Cost-effectiveness analysis of stents, balloon angioplasty, and surgery for the treatment of branch pulmonary artery stenosis Trant C A, O'Laughlin M P, Ungerleider R M, Garson A 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 The health interventions examined in the study were surgical angioplasty, balloon angioplasty and balloon expandable stent placement to treat branch pulmonary artery stenosis. Type of intervention Treatment. Economic study type Cost-effectiveness analysis. Study population The study population consisted of patients admitted to hospital for treatment of branch pulmonary artery stenosis. Patients were excluded if they had other diagnoses that required surgery in addition to branch pulmonary artery stenosis, such as conduit replacement, pulmonary artery angioplasty, aortopulmonary shunt placement, unrepaired ventricular septal defect, unrepaired tetralogy of Fallot, and unrepaired truncus arteriosus. Setting The setting was secondary care. The economic study was carried out at the Duke University Medical Center, NC, USA. Dates to which data relate The effectiveness and resource use data refer to the period 1983 to 1994. The price year was 1994. Source of effectiveness data Effectiveness data were derived from a single study. Link between effectiveness and cost data Retrospective costing was carried out on the same patient sample as that used in the effectiveness analysis and was based on patients' charges. Study sample From the total of 48 patients admitted for evaluation and treatment of pulmonary artery stenosis in the study period, 18 patients were excluded because they did not meet the eligibility criteria. The 30 remaining patients (16 males and 14 females) underwent 46 procedures for the treatment of branch pulmonary artery stenosis. Thirteen procedures (patients' mean age: 8.14 +/- 1.59 years) were performed in the balloon group, 20 procedures (patients' mean age: 7.35 +/- 2.50 years) in the stent group, and 13 procedures (patients' mean age: 4.04 +/- 1.35 years) in the surgery group. No power Page: 1 / 5
calculations were reported. Study design A single-centre retrospective case-control study was conducted. Follow-up started at the time of the intervention and finished in December 1994, the closing date of the study. In the surgical group the range of follow-up was 7 months to 11 years (mean 6.67 years), in the balloon group 1 to 8 years (mean 3.4 years) and in the stent group 3 months to 2 years (mean 0.89 years). Analysis of effectiveness It appears that all patients included in the study were accounted for in the analysis. The primary health outcome was the success of a procedure, defined by the following criteria: an increase in vessel diameter by greater than or equal to 50% of predilation diameter, a decrease in right ventricular to left ventricular or aortic systolic pressure ratio by greater than or equal to 20%, or a decrease in peak to peak pressure gradient by greater than or equal to 50%. The procedure was considered a failure if the previously mentioned criteria were not met or if the patient required a second procedure for the same stenosis within a three-year period. Two types of success were evaluated: acute success was defined as the patient meeting one or more of the above criteria on the basis of data obtained in the operating room or in the catheterisation laboratory, and intermediate term (IT) success was defined by results at follow-up and not requiring a second intervention. The complications occurring in the three study groups were also assessed. Study groups appear to have been comparable at baseline. Surgical patients tended to be younger, but this did not reach statistical significance (p=0.058). In addition, there was no statistically significant difference between the primary diagnosis and type of procedure performed, (p=0.73). Effectiveness results In terms of acute and intermediate term success, the results showed that stent placement was most successful and was significantly more effective than balloon dilation (acute success: 18/20 (90%) versus 4/13 (31%), (p=0.004); IT success: 17/20 (85%) versus 3/13 (23%), (p=0.004)) but was statistically not more effective than surgery (acute success: 8/13 (62%); IT success: 8/13 (62%)). Surgery was not more effective than balloon dilation in terms of acute success, (p=0.116), but was more effective over the IT success (8/13 (62%) versus 3/13 (23%)), (p=0.047)). There was no significant change in success for each intervention type as compared over time. In terms of failure, 5 of 13 surgical procedures, 9 of 13 balloon dilation procedures, and 2 of 20 stent procedures required a second procedure to treat the same stenosis, (p<0.005). Most of the complications occurred to surgery patients (junctional ectopic tachycardia, prointermediated atelectasis requiring mechanical ventilation, pulmonary artery to pulmonary vein fistula, diaphragmatic palsy, postpericardiotomy syndrome), although the most serious complication (cardiac arrest during balloon dilation of the pulmonary arteries, but no dissection) occurred to a stent patient (who went on to do well). One dislodged stent was reported in a stent patient. None of the balloon patients reported any complications. Clinical conclusions Stents were at least as effective as surgery and were more effective than balloon angioplasty in both acute and intermediate term follow-up. Measure of benefits used in the economic analysis Health outcomes were left disaggregated and no summary measure of benefits was employed. As a result, a costconsequences analysis was carried out. Page: 2 / 5
