Nevus Doctor Clinical Decision Support for GPs

The study investigates if a computer-based clinical decision support tool for skin cancer may improve the diagnostic accuracy of general practitioners (GPs). The aim of the program is to help GPs increase their diagnostic accuracy, in particular regarding the selection of suspicious skin lesions that need biopsy or referral to specialist health care for further assessment. Half of the physicians in the trial will have the clinical decision support tool available during consultations, while the other half has no such tool available. We hypothesize that general practitioners using the clinical decision support tool will have a higher number of correct classifications of skin lesions compared to doctors without the tool.

General practitioners (GPs) examine patients who attend a primary health care center. In the intervention group the computer-based clinical decision support tool "Nevus doctor" in a first step assists doctors in the process of selecting skin lesions that are suggestive of cancer. In the next step a given skin lesion is photographed using a dermatoscope attached to the lens of the camera. The dermatoscopic image is then processed by the computer program "Nevus doctor" and a preliminary result is presented. Finally the GP reviews the result and assesses the clinical significance of the output by using guidelines presented by "Nevus doctor". The patient is subsequently referred to a dermatologist and a complete skin examination is performed. The assessment of the dermatologist serves as the gold standard.

The computer program analyzes dermatoscopic images. The output is an estimate of the risk of the skin lesion representing skin cancer. The decision support tool helps the doctor to assess the significance of the computer output by taking into account clinical information.

Skin lesions selected by the GP are classified into three classes: 1 Not suspicious for skin cancer, 2 Somewhat suspicious for skin cancer, 3 Very suspicious for skin cancer. The reference standard is the specialist's classification. The number of correct classifications are counted. Sensitivity and specificity scores are calculated.

Skin lesions that were not selected by the GP but were later classified by the specialist to be suspicious for skin cancer or very suspicious for skin cancer are counted.

The GPs are asked to answer a questionnaire to assess the user experiences of operating the clinical decision support tool.

Inclusion Criteria: Patients concerned about one or several skin lesion(s) Patients with any other condition if doctor has observed a skin lesion suspicious for skin cancer (incl. actinic keratosis) Exclusion Criteria: Patients not able to give consent