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Excision of head and neck basal cell carcinoma with a rapid, cross-sectional, frozen-section technique |
Bentkover S H, Grande D M, Soto H, Kozlicak B A, Guillaume D, Girouard 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 The use of a rapid, cross-sectional frozen-section technique (FST) for the excision of head and neck basal cell carcinoma (BCC). The FST was described in detail in the paper.
Economic study type Cost-effectiveness analysis.
Study population The study population comprised patients who had undergone excision of head and neck BCC.
Setting The setting was a hospital. The economic study was carried out at the Fallon Clinic in Worcester (MA), USA.
Dates to which data relate The effectiveness and resource use data were gathered from January 1985 to December 1995, and the patients were further evaluated from 14 October 1997 to 12 February 1998. The effectiveness evidence concerning MMS was derived from studies published between 1981 and 1992. The price year was 2002.
Source of effectiveness data The effectiveness evidence came mainly from a single study. However, published studies were used to derive further evidence in relation to MMS.
Link between effectiveness and cost data The costing was performed retrospectively on the same sample of patients as that used in the effectiveness study for the study intervention.
Study sample Power calculations to determine the sample size were not reported. Patients who had undergone the excision of head and neck BCC at the study hospital from January 1985 to December 1995 were enrolled in the analysis. A study sample of 318 patients (557 tumours) was included in the study. There were 176 men (335 tumours) and 142 women (222 tumours) with a mean age of 66.3 years (66.6 years for men and 66.0 for women). Of the 557 tumours, 536 (96.2%) were excised using FST and 21 (3.8%) with MMS, although according to the indications for Mohs surgery there should have been only 19 patients in the MMS group.
Study design This appears to have been a retrospective cohort study. It was carried out in a single centre, although the patients who underwent MMS were operated on at the Fallon Clinic's New England Center for Facial Plastic Surgery or in the private office of the contracted surgeon. The mean length of follow-up was 4.5 years (median 3.8 years; range: 0 days to 14.5 years). The loss to follow-up was not reported.
Analysis of effectiveness It was unclear whether all the patients included in the study were accounted for in the clinical analysis. The health outcomes used in the analysis were the 5-year recurrence rate, tumour diameter, time to recurrence, and percentage of tumour-free sites up to 5 years. Recurrence was defined as a subsequently diagnosed BCC within 5 mm of the original resection margin, that is, 7 to 8 mm from the edge of the original tumour. The 5-year recurrence rate was estimated using both rough data from the trial and through the Kaplan-Meier method. A satisfaction survey was conducted on a sub-sample of 174 patients who agreed to participate in the study, to evaluate patient satisfaction with the aesthetic outcome of the intervention and the overall satisfaction with the treatment experience (preoperative, intraoperative and postoperative care). The comparability of the study groups was not discussed.
Effectiveness results The approximated 5-year recurrence rate was 1.9% (10 cases of the 536 tumours excised) with FST and 0% with MMS.
The Kaplan-Meier approach led to a 5-year recurrence rate of 2.1% (95% confidence interval: 1.0 - 4.55) with FST and 0% with MMS.
The recurrence rate could not be evaluated for longer than 5 years because the standard deviation value was smaller than 1%.
Tumour diameter was larger in patients with recurrent disease than among those who did not present any recurrence.
The mean time to recurrence was 4.3 years (median 4.0 years).
The proportion of original tumour sites that were tumour-free up to 5 years was 97.9%.
The proportion of patients satisfied with the aesthetic outcome of the surgery was 86.6%, while 81.5% were satisfied with the treatment experience.
Clinical conclusions The effectiveness analysis showed that MMS was effective in excising tumours without any recurrence. The FST approach led to a recurrence rate of 2.1% in 5 years.
Outcomes assessed in the review The health outcome estimated from the published studies was the recurrence rate with MMS.
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 The effectiveness evidence was derived from five primary studies.
Methods of combining primary studies Investigation of differences between primary studies Results of the review The recurrence rate with MMS ranged from 0.7 to 1.8%.
Measure of benefits used in the economic analysis The health outcomes were left disaggregated and no summary benefit measure was used. A cost-consequences analysis was therefore carried out.
