Moving beyond the cost per quality-adjusted life year: modelling the budgetary impact and clinical outcomes associated with the use of sirolimus-eluting stents

Restenosis is a major limitation to the long-term success of percutaneous coronary intervention. Drug-eluting stents are the most recent technological advance in restenosis prevention. While they are effective, their use is associated with a significant incremental cost, and a recent economic evaluation performed by the authors suggested that their use is associated with a cost per quality-adjusted life year of $58,721. How should decision-makers react to this value, particularly given that the use of sirolimus-eluting stents appears more attractive in certain patient subgroups, such as those with complex coronary lesions? In the present paper, the authors explore an alternative method of presenting the results of their economic evaluation, rather than the usual cost per quality-adjusted life year rubric, in an attempt to assist decision-makers in deciding whether, and for whom, to fund sirolimus-eluting stents. Several issues that decision-makers and providers may wish to consider when making such funding decisions are discussed.     

Sex differences in outcomes after cardiac catheterization: effect modification by treatment strategy and time

Context  Studies comparing outcomes of cardiac care in women vs men yield various results, with some suggesting worse outcomes for women and others suggesting equivalent outcomes. Objective  To determine whether extent of coronary disease, treatment strategy, and follow-up time influence the risk of death in women vs men among patients who have had cardiac catheterization. Design, Setting, and Patients  We studied a large inception cohort by using detailed clinical data from a registry of 37 401 patients undergoing cardiac catheterization in Alberta, Canada, from 1995-2000, with follow-up through December 31, 2001. Main Outcome Measures  The risk of death for women vs men was assessed for all patients combined and then in analyses stratified by degree of coronary anatomic risk and by treatment strategy (no revascularization, percutaneous coronary intervention [PCI], coronary artery bypass graft [CABG] surgery). The latter analysis included a graphic assessment of the changing relative risk over time for women vs men. Results  Women had higher 1-year mortality than men did (5.6% vs 4.6%; P<.001). However, stratified analyses demonstrated that sex differences in risk occurred only early after catheterization and were most apparent among patients undergoing revascularization. The early risk-adjusted relative risks for women vs men were elevated at 3.49 (95% confidence interval [CI], 1.95-6.24) for CABG surgery and 2.38 (95% CI, 1.48-3.83) for PCI on day 1 after catheterization, with a subsequent decrease in relative risk over time to equivalence in risk between sexes before 1 year. Conclusions  Sex-based differences in death rates after cardiac catheterization are time- and treatment-specific. This finding may at least partially explain the discrepancies in results from earlier studies on sex differences in outcomes of cardiac care.      

Diagnostic cardiac catheterization and revascularization rates for coronary heart disease

BACKGROUND: Despite evidence of regional variation across North America, there have been no comprehensive studies of cardiac procedure rates for coronary heart disease in Canada. OBJECTIVES: To use available administrative data and a survey of catheterization facilities to examine regional and demographic variations in cardiovascular procedure rates. METHODS: A survey of all cardiac catheterization facilities in Canada was conducted, and the procedure counts from these facilities were used to determine provincial catheterization rates from 1997/1998 to 2001/2002. Procedure counts for 1997/1998 to 1999/2000 for coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention (PCI) were provided by the Canadian Institute for Health Information and used to calculate revascularization procedure rates. Population projections provided by Statistics Canada were used as denominators for calculating the rates, and direct standardization was used to obtain age- and sex-adjusted rates. RESULTS AND CONCLUSIONS: The crude rate of cardiac catheterization in Canada increased from 359.9 to 471.5 per 100,000 population across the five years studied. There was considerable variation in revascularization procedure rates across health regions and provinces. Between 1997/1998 and 1999/2000, there was little increase in the rate of CABGs performed in Canada but a marked increase in the rate of PCIs. For both CABG and PCI, rates were higher for men than women, and highest in the 65- to 74-year-old age category. This study provides a valuable 'snapshot' of cardiac procedure use rates but indicates a clear need for more comprehensive collection of cardiac care data in Canada.     

Validity of information on comorbidity derived rom ICD-9-CCM administrative data

BACKGROUND: The comorbidity variables that constitute the Charlson index are widely used in health care research using administrative data. However, little is known about the validity of administrative data in these comorbidities. The agreement between administrative hospital discharge data and chart data for the recording of information on comorbidity was evaluated. The predictive ability of comorbidity information in the two data sets for predicting in-hospital mortality was also compared. METHODS: One thousand two hundred administrative hospital discharge records were randomly selected in the region of Calgary, Alberta, Canada in 1996 and used a published coding algorithm to define the 17 comorbidities that constitute the Charlson index. Corresponding patient charts for the selected records were reviewed as the "criterion standard" against which validity of the administrative data were judged. RESULTS: Compared with the chart data, administrative data had a lower prevalence in 10 comorbidities, a higher prevalence in 3 and a similar prevalence in 4. The kappa values ranged from a high of 0.87 to a low of 0.34; agreement was therefore near perfect for one variable, substantial for six, moderate for nine, and only fair for one variable. For the Charlson index score ranging from 0 to 5 to 6 or higher, agreement was moderate to substantial (kappa = 0.56, weighted kappa = 0.71). When 16 Charlson comorbidities from administrative data were used to predict in-hospital mortality, 10 comorbidities and the index scores defined using administrative data yielded odds ratios that were similar to those derived from chart data. The remaining six comorbidities yielded odds ratios that were quite different from those derived from chart data. CONCLUSIONS: Administrative data generally agree with patient chart data for recording of comorbidities although comorbidities tend to be under-reported in administrative data. The ability to predict in-hospital mortality is less reliable for some of the individual comorbidities than it is for the summarized Charlson index scores in administrative data.