Joseph L. Lyon

Healthcare claims data were used to better understand the diagnostic investigation and treatment of cancer. A retrospective cohort study was used involving claims data from a large insurance company. Analyses were based on electronic claims data from 1997 through 2006 for enrollees aged 15-64 years. This study showed that 96% of all first time cancer-related claims involved physician services. The percentage of physician services involving diagnostic workup in the form of some combination of blood testing, radiology, and surgery was 89% for non-skin cancer and 95% for skin cancer. The percentage of physician services involving some combination of chemotherapy, radiation, and surgery was 24% for non-skin cancer and 14% for skin cancer. Thus, for cancer (excluding skin cancer) the ratio of diagnostic workup to treatment was 2.7 to 1. For skin cancer, the ratio was 6.3 to 1. The percentage receiving treatment ranged from 13% for the male genital system to 46% for cancers of the bones and joints. Beyond cancers of the male or female genital systems, cancer-related claims involving treatment were 34% (95% CI 17-54%) higher for females than males. Healthcare claims data can be used to generate useful information for physicians and their patients about the process and nature of the diagnostic workups and treatment that typically occur when cancer is suspected.

A study was begun in 1965 to 1966 to determine whether children exposed to radioactive iodine from nuclear weapons testing at the Nevada Test Site from 1951 through 1962 were at higher risk of thyroid disease. In 1993, we reported that among those examined in 1985 to 1986 (Phase II) there was an association between radiation from the Nevada Test Site and thyroid neoplasms. We reevaluated the relationship between exposure to Nevada Test Site fallout and thyroid disease using newly corrected dose estimates and disease outcomes from the Phase II study. A prospective cohort of school children 12 to 18 years old living in Utah, Nevada, and Arizona was first examined for thyroid disease in 1965 to 1966 and reexamined in 1985 to 1986. In the Phase II report, 2497 subjects formed the basis for this analysis. Thyroid disease, including thyroid neoplasms and thyroiditis, was expressed as cumulative incidence and risk ratios (RRs) with a dose–response expressed as excess risk ratio (ERR/Gy). The RR between thyroid radiation dose in the highest dose group and thyroid neoplasms increased from 3.4 (in the earlier analysis) to 7.5. The RR for thyroiditis increased from 1.1 to 2.7 with an ERR/Gy of 4.9 (95% confidence interval = 2.0 to 10.0). There were too few malignant thyroid neoplasms to estimate risk. Persons exposed to radioactive iodine as children have an increased risk of thyroid neoplasms and autoimmune thyroiditis up to 30 years after exposure.

Radon is a well-established cause of lung cancer in miners. Residents of homes with high levels of radon are potentially also at risk. Although most individual studies of indoor radon have failed to demonstrate significant risks, results have generally been consistent with estimates from studies of miners. We studied 1474 incident lung cancer cases aged 40–79 yr in Connecticut, Utah, and southern Idaho. Population controls (n = 1811) were identified by random telephone screening and from lists of Medicare recipients, and were selected to be similar to cases on age, gender, and smoking 10 yr before diagnosis/interview using randomized recruitment. Complete residential histories and information on known lung cancer risk factors were obtained by in-person and telephone interviews. Radon was measured on multiple levels of past and current homes using 12-mo alpha-track etch detectors. Missing data were imputed using mean radon concentrations for informative subgroups of controls. Average radon exposures were lower than anticipated, with median values of 23 Bq/m³ in Connecticut and 45 Bq/m³ in Utah/southern Idaho. Overall, there was little association between time-weighted average radon exposures 5 to 25 yr prior to diagnosis/interview and lung cancer risk. The excess relative risk (ERR) associated with a 100-Bq/m³ increase in radon level was 0.002 (95% CI −0.21, 0.21) in the overall population, 0.134 (95% CI −0.23, 0.50) in Connecticut, and −0.112 (95% CI −0.34, 0.11) in Utah/Idaho. ERRs were higher for some subgroups less prone to misclassification, but there was no group with a statistically significant linear increase in risk. While results were consistent with the estimates from studies of miners, this study provides no evidence of an increased risk for lung cancer at the exposure levels observed.

A population-based insurance claims database was used to examine cellulitis incidence, anatomical sites of infection, complicating diagnoses, source of health service, and recurrence rates. Insurance claim files were searched for cellulitis ICD-9-CM codes 681.0–682.9. Complications of cellulitis including erysipelas, lymphadenitis, lymphangitis, and necrotizing fasciitis were also identified by ICD-9-CM codes. We found a cellulitis incidence rate of 24·6/1000 person-years, with a higher incidence among males and individuals aged 45–64 years. The most common site of infection was the lower extremity (39·9%). The majority of patients were seen in an outpatient setting (73·8%), and most (82·0%) had only one episode of cellulitis during the 5-year period studied. There was a very low incidence of cellulitis complications, including necrotizing fasciitis. Cellulitis is fairly common, usually treated in outpatient settings, and is infrequently complicated by erysipelas, lymphadenitis, lymphangitis, or necrotizing fasciitis.