The impact of subspecialization and dermatoscopy use on accuracy of melanoma diagnosis among primary care doctors in Australia

BackgroundDermatoscopy improves accuracy of melanoma diagnosis, but the impact of subspecialization in skin cancer practice among general practitioners on melanoma diagnostic accuracy is not known.ObjectiveTo assess the impact of dermatoscopy use and subspecialization on the accuracy of melanoma diagnosis by general practitioners.MethodsWe did a prospective study on the Skin Cancer Audit Research Database and measured melanoma ‘number needed to treat’ (NNT), with 21,900 lesions excised to diagnose 2367 melanomas.ResultsMelanoma NNT fell from a high of 17.0 (95% confidence interval [CI] 14.5-20.7) among general practitioners with a generalist practice to 9.4 (CI 8.9-10.1) among those with a specific interest in skin cancer, and 8.5 (CI 8.1-9.0) among those practicing only skin cancer medicine (P < .0001). Melanoma NNT fell from a high of 14.6 (CI 12.0-18.6) among dermatoscopy low/non-users to 10.9 (CI 9.8-12.4) among medium users, and 8.9 (CI 8.6-9.3) among high users (P < .0001). The association between NNT and practice type remained (P < .0001) when adjusted for dermatoscopy use and other variables. The association between NNT and dermatoscopy use disappeared (P = .41) when adjusted for practice type and other variables.LimitationsThere is selection bias with respect to participating doctors and completeness and accuracy of data are not independently verified in the Skin Cancer Audit Research Database (SCARD).ConclusionsGeneral practitioners who subspecialize in skin cancer have a higher use of dermatoscopy and diagnose melanoma with greater accuracy than their generalist counterparts.