Wendy W. Huebner

Strategies for Using the National Death Index and the Social Security Administration for Death Ascertainment in Large Occupational Cohort Mortality Studies

This paper describes a multistage process to improve the completeness and time-/cost-effectiveness of ascertaining deaths in large employee cohorts. The process uses the vital status data service of the Social Security Administration (SSA) to identify people who can be confirmed as living, in order to reduce the number of records submitted for a National Death Index (NDI) search. The accuracy of SSA results is verified by submitting a sample of known-living and known-deceased people. For the NDI search results, an algorithm based on a discrete combination of matching variables is applied to distinguish NDI records as true, false, or questionable matches to reduce the number of death certificate requests to state offices. Subsequent decision making is based on manual reviews at various stages. In a cohort of over 200,000 employees, an SSA vital status search reduced the size of the NDI death record search by 85%. The algorithm sorted thousands of NDI records into 15 distinct strata and reduced the number of death certificate requests by 76%. The authors believe that the matching process is enhanced by obtaining paper copies of death certificates from the states, because death certificates often provide additional information and aid in determining true matches to company employees.

Influence of parental and biological factors on the male birth fraction in the United States: an analysis of birth certificate data from 1964 through 1988.

OBJECTIVE To determine the role of parental and biological factors on the U.S. male birth fraction from 1964 through 1988. DESIGN Logistic regression on annual U.S. male births by race group. SETTING Population-based data. PATIENT(S) Live births in the United States 1964 through 1988. INTERVENTION(S) None. MAIN OUTCOME MEASURE(S) Annual U.S. male birth fraction by parental and biological factors. RESULT(S) During the study period, the annual U. S. male birth fraction showed changes based on race group, parental age, and low birth weight. The overall influence of parental age on the U.S. male birth fraction is strong and is stronger in nonwhites than in whites. The U.S. male birth fraction is also strongly influenced by the percentage of low birth weight infants in nonwhites, but not in whites. The male birth fraction declines with increasing age of either parent and with an increase in the percentage of low birth weight infants. CONCLUSION(S) The relative magnitude of influences on the U.S. male birth fraction depend on the race group, which may be a reflection of the range of observed data rather than biological differences. The developed models have reasonable predictive power and are an appropriate first step in understanding the factors influencing the male birth fraction. These types of parental and biological variables should be included in models before examining other exogenous and population level variables.

Mortality experience of a young petrochemical industry cohort : 1979-1992 follow-up study of US-based employees

This retrospective study examines the mortality patterns of a relatively young cohort of 81,746 former and current petrochemical company employees. Standardized mortality ratios (SMR) for 1979 through 1992 are generally from about unity to well below unity for major causes and numerous specific causes of death studied by gender/race/job subgroups. Findings of note include a SMR (based on incidence rates) of 1.94 (95% confidence interval [CI], 1.04 to 3.33) for mesothelioma, and a SMR of 1.81 (95% CI, 0.90 to 3.24) for chronic lymphocytic leukemia, both among males hired before 1960. All male semiskilled operatives have a 1.6-fold increase (95% CI, 1.07 to 2.29) in motor vehicle accident deaths, with declining rates since the mid-1980s. The overall SMR for acquired immunodeficiency syndrome (AIDS) is at unity (69 deaths), with excesses in technician and office worker subgroups. Four decedents with lymphoma (code 202.8 in 9th revision ICD) had AIDS as a secondary cause of death, suggesting the need to examine secondary causes when studying lymphopoietic conditions. This routine surveillance activity provides leads regarding the presence or absence of excess mortality risk.

Mortality Patterns and Trends Among 127,266 U.S.-Based Men in a Petroleum Company: Update 1979-2000

Objective: To assess patterns and trends in mortality among men employed in U.S. operating segments of a petroleum company. Methods: We defined a cohort of 127,266 men with at least 1 day of employment during the period of 1979 through 2000. Computerized human resources databases were the basis of the cohort definition as well as the source of demographic and most work history information. Standardized mortality ratios (SMR) and 95% confidence intervals (CI) were calculated for 94 causes of death, including analyses by operating segment and job type. Results: Most SMR results are below unity. The main exception is mesothelioma (SMR = 1.49; 95% CI = 1.15 to 1.90), which has elevations three times greater than expectation among some groups of men working in manufacturing sites who were hired before 1960. SMRs for cancers of the blood and blood-forming organs are generally close to unity, whereas men in the chemicals segment have 17 deaths due to acute non-lymphocytic leukemia (SMR = 1.81; 95% CI = 1.06 to 2.90), with no temporal or job type patterns. Men in the downstream segment have an elevation of aplastic anemia (SMR = 2.19; 95% CI = 0.95 to 4.32), based on eight deaths. There are eight deaths from malignant melanoma among downstream drivers (SMR = 2.46; 95% CI = 1.06 to 4.84), and motor vehicle accident rates are slightly elevated among some groups of younger and shorter-term operators. Conclusions: This comprehensive study indicates an overall favorable mortality profile for this workforce. For a few elevations, the study helps guide decisions about future surveillance, focused studies, and other follow-up actions.

An analysis of the risk of B-lymphocyte malignancies in industrial cohorts

Abstract Among numerous studies of occupational groups with varied chemical exposures (e.g., farmers, petroleum workers, and rubber workers), some have reported excess risk for non—Hodgkins lymphoma (NHL), multiple myeloma, and other cancers of the B-lymphocyte cell line. While not conclusive, these studies raise questions about the effects of chemical exposures on the lymphocytic versus myeloid cell lines. Almost 70 occupational cohort studies were identified that addressed B-cell cancer risks in 9 major industrial categories, in order to look for common patterns across industries. This effort was substantially limited by the inconsistent nature of lymphohematopoietic (LH) classification schemes across studies and over time, and the relative paucity of B-cell-specific results in studies for any given industry. Taking these limitations into consideration, a descriptive, graphical analysis suggested a pattern of B-cell cancer elevations in the rubber and “general chemical” industries, but no consistent patterns in petroleum production/distribution or petrochemical production. The limited data sources, which lack detail about differences in hazard and exposure for different types of products/chemicals, did not allow a comprehensive look at possible common exposures associated with B-cell cancer elevations across industries. This study suggests that evaluation of possible associations between specific chemical exposures and B-cell malignancies would require additional studies with clear and common definitions of B-cell outcomes. The article concludes by giving an example of a possible common framework for categorizing NHL, the diseases for which most classification issues arise.

Mesothelioma in occupational cohort studies: methodological considerations.

Objective:This article describes effective strategies for the identification and valid assessment of mortality due to mesothelioma. Methods:We manually reviewed all death certificates for mention of mesothelioma for all International Classification of Diseases (ICD) revisions. We tested the accuracy of our ascertainment method by comparing New Jersey death certificate data from our health status registry with histologically confirmed cases from the New Jersey State Cancer Registry. Results:We found reasonably good agreement between death certificate diagnoses and histologically confirmed cases, &kgr; coefficient 0.86 (95% confidence interval, 0.76 to 0.95). Most mesothelioma deaths in our test and North American cohorts were coded to unspecified anatomical sites. Conclusions:Limiting ascertainment to pleura and peritoneum ICD codes underestimates mesothelioma deaths. Reviewing all ICD codes that could contain mesothelioma is the only effective method for complete capture of mesothelioma diagnoses.