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David Alter

Publications and source records attributed to David Alter.

8 recordsLinked to original sources
PubMed2005

Acute treatment of myocardial infarction in Canada 1999-2002.

BACKGROUND: Therapy for management of acute myocardial infarction (AMI) varies according to patient, prescriber and geographical characteristics. OBJECTIVES: To describe the in-hospital use of reperfusion therapy for ST elevation MI (STEMI) and discharge use of acetylsalicylic acid, beta-blockers, angiotensin-converting enzyme inhibitors (ACEIs) and statins in patients presenting with either STEMI or non-STEMI in Canada from 1999 to 2002. METHODS: Four Canadian registries (FASTRAK II, Canadian Acute Coronary Syndromes, Enhanced Feedback for Effective Cardiac Treatment and Improving Cardiovascular Outcomes in Nova Scotia) were used to identify patients with AMI in Canada and to measure in-hospital reperfusion and medication use. Use rates were compared by age, sex, time period and geographical area, according to available data. RESULTS: Use rates for reperfusion in STEMI patients ranged from 60% to 70%, primarily representing fibrinolytic therapy. A delay in presentation to hospital after symptom onset represented an impediment to timely therapy, which was particularly pronounced for women and elderly patients. Overall, less than 50% of patients met the door-to-needle target of less than 30 min. Medication use rates at discharge increased from 1999/2000 to 2000/2001 across the different data sources: acetylsalicylic acid, 83% to 88%; beta-blockers, 74% to 89%; ACEIs, 54% to 67%; statins, 41% to 53%; and calcium antagonists, 21% to 32%. CONCLUSIONS: Canadian and provincial rates of use of evidence-based medications for the treatment of AMI have increased over time, although there remains room for improvement. A single, comprehensive data source would supply better insights into the management of AMI in Canada.

Adrenergic beta-Antagonists↗
PubMed2004

Predictors of repair and effect of gender on treatment of ruptured abdominal aortic aneurysm.

OBJECTIVE: The purpose of this study was to determine factors associated with increased likelihood of patients undergoing surgery to repair ruptured abdominal aortic aneurysms (AAAs). Specifically, we investigated whether men were more likely than women to be selected for surgery after rupture of AAAs. METHODS: All patients with a ruptured AAA who came to a hospital in Ontario between April 1, 1992, and March 31, 2001, were included in this population-based retrospective study. Administrative data were used to identify patients, patient demographic data, and hospital variables. RESULTS: Crude 30-day mortality for the 3570 patients who came to a hospital with a ruptured AAA was 53.4%. Of the 2602 patients (72.9%) who underwent surgical repair, crude 30-day mortality was 41.0%. Older patients (odds ratio [OR], 0.649 per 5 years of age; P<.0001), with a higher Charlson Comorbidity Index (OR, 0.848; P<.0001), were less likely to undergo AAA repair. Patients treated at high-volume centers (OR, 2.674 per 10 cases; P<.0001) and men (OR, 2.214; P<.0001) were more likely to undergo AAA repair. CONCLUSION: Men are more likely to undergo repair of a ruptured AAA than women are, for reasons that are unclear. Given the large magnitude of the effect, further studies are clearly indicated.

Aged↗
PubMed2004

Survival after ruptured abdominal aortic aneurysm: effect of patient, surgeon, and hospital factors.

OBJECTIVE: The purpose of this study was to determine the effects of patient, surgeon, and hospital factors on survival after repair of ruptured abdominal aortic aneurysm (AAA) and to compare them with risk factors for survival after elective AAA repair. It was hypothesized that patients operated on by high-volume surgeons with subspecialty training would have better outcomes, which might argue for regionalization of AAA surgery. METHODS: In this population-based retrospective cohort study, surgeon billing and administrative data were used to identify all patients who had undergone AAA repair between April 1, 1992, and March 31, 2001, in Ontario, Canada. Demographic information was collected for each patient, as well as numerous variables related to the surgeons and hospitals. RESULTS: There were 2601 patients with ruptured AAA repair, with an average 30-day mortality rate of 40.8%. Significant independent predictors of lower survival were older age, female gender, lower patient income quintile, performance of surgery at night or on weekends, repair in larger cities, surgeons with lower annual volume of ruptured AAA operations, and surgeons without vascular or cardiothoracic fellowship training. There were 13,701 patients with elective AAA repair, with an average 30-day mortality rate of 4.5%. Significant independent predictors of lower survival were similar, except gender was not significant, but the Charlson Comorbidity Index was. When the hazard ratios associated with predictive factors were compared, surgeon factors appeared to be more important in ruptured AAA repair, and patient factors appeared more important in elective AAA repair. CONCLUSION: For elective AAA repair, and even more so for ruptured AAA repair, high-volume surgeons with subspecialty training conferred a significant survival benefit for patients. Although this would seem to argue in favor of regionalization, decisions should await a more complete understanding of the relationship between transfer time, delay in treatment, and outcome.

Aged↗
PubMed2004

Long-term survival and temporal trends in patient and surgeon factors after elective and ruptured abdominal aortic aneurysm surgery.

