Project Name: The National Longitudinal Mortality Study (NLMS)
Description of Project:
The National Longitudinal Mortality Study (NLMS) consists of a database developed for the purpose of studying the effects of demographic and socio-economic characteristics on differentials in U.S. mortality rates. The NLMS is a unique research database in that it is based on a random sample of the non-institutionalized population of the United States. It consists of U.S. Census Bureau data from Current Population Surveys, Annual Social and Economic Supplements and a subset of the 1980 Census combined with death certificate information to identify mortality status and cause of death. The study currently consists of approximately 3.0 million records with over 250,000 identified mortality cases. The content of the socio-economic variables available offers researchers the potential to answer questions on mortality differentials for a variety of important socio-economic and demographic subgroups not covered as extensively in other databases. This project has generated over 60 publications in various prominent scholarly, scientific and public health related journals.
Project Objective:
To provide an analytical research database for the purpose of studying the effect of demographic and socio-economic differentials on U.S. mortality rates. Specific objectives of this project are:
- To provide answers to specific public health questions which are not available from other sources.
- To publish research findings in scholarly, scientific and health related journals.
- To release a public-use file. This file will be released only after extensive review to ensure that the confidentiality of respondents has been protected. The Census Bureau’s Disclosure Review Board and organizations contributing data to the file must approve the release of the public-use file.
Confidentiality of NLMS data:
Title 13 of the United States Code (U.S.C.) provides the assurance of confidentiality of Census Bureau data. As such, NLMS operational procedures carefully follow well-defined practices designed to maintain the confidentiality of personal records as required by Title 13. These practices include the prevention of disclosure through the elimination of sparse cells in publications, the prohibited release of small-area geographical information on the NLMS public-use file, the use of an individually assigned NLMS control number to identify records instead of the use of personal identifiers for these purposes, and the restriction of persons having direct access to the NLMS database. A violation of Title 13 includes assessment of severe penalties including a prison term of up to 5 years and/or fines of up to $250,000, for any individual found guilty of releasing confidential information. In addition, any data acquired for NLMS purposes from an external agency is acquired under strict confidentiality protections and agreements that govern its use and subsequent release.
Sponsoring Organizations:
- The National Heart, Lung, and Blood Institute (NHLBI),
- The National Cancer Institute (NCI),
- The National Institute on Aging (NIA), and
- The National Center for Health Statistics (NCHS).
- The U.S. Census Bureau (CB) is a non-funding sponsor of the NLMS.
Principal Investigators:
Each sponsoring organization has a principal investigator/representative on the NLMS Steering Committee. The NLMS Steering Committee oversees the operation and coordinates the research efforts of the NLMS. The principal investigators for each sponsoring agency are listed at the end of this document.
Study Design:
The NLMS currently consists of Annual Social and Economic Supplements which cover the period from March 1973 to March 2002, Current Population Surveys for February 1978, April 1980, August 1980, December 1980, and September 1985, and one 1980 Census cohort, 30 cohorts in all. Mortality information is obtained from death certificates available for deceased persons through the National Center for Health Statistics. Important variables available for analyses are standard demographic and socio-economic variables such as, education, income and employment as well as information collected from death certificates, including cause of death.
Data Limitations:
The NLMS is based on specific survey months of the Current Population Survey, the Annual Social and Economic Supplement, and a subset of the 1980 Census. These are one-time data collection processes with no subsequent data collection. Therefore, one limitation of NLMS data is that they provide a one-time only baseline measurement of subjects in a long-term follow-up situation. Another limitation of these data is that, although the CPS and census instruments do provide extensive data collection capabilities in specific subject matter areas, desirable general or specific health information is not collected, and smoking status is available on only a limited number of records.
Future Plans:
The current plan for the NLMS is to integrate information on mortality into the NLMS every two years from 1998 through 2006 with research on the resulting database to continue, at least, through 2009. The NLMS will continue to incorporate data from the yearly Annual Social and Economic Supplement into the study as the data become available. Based on the expected size of the Annual Social and Economic Supplements to be conducted, the expected number of deaths to be added to the NLMS through the updating process will increase the mortality content of the study to nearly 500,000 cases out of a total number of approximately 3.3 million records.
In addition to the socio-economic and mortality data available, extensive geographical and demographic summary information at the census tract level, may be incorporated into NLMS records. To further enhance the research potential of NLMS data, information from sources outside the Census Bureau defined at the tract level may also be incorporated. An example of these types of data would be environmental pollution data from the Environmental Protection Agency.
Data Availability:
An NLMS public-use file is available to interested researchers upon request through NLMS-Census Bureau principal investigator, Norm Johnson. Due to the confidential nature of the NLMS Title 13 data, the NLMS Public-use file consists of a restricted set of NLMS variables.
