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Costs and effects of using specialized breast technologists in prereading mammograms in a clinical patient population |
van den Biggelaar FJ, Kessels AG, van Engelshoven JM, Flobbe K |
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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. CRD summary This study examined the clinical and economic impact of strategies that involved technologists reading mammograms for referral to radiologists, in a clinical population without an immediate indication for further testing before assessment, compared with conventional evaluation by radiologists. The authors concluded that using technologists to pre-read mammograms was as effective as, and cheaper than, the standard use of radiologists. The methods were valid and the study was reported well. The authors’ conclusions appear to be appropriate. Type of economic evaluation Cost-effectiveness analysis Study objective This study examined the clinical and economic impact of four strategies in which technologists assessed mammograms for referral to radiologists, in a clinical population that did not have an immediate indication for further testing before assessment. These strategies were compared with the usual strategy of evaluation by radiologists. Interventions Standard evaluation by a radiologist was compared with four strategies for pre-reading mammograms, where specialised technologists selected the examinations that required further evaluation by a radiologist. Mammograms were graded according to their Breast Imaging - Reporting and Data System (BI-RADS) score.
In strategy one, mammograms were evaluated by one technologist, who discharged patients who had no mammographic abnormalities (BI-RADS 1), and referred all patients with any mammographic abnormality (BI-RADS 2 to 5) or requiring additional imaging (BI-RADS 0) to the radiologist. This strategy was subdivided into a and b, representing the results of the two participating technologists.
In strategy two, two technologists read the mammograms independently. When mammographic abnormalities (BI-RADS 2 to 5) were reported by at least one technologist or at least one technologist recommended additional imaging evaluation (BI-RADS 0), the mammogram was referred to the radiologist for evaluation.
Strategies three and four were the same as one and two except that a cut-off score between BI-RADS 2 (benign finding) and 3 (probably benign finding) was used for referral, with mammograms with BI-RADS 1 and 2 scores not referred. Location/setting Netherlands/out-patient setting. Methods Analytical approach:The analysis was based on a decision tree with a short-term horizon. The authors did not explicitly state the perspective adopted.
Effectiveness data:The clinical data were derived from a large prospective study, with a sample of 1,389 consecutive mammography examinations of patients referred to the Maastricht University Medical Center. The mean age of the participants was 53 years (range 21 to 90 years). All mammograms were evaluated by the radiologist on duty and independently by two technologists. The reference standard for the presence or absence of breast cancer was the pathology results of biopsies. The key outcome was the number of malignancies that were not detected by the technologists (false-negative results). The length of follow-up was one year.
Monetary benefit and utility valuations:Not included.
Measure of benefit:No summary benefit measure was used and the number of false-negatives was the key outcome.
Cost data:The economic analysis included the cost of mammograms (hospital stay and radiologist and technologist’s time), ultrasound examination, fine needle aspiration cytology, core needle biopsy, and the cost of cancer treatment (surgery, adjuvant therapy, local recurrence, palliative care, and follow-up care in disease-free patients). All costs were based on average Dutch reimbursement rates, except for the costs of cancer care, which were from a published study. All costs were in Euros (EUR) and the price year was 2008.
Analysis of uncertainty:A threshold analysis was undertaken to examine the impact of variations in the technologist costs on the total costs. Results The clinical analysis showed that those malignancies that were not detected in the technologist strategies were also not detected in the standard strategy. So no additional false-negatives were observed with any of the technologists strategies compared with the standard strategy.
The costs of cancer were the same for all strategies because the same numbers of malignancies were detected and so these costs were excluded. The total diagnostic costs were EUR 150,602 with the standard strategy, EUR 139,781 with strategy one a, EUR 136,758 with strategy one b, EUR 150,612 with strategy two, EUR 126,834 with strategy three a, EUR 122,494 with strategy three b, and EUR 137,999 with strategy four. All technologist strategies, except strategy two which was equally costly, were cheaper than the standard evaluation. This was due to fewer mammogram re-evaluations and fewer ultrasound examinations by a radiologist.
The threshold analysis showed that, for the standard strategy to be cheaper, the technologist's hourly wage had to increase from EUR 33 to over EUR 59 for strategy four, EUR 84 for strategy one, and EUR 141 for strategy three. Authors' conclusions The authors concluded that using technologists to pre-read mammograms was as effective as, and cheaper than, the standard use of radiologists. CRD commentary Interventions:The rationale for the selection of the comparators was clear as various experimental diagnostic strategies involving technologists were compared with the conventional evaluation by radiologists.
Effectiveness/benefits:The clinical evidence was derived from a large prospective study, with a sample of consecutive patients. The clinical endpoints from this study were attributed to each experimental strategy. A large sample was used and patients were followed up for an appropriate period. The evidence was derived from a single institution, which might not be representative of other institutions. The outcome measure (cases correctly detected) was disease specific, but this was typical of diagnostic studies.
Costs:The economic viewpoint was not explicitly stated, but the cost categories suggested a health care perspective. The unit costs were reported only for diagnostic procedures. The costs of cancer care were not broken down in individual items, but these costs were also not included in the analysis as they were identical for all strategies. The sources of costs and the price year were reported. In general these sources were representative of the Dutch setting.
Analysis and results:The costs and benefits were not synthesised, as a cost-consequences analysis was conducted. The results were clearly presented. The issue of uncertainty was partially investigated in a threshold analysis that considered only variations in the wages of technologists. The generalisability of these results to other settings was not investigated and the results appear to be specific to the Dutch setting. The decision model was extensively described and the accuracy for the strategies was appropriately obtained from a large prospective clinical study.
Concluding remarks:The methods were valid and the study was reported well. The authors’ conclusions appear to be appropriate. Funding Supported by the Netherlands Organization for Health Research and Development (ZonMw). Bibliographic details van den Biggelaar FJ, Kessels AG, van Engelshoven JM, Flobbe K. Costs and effects of using specialized breast technologists in prereading mammograms in a clinical patient population. International Journal of Technology Assessment in Health Care 2009; 25(4): 505-513 Indexing Status Subject indexing assigned by NLM MeSH Adult; Aged; Aged, 80 and over; Allied Health Personnel /economics; Cost-Benefit Analysis; Female; Humans; Mammography /economics; Middle Aged; Prospective Studies AccessionNumber 22010000238 Date bibliographic record published 07/07/2010 Date abstract record published 08/09/2010 |
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