National Longitudinal Mortality Study (NLMS)

The NLMS is a unique research database in that it is based on a random sample of the noninstitutionalized population of the United States. It consists of U.S. Census Bureau data from Current Population Surveys (CPS) and a subset of the 1980 Census combined with death certificate information to identify mortality status and cause of death.

• Administrative records

• Last year/last 12 months

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 follow up. 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.

The NLMS Database consists of the NLMS Analysis File and supplemental files. Supplemental files include Medicare and Medicaid data, SEER information for selected records, Decennial Census information at the tract and county level and characteristics of the area near the respondent's location at the time of the survey (e.g. distance to nearby hospitals, parks, etc.). The NLMS Analysis File is the core file for analysis purposes. This file contains Current Population Survey (CPS) responses for selected survey samples from 1973 to 2011 with mortality follow up information from 1979 through 2011 for each respondent. Mortality information is obtained from death certificates available for deceased persons through the National Center for Health Statistics.

An important variable on this file is the state of residence at the time of survey. The inclusion of this variable in the file is permitted as long as the area represented by the intersection of the geographical variables on the file did not contain less than 100,000 persons of the U.S. population, a Census Bureau requirement that protects the confidentiality of CPS participants. In order to meet this requirement, the intersection of the three geographic variables on this public-use file—state of residence, urban/rural status, and SMSA status—was examined to identify areas of sparse population. For those areas not meeting the 100,000-population minimum requirement, the levels of urban/rural or SMSA status were adjusted in a manner to have the least misleading impact on the geographical definition. No change in the defined state of residence was made in this adjustment process.

The NLMS Analysis File is derived from multiple data sources including survey and administrative records data.