Background: Skin cancer is the most common type of cancer worldwide. Family physicians (FPs) need to differentiate between nonmalignant 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 examine the diversity of skin-related questions in Dutch primary care. Method: This study is a retrospective cohort of all new skin-related health questions between January 1, 2018, and July 1, 2018, in a Dutch primary care registration network with data from 26 FPs in 6 practices, with a follow-up of at least 1 year. The initial FP diagnosis was dichotomized as malignant or nonmalignant and compared in a crosstab to the final diagnosis registered after the follow-up period (reference standard). Results: Our study population included 2952 patients. During 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 positive predictive value and negative predictive value was 21.5% (95% CI, 17.2% to 26.5%) and 99.7% (95% CI, 99.5% to 99.8%), respectively. Seventy-two 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 can deliver safe and effective dermatologic care.

中文翻译：

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家庭医生对皮肤癌的诊断准确性

背景：皮肤癌是全世界最常见的癌症类型。家庭医生 (FP) 需要区分非恶性和恶性皮肤病，但从未在初级保健中研究过 FP 的诊断准确性。目的：评估 FP 诊断皮肤癌的准确性。我们的次要目的是分析癌前病变患者的数量，并检查荷兰初级保健中皮肤相关问题的多样性。方法：本研究是对 2018 年 1 月 1 日至 2018 年 7 月 1 日期间在荷兰初级保健注册网络中所有新皮肤相关健康问题的回顾性队列，数据来自 6 个实践中的 26 个 FP，并随访至少 1 年。最初的 FP 诊断分为恶性或非恶性，并在交叉表中与随访期后登记的最终诊断（参考标准）进行比较。结果：我们的研究人群包括 2952 名患者。在研究期间，35 名患者最终被诊断为皮肤癌。FP诊断恶性肿瘤的敏感性和特异性分别为74.3%（95% CI，56.7%～87.5%）和97.3%（95% CI，96.7%～97.8%），阳性预测值和阴性预测值值分别为 21.5%（95% CI，17.2% 至 26.5%）和 99.7%（95% CI，99.5% 至 99.8%）。72 名患者被诊断为癌前病变。包括的患者接受了 141 种不同的诊断。结论：FPs 的计算诊断准确率很高，表明 FPs 在排除恶性肿瘤方面特别准确。这项研究显示了初级保健中的各种皮肤问题，并表明 FP 可以提供安全有效的皮肤科护理。