Determinants of variations in coronary revascularization practices.

BACKGROUND: The ratio of percutaneous coronary interventions to coronary artery bypass graft surgeries (PCI:CABG ratio) varies considerably across hospitals. We conducted a comprehensive study to identify clinical and nonclinical factors associated with variations in the ratio across 17 cardiac centres in the province of Ontario. METHODS: In this retrospective cohort study, we selected a population-based sample of 8972 patients who underwent an index cardiac catheterization between April 2006 and March 2007 at any of 17 hospitals that perform invasive cardiac procedures in the province. We classified the hospitals into four groups by PCI:CABG ratio (low [< 2.0], low-medium [2.0-2.7], medium-high [2.8-3.2] and high [> 3.2]). We explored the relative contribution of patient, physician and hospital factors to variations in the likelihood of patients receiving PCI or CABG surgery within 90 days after the index catheterization. RESULTS: The mean PCI:CABG ratio was 2.7 overall. We observed a threefold variation in the ratios across the four hospital ratio groups, from a mean of 1.6 in the lowest ratio group to a mean of 4.6 in the highest ratio group. Patients with single-vessel disease usually received PCI (88.4%-99.0%) and those with left main artery disease usually underwent CABG (80.8%-94.2%), regardless of the hospital's procedure ratio. Variation in the management of patients with non-emergent multivessel disease accounted for most of the variation in the ratios across hospitals. The mode of revascularization largely reflected the recommendation of the physician performing the diagnostic catheterization and was also influenced by the revascularization "culture" at the treating hospital. INTERPRETATION: The physician performing the diagnostic catheterization and the treating hospital were strong independent predictors of the mode of revascularization. Opportunities exist to improve transparency and consistency around the decision-making process for coronary revascularization, most notably among patients with non-emergent multivessel disease.

Impracticability of informed consent in the Registry of the Canadian Stroke Network.

BACKGROUND: Government legislators and research ethics boards in some jurisdictions require all patients to give written informed consent before enrollment in clinical registries. However, the effect of such a requirement on the use of clinical registries and the extent to which registry data can be generalized remain uncertain. METHODS: We examined the effectiveness of a comprehensive attempt to obtain informed consent between June 2001 and December 2002 on the overall participation rate and the characteristics of participating patients in the Registry of the Canadian Stroke Network, a prospective registry based at 20 major stroke centers across Canada. RESULTS: The overall participation rate (i.e., the consent rate among all potential participants) was 39.3 percent of 4285 eligible patients during phase 1 of the project (June 2001 through February 2002) and 50.6 percent of 2823 eligible patients during phase 2 (June 2002 through December 2002), despite the presence of neurologic research nurse coordinators at each site. Many patients died or left the hospital before they could be approached for consent. Major selection biases were found; the in-hospital mortality rate was much lower among patients who were enrolled (6.9 percent) than among those who were not enrolled (21.7 percent) (relative risk of in-hospital death, 3.13; 95 percent confidence interval, 2.65 to 3.70; P<0.001). We estimate that approximately 500,000 dollars (Canadian dollars) was spent on consent-related issues during the first two years of the registry. CONCLUSIONS: Obtaining written informed consent for participation in a stroke registry led to important selection biases, such that registry patients were not representative of the typical patient with stroke at each center. These findings highlight the need for legislation on privacy and policies permitting waivers of informed consent for minimal-risk observational research.

International experience in stroke registries: lessons learned in establishing the Registry of the Canadian Stroke Network.

This paper discusses the early lessons learned in establishing the Registry of the Canadian Stroke Network (RCSN), particularly the pitfalls related to the requirement for informed patient (or surrogate) consent for inclusion in the registry. The need for stroke registries to collect accurate data that are representative of all patients with acute stroke in a given community is emphasized, and how the current methodology strives to reach this goal is outlined.

Variation in recruitment across sites in a consent-based clinical data registry: lessons from the Canadian Stroke Network.

