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Cost-effectiveness of hepatic arterial chemoembolization for colorectal liver metastases refractory to systemic chemotherapy |
Abramson R G, Rosen M P, Perry L J, Brophy D P, Raeburn S L, Stuart K E |
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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 Hepatic arterial chemoembolization (HACE) for treatment of colorectal liver metastases (CLM) refractory to systemic chemotherapy.
Economic study type Cost-effectiveness analysis.
Study population The study consisted of patients with a diagnosis of colorectal carcinoma that was metastatic to the liver, as confirmed at surgery and/or biopsy, and that had been deemed to be unresponsive to systemic chemotherapy.
Setting The setting was secondary care. The economic analysis was carried out in the USA.
Dates to which data relate Dates for the effectiveness data related to the period 1996-1998. Some of the resource use data related to the same period, other dates were not specified. The price year was 1998.
Source of effectiveness data The effectiveness data were based on patient series data and on a review of the literature.
Link between effectiveness and cost data The costing was performed for hypothetical patients retrospective to the analysis of effectiveness.
Study sample The sample consisted of a series of 21 patients who underwent HACE at the authors' institution. No randomisation was applied.
Study design A single centre case series' study was performed.
Analysis of effectiveness The primary health outcomes evaluated were the number of additional reembolisation procedures and the probability of undergoing complications. Although the survival time per patient was reported, these data were not used in the analysis.
Effectiveness results The effectiveness results were as follows:
Each patient underwent a mean of 1.57 additional reembolisation procedures.
The probabilities of sustaining complications were as follows:
the probability of pulmonary embolism was 0;
the probability of sepsis and/or pneumonia was 0;
the probability of complication requiring laparotomy was 0;
the probability of complication requiring ventilation-perfusion scan was 0;
the probability of complication requiring a percutaneous drainage was 0.02;
the probability of complication requiring esophagogastroduodenoscopy was 0.
The mean survival time of patients with CLM undergoing palliative care was assumed to be 12 months, based on data from a published study.
Clinical conclusions There were no clinical conclusions pertaining to the data from the patient series, since the authors could not compare patients undergoing HACE to matched controls. The authors reported that the HACE procedure has been reported elsewhere in the literature to be safe and efficacious.
Modelling A decision-analytic model of cost-effectiveness of HACE for the treatment of CLM refractory to systemic chemotherapy was developed.
Measure of benefits used in the economic analysis Life-years (LYs) gained were used as the measure of benefits in the economic analysis. A decision tree model was employed to analyse the LYs of HACE and palliative care for treatment of CLM. The model was used to perform sensitivity analysis and a break-even analysis to determine the survival benefits at which HACE would be considered cost-effective.
Direct costs Discounting was not appropriate on the ranges up to 12 months, discounting should however be applied to time periods beyond 12 months. Some quantities (drug dosages) were reported separately from costs. The perspective of the analysis was the payer. The direct costs of HACE included in the analysis were the costs associated with the initial clinical evaluation (a physician office visit, a non-enhanced CT examination of the abdomen, and a laboratory measurement of serum carcinoembryonic antigen (CEA) level), chemoembolisation procedures (each includes an inpatient hospitalisation component, all laboratory work and postprocedural inpatient medications; and a practitioner procedural component; the costs of complications are included), follow-up evaluation (a physician office visit, a non-enhanced CT examination of the abdomen, and a measurement of CEA level), and symptom control (separate components for iatrogenic and disease-related symptom relief). The quantity of resources was based on the estimated probability of complications and protocols of treatment. The unit costs employed were 1998 Medicare reimbursements for inpatient hospitalisations, procedural and outpatient visit cost, Health Care Financing Administration (HCFA) Federal Upper Limit 1998 prices for outpatient drug costs or wholesale prices for generic equivalents. The direct costs of palliative care included costs associated with initial evaluation (see above), follow-up evaluation (see above), and symptom control (including only disease related symptom relief). The price year was 1998.
Statistical analysis of costs No statistical analysis of costs was performed.
Indirect Costs No indirect costs were analysed.
Sensitivity analysis Sensitivity analyses for survival expectations of 6 and 3 months for patients on palliative care, as well as for variations in all key input parameters, including the 25% increase and decrease of cost of non-enhanced CT examination, cost of measuring the CEA level, cost of chemoembolisation (both inpatient hospitalisation and practitioner procedural components), cost of postchemoembolisation symptom control regimen, variation of complication rates and mean number of reembolisation procedures per patient, were undertaken.