Direct costs Discounting was not conducted, which was appropriate as the per-patient costs were incurred in less than 2 years. The unit costs were reported separately from the quantities of resources used. The health service costs included in the economic evaluation were for the pathological services, which were based on Current Procedural Terminology (CPT) codes (88331 and 88305 for FST and 17304 through 1706 for MMS). A more expensive, alternative-billing system for FST was further considered. The cost/resource boundary adopted in the study appears to have been that of the third-party payer. The main assumption of the cost analysis was that the type of frozen-tissue examination was not related to where the surgery was performed. The resource use was estimated using actual data derived from the retrospective review of the charts of the patients involved in the effectiveness study. Thus, the resource consumption was evaluated from January 1985 to December 1995. The observed average rate of FST per tumour was 1.1 and a similar rate was assumed for MMS. The price year was 2002.
Statistical analysis of costs The costs were treated deterministically.
Indirect Costs The indirect costs were not included, which was consistent with the perspective adopted.
Sensitivity analysis No sensitivity analyses were carried out.
Estimated benefits used in the economic analysis See the 'Effectiveness Results' section.
Cost results The average cost per tumour was $219.16 with FST and $689.66 with MMS. Thus, FST resulted in a cost-saving of $470.50.
With the use of a more expensive billing method, the average cost per tumour rose to $534.83 with FST. Thus, FST resulted in a cost-saving of $154.83.
If all tumours had been removed using the MMS approach, then the overall costs would have been $384,140.62. If the indications for Mohs surgery had been followed (19 MMS and 538 FST), then the overall costs would have been $131,011.62 ($300,842.08 with the more expensive billing method).
Synthesis of costs and benefits Not relevant as a cost-consequences analysis was carried out.
Authors' conclusions The specific indications for Mohs surgery were appropriate for the correct identification of patients requiring Mohs micrographic surgery (MMS) rather than the frozen-section technique (FST). The recurrence rate was slightly higher with FST, but MMS would have eliminated approximately 2 or 3 recurrences. The costs were far lower with FST and patient satisfaction was fairly high.
CRD COMMENTARY - Selection of comparators The rationale for the choice of the comparator was clear. MMS was selected, as many surgeons considered it to be the standard approach for the excision of head and neck BCC. You should evaluate whether it represents a valid comparator in your own setting.
Validity of estimate of measure of effectiveness The analysis of effectiveness mainly used a retrospective cohort study. This was appropriate for the study question, although the retrospective design may have affected the internal validity of the analysis. The study sample was representative of the study population since unselected patients were enrolled in the analysis. Power calculations were not reported and no evidence was provided that the initial study sample was appropriate for the study question. The group of patients who underwent MMS was quite small and no baseline comparison of the study groups was performed. Consequently, in order to evaluate the main outcome measure, the authors searched the literature but a formal review was not undertaken. These issues tend to limit the internal validity of the analysis.
Validity of estimate of measure of benefit No summary benefit measure was used in the economic analysis and the health outcomes were left disaggregated. The analysis was therefore categorised as a cost-consequences study.
Validity of estimate of costs The perspective adopted in the study was implicitly reported and only the costs strictly related to the pathologic examination were included. The authors discussed the reasons for excluding other categories of costs. The costs were estimated on the basis of CPT codes and the authors discussed the implications of using different pathologist codes. The unit costs (CPT) were reported separately from the quantities of resources used and the price year was given. These factors facilitate reflation exercises in other settings. The costs were treated deterministically and no sensitivity analyses were performed. The cost estimates were specific to the study setting.
Other issues The authors did not compare their findings with those from other published studies. They also did not address the generalisability of the study results to other settings. However, the reproducibility of the study in other contexts was enhanced by the fact that the economic evaluation process was described in detail. The study enrolled patients with head and neck BCC and this was reflected in the conclusions of the analysis.
Implications of the study The study suggests that patients with head and neck BCC may be effectively and efficiently managed with FST. In addition, referral to MMS should be limited to those cases identified through the specific indications for Mohs surgery elaborated at the study hospital. The authors stated that their definition of recurrence could be used in future publications.
Bibliographic details Bentkover S H, Grande D M, Soto H, Kozlicak B A, Guillaume D, Girouard S. Excision of head and neck basal cell carcinoma with a rapid, cross-sectional, frozen-section technique. Archives of Facial Plastic Surgery 2002; 4(2): 114-119 Indexing Status Subject indexing assigned by NLM MeSH Aged; Biopsy /economics /methods; Carcinoma, Basal Cell /economics /pathology /surgery; Costs and Cost Analysis; Female; Frozen Sections /economics /methods; Head and Neck Neoplasms /economics /pathology /surgery; Humans; Male; Mohs Surgery /economics /methods; Neoplasm Recurrence, Local; Patient Satisfaction; Retrospective Studies; Treatment Outcome; United States AccessionNumber 22002006414 Date bibliographic record published 30/09/2003 Date abstract record published 30/09/2003 |
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