Screening for malignant melanoma: a cost-effectiveness analysis Freedberg K A, Geller A C, Miller D R, Lew R A, Koh H K

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1 Screening for malignant melanoma: a cost-effectiveness analysis Freedberg K A, Geller A C, Miller D R, Lew R A, Koh H K 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 Using a visual one-time screening programme by a dermatologist to diagnose malignant melanoma in adults at high risk of experiencing skin cancer. Type of intervention Screening. Economic study type Cost-effectiveness analysis and cost-utility analysis. Study population Adults (aged over 20 years) at high risk of experiencing skin cancer. Setting Secondary care. The economic study was carried out in the USA. Dates to which data relate Effectiveness data were obtained from screening programmes conducted between 1986 and 1994, and studies published between 1989 and Resource use data and their corresponding collection dates were not reported. The price year was Source of effectiveness data Effectiveness data were derived from a review of the literature and assumptions made by the authors. Modelling A decision analytic model was developed to project the costs and effects associated with the screening strategies considered. Outcomes assessed in the review The following outcomes were assessed: prevalence of melanoma; percentage of local or late stage melanomas; percentage of local melanomas in situ or invasive; Page: 1 / 5

2 thickness levels among invasive melanomas (less than 0.76 mm, mm, mm, and greater than 4.00 mm); 5-year survival for melanoma by stage (IA (less than 0.76 mm), IB and II (greater than 0.76 mm), III (nodal), and IV (metastatic)); prevalence of nonmelanoma skin cancer (NMSC); percentage of NMSC identified by screening and no screening strategies; five-year survival for NMSC. Study designs and other criteria for inclusion in the review Population-based studies (Massachusetts-only and United States-wide American Academy of Dermatology (AAD) screening programmes) between 1986 and 1994, the 1990 SEER Program (Surveillance, Epidemiology, and End Results), and other available data from nonrandomized studies were included 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 A total of 7 studies or reports were included in the review. Methods of combining primary studies Investigation of differences between primary studies Results of the review The results were as follows: prevalence of melanoma, ; percentage of local melanoma, 98.9% for screening programme versus 93.9% for no screen option; percentage of late stage melanomas, 1.1% for screening programme versus 6.1% for no screen option; percentage of local melanomas in situ, 41.9% for screening programme versus 29.7% for no screen option; percentage of local melanomas which were invasive, 58.1% for screening programme versus 70.3% for no screen option; Page: 2 / 5

3 Thickness levels among invasive melanomas: less than 0.76 mm, 61.2% (screening)versus 56.9% (no screen); mm, 26.2% (screening)versus 23% (no screen); mm, 10.7% (screening)versus 15% (no screen) greater than 4.00 mm, 1.9% (screening)versus 5.1% (no screen ). percentage of 5-year survival for melanoma by stage: IA (less than 0.76 mm), 96%; IB and II (greater than 0.76 mm), 74%; III (nodal), 36%; IV (metastatic), 5%). prevalence of NMSC, ; percentage of NMSC identified by screening strategies, 88.1% and no screening strategies, 50%; five-year survival for NMSC, 99%. These data were used as input parameters for the decision tree. Methods used to derive estimates of effectiveness Assumptions about effectiveness were also made by the authors. Estimates of effectiveness and key assumptions It was assumed that survival for stage III or IV melanoma, and for NMSC was not improved by screening. Measure of benefits used in the economic analysis The benefit measures were life expectancy and quality-adjusted life years (QALYs). An expert panel comprising a medical oncologist, a dermatologist, a dermatologic surgeon, and an oncologic surgeon, all having experience in the management of melanoma and NMSC, were employed to estimate the quality-adjustment values using a 100-point visual analogue rating scale. Direct costs Costs were discounted. Quantities were not reported separately from the costs. Cost items were reported separately. The cost analysis covered the direct medical costs of screen, follow-up visit, biopsy, pathology, and treatment (stage I and II, outpatient; stage I and II, inpatient; stage III and stage IV; and nonmelanoma skin cancer). The perspective adopted in the cost analysis was that of the third-party payer. The sources of cost data were the Office of Payment in Boston Medical Center and 1993 Health Care Financing Administration (HCFA) reimbursements. Charge data and sitespecific cost-to-charge ratios were used in the cost calculations price data were used. Statistical analysis of costs Not applicable. Page: 3 / 5

