Validity of Patient Self-reported History of Skin Cancer

Abstract

Objective To determine the validity of patient self-report of skin cancer history. Design A cohort of patients was randomly selected from the case group in a prior case-control study involving skin cancer, and a second cohort was randomly selected from the controls of that study. Patient self-reported history (as determined by responses to a survey) was compared with the gold standard of chart documentation of a pathology report or a procedure note from Mohs micrographic surgery demonstrating skin cancer. Setting University-based outpatient dermatology clinic. Patients Three hundred patients were selected. Main Outcome Measures Patients were considered to have correctly classified their skin cancer history if their self-reported history was consistent with chart documentation. Results We obtained chart information for 258 patients.Of those patients, 183 (70.9%) had chart documentation of nonmelanoma skin cancer, and 16 (6.2%) had chart documentation of a melanoma. Using chart documentation as the gold standard, we found that patients correctly identified their basal cell carcinoma status in 84.3% of cases; their squamous cell carcinoma status in 81.5% of cases; their overall nonmelanoma skin cancer status in 91.8% of cases; their melanoma status in 94.8% of cases; and their overall skin cancer status in 92.6% of cases. Patients' self-reported history of skin cancer of any type had a positive predictive value of 95.1% and a negative predictive value of 85.9%. Conclusions Self-reported history of skin cancer had a high degree of sensitivity and specificity and a high positive and negative predictive value within the study population. Obtaining medical information by patient report appears to be a useful tool for determining medical history of skin cancer.