The invasive management of angina: issues for consumers and commissioners

Angioplasty and noncardiac surgery: risks of myocardial infarction

Prophylactic percutaneous transluminal coronary angioplasty is one revascularization strategy employed to reduce risks of cardiac complications after noncardiac surgery in certain patients. Reduced adverse cardiac event rates are at least partially offset by costs and complications of angioplasty. Patients who undergo noncardiac surgery within 90 days of coronary angioplasty may be at increased risk for postoperative cardiac complications.

Overview of systematic reviews on invasive treatment of stable coronary artery disease

Objectives: The aim of the study was to evaluate the validity of the systematic reviews as a source of best evidence and to present and interpret the evidence of the systematic reviews on effectiveness of surgery and percutaneous interventions for stable coronary artery disease.

Methods: Electronic databases were searched without language restriction from January 1966 to March 2004. The databases used included the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, DARE, the Health Technology Assessment Database, MEDLINE(R), MEDLINE(R) In-Process & Other Non-Indexed Citations. We included systematic reviews of randomized clinical trials on patients with stable coronary heart disease undergoing percutaneous coronary intervention or coronary artery bypass surgery in comparison with medical treatment or a comparison between invasive techniques. At least one of the following outcomes had to be reported: death, myocardial infarction, angina pectoris, revascularization. The methodological quality was assessed using a modified version of the scale devised by Oxman and Guyatt (1991). A standardized data-extraction form was used. The method used to evaluate clinical relevance was carried out with updated method guidelines from the Cochrane Back Research Group. Quantitative synthesis of the effectiveness data is presented.

Results: We found nineteen systematic reviews. The median score of validity was 13 points (range, 6–17 points), with a maximum of 18 points. vCoronary artery bypass surgery gives better relief of angina, and the need for repeated procedures is reduced after bypass surgery compared with percutaneous interventions. There is inconsistent evidence as to whether bypass surgery improves survival compared with percutaneous intervention. A smaller need for repeated procedures exists after bare metal stent and even more so after drug-eluting stent placement than after percutaneous intervention without stent placement. However, according to the current evidence, these treatment alternatives do not differ in terms of mortality or myocardial infarction.

Conclusions: We found some high-quality systematic reviews. There was evidence on the potential of invasive treatments to provide symptomatic relief. Surgery seems to provide a longer-lasting effect than percutaneous interventions with bare metal stents or without stents. Evidence in favor of drug-eluting stents so far is based on short-term follow-up and mostly on patients with single-vessel disease.

The which-hunt: assembling health technologies for assessment and rationing

To rationalize and restrict health care spending, policy, makers in many jurisdictions have withdrawn insurance or funding for selected health care technologies. Numerous analytic frameworks and applied exercises have emerged to guide decisions about "which" services to cut. But in their focus on choice-making processes, these efforts have paid little attention to the problem of defining and dividing the set of technologies to choose among. If technology assessment refers to methods for weighing services for their relative value, the term technology assembly might be used to refer to methods for framing the technological trade-offs to enroll in such contests. This article examines technology assemblies found in several types of theoretical and applied rationing exercises (including Oregon's Medicaid rationing process, economic evaluation literature, citizen "values" surveys, and Canadian provincial deinsurance policies). Based on this review, some key conceptual conventions and problems in technology assembly can be identified. The boundaries between health technologies are fuzzy, interlocked, layered, and continuously moving. Consequently, the defining features of technological trade-offs are inevitably socially constructed and negotiated. Trade-offs can be arranged along numerous dimensions, and the divisions typically correspond to broader political, administrative, and ethical dilemmas in health policy. Examples include equity among demographic classes, concepts of need, legitimacy of therapeutic goals, and so forth. Insights into the process of constructing technological trade-offs may help policy makers better question what technologies they are looking at and why, before moving on to the task of determining which ones to cover.

Quality of reviews in epidemiology

OBJECTIVES

This study examined the quality of recent reviews in epidemiology.

METHODS

All 1995 issues of 7 widely read epidemiology journals were searched to identify reviews.

RESULTS

Twenty-nine reviews were identified. Methodology was not specified or incomplete for literature searches in 79% of reviews; the same was true for inclusion criteria in 83% and for combining studies in 62%. More than 60% of the reviews were not methodologically systematic.

CONCLUSIONS

There is a need to improve the quality of review papers in epidemiology. If systematic methodology were followed more frequently, epidemiologic science and its application could be improved.

Variation in purchasing for the invasive management of coronary heart disease

This paper reports the results of a postal questionnaire survey of Directors of Public Health in all health authorities in the United Kingdom (as at March 1994). Our aim was to examine variations in the purchasing of coronary artery bypass grafting, percutaneous transluminal coronary angioplasty and coronary angiography. Information on planned service developments in cardiology was also sought. The response rate was 62%. The mean rate of CABG was 374 per million total population (range 162-710); PTCA 183 (range: 18-648); and coronary angiography 1,010 (range 581-2,334). The mean ratio of invasive treatment to angiography was 1:2 Variations in provision were not related to mortality from coronary heart disease or the availability of a local provider. Those districts purchasing higher levels of CABG tended to purchase higher levels of PTCA (Spearman's r = 0.52). Observed variations in purchasing of invasive treatments and investigation for coronary heart disease do not relate to population "need' as defined by mortality rates from CHD. The greatest variations are seen in the purchasing of PTCA, an intervention whose place in the management of CHD is as yet not fully defined. Consensus guidelines on the appropriate use of these interventions and on population needs are required.