OBJECTIVE: Records for all patients in Ontario who underwent elective repair of abdominal aortic aneurysms (AAAs) or repair of ruptured AAAs between 1993 and 1999 were studied to determine whether the profile of surgeons or patients changed and to determine whether postoperative mortality changed over time. The secondary objective was to describe long-term survival after AAA surgery. METHODS: A population-based retrospective cohort was assembled from administrative data. Surgeon billing records were used to identify operations performed between 1993 and 1999. Chi(2) and linear regression analyses were used to determine whether variables changed over time. Kaplan-Meier survival curves were used to estimate long-term survival. RESULTS: For patients undergoing elective AAA repair, average annual surgeon volume (P <.0001) and proportion of patients operated on by vascular surgeons (P =.02) increased over the study period; similar trends were noted for patients undergoing repair of ruptured AAAs. Surgeon volume was clearly correlated with mortality after both elective AAA repair and repair of ruptured AAAs; however, the benefit of this effect was modest beyond a surgeon volume of 6 to 10 ruptured AAA repairs per year or 20 to 30 elective AAA repairs per year. No change in crude 30-day mortality (4.5% for elective AAA repair and 40.4% for repair of ruptured AAAs) was noted during the study. CONCLUSION: Despite the finding that surgery to repair ruptured AAAs and elective repair of AAAs is being increasingly performed by high-volume vascular surgeons, there was no change in early mortality between 1993 and 1999. This may have been because average surgeon volume was already relatively high at the beginning of the study period, which translated into only modest benefit to further increases in surgeon volume.

Aged↗
PubMed2004

Secondary prevention after acute myocardial infarction in four Canadian provinces, 1997-2000.

BACKGROUND: Publication of population-based analyses of medication use after acute myocardial infarction (AMI) could encourage the use of effective secondary prevention medications. OBJECTIVE: To describe outpatient use of beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, statins, calcium channel blockers and nitrates in elderly survivors of AMI over the fiscal years from 1997/98 to 1999/2000 in Nova Scotia, Quebec, Ontario and British Columbia. METHODS: Linked administrative databases were used to identify all AMI patients 65 years of age or older admitted in Quebec (n=14,880), Ontario (n=28,647) and British Columbia (n=7549) over the study period, and to measure 90-day postdischarge utilization rates of cardiac medications for these patients. A population-based clinical registry was used to measure rates of prescription at discharge for elderly patients in Nova Scotia admitted to an acute care hospital from 1997 to 2000 (n=1997). RESULTS: Utilization rates for beta-blockers, ACE inhibitors and statins increased over time, while rates for calcium channel blockers and nitrates decreased only slightly. The largest increases were for statins (Nova Scotia: 26% to 42%, Quebec: 27% to 43%; Ontario: 28% to 40%; British Columbia: 30% to 42%) and for ACE inhibitors in Ontario (55% to 65%) and Nova Scotia (46% to 68%). Of the three drugs recommended for secondary prevention, overall utilization rates for beta-blockers were highest in Nova Scotia, lowest in British Columbia, and similar in Quebec and Ontario. Rates for ACE inhibitors were highest in Ontario and similar in Quebec, Nova Scotia and British Columbia. Rates for statins were slightly higher in Quebec and British Columbia than in Ontario and Nova Scotia. The proportion of patients without a prescription for any of the recommended drugs was highest in British Columbia (20%), lowest in Nova Scotia (8%), and similar in Quebec and Ontario (Ontario: 12%; Quebec: 13%). There was marked regional variation in utilization rates within the four provinces. CONCLUSIONS: Although utilization rates for recommended cardiac medications are increasing over time, there remains room for improvement. Overall utilization rates and temporal trends are generally similar in all four provinces, but there are wide regional variations within provinces.

Adrenergic beta-Antagonists↗
PubMed2004

Cardiac procedures after an acute myocardial infarction across nine Canadian provinces.

BACKGROUND: Geographical variations in the use of invasive cardiac procedures have been documented. It remains unclear to what extent these variations exist across the Canadian provinces. OBJECTIVE: To describe variation in the use of invasive cardiac procedures and waiting times for these procedures across nine Canadian provinces. METHODS: Using longitudinal, de-identified patient data from the Canadian Institute for Health Information, records of patients who had suffered an acute myocardial infarction (AMI) in each of nine Canadian provinces between 1997/1998 and 1999/2000 were selected. Rates and median waiting times for percutaneous coronary intervention and coronary artery bypass graft surgery were calculated by age, sex and health region. RESULTS: There was a large variation in the use of and waiting times for invasive cardiac procedures across the Canadian provinces studied. In general, cardiac procedure rates in Western provinces were higher than in Eastern provinces, most notably higher than in the Maritime provinces and Ontario. In addition to interprovincial variation, there was also significant regional variation in the rates of revascularization and waiting times. Rates of percutaneous coronary intervention increased over the study period, whereas rates of bypass surgery remained relatively stable. CONCLUSIONS: Significant variation in the use of cardiac procedures after AMI exists across Canada and this April represent potential inequalities in the treatment of AMI across Canada.

Adult↗