A systematic review including 27 studies with a total of 9821 lesions was abstracted in DARE. The prevalence of melanoma ranged from 1.6 to 60.8% (mean 28.3). The mean or median Breslow thickness was reported in 15 studies and ranged from 0.40 to 1.11 mm (median 0.70). In the 13 studies that directly compared the accuracy of melanoma diagnosis with and without dermoscopy, the diagnostic accuracy for melanoma was significantly higher with dermoscopy (OR 4.0, 95% CI 3.0 to 5.1) than without (OR 2.7, 95% CI 1.9 to 3.4); an improvement of 49% (p=0.001). For all 27 studies, the results were similar; the ORs were 3.4 (95% CI 2.9 to 3.9) and 2.5 (95% CI 1.9 to 3.1), respectively (p=0.03). The diagnostic accuracy of dermoscopy significantly depended on the degree of experience of the examiners. The OR was 3.8 (95% CI 3.3 to 4.3) for experts versus 2.0 (95% CI 1.4 to 2.6) for non-experts (p=0.001). Dermoscopy by untrained or less experienced examiners was no better than clinical inspection without dermoscopy. The diagnostic performance of dermoscopy improved when the diagnosis was made by a group of examiners in consensus and diminished as the prevalence of melanoma increased.
Comment: The quality of evidence is downgraded by study limitations.