Sarina Trejić, Hans J. G. Peters, Satish F. K. Lubeek, Floris A. van de Laar
Corresponding Author: Floris A. van de Laar; Department of Primary and Community Care - Radboud University Medical Centre. Email: Floris.vandeLaar@radboudumc.nl
Section: Original Research
Publication: September 16, 2021
Background: Skin cancer is the most common type of cancer worldwide. It is important for family physicians (FPs) to differentiate between non-malignant and malignant skin conditions, but the diagnostic accuracy of FPs has never been studied in primary care. Aim: To assess the accuracy of skin cancer diagnoses by FPs. Our secondary aim was to analyze the number of patients with premalignant lesions and to examine the diversity of skin related questions in Dutch primary care. Design and Setting: Retrospective cohort study of all new skin related health questions between 1-1-2018 and 7-1-2018 in a Dutch primary care registration network with data from 26 FPs in 6 practices, with a follow-up of at least one year. Method: The initial FP diagnosis was dichotomized in malignant or non-malignant and compared in a crosstab to the final diagnosis registered after the follow-up period (reference standard). Results: Our study population included 2,952 patients. In the research period 35 patients received a final diagnosis of skin cancer. The sensitivity and specificity of the FP diagnosis of malignancy was 74.3% (95% confidence interval [CI]= 56.7 to 87.5%) and 97.3% (95% CI= 96.7 to 97.8%), the PPV and NPV 21.5% (95% CI= 17.2 to 26.5%) and 99.7% (95% CI=99.5 to 99.8%). 72 patients were diagnosed with a premalignant lesion. Included patients received 141 different diagnoses. Conclusion: The calculated diagnostic accuracy of FPs is high and shows that FPs are especially accurate in excluding malignancy. This research shows the variety of skin problems in primary care and shows that the FP is able to deliver safe and effective dermatologic care.