Estimated benefits used in the economic analysis Using the baseline survival expectation of 12 months for patients receiving only palliative care, additional survival benefits ranging from 0 to 24 months for patients having received HACE were used.
Cost results The marginal direct cost of HACE compared with palliative care was in the range $20,596 - $21,494 for survival benefits of HACE versus palliative Care of 0 to 24 months.
Synthesis of costs and benefits For survival benefits of 3, 6 and 12 months, the marginal cost-effectiveness of HACE was $82,385, $41,193 and $21,045 per LY gained, respectively. The break-even analysis resulted in a survival benefit of 12.63 months if a cost-effectiveness threshold of $20,000 per LY was applied, 4.94 months for a $50,000 threshold and 2.47 for a $100,000 threshold. Sensitivity analysis demonstrated that the model was robust to changes in the cost of non-enhanced CT examination, cost of measuring the CEA level, complication rates, and baseline survival assumption, but it demonstrated that the model was less robust to changes in the cost of chemoembolisation, reembolisation rate, and follow-up regimen after HACE.
Authors' conclusions The cost-effectiveness of HACE for the treatment of CLM varied considerably according to the anticipated survival benefit. A survival benefit of nearly 5 months must be demonstrated for HACE to meet the moderate cost-effectiveness standard of $50,000 per LY gained.
CRD COMMENTARY - Selection of comparators No explicit justification for the choice of palliative care as comparator was provided. The users of this database should consider whether it is a widely used alternative treatment strategy in their own setting.
Validity of estimate of measure of benefit No robust estimate of benefit was identified and the range of benefits used in the study was based on the assumptions of the authors. However, the authors argued that available data did not provide a comparison of HACE with palliative care for matched patients, so, rather than use data from different studies, a range of survival benefits was used. The results were sensitive to reembolisation rates and follow-up schedule incorporated. The clinical parameters to inform the model were compiled from the series of 21 patients. The authors acknowledged that several reembolisation protocols existed and that they had applied just one of them.
Validity of estimate of costs Good points pertaining to the analysis of costs were that, from the cost perspective adopted, all relevant categories of costs were included, sensitivity analyses were conducted and the price year was reported. However one drawback was that charges were used to proxy costs.
Other issues Appropriate comparisons with other studies could not be made, since the literature search yielded no comparable studies. The issue of generalisability to other settings was addressed. The authors do not appear to have presented their results selectively. The study considered patients with CLM and this was reflected in the authors' conclusions. The authors acknowledged several limitations to the study. No quality of life was analysed in the study, while there is a debate between clinicians on whether HACE affects quality of life positively or negatively. The indirect costs of treating unrelated diseases in the extended survival time were also excluded from the analysis.
Implications of the study Future work is required to assess the benefit of HACE for treatment of CLM compared to palliative care and quality-adjusted cost-effectiveness of HACE.
Bibliographic details Abramson R G, Rosen M P, Perry L J, Brophy D P, Raeburn S L, Stuart K E. Cost-effectiveness of hepatic arterial chemoembolization for colorectal liver metastases refractory to systemic chemotherapy. Radiology 2000; 216(2): 485-491 Indexing Status Subject indexing assigned by NLM MeSH Antibiotics, Antineoplastic /administration & Antimetabolites, Antineoplastic /administration & Antineoplastic Agents /therapeutic use; Benchmarking; Chemoembolization, Therapeutic /adverse effects /economics; Colonic Neoplasms /pathology; Cost-Benefit Analysis; Direct Service Costs; Fluorouracil /administration & Follow-Up Studies; Gelatin Sponge, Absorbable /administration & Health Care Costs; Hepatic Artery; Humans; Liver Neoplasms /drug therapy /secondary /therapy; Medicare /economics; Mitomycin /administration & Palliative Care /economics; Probability; Randomized Controlled Trials as Topic; Rectal Neoplasms /pathology; Retreatment; Retrospective Studies; Survival Analysis; Treatment Failure; United States; Value of Life; dosage; dosage; dosage; dosage; dosage AccessionNumber 22000001285 Date bibliographic record published 31/07/2001 Date abstract record published 31/07/2001 |
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