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Cancer Diagnosis Accuracy by PAs vs Dermatologists

JAMA Dermatology; ePub 2018 Apr 18; Anderson, et al

Compared with dermatologists, physician assistants (PAs) performed more skin biopsies per case of skin cancer diagnosed and diagnosed fewer melanomas in situ, suggesting that the diagnostic accuracy of PAs may be lower than that of dermatologists, according to a recent study. Researchers conducted a medical record review of 33,647 skin cancer screening examinations in 20,270 unique patients who underwent screening at University of Pittsburgh Medical Center–affiliated dermatology offices from January 1, 2011, to December 31, 2015. They found:

  • Of total unique patients, 12,722 (62.8%) were female, mean (SD) age at the first visit was 52.7 (17.4) years.
  • To diagnose 1 case of skin cancer, the number needed to biopsy (NNB) was 3.9 for PAs and 3.3 for dermatologists.
  • Per diagnosed melanoma, the NNB was 39.4 for PAs and 25.4 for dermatologists.
  • Patients screened by a PA were significantly less likely than those screened by a dermatologist to be diagnosed with melanoma in situ (1.1% vs 1.8% of visits), but differences were not significant for invasive melanoma (0.7% vs 0.8% of visits) or non-melanoma skin cancer (6.1% vs 6.1% of visits).


Anderson AM, Matsumoto M, Saul MI, Secrest AM, Ferris LK. Accuracy of skin cancer diagnosis by physician assistants compared with dermatologists in a large health care system. [Published online ahead of print April 18, 2018]. JAMA Dermatology. doi:10.1001/jamadermatol.2018.0212.