In Reply We would like to thank Marchetti and colleagues for their insightful comments on our article. They point out that number needed to biopsy (NNB) is influenced by clinicians’ thresholds to biopsy as well as disease prevalence. This is an important concept because dermatology clinics are certainly enriched with patients at higher risk of skin cancer.
Still, the effect of skill on the NNB cannot be discounted. Skin cancer clinics in Australia staffed by general practitioners are also enriched with patients at greater risk, yet their NNBs for melanoma detection are similar to those seen in general primary care clinics.1- 3 In addition, there can be wide variation in NNB within a single practice, as demonstrated by Wilson et al.4
Shahwan KT, Kimball AB. A Closer Inspection of the Number Needed to Biopsy—Reply. JAMA Dermatol. 2016;152(8):953. doi:10.1001/jamadermatol.2016.0937