M., Rudnik, L., Barasch, E., Mahul, N., Blondheim, D., Gelvan, A., Barbash, G., Israeli Thrombolytic Survey Group, , Schlesinger, Z., Reisin, L., Sclarovsky, S., Stern, S., Abinader, E., Luis, B., Palant, A., Rosenfeld, T., Gotesman, M., Weiss, T., Zahavi, I., Pelled, B., Laniado, S., Gelvan, A., Caspi, A., Barasch, E., David, D., Rudnik, L., Markiewicz, W., Marmour, A., Tzivoni, D., Kaplinsky, E., Cristal, N., Rougin, N., Kishon, Y.
(1995). On-Site Catheterization Laboratory and Prognosis After Acute Myocardial Infarction. Arch Intern Med
155: 813-817
[Abstract]
Hamilton, V. H., Racicot, F.-E., Zowall, H., Coupal, L., Grover, S. A.
(1995). The Cost-effectiveness of HMG-CoA Reductase Inhibitors to Prevent Coronary Heart Disease: Estimating the Benefits of Increasing HDL-C. JAMA
273: 1032-1038
[Abstract]
Cairns, J. A., Markham, B. A.
(1995). Economics and Efficacy in Choosing Oral Anticoagulants or Aspirin After Myocardial Infarction. JAMA
273: 965-967
[Abstract]
Mark, D. B., Naylor, C. D., Hlatky, M. A., Califf, R. M., Topol, E. J., Granger, C. B., Knight, J. D., Nelson, C. L., Lee, K. L., Clapp-Channing, N. E., Sutherland, W., Pilote, L., Armstrong, P. W.
(1994). Use of Medical Resources and Quality of Life after Acute Myocardial Infarction in Canada and the United States. NEJM
331: 1130-1135
[Abstract][Full Text]
McGlynn, E. A., Naylor, C. D., Anderson, G. M., Leape, L. L., Park, R. E., Hilborne, L. H., Bernstein, S. J., Goldman, B. S., Armstrong, P. W., Keesey, J. W., McDonald, L., Pinfold, S. P., Damberg, C., Sherwood, M. J., Robert H.,
(1994). Comparison of the Appropriateness of Coronary Angiography and Coronary Artery Bypass Graft Surgery Between Canada and New York State. JAMA
272: 934-940
[Abstract]
McClellan, M., McNeil, B. J., Newhouse, J. P.
(1994). Does More Intensive Treatment of Acute Myocardial Infarction in the Elderly Reduce Mortality? Analysis Using Instrumental Variables. JAMA
272: 859-866
[Abstract]
Pilote, L., Racine, N., Hlatky, M. A.
(1994). Differences in the Treatment of Myocardial Infarction in the United States and Canada: A Comparison of Two University Hospitals. Arch Intern Med
154: 1090-1096
[Abstract]
Ayanian, J. Z.
(1994). Race, Class, and the Quality of Medical Care. JAMA
271: 1207-1208
[Abstract]
Mirvis, D. N.
(1994). Health System Reform: A Provider or a Patient Perspective?. Arch Fam Med
3: 241-245
[Abstract]
Hamilton, V., Benk, V., Fortin, P., Ayanian, J. Z., Kohler, B. A., Epstein, A. M.
(1993). Health Insurance Coverage and Clinical Outcomes in Women with Breast Cancer. NEJM
329: 2039-2040
[Full Text]
Schneider, J. F., Roth, S. L., Cornell, C., Mendelssohn, D.C., Skorecki, K.L., Cardella, C.J., Uretsky, B. F., Redelmeier, D. A., Fuchs, V. R., Rouleau, J. L., Braunwald, E., Pfeffer, M. A.
(1993). Health Care in Canada and the United States. NEJM
329: 964-966
[Full Text]
Every, N. R., Larson, E. B., Litwin, P. E., Maynard, C., Fihn, S. D., Eisenberg, M. S., Hallstrom, A. P., Martin, J. S., Weaver, W. D., The Myocardial Infarction Triage and Intervention,
(1993). The Association between On-Site Cardiac Catheterization Facilities and the Use of Coronary Angiography after Acute Myocardial Infarction. NEJM
329: 546-551
[Abstract][Full Text]
Bittl, J. A.
(1993). Directional Coronary Atherectomy versus Balloon Angioplasty. NEJM
329: 273-274
[Full Text]
Detsky, A. S.
(1993). Northern Exposure -- Can the United States Learn from Canada?. NEJM
328: 805-807
[Full Text]
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