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Cost-efficacy of endoscopic ultrasonography with fine-needle aspiration vs. mediastinotomy in patients with lung cancer and suspected mediastinal adenopathy |
Aabakken L, Silvestri G A, Hawes R, Reed C E, Marsi V, Hoffman B |
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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 The use of endoscopic ultrasonography (EUS) guidance for fine-needle aspiration (FNA) of mediastinal lymph nodes in the pre-operative staging of non-small cell lung cancer.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients with verified non-small cell lung cancer and pathologically enlarged mediastinal lymph nodes. Mediastinal lymph nodes were defined as nodes of more than 10 mm short axis measurement, as detected by a CT scan. Patients with at least one enlarged station 5, 6 or 7 node underwent either EUS or MED as their next stage of treatment.
Setting The setting was secondary care. The study was performed in a hospital in South Carolina, USA.
Dates to which data relate The probability and outcome data were obtained from literature published between 1987 and 1997. The price year was not stated.
Source of effectiveness data The effectiveness data were taken from a review of published studies.
Modelling A decision-analytical model was used to estimate the expected costs and health benefits.
Outcomes assessed in the review The following outcomes were assessed: the negative predictive value of EUS, the negative predictive value of MED, and the life expectancies after complete resection, incomplete resection and palliation only.
Study designs and other criteria for inclusion in the review The design of the studies included in the review was unclear. The review included articles published between 1986 and 1997, but no inclusion or exclusion criteria were reported.
Sources searched to identify primary studies The authors did not report the sources searched or the search strategy used to identify studies for the data synthesis.
Criteria used to ensure the validity of primary studies There were no criteria reported for ensuring the validity of the primary data sources.
Methods used to judge relevance and validity, and for extracting data The authors did not report the methods used to judge the relevance or validity of the data, or to extract data.
Number of primary studies included The data from six primary studies were used to estimate the effectiveness parameters.
Methods of combining primary studies The primary data sources were not combined.
Investigation of differences between primary studies The authors did not report or investigate any differences between the primary data sources.
Results of the review The baseline probabilities and utilities included in the model were:
the negative predictive value of EUS, 0.89 (range: 0.5 - 1.0);
the negative predictive value of MED, 0.94 (range: 0.5 - 1.0);
the life expectancy after complete resection, 5 years (range: 3 - 7);
the life expectancy after incomplete resection, 1 (range: 0.5 - 2); and
the life expectancy after palliation only, 0.5 years (range: 0 - 1).
Measure of benefits used in the economic analysis The measure of benefit used in the economic analysis was the difference in life expectancy between the two strategies, EUS and MED.
Direct costs The following costs were included in the model: EUS ($480), MED ($1,700), thoracotomy ($7,600) and the CT scan ($270). Itemised data for the relevant procedures were collected from the hospital in South Carolina in which the study was based. The computerised billing system was used to track relevant patients and to obtain the actual billing information. The charge data were converted into real cost data, and the costs of the physician were added, assuming a standard year's salary to be $120,000. The method of converting the charges to costs was not reported. The price year was not reported. The authors did not report whether the costs were discounted. However, since the costs only included immediate diagnosis and treatment, discounting was unnecessary.
Statistical analysis of costs No statistical analysis of costs was carried out.
Indirect Costs No indirect costs were included in the analysis.
Currency US dollars ($). No currency conversions were reported.
Sensitivity analysis The sensitivity analysis was presented clearly. A one-way sensitivity analysis was performed in order to determine the variation in the data. The following parameters were varied: the operative mortality rate, the life expectancy of the different outcomes, the costs of the various procedures, and the performance characteristics of CT, MED and EUS. The ranges were specified from published sources or the authors' opinions.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results In the baseline analysis, the costs were $480 for EUS, $1,700 for MED, $7,600 for thoracotomy, and $270 for a CT scan. The costs of adverse effects, and the total costs of EUS and MED were not reported. The timeframe of the costs was not reported.
Synthesis of costs and benefits The health benefits and costs were reported as the cost per year of expected survival. The cost per year of expected survival was $1,729 with the EUS strategy and $2,411 with the MED strategy. None of the parameters in the sensitivity analysis had significant effects on the cost per year of expected survival. The authors stated that the EUS strategy would remain at least as cost-effective as the MED strategy if the negative predictive value of EUS fell to as low as 0.22.
Authors' conclusions The use of endoscopic ultrasonography (EUS) guidance for fine-needle aspiration (FNA) of mediastinal lymph nodes in the pre-operative staging of non-small cell lung cancer offered a low cost, high yield and thus, cost-effective alternative to the MED strategy.
CRD COMMENTARY - Selection of comparators The study compared the use of EUS and MED in the pre-operative staging of patients with non-small cell lung cancer. The choice of the comparator was explicitly justified, since MED is the standard approach to care in pre-operative mediastinal staging.
Validity of estimate of measure of effectiveness The authors derived probability data from different sources to estimate the measure of effectiveness used in the economic model. They did not, however, report whether a systematic search and review of the literature had been undertaken. They also did not report whether the estimates taken from the studies were combined to derive the estimates used in the model, whether the data from the studies reviewed were used selectively, or whether any differences between the primary studies had an impact on the results.
Validity of estimate of measure of benefit The estimation of benefits was obtained directly from the effectiveness analysis. A one-way sensitivity analysis was undertaken to test for variation in the data used in the model, although it was not reported whether or how the model structure was validated. The authors presented the decision model in a diagrammatic form. The description of the events covered by the model did not seem to correspond to the labels assigned to the probability, cost and outcome variables. The values of the variables were not reported for every branch of the decision tree.
Validity of estimate of costs The authors limited their analysis to direct hospital cost data. The costs of adverse events were not included, and the indirect and intangible costs of the treatment strategies were not considered. The cost year was not stated.
Other issues The authors did not compare the results of their study with those from other studies. In addition, they noted some cases when the interventions were not appropriate diagnostic techniques. They also suggested that the performance characteristics of the procedures relied on local expertise. Other aspects, which may have limited the generalisability of the results to other settings, were not considered. These included local practice and the availability of services, resource use or costs. The authors did not present all the data to support the results or conclusions.
Implications of the study The authors suggested that the use of EUS guidance for FNA of mediastinal lymph nodes in the pre-operative staging of patients with non-small cell lung cancer, offered a less invasive, more productive and ultimately cost-effective treatment strategy than the standard MED approach.
Bibliographic details Aabakken L, Silvestri G A, Hawes R, Reed C E, Marsi V, Hoffman B. Cost-efficacy of endoscopic ultrasonography with fine-needle aspiration vs. mediastinotomy in patients with lung cancer and suspected mediastinal adenopathy. Endoscopy 1999; 31(9): 707-711 Indexing Status Subject indexing assigned by NLM MeSH Biopsy, Needle /economics; Carcinoma, Bronchogenic /economics /pathology; Carcinoma, Non-Small-Cell Lung /economics /pathology; Cost-Benefit Analysis; Decision Support Techniques; Endosonography /economics; Humans; Lung Neoplasms /economics /pathology; Lymph Nodes /pathology; Lymphatic Metastasis; Mediastinoscopy /economics; Neoplasm Staging; Predictive Value of Tests AccessionNumber 22000000093 Date bibliographic record published 31/03/2002 Date abstract record published 31/03/2002 |
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