Plan and Operation of the NHANES II Mortality Study

No. 38. Plan and Operation of the NHANES II Mortality Study, 1992. 24 pp. (PHS) 99-1314-1-38. GPO stock number 017-022-01449-1 price forthcoming
View/download PDF 286 KB

The NHANES II Mortality Study (NH2MS) is a prospective cohort study, which passively followed a subset of participants in the Second National Health and Nutrition Examination Survey (NHANES II). NHANES II, conducted between 1976-80, collected data from a national probability sample of the U.S. civilian, noninstitutionalized population aged 6 months to 74 years. The survey included a standardized physical examination, laboratory tests, and questionnaires that covered various health-related topics.

The NH2MS cohort consists of adults who were 30-75 years of age at the time of their NHANES II examination. This cohort is a subset of the approximately 28,000 persons selected to participate in NHANES II. Some participants were interviewed but not examined and only those examined were followed for mortality status. Age at exam was used to identify participants aged 30 years and over for selection into the NH2MS cohort. Therefore, the upper age limit for the NH2MS cohort is 75 years. At baseline, 12,102 adults 30-74 years of age agreed to be interviewed and 9,252 (76 Percent) completed a physical examination.

Mortality status was ascertained by searching two computerized data bases containing information on deaths occurring in the United States. The National Death Index (NDI), compiled by the National Center for Health Statistics (NCHS), contains a standard set of identifying data for each decedent provided by State vital statistics offices. The Social Security Administration’s (SSA) Death Master File contains information on all U.S. decedents whose beneficiaries received death benefits from the SSA. The Death Master File pools data from a variety of SSA files, including the SSA Master Beneficiary Record that contains a record for each person entitled to receive retirement or survivor’s benefits and disability insurance.

The NDI was searched for deaths occurring between 1979-1992. At the time the NH2MS data were collected, 1992 was the latest year for which cause of death data were available. Social Security numbers were not collected during NHANES II, therefore, potential matches with the NDI were initially identified using name, data of birth, and sex according to the standard NDI matching process.

The survival probabilities for the NH2MS cohort were larger than for the U.S. population in each of the four race-sex groups. Differences between probabilities for the NH2MS cohort and the U.S. were most similar among white males and females. In both groups, the largest differences after 5 years were observed in the oldest age group but after 10 years, groups with the largest differences expanded to include 65-69 year-olds and 60-64 year-old females. The largest discrepancies between NH2MS and U.S. survival patterns were found among blacks. Compared with whites, differences between survival probabilities after 5 years of follow-up were consistently larger in all age groups, and much larger among black males 70-75 years of age.

This page last reviewed January 11, 2007