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The cost-effectiveness of ibutilide versus electrical cardioversion in the conversion of atrial fibrillation and flutter to normal rhythm |
Zarkin G A, Bala M V, Calingaert B, VanderLugt J T |
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Record Status This is a critical abstract of an economic evaluation that meets the criteria for inclusion on NHS EED. Each abstract contains a brief summary of the methods, the results and conclusions followed by a detailed critical assessment on the reliability of the study and the conclusions drawn. Health technology Ibutilide in the conversion of atrial fibrillation and flutter to normal rhythm. Intravenous ibutilide treatment was administered in two 10-minute doses 10 minutes apart. The initial dose was 1 mg and the second dose was either 1 mg or 0.5 mg.
Economic study type Cost-effectiveness analysis.
Study population A hypothetical cohort of hemodynamically stable patients who had exhibited atrial fibrillation and atrial flutterfor over 3 hours and less than 45 days.
Setting Hospital. The economic study was conducted in North Carolina, USA.
Dates to which data relate The main effectiveness data were obtained from a single study conducted in 1996. Resource and cost data were taken from 1993-95 sources. The price year was 1996. The inflation rate used was obtained from the Bureau of Labor Statistics.
Source of effectiveness data The estimates of overall success rates were obtained from a single study. Success was defined as termination of AF or AFL, either as a result of EC or ibutilide (for any length of time within 1.5 hours of the initial infusion).
Modelling A decision tree model was used to compare the two first-line conversion options (ibutilide and EC) and their associated outcomes: success and lack of response.
Outcomes assessed in the review The outcome measures were success rate probabilities for each treatment, namely ibutilide followed by EC or EC alone.
Study designs and other criteria for inclusion in the review Sources searched to identify primary studies Criteria used to ensure the validity of primary studies Methods used to judge relevance and validity, and for extracting data Number of primary studies included Methods of combining primary studies Investigation of differences between primary studies Results of the review The expected success rate with AF for ibutilide followed by EC was 0.92 and for first-line EC was 0.78. The expected success rate with AFL for ibutilide followed by EC was 0.98 and for first-line EC was 0.86.
Measure of benefits used in the economic analysis The outcome measure used in the economic analysis was the overall success rate in achieving conversion to normal rhythm.
Direct costs Physician, hospital and drugs costs were included in the analysis. The costs of the physician component of treatment were taken from 1993 calendar year national averages for physician charges by procedure submitted for Medicare reimbursement according to the Health Care Financing Administration which administers Medicare. The costs of the hospital component of treatment were taken from charge data adjusted by cost-to-charge ratios appropriate for each cost centre from Duke University Hospital. The costs of drugs were taken from wholesale drug prices reported in the Red Book. The quantities were reported separately from the prices. Discounting was not undertaken. The prices were adjusted to 1996 dollars based on the inflation rate for medical expenditures obtained from the Bureau of Labor Statistics.
Statistical analysis of costs Sensitivity analysis A one-way sensitivity analysis was conducted on the number of days hospitalized and the cost of the EC procedure.
Estimated benefits used in the economic analysis The expected success rate with AF for ibutilide followed by EC was 0.92 and for first-line EC was 0.78. The expected success rate with AFL for ibutilide followed by EC was 0.98 and for first-line was EC 0.86.
Cost results The expected cost per patient with AF was $1,881 for EC and $1,621 for ibutilide followed by EC. The corresponding figures with AFL were $1,330 and $ 1,725, respectively.
Synthesis of costs and benefits Costs and benefits were not combined. The sensitive analysis indicated that by changing resource use and cost assumptions ibutilide followed by EC was still cheaper than first-line EC ($1,559 versus $1,715, $1,539 versus $ 1,758, for AF;$1,315 versus $1,619, $1,287 versus $1,606, for AFL).
Authors' conclusions The most cost-effective strategy is to first attempt conversion with ibutilide and then treat patients that fail to respond to ibutilide with EC. Patients who convert from AF to AFL to normal rhythm with first-line ibutilide treatment will save the additional resources required for EC conversion.
CRD COMMENTARY - Selection of comparators The reason for the choice of the comparator is clear. EC is the most common non-pharmacologic intervention used to convert AF and AFL to normal rhythm, but it is more traumatic and resource intensive than pharmacologic treatment. A new rapid-acting drug, ibutilide, has recently been introduced. It should be noted, however, that other valid comparators exist (for example, several pharmacologic agents, including digoxin, beta-blockers and calcium antagonists) which were not assessed in the present study. You, as a user of this database, should consider whether these are available health technologies in your own setting.
Validity of estimate of measure of benefit The estimate of measure of benefit used in the economic analysis is likely to be internally valid although the literature search criteria were not fully explained, the bulk of the clinical data being derived from a recent RCT. The modelled solutions were tested using sensitivity analysis in order to validate the robustness of the findings. However, resource use data were derived from a clinical algorithm which will have some limitations compared with an economic evaluation alongside a clinical trial.
Validity of estimate of costs Resource quantities were reported separately from the prices. Adequate details of the methods of quantity/cost estimation were given. Important cost items do not appear to have been omitted.
Other issues The authors' conclusions are likely to be justified as the results were tested by rigorous sensitivity analysis. The issue of generalisability to other settings or countries was not addressed. However, appropriate comparisons were made with other studies, particularly in relation to the cost-effectiveness of alternative anti-arrhythmic therapies. The study suffers from the limitation of being based on a hypothetical patient sample and covering a relatively short time period. Moreover, as the authors noted, the first-line treatment options for AF and AFL are limited to ibutilide and EC and other anti-arrhythmic drugs are not included in the analysis.
Implications of the study More research is needed considering other anti-arrhythmic drugs within a longer time period. Furthermore, resource use data should be collected prospectively in the trial as modelled solutions suffer from a disconnection of efficacy and resource data.
Bibliographic details Zarkin G A, Bala M V, Calingaert B, VanderLugt J T. The cost-effectiveness of ibutilide versus electrical cardioversion in the conversion of atrial fibrillation and flutter to normal rhythm. American Journal of Managed Care 1997; 3(9): 1387-1394 Indexing Status Subject indexing assigned by NLM MeSH Anti-Arrhythmia Agents /adverse effects /economics /therapeutic use; Atrial Fibrillation /drug therapy /physiopathology /therapy; Atrial Flutter /drug therapy /physiopathology; Cost-Benefit Analysis; Double-Blind Method; Electric Countershock /economics; Health Resources /economics /utilization; Humans; Placebos; Sulfonamides /adverse effects /economics /therapeutic use; Technology Assessment, Biomedical /economics AccessionNumber 21998000030 Date bibliographic record published 31/05/1999 Date abstract record published 31/05/1999 |
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