Clinicans performed a two-step examination for skin cancer, with clinical examination of individual lesions was aided by the use of dermoscopy, as needed. In the first step, physicians performed inspection of problem areas and uncovered areas only, and lesions suggestive of melanoma or non-melanoma skin cancer were noted. In the second step, TBSE was performed. Following both examinations, lesions suggestive of melanoma or non-melanoma skin cancer were excised or biopsied. Histopathologic diagnosis was recorded for each of the biopsied or excised lesions.
Statistical analysis: We calculated absolute risks as the proportion of individuals with the target disease divided by all individuals at risk. The number needed to examine was calculated by dividing the individuals at risk by the numbers of individuals with the target disease. Confidence intervals for proportions were calculated using standard formulas based on the binomial distribution. Chi square tests were used for comparison of proportions.
Continuous variables are presented as mean and standard deviation (SD) unless otherwise specified. For univariate and multivariate analyses we used odds ratios derived from logistic regression to estimate relative risks and their confidence intervals. All p-values reported are 2-tailed. Statistical significance is defined as P \<0.05. Statistical analysis was performed using SPSS software, version 16.0 (SPSS, Chicago, Ill, US).
