Errata: SF-8 Variables on Files Accessed Before January 2017
We incorrectly calculated the SF-8 mental component summary (MCS) and physical component summary (PCS) scores provided in the original National Beneficiary Survey (NBS) data files. The original values excluded an intercept constant needed to scale the scores to general population norms. The intercept constant values are -10.11675 for the MCS and -9.36839 for the PCS.
Because we did not apply the intercept constants, the scores provided in the original data files were too high relative to what they should be on the population-based scale. Thus, if comparing NBS respondents to the general population, NBS respondents would appear healthier than they should. However, within the NBS respondent sample, the scores still appropriately represented greater or lesser mental and physical health according to the design of the SF-8.
We have corrected the MCS and PCS variables included in the current data files so they are now valid for comparisons to other populations.
National Beneficiary Survey (NBS) Round Two
In 2005, we fielded the round-two NBS to four sub-samples: (1) the second national cross-sectional survey of all beneficiaries (the Representative Beneficiary Sample), (2) the second cross-sectional survey of Ticket participants in the Phase 1 States, (3) the first cross-sectional survey of Ticket participants in the Phase 2 States, and (4) the first longitudinal follow-up survey of Ticket participants who were first interviewed in round one (combined, these last three sub-samples make up the round two Ticket Participant Sample).
For round two, we completed interviews with 4,864 individuals in the national sample of beneficiaries and 3,091 from the Phase 1 and Phase 2 cross-sectional Ticket Participant cohorts, for a total of 7,955 interviews completed across all sub-samples. The weighted response rate for the Representative Beneficiary Sample was 78.7 percent. The weighted response rate for the Ticket Participant Cross-Sectional Sample was 80.4 percent. In round two, we also completed interviews with 1,019 longitudinal cases (70 percent of the total sample) for an overall weighted response rate of 78.2 percent. Of the Phase 1 longitudinal cases, 897 (61 percent of the total sample) completed a round 1 and a round 2 interview.
We are providing the following NBS documentation in PDF format (these documents relate to the full restricted use version of the NBS data, but most of the information in these files is applicable to the public use files as well):
The public use files are only available for the Representative Beneficiary Samples for each round. The Ticket Participant Samples are not available for public use. For more information on the public use files, visit the public use files page.
We are providing the following NBS documentation in PDF format:
NBS R2 PUF Codebook.pdf