To assess specialists' adaptation to long waiting lists for coronary revascularization, and their acceptance of a formal queue-ordering schema proposed by an expert panel.
Mail survey of practitioners in referral centers using 49 hypothetical case scenarios. Scenarios were rated for maximum acceptable delay prior to coronary surgery, on a scale with seven interventional time frames graded from emergency to three to six months' permissible delay. The survey included the proposed schema and rating system; respondents were invited to differ as they saw fit. HYPOTHETICAL PATIENTS: Assumed uniformly to be middle aged with typical angina, but clinical factors varied, eg, severity and stability of angina, response to medical therapy, coronary anatomy, and noninvasive test results. PHYSICIAN SUBJECTS: There were 122 respondents, for a 60 percent response rate, including a majority of cardiac surgeons and invasive cardiologists on staff in Ontario teaching hospitals.
Fifty-seven percent rated some scenarios for acceptable waiting times of three to six months; another 39 percent rated their least urgent scenarios to wait six weeks to three months. Interpractitioner agreement was high: for 48/49 scenarios, at least 75 percent of urgency ratings fell within two contiguous points on the scale. Symptom status was the dominant determinant of waiting time, with mean maximum acceptable wait of 74 days for patients with mild-moderate stable angina but three days for those receiving parenteral nitroglycerin (p less than 0.00001). About half the ratings matched those predicted based on the original panel's consensus criteria; 90 percent were within one scale point.
Specialist practitioners in Ontario have adapted to waiting lists for coronary artery bypass surgery/percutaneous transluminal coronary angioplasty, and assess the priority of hypothetical patients in similar ways and in reasonable accord with formal queue-ordering criteria. This behavior may help mitigate the impact of resource constraints, allowing delay of services for those with less acute need--a potential contrast to delayed access in America based on low income or lack of insurance.
To assess death rates among patients waiting for cardiac valve surgery or isolated coronary artery bypass surgery (CABG), and to determine independent risk factors for death while waiting for isolated CABG.
Prospective cohort analysis based on an inclusive registry.
Nine cardiac surgical units in Ontario, Canada.
29,293 consecutive patients scheduled for cardiac surgery between October 1991 and June 1995.
Death rates while waiting for surgery were determined among patients scheduled for isolated CABG, isolated valve surgery, or combined procedures. Predictors of death among patients with isolated CABG were determined from multivariate analysis.
There were 141 deaths (0.48%) among 29,293 patients. Adjusting for age, sex, and waiting time, patients waiting for valve surgery had a significantly increased risk of death compared with patients waiting for CABG alone (adjusted odds ratio 1.88, 95% confidence interval (CI) 1.23 to 2.88, p = 0.004). Results were similar for patients waiting for combined valve and CABG procedures compared with those who were waiting for isolated CABG. Independent risk factors for death while waiting for isolated CABG included: impaired left ventricular function (odds ratio 2.47, 95% CI 1.59 to 3.84, p
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To compare the appropriateness of case selection for primary hip and knee replacements between two regions in Ontario: one with a high population-based utilization rate and one with a low rate.
Random audit of medical records sampled from hospital discharge abstracts, with subsequent implicit and explicit criteria-based assessments of the appropriateness of surgery.
People aged 60 years or over who underwent elective, single-joint, non-fracture-related, primary hip or knee replacement between Apr. 1, 1992, and Mar. 31, 1993, at one of seven hospitals in a high-rate region (comprising Brant, Huron and Oxford countries) or one of eight hospitals in a low-rate region (comprising the cities of Scarborough and Toronto).
Structured review of hospital medical records, with additional review of information from surgeons and family physicians' office charts if necessary. Three physicians reviewed patient data and rated the preoperative pain level and functional status of patients, with agreement among at least two reviewers. The proportion of inappropriate cases was then assessed according to explicit criteria defined by a multidisciplinary panel using the delphi process. Profiles of each case were also subjected to independent implicit review by two rheumatologists and two orthopedic surgeons.
Proportion of joint replacements deemed inappropriate in the high- and low-rate regions according to either the explicit criteria or the implicit review, as well as preoperative pain levels and functional status of patients in the high- and low-rate regions.
Hip replacements were more common among patients sampled in the low-rate region than among those in the high-rate region (57.3% v. 39.3%; p
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Population-based rates of surgery vary within and between health-care systems, causing concern that case selection is less appropriate in high-rate areas. This inverse relationship has not been shown with appropriateness criteria generated by expert panels. We applied a trials-based measure of the potential survival benefit of coronary artery bypass graft surgery (CABG) to patients in a provincial registry, to determine the relationship between survival gains and rates of CABG.
