Estimating the cost of skin cancer detection by dermatology providers in a large health care system

Background: Data on the cost and efficiency of skin cancer detection through total body skin examination are scarce. Objective: To determine the number needed to screen (NNS) and biopsy (NNB) and cost per skin cancer diagnosed in a large dermatology practice in patients undergoing total body skin examination. Methods: This is a retrospective observational study. Results: During 2011-2015, a total of 20,270 patients underwent 33,647 visits for total body skin examination; 9956 lesion biopsies were performed yielding 2763 skin cancers, including 155 melanomas. The NNS to detect 1 skin cancer was 12.2 (95% confidence interval [CI] 11.7-12.6) and 1 melanoma was 215 (95% CI 185-252). The NNB to detect 1 skin cancer was 3.0 (95% CI 2.9-3.1) and 1 melanoma was 27.8 (95% CI 23.3-33.3). In a multivariable model for NNS, age and personal history of melanoma were significant factors. Age switched from a protective factor to a risk factor at 51 years of age. The estimated cost per melanoma detected was $32,594 (95% CI $27,326-$37,475). Limitations: Data are from a single health care system and based on physician coding. Conclusion: Melanoma detection through total body skin examination is most efficient in patients ≥50 years of age and those with a personal history of melanoma. Our findings will be helpful in modeling the cost effectiveness of melanoma screening by dermatologists.