Research access to the entire NLMS database may be arranged through the principal investigators of the NLMS sponsoring agencies. Research topics of interest should fall within the general health interests of the agency. Principal investigators sponsor research through a quick-turn-around approval process established by the NLMS Steering Committee. The committee determines the priority of all NLMS research. Committee approved projects are assigned to an NLMS statistician who works directly with the researcher as a statistical consultant and as the interface to the NLMS database. Results are delivered to researchers on a, short-turnaround, flow basis through the most convenient means available in either electronic or hard copy format.
Researchers may also be interested in gaining access to a file containing the same information as the NLMS public-use file but which also includes geographical information. This file is available through the Census Bureau's Research Data Centers. For complete information on the use of the Census Bureau's Research Data Centers go to the Center for Economic Studies Census Bureau’s website: www.ces.census.gov
A researcher may work directly with an NLMS statistician on-site at the Census Bureau by becoming a Special Sworn Census Bureau employee. A person interested in this option must first gain research sponsorship of a project through an NLMS sponsoring agency according to the NLMS Steering Committee approval process and then apply for Special Sworn status through Norm Johnson, Census Bureau NLMS Principal Investigator, see list of Principal Investigators below.
NLMS Bibliography:
A current, bibliography and annotated bibliography of all publications emanating from the NLMS is a selection option on this website.
NLMS Steering Committee Members:
| Paul Sorlie, Steering Committee Chair, National Heart, Lung, and Blood Institute |
Elizabeth Hamilton, National Institute on Aging |
Barry Miller, National Cancer Institute |
| Norman J. Johnson, U.S. Census Bureau |
Sean Coady, National Heart, Lung, and Blood Institute |
Elizabeth Arias, National Center for Health Statistics |
NLMS Principal Researchers Contact Information:
| U.S. Census Bureau: Principal Investigator: Norman J. Johnson U.S. Census Bureau 4700 Silver Hill Road DID Rm. 6H023 Suitland, MD 20746 Ph: (301) 763-4270 FAX: (301) 763-4310 email: norman.j.johnson@census.gov |
National Institute on Aging: Principal Investigator: Elizabeth Hamilton, Demographic and Population Epidemiology Behavioral and Social Research Program National Institute on Aging, NIH 7201 Wisconsin Avenue, Suite 533 Bethesda, MD 20892 Ph: (301) 402-4582 FAX: (301) 402-0051 email: hamiltone@mail.nih.gov |
National Cancer Institute: Principal Investigator: Barry Miller National Cancer Institute Surveillance Research Program Suite 504, MSC 8316 6116 Executive Boulevard Bethesda, MD 20892-8316 (Normal mail) or [Rockville, MD 20852 (Overnight mail)] Ph: (301) 402-4248 FAX (301) 496-9949 email: millerb@mail.nih.gov |
| National Heart, Lung, and Blood Institute: Principal Investigator: Sean Coady Epidemiology and Biometry Program II Rockledge Center, MSC 7934, Room 8176 6701 Rockledge Drive Bethesda, MD 20892 Phone: (301) 435-1289 FAX: (301) 480-1455 email: coadys@nhlbi.nih.gov |
National Center for Health Statistics: Principal Investigator: Elizabeth Arias Division of Vital Statistics National Center for Health Statistics Centers for Disease Control and Prevention Room 7330 3311 Toledo Road Hyattsville, MD 20782 Phone: (301) 458-4727 FAX: (301) 458-4034 email: efa3@cdc.gov |
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NLMS Key Census Bureau Staff:
Norman J. Johnson, Ph.D. Statistics 1974. Yale University.
Mathematical Statistician, U.S. Census Bureau
Principal Investigator to NLMS
24 years experience as major developer, statistician, database coordinator for the NLMS.
Areas of expertise: database coordinator, bio-statistical analysis, data analysis, survival analysis
Charles Lin, Ph.D. Statistics 1978. Iowa State University.
Mathematical Statistician, U.S. Census Bureau
5 years of experience as statistical analyst and consultant to the NLMS.
15 years of experience as developer of survival analysis software for the SAS Institute.
Areas of expertise: statistical analysis, survival analysis, SAS programming.
William S. Schauman, MS Mathematics 1978. York University.
IT Specialist, U.S. Census Bureau
4 years of experience as statistical programmer and database coordinator for the NLMS.
15 prior years of experience as a SAS programmer for private contracting company.
Areas of expertise: SAS programming, database coordinator
Kimber Reeves
1 year of experience as administrative coordinator for the NLMS and liaison to certificate
processing at the U.S. Census Bureau National Processing Center.
John L. Boies, Ph.D., Sociology, 1991, University of Michigan, Ann Arbor
Mathematical Statistician, U.S. Census Bureau
New appointment to the NLMS as a statistical programmer and consultant to the NLMS.
7 years as Mathematical Statistician for the Survey of Income Program Participation
24 years as a statistical consultant, analyst, and university faculty member
Areas of expertise: time series, sample design, weighting, logistic regression, survival
analysis, variance estimation, SAS programming