4 Indirect Costs Not considered. Currency US dollars ($). Sensitivity analysis A series of one-way sensitivity analyses was performed on all parameters of the model. Threshold values were calculated for the sensitive parameters of the model. Cost per QALY was also calculated in the sensitivity analysis. Estimated benefits used in the economic analysis The strategy of no screening was associated with a mean projected discounted life expectancy of versus years in the screening strategy for an index patient with a mean age of 48 years. This leads to an increase of years for each patient with melanoma due to the screening programme based on a prevalence of The discount rate was 5%. Cost results The strategy of no screening was associated with a mean lifetime total cost of $826 for an index patient with a mean age of 48 years versus $861 in the screening strategy. The discount rate was 5%. Synthesis of costs and benefits The incremental cost per year of life saved (YLS) and per QALY saved were calculated as measures of costeffectiveness and cost-utility analyses. The incremental cost per year of life saved was $29,170 compared to the no screen strategy. The corresponding value in terms of incremental cost per QALY saved was $30,360. The sensitivity analysis demonstrated that prevalence of melanoma, probability of localised lesions by screen, cost of screening, and percentage of in situ melanoma were the most sensitive parameters of the model. For the screening strategy to remain in a range of cost-effectiveness ratios below $50,000/YLS, the threshold values for prevalence of melanoma were , the probability of localised lesions by screen was 94.8%, and cost of screening was $57. Authors' conclusions Skin cancer screening in high-risk patients is likely to be associated with a small increase in discounted life expectancy and is reasonably cost-effective compared with other cancer screening strategies. CRD COMMENTARY - Selection of comparators The authors chose a no screening strategy as the comparator. This allows the active value of the screening programme to be evaluated. Validity of estimate of measure of effectiveness The reliability of the parameters used in the model is uncertain as there is no evidence of a systematic review of the literature, and the way in which differences found in the literature were dealt with was not fully explained. The authors justified their assumptions by stating that they made conservative assumptions to ensure that the model was not biased in favour of screening. This issue may have been compensated for in the sensitivity analysis. Validity of estimate of measure of benefit The estimation of benefits was modelled based on clinical probabilities from the effectiveness analysis plus qualityadjustment values derived by a panel of experts. The authors acknowledged this limitation by noting that patients' utilities would have higher validity. Page: 4 / 5

5 Powered by TCPDF ( Validity of estimate of costs All relevant costs, other than potential indirect costs, seem to be included in the analysis. Costs and quantities were not reported separately. It was not stated whether a sensitivity analysis of the quantities of resource use was conducted. This may limit the interpretation of the study findings. Prices mainly related to the authors' setting. You, as a database user, should therefore consider the relevance of these prices to your own setting. A sensitivity analysis of costs was also performed. Other issues The authors reported a number of limitations to their study, principally: the use of primary studies with nonrandomized study designs (due to lack of availability of data from randomized trials), the possibility of existence of lead time and length bias in the apparent survival advantage seen with thinner melanoma lesions, and the reliance of the analysis on a one-time screen only. The authors did make appropriate comparisons of their findings with those from other studies. The issue of generalisability to other settings or countries was addressed by performing sensitivity analysis and by stressing the need for another study to be performed on the impact of melanoma screening by primary care physicians. The authors do not appear to have presented their results selectively. The study considered the one-time screening programme by a dermatologist rather than primary care physicians and this was reflected in the authors' conclusion. Implications of the study The authors stated that better data on the incidence rates and growth rates of melanoma should ideally be incorporated into Markov state-transition models as they become available. Since this study does not address the impact of melanoma screening by primary care physicians, future studies should test the efficacy of primary care provider screening in skin cancer. Furthermore, quality of life estimates should also be derived from patients with melanoma and NMSC, or from a general population survey. Source of funding Supported in part by The Dr Donald Gauthier Melanoma Research Fund. Bibliographic details Freedberg K A, Geller A C, Miller D R, Lew R A, Koh H K. Screening for malignant melanoma: a cost-effectiveness analysis. Journal of the American Academy of Dermatology 1999; 41(5 Part 1): PubMedID Indexing Status Subject indexing assigned by NLM MeSH Cost-Benefit Analysis; Decision Trees; Humans; Mass Screening /economics; Melanoma /diagnosis /epidemiology; Prevalence; Sensitivity and Specificity; Skin Neoplasms /diagnosis /epidemiology AccessionNumber Date bibliographic record published 30/06/2000 Date abstract record published 30/06/2000 Page: 5 / 5