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Prostate-cancer surveillance: a cost-effective strategy |
Schapira D V, Jarrett A R |
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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 Surveillance strategies involving history, physical examination, complete blood cell count, chemistry panel, prostate specific antigen (PSA), and annual bone scan techniques for the earlydetection of metastases in patients who might suffer a recurrence of prostate cancer.
Economic study type Cost-effectiveness analysis.
Study population Patients with local and regional prostate cancer undergoing surveillance for possible recurrence after initial remission.
Setting Hospital/secondary care. The economic study was carried out in Tampa, Florida, USA.
Dates to which data relate Effectiveness data were derived from literature covering the period 1982 to 1991. Resource use at follow-up was based on the protocols and some survival population-based data for the US in 1988 and 1992. Although the authors stated that 1992 prices were used in the presentation of results, in actual fact they presented results in nominal prices for the period 1986-2000.
Source of effectiveness data Effectiveness data were derived from a review or synthesis of previous studies.
Modelling An actuarial model of the US health care sector was used in estimating costs over the period 1986-2000. This model was derived from US population-based data and medical care cost inflation data published by the US Health Care Financing Administration. The model assumed a 5-year surveillance programme or less, if recurrence occurs before 5 years after treatment.
Outcomes assessed in the review The effectiveness of PSA, prostatic acid phosphate (PAP), alkaline phosphatase, CBC, and bone scanning were assessed.
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 Two studies were referred to for PAP, two for alkaline phosphatase, two for bone scanning, and nine for PSA. The types of study were not stated.
Methods of combining primary studies Investigation of differences between primary studies Results of the review PSA levels are more sensitive than any other method of early detection of the recurrence of prostate cancer and the inclusion of additional tests (bone scans, PAP and alkaline phosphate) provides no further clinically useful information beyond that obtained from a PSA level.
Measure of benefits used in the economic analysis The measure of benefit was early detection of recurring prostate cancer.
Direct costs Costs were not discounted even though the time period of analysis for each unit (patient) was, in most cases, longer than 1 year. The actuarial model of the incidence method of estimating costs was used to calculate population-based resource use. Costs for the surveillance strategies were estimated assuming a 5-year follow-up period, which accounted for 5-year survival and recurrence rates. The sources of data for the unit costs of diagnostic tests used were not provided (CBC, Chemistry Panel, PSA and bone scan). Population-based cost estimates covered the period from 1986-2000. Current prices for those years were used by reflating/deflating 1992 prices using information from the Health Care Financing Administration (HCFA) on health care inflation. Annual additional costs of programmes 2, 3 and 4 over the base surveillance programme (programme 1) were calculated.
Sensitivity analysis No sensitivity analysis was performed.
Estimated benefits used in the economic analysis No additional cases of recurring prostate cancer would be found using strategy 4 which includes additional tests to PSA levels.
Cost results The annual additional costs of strategies 2, 3 and 4 over the reference of history and physical exam only, for the year 2000 in that year's prices were as follows: strategy 2,$174.4 million; strategy 3, $268.3 million and strategy 4, $1,764 million.
Synthesis of costs and benefits Apart from the dominance of strategy 2 and 3 over strategy 4, a combination of costs and benefits was not reported. The authors only referred to the crucial information needed regarding the beneficial effects of early detection of recurrences. They argued that, given that patients in Stage A have a 90% rate of disease free survival after five years, a further $100 million (over the $1,500 saved by choosing strategy 3 over 4) could be devoted to other priorities if PSA were performed only on patients in stages B & C (strategy 2).
Authors' conclusions The use of treatment beyond PSA is not cost-effective as it provides no useful clinical information and incurs significant extra costs.
CRD Commentary No justification was provided for the inclusion of the primary studies selected. The effectiveness study used only an intermediate outcome, namely early detection of recurrence. Costs were not discounted, even though the time frame involved was longer than 1 year. The reference made to discounting, in fact refers to deflation of current prices so as to obtain annual current estimates for years prior to 1992. No sensitivity or statistical analysis was performed on the findings.
Implications of the study A well-designed randomised control trial investigating the quantity-and quality-of-survival effects of surveillance should be implemented to examine the cost-effectiveness of using PSA in patients with stages B & C cancer and in patients in stage A, B & C, keeping 'history and physical exam alone' as a relevant comparator.
Bibliographic details Schapira D V, Jarrett A R. Prostate-cancer surveillance: a cost-effective strategy. International Journal of Oncology 1993; 2(3): 473-477 Indexing Status Subject indexing assigned by CRD MeSH Bone Neoplasms /radionuclide imaging; Follow-Up Studies; Neoplasm Invasiveness; Neoplasm Metastasis; Neoplasm Recurrence, Local; Neoplasm Staging; Predictive Value of Tests; Prognosis; Prostate-Specific Antigen /blood; Prostatic Neoplasms /mortality /diagnosis /prevention & Risk; Risk Factors; Survival Analysis; Survival Rate; Time Factors; control AccessionNumber 21996008076 Date bibliographic record published 31/07/1999 Date abstract record published 31/07/1999 |
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