We did a population-based retrospective review of linked registry and administrative datasets. 5058 patients in the linked datasets underwent isolated CABG in Ontario between April 1, 1992, and March 31, 1993. Potential survival benefit of surgery was scored with an algorithm derived from a published overview of trials comparing CABG to medical treatment, analysed by county and by referral regions.
Overall, case selection was appropriate whether assessed clinically (96.3% had either severe disease as judged on the coronary arteries affected or moderate to severe angina) or on the basis of survival benefit scores (94.0% predicted to obtain moderate or high benefit). There was significant variation in benefit scores across referral regions (p
We sought to determine whether more comprehensive risk-adjustment models have a significant impact on hospital risk-adjusted mortality rates after coronary artery bypass graft surgery (CABG) in Ontario, Canada.
The Working Group Panel on the Collaborative CABG Database Project has categorized 44 clinical variables into 7 core, 13 level 1 and 24 level 2 variables, to reflect their relative importance in determining short-term mortality after CABG.
Using clinical data for all 5,517 patients undergoing isolated CABG in Ontario in 1993, we developed 12 increasingly comprehensive risk-adjustment models using logistic regression analysis of 6 of the Panel's core variables and 6 of the Panel's level 1 variables. We studied how the risk-adjusted mortality rates of the nine cardiac surgery hospitals in Ontario changed as more variables were included in these models.
Incorporating six of the core variables in a risk-adjustment model led to a model with an area under the receiver operating characteristic (ROC) curve of 0.77. The ROC curve area slightly improved to 0.79 with the inclusion of six additional level 1 variables (p = 0.063). Hospital risk-adjusted mortality rates and relative rankings stabilized after adjusting for six core variables. Adding an additional six level 1 variables to a risk-adjustment model had minimal impact on overall results.
A small number of core variables appear to be sufficient for fairly comparing risk-adjusted mortality rates after CABG across hospitals in Ontario. For efficient interprovider comparisons, risk-adjustment models for CABG could be simplified so that only essential variables are included in these models.
To develop guidelines for ranking the urgency with which patients with angiographically proven coronary disease need revascularisation procedures, factors that a panel of cardiac specialists agreed were likely to affect urgency were incorporated into 438 fictitious case-histories. Each panelist then rated the cases on a 7-point scale based on maximum acceptable waiting time for surgery; 1 on the scale represented emergency surgery and 7 delays of up to 6 months. For only 1% of cases was there agreement on a single rating by at least 12/16 panelists. Results of this ranking exercise were used by the panel to draw up triage guidelines. The three main urgency determinants were severity and stability of symptoms of angina, coronary anatomy from angiographic studies, and results of non-invasive tests for risk of ischaemia. Together these three factors generally gave an urgency rating for any given case to within less than 0.25 scale points of the value predicted with all factors. A numerical scoring system was derived to permit rapid estimation of the panel's recommended ratings.
Comment In: Lancet. 1990 Aug 4;336(8710):310-11973994
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.
Deaths among patients awaiting coronary artery bypass grafting (CABG) are a source of private grief and public concern in Canada. However, some deaths are expected over time among patients with coronary artery disease. Methods of benchmarking the burden of delayed care may be useful in understanding and managing waiting lists for CABG and other health services. The authors therefore determined the vital risk among people waiting for CABG in Ontario and compared it with the risk in the general population and among people living with coronary artery disease.
Patients registered to undergo CABG in Ontario between 1991 and 1995 were followed to ascertain numbers and dates of preoperative deaths or completed operations. Linking hospital discharge abstract data to vital statistics for 1991 to 1994, the authors defined a cohort of people who had survived 6 months after an acute myocardial infarction (AMI) and followed them for an additional 6 months to determine numbers and dates of deaths. They matched patients by age and sex and then calculated the standardized mortality ratio for each cohort (i.e., the ratio of observed deaths to those expected based on age- and sex-specific daily probabilities of death for the provincial population).
Among 21,220 patients awaiting CABG, there were 82 preoperative deaths over a median follow-up of 18 days; the standardized mortality ratio was 2.92 (95% confidence limit [CL] 2.29-3.55). Among 21,220 matched 6-month survivors of an AMI, there were 663 deaths over a median follow up of 185 days; the standardized mortality ratio was 3.84 (95% CI 3.54-4.14).
Patients awaiting CABG in Ontario are at a much greater risk of death than the general population. However, when compared with thousands of other patients living with coronary artery disease, they are at similar or decreased vital risk.
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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.
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.
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).
Even in difficult decisions such as rationing postlumpectomy breast cancer radiation therapy, TOTs can inform policy formulation by indicating the distributions of patients' preferences.