Overview of the NLTCS
The NLTCS has completed six waves, nominally at five-year intervals, 1982, 1984, 1989, 1994, 1999, and 2004. The NLTCS is a nationally-representative sample both of the community and of institutional populations and is longitudinal in that sample persons age in once they reach 65 years of age and stay in the survey until they either die or are lost to follow-up. At each wave, a screener questionnaire is administered to the sample which divides the sample into three parts: the non-disabled (frequently called screen-outs), the disabled but living in the community, and the disabled living in an institution. About 5,000 people die between waves and are replaced by a sample of about that size of people who have become age 65 since the prior wave. Because of budget considerations it usually has not been possible to continue the entire non-disabled sample into the next wave. Instead a sample of the non-disabled is drawn to keep the total sample size for a wave at about 20,000. The sampling fraction for prior non-disabled participants has been frequently adjusted to compensate for low representation in some survey components, in particular the 75+ component, and the sample has been supplemented to increase the size of the 95+ component.
The NLTCS is a very data-rich resource with many components, including disability measures, medical conditions, attained education levels, and income. Numerous papers have used it as a source of data addressing a wide variety of topics related to aging and disability. The NLTCS website currently categorizes the varied types of publications under the headings of Active Life Expectancy, Activities of Daily Living, Aging, Assistive Devices, Caregiver Income, Cognitive Functioning, Disability Trends, Disease, Ethnicity, Family Support, Gender, Institutionalization, Instrumental Activities of Daily Living, Insurance, Mathematical Modeling, Medical Providers, Medicare and Medicaid, Military Service, Mortality, Paid Caregiver, and Unpaid Caregiver.
NLTCS data have been used by researchers to examine health and behavioral factors associated with changes in chronic disability and mortality.
Ancillary surveys have been added to measure other characteristics of the 65 and older population, to include a Caregiver Survey to acquire data on informal caregivers themselves (done in 1982, 1989, 1999, and 2004) and Next-of-Kin (NOK) surveys administered to the survivors of sample persons who had died between 1982 and 1984 and again between 1994 and 1999.
In 1999, physical specimens (blood and buccal) were drawn from a sample of persons who responded to the survey. Because of increased emphasis on privacy and the harm that could potentially result from inadvertent identity disclosure for genetic data, data release procedures have been developed for physical specimen data. Rules have also been developed for releasing samples of the physical specimen itself. These will be made public in the near future and will be announced on the NLTCS website.
A complete Medicare billing record is available for each sample person that can be associated to the survey record through an anonymous linking identifier.
Several organizations are (or have been) participants in the NLTCS. Centers for Medicare and Medicaid Services (formerly Health Care Financing Administration) conducted the 1982 and 1984 waves of the survey. NLTCS data collection is done by the U.S. Bureau of the Census. The Next-of-Kin surveys are conducted by the Research Triangle Institute (RTI) with funding provided by Office of the Assistant Secretary for Planning and Evaluation (ASPE).