Figure 1 shows the populations, interventions, and outcome measures we examined. We did not find direct evidence from controlled studies of the effect of screening on health outcomes (Arrow 1) such as mortality and quality of life. We examined the consequences of screening on detection of squamous cell carcinoma and basal cell carcinoma (Arrow 2a) and on malignant melanoma (Arrow 2b). Specifically, we examined how often patients are found to have skin cancer, how often suspected skin cancer is confirmed by biopsy, and at what stage cancer is found. We also sought evidence about the effect of screening on patients' health beliefs and practices regarding skin cancer prevention, such as increased use of sun protection, sun avoidance, and self-examination (Arrow 2c), and about the adverse effects of screening (Arrow 3).