Malignant Melanoma in the Kaiser Foundation Health Plan of Northern California: A Comparison of Incidence and Measures of Health Care Utilization Between the Lawrence Livermore National Laboratory and Surrounding Health Plan Group

摘要

We investigated the hypothesis that the increased incidence of malignant melanoma at Lawrence Livermore National Laboratory (LLNL) was due to a difference in the medical care received by LLNL employees compared to nonLLNL residents of the same geographic area. Utilizing records of the Kaiser Foundation Health Plan (KFHP) to which about half of the LLNL employees belong, we confirmed that the incidence of melanoma at LLNL was about three times that in the surrounding community (62.4/100,000 vs 20.9/100,000 in the members served by the Walnut Creek KFHP facility, p = 0.040. Furthermore, rates of biopsy for junctional, compound and dermal nevi were also higher among LLNL employees than the Walnut Creek membership. The melanoma rate among LLNL spouses was close to that of the employees themselves, but was based on only six cases. Rates among employees of the University of California at Davis, a group likely to be similar to LLNL employees in academic background and sun exposure, were not elevated compared to overall KFHP rates. In a comparison between LLNL employees without melanoma and comparable controls in the Walnut Creek membership, there was no clear difference in the number of visits for skin problems. However, LLNL employees had substantially more skin biopsies than the controls. After 1976 when the excess of melanoma at LLNL first received publicity, the difference in the mean number of biopsies was significantly greater (p = 0.048). We conclude that the sustained increase in melanoma incidence at LLNL is associated with an increased likelihood of being biopsied for pigmented skin lesions. This association may be because physicians caring for LLNL employees are more concerned about the potential malignancy of pigmented lesions. (ERA citation 09:029416)