Mortality Rates by Occupation among US Workers: The National Health Interview Survey (NHIS)

1. Mortality Rates by Occupation among US Workers: The National Health Interview Survey (NHIS) Lora E Fleming MD PhD, William LeBlanc PhD, David Lee PhD, Alberto Caban Jr MPH, Orlando Gómez-Marín PhD MSc, Terry Pitman BS University of Miami School of Medicine Funding provided in part by NIOSH Grant number R01 0H03915; Worker Photographs by Dr David Parker http://www.rsmas.miami.edu/groups/niehs/niosh/ Objectives: This study examines overall as well as cause specific mortality rates of US workers by occupation and by gender. Methods The National Health Interview Survey, conducted annually by the National Center for Health Statistics, is a continuous, multipurpose, and multistage area probability cross-sectional survey of the US civilian non-institutionalized population living at addressed dwellings. During the study period, NHIS survey response rate reportedly ranged from 95-98%. Beginning with the 1986 survey year, information was collected by the NCHS to perform a mortality follow up through linkage with the National Death Index (NDI). The linkage is complete through December 31, 1997, and includes all participants from the 1986-94 NHIS survey years. The linkage was performed completely by computer. The linkage used an algorithm with a match class and score; on average, the linkage was 97% complete. Because of the multi-stage sampling design, all analyses were performed with adjustments for sample weights and design effects using the SUDAAN statistical package. The study sample was defined as persons aged 18 years and older who reported working within the 2 weeks prior to their participation in the NHIS 1986-1994 surveys. Sample weights were further adjusted for analysis of data from combined survey years, as specified by Botman and Jack (1995). Mortality rates by occupation were age adjusted to the 2000 population. Cause specific age adjusted mortality was evaluated for 206 occupations with an average of 100,000 US workers/year, as well as 13 and 41 broader occupational categories. RESULTS There were 440,302 total workers (205,080 women workers) in the mortality analysis with 12,181 total deaths (3,800 women worker deaths) during the study period from 1986-1994 with mortality follow up through 1997. The distribution of these deaths and the crude and age adjusted mortality rates for the broad 13 occupational categories are displayed in Table 1. With regards to age adjusted overall mortality by gender (Table 2), in the 206 detailed occupational categories containing at least 100,000 US workers, for women workers the highest mortality rates were seen for Vehicle Washers/Equipment Cleaners, Waitresses, Truck Drivers, Cleaners, Correctional Officers, Managers, Punch Press Machine Operators, Launders/Dry Cleaners, Interviewers, and Typists. For male workers the highest overall mortality rates were seen among Childcare Workers, Door-to-Door Sales Workers, Food Preparers, Licensed Nurse Practitioners, Health Aids, Roofers, Freight/Stock Handlers, General Clerks, Cashiers, and Private Household Cleaners/Servants. There were no or < 5 deaths among 33 occupations for female workers; Medicine/Health Managers (6.0) had the lowest recorded age adjusted mortality rate (data not shown). Only 7 occupations had no or <5 deaths for male workers; Operations Systems Researchers/Managers had the lowest age adjusted mortality rate (3.9) (data not shown). The highest age adjusted cardiovascular mortality rates (Table 3) were seen among Messengers, Plumbers/Pipefitters, Bus/Truck Mechanics Tool/Die Workers, Operating Engineers, Pharmacists, Hairdressers, Maids/Housemen, Civil Workers, and Distribution Supervisors. The highest age adjusted cancer mortality rates (Table 4) were seen among Agricultural Supervisors, Vehicle Washers, Roofers, Mechanic Supervisors, Sales Workers, Construction Workers, Educational Counselors, Typists, and Punch Press Machine Operators. CONCLUSIONS The NHIS database offers an opportunity to investigate the overall and disease-specific mortality experience by specific occupation among US workers. This provides a unique view of the US worker mortality which can be used to target disease prevention programs, as well as allow for international comparisons with other worker populations. An Occupational Mortality Monograph of the 1986-94 NHIS with follow up through 1997 is being created and will be available with downloadable and interactive tables from our Study Web page at www.rsmas.miami.edu/groups/niehs/niosh/