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Endovascular AAA treatment: expensive prestige or economic alternative |
Holzenbein J, Kretschmer G, Glanzl R, Schon A, Thurnher S, Winkelbauer F, Trubel W, Minar E, Ahmadi A, Huk I, Ingruber H, Ehringer H, Lammer J, Polterauer P |
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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 Endovascular treatment of abdominal aortic aneurysm.
Economic study type Cost-effectiveness analysis.
Study population Patients due to undergo elective surgery for infrarenal AAA, aged between 54 and 84. Patients were excluded for the following reasons: complex aneurysms, simultaneous main renal artery reconstruction, or revascularisation of the lower extremities during the same stay. All patients undergoing the endovascular procedure were also required to be fit to undergo open surgery. Patients had a history of one or more of the following: smoking, diabetes, hypertension, dyslipidaemia, pulmonary disease, previous laparotomies, cardiac disease, ischaemic heart disease, previous CABG, previous vascular surgery.
Setting The setting was an academic teaching hospital. The study was carried out in Vienna, Austria.
Dates to which data relate The effectiveness data and the resources used were collected from February 1995 to March 1996. Prices were expressed in 1996 values.
Source of effectiveness data Effectiveness data were derived from a single study.
Link between effectiveness and cost data The costing was undertaken prospectively on the same patient sample as that used in the effectiveness study.
Study sample 44 patients were equally divided into two groups.22 underwent open aneurysm (control group) and 22 endovascular aneurysm treatment. No power calculations were reported. Patients included all who were eligible during the months of the study. The percentage of patients excluded from the study was not stated.
Study design Retrospective cohort study. The follow-up period appears to have been the time until discharge from hospital. No patients were reported as having been lost to follow-up.
Analysis of effectiveness Analysis was based on intention to treat. The main outcomes were operative duration, time to implant tube grafts and bifurcated grafts, number of blood units, duration of admission, post-operative ICU stay, overall post-operative length of stay and mortality rates. The two groups were comparable with regard to age, sex, morphological parameters and general risk factors for vascular disease.
Effectiveness results The overall operative time was not significantly different between the EAT and OAS procedures. Endovascular implantation of tube grafts required less time than open surgery for tube grafts (OAS: 246.7 minutes, EAT: 167.1 minutes, p=0.024). Bifurcated grafts took more operative time in the endovascular group (OAS: 185 mins., EAT: 241 mins., p=0.017). Blood requirement was significantly less in the EAT group (EAT: 0.55 units, OAS: 2.73 units, p=0.009). Post-operative ICU stay was significantly longer for patients undergoing OAS (EAT: 22.7 hours, OAS: 55 hours, p=0.017). The average duration of admission was 14.9 days in the EAT group and 22.8 in the OAS group (p<0.001). The post-operative length of stay was significantly shorter in the EAT group (EAT: 5.6 days, OAS: 13.3 days, p=0.001). Mortality rates were not significantly different.
Clinical conclusions Endovascular aneurysm treatment entails a shorter operative time, post-operative intensive care unit stay and recovery period.
Measure of benefits used in the economic analysis The main benefit measures were length of stay and mortality.
Direct costs For the purpose of this study costs and not charges were used. Quantities and costs were reported separately for the costs associated with the operative procedure, i.e. labour costs, medical article requirements and installation costs. Costs for ICU stay and for admission were also reported. The quantity/cost boundary adopted was that of the hospital. The estimation of the quantities and costs was based on actual data. Cost calculations were performed by the hospital's controlling and finance departments. Prices refer to 1996.
Statistical analysis of costs Student's t tests were used.
Indirect Costs No indirect costs were included.
Currency European Currency Units (ECUs), calculated at the exchange rate for30 April 1996 (100 ECU = 1322.50 Austrian Schillings).
Sensitivity analysis No sensitivity analysis was undertaken.
Estimated benefits used in the economic analysis The study showed no statistically significant difference between the groups in terms of mortality. There was a significant difference between the groups regarding length of stay, with the OAS group staying 7.9 days longer in hospital.
Cost results The cost for the operative procedure was higher for EAT (ECU10,699) than for OAS (ECU4,032), (p<0.001). The costs for ICU stay were higher for OAS compared to EAT (ECU4,934 versus ECU2,036, p<0.001). The costs for admission were ECU9,533 for EAT and ECU16,408 for OAS. Total average cost for an EAT procedure was ECU22,269 as compared to ECU25,374 for OAS.
Synthesis of costs and benefits Costs and benefits were not combined. However, EAT was the dominant strategy in terms of costs and effectiveness.
Authors' conclusions Endovascular aneurysm treatment is cost-effective and less expensive than open surgery. The main reason for cost saving is faster patient recovery after surgery, associated with a shorter length of stay in the patients treated with the endovascular procedure.
CRD COMMENTARY - Selection of comparators The reason for choice of comparator is clear.
Validity of estimate of measure of benefit This measure of benefit is probably not comprehensive from the hospital perspective since many patients are readmitted to hospital or need rehabilitation. The measure of benefit may also be improved by looking at other issues of quality of care and quality of life.
Validity of estimate of costs The estimate of costs is valid from a hospital perspective. However, cost factors associated with rehabilitation and further admissions for procedure-related reasons should be included.
Other issues No sensitivity analysis was carried out which makes it difficult to assess the robustness of the results. A randomised controlled trial should be conducted to verify the results of this study. As already noted, no attempt was made to extend the analysis to rehabilitation after discharge.
Implications of the study The main implication is that endovascular aneurysm treatment is a cost-effective procedure. However, due to the experimental nature of this procedure, more work is needed to optimise the treatment procedure and calculate its cost-effectiveness.
Source of funding Supported in part by grant No 4606 of the "Jubilaumsfonds der Oesterreichischen Nationalbank", and by a grant of the "Fonds des Burgermeisters der Bundeshauptstadt Wien" distributed on behalf of the Mayor of Vienna, Austria.
Bibliographic details Holzenbein J, Kretschmer G, Glanzl R, Schon A, Thurnher S, Winkelbauer F, Trubel W, Minar E, Ahmadi A, Huk I, Ingruber H, Ehringer H, Lammer J, Polterauer P. Endovascular AAA treatment: expensive prestige or economic alternative. European Journal of Vascular and Endovascular Surgery 1997; 14(4): 265-272 Other publications of related interest Cappeller W A, Hinz M, Thomusch O, Lauterjung L. Abdominal aortic aneurysm: post-operative 10-year follow-up with cost analysis. Zentralblatt fur Chirurgie 1997;122(9):747-751.
Seiwert A J, Elmore J R, Youkey J R, Franklin D P. Ruptured abdominal aortic aneurysm repair: the financial analysis. American Journal of Surgery 1995;170(2):91-96.
Katz D, Cronenwett J. The cost-effectiveness of early surgery versus watchful waiting in the management of small aortic aneurysms. Journal of Vascular Surgery 1994;19:980-991.
Indexing Status Subject indexing assigned by NLM MeSH Aged; Aorta, Abdominal /surgery; Aortic Aneurysm, Abdominal /economics /therapy; Austria; Cost-Benefit Analysis; Endoscopy /economics /statistics & Female; Hospital Costs /statistics & Hospitals, University /economics; Humans; Length of Stay /economics /statistics & Male; Middle Aged; Retrospective Studies; Vascular Surgical Procedures /economics /statistics & numerical data; numerical data; numerical data; numerical data AccessionNumber 21997001445 Date bibliographic record published 31/01/1999 Date abstract record published 31/01/1999 |
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