BACKGROUND: In earlier work, we found important selection biases when we tried to obtain consent for participation in a national stroke registry. Recognizing that not all registries will be exempt from requiring consent for participation, we examine here in greater depth the reasons for the poor accrual of patients from a systems perspective with a view to obtaining as representative sample as possible. METHODS: We determined the percent of eligible patients who were approached to participate and, among those approached, the percent who actually consented to participate. In addition we examined the reasons why people were not approached or did not consent and the variation across sites in the percent of patients approached and consented. We also considered site variation in restrictions on the accrual and data collection process imposed by either the local research ethics board or the hospital. RESULTS: Seventy percent of stroke patients were approached, with wide variations in approach rates across sites (from: 41% to 86%), and considerable inter-site variation in hospital policies governing patient accrual. Chief reasons for not approaching were discharge or death before being approached for consent. Seventeen percent of those approached refused to participate (range: 5% to 75%). Finally, 11% of those approached did not participate due to language or communication difficulties. CONCLUSION: We found wide variation in approach and agree rates across sites that were accounted for, in part, by different approaches to accrual and idiosyncratic policies of the hospitals. This wide variation in approach and agree rates raises important challenges for research ethics boards and data protection authorities in determining when to waive consent requirements, when to press for increased quality control, when to permit local adaptation of the consent process, and when to permit alternatives to individual express consent. We offer several suggestions for those registries that require consent for participation.

TPA use for stroke in the Registry of the Canadian Stroke Network.

BACKGROUND: Thrombolytic therapy with recombinant tissue plasminogen activator (tPA) has been shown to be cost-effective and safe. Thrombolysis for stroke with tPA is now a standard of care in North America. However, it is only used on a small percentage of patients. METHODS: The Registry of the Canadian Stroke Network was a consent-based stroke registry from 21 hospital sites across Canada. Using the thrombolysis data in phase 1 and 2 of the Registry, we sought to describe the use of stroke thrombolysis and its outcomes. RESULTS: A total of 4107 patients were diagnosed with ischemic stroke in phase 1 and 2 of the Registry, of which 8.9% were treated with tPA. In consented tPA patients, the method of tPA administration was 85.8% i.v. only, 9.0% ia only, and 5.2% i.v./i.a. combined. Patients had a median onset-to-treatment time of 167 minutes [IQR 140-188]. One quarter (25.5%) of eligible candidates (time from onset <150 minutes) were treated with tPA. Protocol violations occurred in 27.7% (67/242) of patients with 14.9% (10/67) mortality. Overall, in-hospital mortality was 11.6%. Lower Canadian Neurological Scale score and higher glucose level were predictive of mortality The symptomatic intracerebral hemorrhage (ICH) rate (phase 2 only) was 4.3%. The mean Stroke Impact Scale-16 score at six months was 73.2, approximately equivalent to a modified Rankin scale score of 2. CONCLUSIONS: At selected hospitals in Canada, thrombolysis use is higher than previously reported rates. Thrombolysis continues to be safe and effective in Canada.

The relationship between need and capacity for multidisciplinary cardiovascular risk-reduction programs in Ontario.

BACKGROUND: Available evidence has demonstrated survival benefits associated with multidisciplinary cardiovascular risk-reduction (CR) (ie, cardiac rehabilitation) programs. The degree to which program capacity meets eligible service demands in Ontario is unknown. We sought to estimate the supply-need care-gap associated with CR programs across regions (Local Health Integration Networks [LHINs]) in Ontario. METHODS: We conducted a cross-sectional, population-based study during 2006. Administrative data provided estimates of the population eligible for multidisciplinary CR services due to (1) recent cardiovascular hospitalizations and (2) incident diabetes. An Ontario-wide survey of CR programs provided service supply estimates. The coverage rate and the absolute supply-need mismatch were use to quantify the care-gap by LHIN. RESULTS: Based on cardiac hospitalizations alone, 53,270 patients in Ontario in 2006 (508.7 per 100,000) were eligible for CR services; 128,869 patients (1245 per 100,000) would have been eligible if newly diagnosed (incident cases) diabetic patients were included. Capacity for CR services was 18,087 patients, corresponding to 34% coverage of the eligible population (absolute unmet needs of 35,189 individuals) if capacity was entirely dedicated to recent hospitalizations and 14% coverage (absolute unmet needs of 110,782) if services were extended to include incident diabetes patients. Marked variation in disease burden, service capacity, and supply-need mismatch was observed across regions, in which supply was not correlated with need. CONCLUSION: Despite proved benefits of multidisciplinary CR programs, unmet population needs remain high in Ontario and are unequally distributed across regions. The magnitude of unmet needs and the lack of correlation between supply and disease burden necessitate broader provincial strategies to plan, allocate, and subsidize CR programs.