The first followup interview conducted with LSOA II sample persons is also known as the LSOA II Wave 2 interview. The basic design of the LSOA II Wave 2 consisted of tracing sample persons to a current address and conducting interviews with the subjects or their proxies. The data collection contractor for the Wave 2 interview was the National Opinion Research Center (NORC) at the University of Chicago. This second interview was scheduled to occur roughly 2 years after the baseline SOA II interview. This interval was chosen in order to replicate the analytic intervals in the original LSOA and to provide similar 2-year transition rates for measures of health and health care utilization. Data collection for Wave 2 took place between May 12, 1997, and May 31, 1998. The majority of interviews, however, were conducted between May 1997 and February 1998, with followup activities occurring between March and May 1998.
Unlike the baseline SOA II interview, which was conducted in person, the followup wave was conducted primarily by telephone using a Computer-Assisted Telephone Interview (CATI) system. In addition, the followup interview questionnaires included CATI and self-administered questionnaire (SAQ) versions, surviving and deceased sample person versions, community dwelling and institutionalized skip patterns, and Spanish language translations. In some cases, an SAQ instrument was administered over the telephone as a last resort to respondents who, because of the length of the CATI interview, would have otherwise refused to participate at Wave 2.
Two questionnaire versions were developed to accommodate five different types of respondents: the Survivor version and the Decedent version. Responses to questions at the beginning of the CATI instrument automatically routed the interviewer to the appropriate questionnaire version and skip patterns for the respondent type.
Sample persons living in the community were defined as those persons who lived alone, with family or friends, in retirement homes, supervised apartments or assisted living facilities and did not reside in a nursing home or a convalescent or rest home. Sample persons living in the community completed their own interviews.
Sample persons who were institutionalized were defined as those persons who lived in a nursing home or a convalescent or rest home and did not return home in the interview window. Retirement homes, supervised apartments, and assisted living facilities were not considered institutions. The question regarding the sample person's type of residence, contained in the screening script of the questionnaire, determined whether the sample person was institutionalized. Sample persons who were institutionalized and capable of responding completed their own interviews.
Sample persons who were institutionalized temporarily and were expected to return home during the data collection period were treated as living in the community and completed their own interviews.
Proxy respondents completed interviews for sample persons who were community dwelling but mentally or physically incapable of completing an interview.
Proxy respondents completed interviews for sample persons when gatekeepers dictated a proxy response.
Proxy respondents completed interviews for sample persons who were institutionalized and not capable of responding for themselves or for sample persons who had no means (e.g., personal telephone in room) by which to participate in the survey.
The LSOA II sample contains 9,447 persons. A total of 8,905 (or 94.6 percent) sample persons were traced and located to a current address at the time of the LSOA II Wave 2 field period. Once located, 7,998 interviews were obtained from a sample person or proxy respondent resulting in a Wave 2 interview rate of 89.8 percent conditional on successful tracing (7,998/8,905).
To calculate the overall Wave 2 response rate we divide the number of completed interviews by the total baseline sample: 7,998/9447 = 84.7 percent. The overall LSOA II response rate as of Wave 2 is 74.0 percent and is calculated as follows:
Overall household response rate from the NHIS Core (94.1 percent) multiplied by the 92.9 percent of the age-eligible persons (age 70 at Phase II) who responded to the SOA II yields an overall SOA II baseline response rate of 87.4 percent. Multiplying this 87.4 percent by the 84.7 percent of SOA II sample persons who completed interview at Wave 2 yields an overall Wave 2 response rate of 74.0 percent.
The LSOA II Wave 2 Survivor data file contains information from several sources, including the 1994 NHIS core questionnaire, the 1994 Family Resources Supplement, Phase I of the 1994 National Health Interview Survey on Disability, the Second Supplement on Aging (baseline interview), and the LSOA II Wave 2 followup interview for living sample persons. Below is an overview of data file variables at a glance:
Two versions of the LSOA II Wave 2 Survivor Interview File have been released to date.
- an ASCII version of the LSOA II Wave 2 Survivor Data File (records=9,447; vars=2,146; lrecl=3,660; approximately 34 mb),
- an ASCII file containing a SAS read-in program with input, label, value, and length statements,
- a PDF version of the codebook containing an overview of the survey design, methodology, and content, as well as data file specifications and variable frequencies, and the
- PDF versions of the questionnaires used in the Wave 2 Survivor Interview (both CATI and Self-Administered Questionnaire versions), as well as the baseline SOAII questionnaire.
- Version SF 1.2 is an ASCII version released on CD-ROM to the public in June 2002. To request a copy, e-mail nchsquery@cdc.gov or telephone 301-458-INFO.
To date, no detailed description of the LSOA II
has been published, however all LSOA II codebooks contain comprehensive
overviews of the sample design and survey methodology. These codebooks
and the survey instruments can be accessed from the file-specific sites
listed above.
National Center for Health
Statistics
3311 Toledo Road
Hyattsville, MD 20782
Phone:
1-800-232-4636
nchsquery@cdc.gov
Centers for Disease Control and Prevention, 1600 Clifton Rd, Atlanta, GA 30333, U.S.A
Tel: (404) 639-3311 / Public Inquiries: (404) 639-3534 / (800) 311-3435