NSHAP uses a national area probability sample of community residing adults born between 1920 and 1947 (aged 57 to 85 at the time of the Wave 1 interview), which includes an oversampling of African-Americans and Hispanics. The NSHAP sample is built on the foundation of the national household screening carried out by the Health and Retirement Study (HRS) in 2004. Through a collaborative agreement, HRS identified households for the NSHAP eligible population. A sample of 4,400 people was selected from the screened households. NSHAP made one selection per household. Ninety-two percent of the persons selected for the NSHAP interview were eligible.
For Wave 2 in 2010 and 2011, NSHAP returned to Wave 1 Respondents and eligible non-interviewed respondents from Wave 1 (Wave 1 Non-Interviewed Respondents). NSHAP also extended the Wave 2 sample to include the cohabiting spouses and romantic partners of Wave 1 Respondents and Wave 1 Non-Interviewed Respondents. Partners were considered to be eligible to participate in NSHAP if they resided in the household with the Wave 1 Respondent/Wave 1 Non-Interviewed Respondent at the time of the Wave 2 interview and were at least 18 years of age.
In Wave 3, in addition to the Wave 2 respondents being re-interviewed, NSHAP will approach Wave 1 respondents who decided not to participate in Wave 2. Also taking into account the higher than average mortality rate of the NSHAP eligible population, the projected number of interviews for Wave 3 is 2,352.
3,005 completed interviews conducted between July, 2005 and March, 2006.
3,377 completed interviews conducted between August, 2010 and May, 2011, including 2,261 Wave 1 Respondent interviews, 161 Wave 1 Non-Interviewed Respondent interviews, 907 Wave 1 Respondent Partner interviews, and 48 Wave 1 Non-Interviewed Respondent Partner interviews.
Overall weighted response rate of 75.5 percent
Overall weighted response rate of 76.9 percent. By sample type: Wave 1 Respondent weighted response rate of 87.8 percent; Wave 1 Non-Interviewed Respondent weighted response rate of 23.1 percent; Wave 1 Respondent Partner weighted response rate of 85.8 percent; Wave 1 Non-Interviewed Respondent Partner weighted response rate of 63.9 percent.
Data Collection Method
NSHAP data collection for both waves consists of three distinct components:
- In-person questionnaire
- Biomeasure collection
- Supplemental self-administered questionnaire (SAQ)
In addition, Wave 2 included a supplemental proxy questionnaire for Wave 1 Respondents who were either deceased or whose health was too poor to participate in Wave 2. The same will be true for Wave 3.
The in-person questionnaire and biomeasures were administered by a NORC field interviewer in the respondent’s home. Questionnaire topics included: 1) demographic characteristics; 2) social networks and social network change; 3) social and cultural activity; 4) physical and mental health including cognition; 5) well-being; 6) illness; 7) healthcare utilization and medications; and 8) history of sexual and intimate partnerships. Given the longitudinal goals of NSHAP, most of the Wave 2 in-person questionnaire remained relatively unchanged from the Wave 1 instrument.
NSHAP continues to collect important health information via biomeasures. All biomeasures included in NSHAP were specifically designed to be implemented by non-medically trained interviewers. The data collection protocols were minimally invasive and safe for both interviewer and respondent. A summary of the biomeasures collected in both waves of NSHAP appears in the table linked below. In-depth information on biomeasure collection changes for Wave 2 will be found in the NSHAP Wave 2 Measurement Booklet.
For a Summary of the Biomeasure Collection and Physical Assessment across Waves, click here
As a new addition to Wave 2, select respondents were asked to participate in a multi-modal, at-home self-administered biomeasure collection called Actigraphy. Actigraphy is a minimally-invasive method used to measure sleep and activity cycles.
Supplemental Self-Administered Questionnaire
At the end of the in-person interview, respondents were given a supplemental paper-and-pencil questionnaire. Respondents were asked to complete this questionnaire and return it via U.S. mail in a provided postage-paid envelope. Approximately 84 percent of respondents in Wave 1 and approximately 87 percent of respondents in Wave 2 returned the supplemental questionnaire.
Since mortality and incapacity are themselves important health outcomes, NSHAP employed a short proxy questionnaire in Wave 2 to collect final health data for Wave 1 Respondents who could not participate in NSHAP due to disability or death. Final health data was collected on 566 Wave 1 Respondents using the Proxy interview, and in Wave 3, final health data will be collected for Wave 2 Respondents.
Average Length of Interview
The in-person interview was about 120 minutes in length and includes the in-person questionnaire and biomeasures. The supplemental SAQ took approximately 30 minutes or less to complete.
Accessing NSHAP Data
NSHAP is dedicated to maintaining the trust of respondents and is diligent in protecting respondent confidentiality while providing data accessible to the public for research. NSHAP data made available to the public does not contain any identifiable respondent information and uses code numbers instead of names for all data. De-identified data from the Wave 1 and Wave 2 interviews are available to researchers through the National Archive of Computerized Data on Aging, located within Inter-University Consortium for Political and Social Research (ICPSR). Learn more about obtaining NSHAP data at ICPSR
. View available data elements and read more about the study here
NSHAP is supported by the National Institutes of Health (R01-AG021487), (R37-AG030481), and (R01-AG033903) including:
- National Institute on Aging
- Office of Research on Women's Health
- Office of AIDS Research
Additional financial support was provided by NORC.