Difference between real and perceived power of dermoscopical methods for detection of malignant melanoma.

Clear proceedings in detection of malignant melanoma and monitoring of melanocytic nevi (MN) have been achieved by dermoscopy in recent years: sensitivity to 95% is possible for experts. Does patients' confidence in methods for detection of malignant melanoma most important for adherence in follow-up reflect this diagnostic power? A self-administered survey was performed in 210 consecutive patients at 13 private dermatological practices and the department of Dermatology of the University of Regensburg. Confidence was assessed by a 5-step ordinal scale ranging from 1 to 5 (higher values indicate higher confidence) and willingness-to-pay (wtp) as health-economic instrument for naked-eye inspection (NEI), handheld dermoscopy (HHD), digital dermoscopy (DD), and teledermoscopy (TD); additional, wtp for a hypothetical method promising 100% accuracy. Data of 143 patients (response rate 69.5%; mean age 37 years, 58% female) could be analysed. Mean confidence was 1.9 0.9 for NEI, 2.8 0.9 for HHD, 4.5 0.7 for DD, and 4.7 0.5 for TD. Mean wtp per examination was 0.64% 1.1 of monthly income for NEI, 1.1% 1.9 for HHD, 2.8% 3.3 for DD, 3.1% 4.6 for TD, and 5.0% 7.8 for hypothetical method. Differences between methods were statistically significant. Compared to the hypothetical method, NEI achieved only 14.9%, HHD 24.8%, DD 58.4%, and TD 60% of maximum confidence. This study was performed without any influence on routine information for patients. Results therefore represent patients' actual knowledge of dermoscopical methods in daily dermatological practices. Patients' confidence was highest for TD, HHD was clearly underestimated. Willingness-to-pay in HHD, DD, and TD was at least 40% below a hypothetical method promising 100% accuracy. Better information about diagnostic accuracy of methods available is necessary to increase patients' knowledge and confidence.