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Cost-effectiveness of colorectal cancer screening |
McMahon P M, Bosch J L, Gleason S, Halpern E F, Lester J S, Gazelle G S |
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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 Four strategies for the screening of colorectal cancer (CRC) were analysed: colonoscopy (CSCPY), double-contrast barium enema examination (DCBE), faecal occult blood testing (FOBT), and flexible sigmoidoscopy (FS). All of these are widely used in current practice.
Economic study type Cost-effectiveness analysis.
Study population The characteristics of the patient population studied were unclear. It seemed that the patient population included all average-risk individuals undergoing CRC cancer screening.
Setting The setting was the community. The economic study was carried out in the USA.
Dates to which data relate The effectiveness and resource data were gathered from studies published from 1990 to 1998. The price year was 1999.
Source of effectiveness data The effectiveness data were derived from published studies.
Outcomes assessed in the review The outcomes assessed in the review were the costs and benefits, i.e. life-years saved, of each screening strategy. These were used to perform an incremental analysis by calculating the ICERs, and to rank the alternative screening interventions. Two of the three studies contributed a single data series, whilst the other study distinguished between men and women undergoing screening strategies. Thus, four groups of data were assessed in the review. Some of the estimates were corrected for both the effectiveness and the cost.
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 Three primary studies were included in the review.
Methods of combining primary studies Primary studies were not combined: each paper provided a single estimate for the costs and benefits of screening strategies.
Investigation of differences between primary studies Results of the review See estimated benefits reported later.
Measure of benefits used in the economic analysis The benefit measure used in the economic analysis was the incremental increased life expectancy, compared with the no screening option, expressed in terms of gained days per person.
Direct costs The costs included in the analysis were the total costs of each screening strategy, and these were derived from the literature review. The resource use data were collected from three studies published in 1990, 1995 and 1998. The price year was 1999. The quantity/cost boundary was not stated. The quantities and costs were not reported separately.
Statistical analysis of costs No statistical analysis was carried out.
Indirect Costs Indirect costs were not included.
Sensitivity analysis A formal sensitivity analysis was not performed. However, the authors reported the impact of the variation in some of the parameters used in the primary studies, on the final results of the study.
Estimated benefits used in the economic analysis There were several estimated benefits that were considered relevant in terms of the nondominated incremental cost-effectiveness ratio (ICER) below the $100,000 threshold, compared with no screening.
In the first study and in the case of male patients, the increased life expectancy was 8.8 days for annual FOBT, and 20.4 days for 5-yearly DCBE with annual FOBT. The corresponding values for female patients were 8.3 and 17.2 days, respectively.
In the second study, the increased life expectancy was 10.64 days for 10-yeraly FS, 20.59 days for 5-yearly DCBE, and 23.04 days for 3-yearly DCBE.
In the third study, the increased life expectancies were 11.42 days for 10-yearly FS, 21.64 days for 10-yearly CSCPY, 24.24 days for 10-yearly FS with annual FOBT, 25.77 days for 10-yearly DCBE with annual FOBT, and 26.75 days for 5-yearly DCBE with annual FOBT.
Cost results Only the cost results relevant in terms of the nondominated ICER below the $100,000 threshold, compared with no screening, are given below.
In the first study and in the case of male patients, the cost per person was $310.94 for annual FOBT, and $1,049.81 for 5-yearly DCBE with annual FOBT. The corresponding values for female patients were $355.58 and $1,208.36, respectively.
In the second study, the costs per patient were $293.22 for 10-yearly FS, $605.76 for 5-yearly DCBE, and $778.51 for 3-yearly DCBE.
In the third study, the total costs were $282.99 for 10-yearly FS, $626.22 for 10-yearly CSCPY, $795.56 for 10-yearly FS with annual FOBT, $917.16 for 10-yearly DCBE with annual FOBT, and $1,067.18 for 5-yearly DCBE with annual FOBT.
Synthesis of costs and benefits The costs and benefits of the different screening strategies were combined by a cost-effectiveness analysis. The dominated and weakly dominated strategies were identified. The results were presented as ICERs for nondominated strategies from each study.
In the first study and in the case of male patients, the ICER ($ per life-year saved) was $12,897 for annual FOBT, and $23,249 for 5-yearly DCBE with annual FOBT. The corresponding values for female patients were $15,637 and $34,974, respectively.
In the second study, the ICER was $10,056 for 10-yearly FS, $11,469 for 5-yearly DCBE, and $25,745 for 3-yearly DCBE.
In the third study, the ICER was $9,041 for 10-yearly FS, $12,258 for 10-yearly CSCPY, $23,851 for 10-yearly FS with annual FOBT, $28,954 for 10-yearly DCBE with annual FOBT, and $55,263 for 5-yearly DCBE with annual FOBT.
The authors reported that the sensitivity and specificity of the diagnostic tests heavily affected the results of the analysis.
Authors' conclusions From the analysis of the results of the single studies, and after the adjustments made by the authors, it was possible to find some common indications about the optimal screening option. The most cost-effective strategies were the use of DBCE every 5 years, either alone or with annual FOBT.
CRD COMMENTARY - Selection of comparators The chosen strategies were selected for comparison on the basis that they were technologies used in current practice. You, as a user of the database, should consider whether they are widely used in your own setting.
Validity of estimate of measure of effectiveness Validity of estimate of measure of benefit The benefit measures were derived from a literature review. However, the data estimated from the analysis of the primary studies were used selectively and were not combined. In addition, the criteria for the identification and inclusion of the primary studies and the validity of the estimates were not investigated. Differences among the studies were not taken into account.
Validity of estimate of costs The costs were estimated from the literature, and the methods and conduct of the review were not reported satisfactorily. The perspective of the study was not stated, and it is unclear which cost items were included in the computation of the total costs of each screening strategy.
Other issues The authors acknowledged that the objective of the study was not to analyse specific tests, but to reconcile the findings of published study in order to reduce the uncertainty associated with CRC screening strategies. The authors reported several limitations in their study: in particular, sensitivity analyses were not performed, and any adjustment of the single variables was likely to be ineffective without a decision model.
Implications of the study The authors highlighted the need for further research. This should focus on the cost-effectiveness of the entire screening process for all the relevant screening strategies, on the basis of formal decision modelling. In addition, it should include measurement of benefits in terms of quality-adjusted life-years.
Bibliographic details McMahon P M, Bosch J L, Gleason S, Halpern E F, Lester J S, Gazelle G S. Cost-effectiveness of colorectal cancer screening. Radiology 2001; 219(1): 44-50 Indexing Status Subject indexing assigned by NLM MeSH Barium Sulfate /economics; Colonoscopy /economics; Colorectal Neoplasms /diagnosis /economics; Contrast Media /economics; Cost-Benefit Analysis; Enema; Humans; Mass Screening /economics; Occult Blood AccessionNumber 22001000784 Date bibliographic record published 28/02/2002 Date abstract record published 28/02/2002 |
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