Direct costs Discounting was not reported, although it would have been methodologically relevant due to the duration of follow-up. Charges were used to proxy the costs of the interventions. Unit costs and quantities of resources used were not reported separately. All charges incurred during the hospitalisation for the procedures and follow-up were included in the analysis. The cost items analysed were catheterisations (pre-procedure and follow-up), all inpatient charges related to the procedure, post-procedure outpatient visits, and subsequent procedures to treat the residual stenosis. The charges that were judged not related to the treatment of branch pulmonary artery stenosis or were similar for all patients (such as pre-procedure clinical visits, echocardiograms, radiographs, electrocardiograms, and laboratory tests) were not included in the analysis. The cost/resource boundary adopted in the analysis was not clearly stated. The outpatient and inpatient charges were corrected to 1994 dollars using the Consumer Price Index (Medical), published by the United States Department of Labor. The estimation of costs and resources was based on actual data, derived from the hospital where the study was carried out. The records with missing data for charges were excluded from the analysis. Quantities of resources were retrospectively collected from 1983 to 1994, which represented the price year. Statistical analysis of costs Statistical analyses of total costs were carried out to test for statistical significance of results. The statistical analyses consisted of chi-square, heteroscedastic t-test and ANOVA. Bonferoni's inequality was employed in examining the data with ANOVA; the significance level being equal to p divided by the number of tests, or 3: therefore the significance level was set at p<0.015. In all other statistical analyses the significance was set at p<0.05. Indirect Costs No indirect costs were included in the analysis. Currency US dollars ($). Sensitivity analysis No sensitivity analyses were carried out. Estimated benefits used in the economic analysis See effectiveness results above. Cost results The charge data showed that balloon angioplasty was the least expensive followed by stents and then by surgery. The average (+/- standard error) total charges per procedure, including outpatient charges, were: surgery $58,068 +/-$4,372, balloon $21,893 +/-$5,018, stents $33,809 +/-$3,533. The difference between balloon and stents did not reach statistical significance, while the cost of surgery was significantly higher than that of balloon. The average total charges per procedure, excluding outpatient charges, were: surgery $52,989 +/-$3,649, balloon $15,653 +/-$1,691, stents $29,531 +/-$2,241, and all differences were statistically significance, (p<0.001). Average total charges per patient, including all procedure types and grouped by initial procedure, were $53,707 +/-$6,388 for surgery, $50,040 +/-$8,412 for balloon, and $34,346 +/-$3,488 for stents, the difference between stent and surgery being the only one reaching statistical significance, (p=0.036). Synthesis of costs and benefits Not relevant. Page: 3 / 5
Authors' conclusions The authors concluded that, in patients who are candidates for stent placement, intravascular stents represented the most cost-effective treatment for branch pulmonary artery stenosis as compared to balloon angioplasty and surgical angioplasty. CRD COMMENTARY - Selection of comparators A justification was given for the alternative interventions studied as the available options for treatment of branch pulmonary artery stenosis. Surgery represented the standard treatment, while stents and balloon angioplasty were considered as more recent alternative treatments in the management of patients with branch pulmonary artery stenosis. You, as a user of this database, should assess which treatments are currently in use in your own setting. Validity of estimate of measure of effectiveness The effectiveness analysis was based on a single-centre retrospective case-control study carried out over several years. The main limitations of the analysis were related to the lack of power calculations, the small sample size, and the possible bias and confounding due to the lack of randomisation, although study groups appear to have been comparable at baseline. As the authors acknowledged, the results could have been variable due to changes in the techniques, the experience of the operators, and changes in the equipment. The following additional limitations were noted: the small number of patients and the lack of long term data on the durability and complication rate associated with stents, possible differences in the severity of disease between groups, and the possibility of some selection bias, as patients with small pulmonary arteries may not be candidates for stent placement. The results of the effectiveness analysis should be viewed in the light of these issues. Validity of estimate of measure of benefit The authors did not derive a measure of health benefit. The analysis was therefore categorised as a cost-consequences study. Although the adoption of a summary benefit measure assessing the impact of the interventions on patient health would have been helpful, the success rate represents a widely used measure in the studies analysing stent procedures. Validity of estimate of costs The perspective of the study was not clearly stated. Costs and quantities were not reported separately. Sensitivity analyses on resource use and prices were not conducted. Charges were used to proxy costs and this could have introduced an error in the analysis. Cost estimates appear to be somewhat specific to the study setting and sensitivity analyses were not carried out. Other issues The authors did not present their results selectively. The findings of the study were not compared with those from other studies and the issue of generalisability to other settings was not addressed. The authors reported a number of limitations arising from the retrospective study design and the small number of patients analysed. The study considered patients requiring treatment for branch pulmonary artery stenosis and this was reflected in the authors' conclusions. Implications of the study The authors suggest that intravascular stents are the most cost-effective treatment for branch pulmonary artery stenosis. Source of funding None stated. Bibliographic details Page: 4 / 5
Powered by TCPDF (www.tcpdf.org) Trant C A, O'Laughlin M P, Ungerleider R M, Garson A. Cost-effectiveness analysis of stents, balloon angioplasty, and surgery for the treatment of branch pulmonary artery stenosis. Pediatric Cardiology 1997; 18(5): 339-344 PubMedID 9270100 DOI 10.1007/s002469900195 Indexing Status Subject indexing assigned by NLM MeSH Adolescent; Adult; Angioplasty /economics; Angioplasty, Balloon /economics; Child; Child, Preschool; Constriction, Pathologic /economics /therapy; Cost-Benefit Analysis; Female; Hospital Charges; Humans; Infant; Male; Pulmonary Artery /surgery; Stents /economics; Treatment Outcome AccessionNumber 21997001148 Date bibliographic record published 31/10/2002 Date abstract record published 31/10/2002 Page: 5 / 5