Robustness of NHANES Estimates of the US Prevalence of a Positive Tuberculin Skin Test.

BACKGROUND: A single 2-year National Health and Nutrition Examination Survey (NHANES) cycle is designed to provide accurate and stable estimates of conditions with prevalence of at least 10%. Recent NHANES-based estimates of a tuberculin skin test (TST) ≥10 mm in the noninstitutionalized US civilian population are at most 6.3%. METHODS: NHANES included a TST in 1971-1972, 1999-2000, and 2011-2012. We examined the robustness of NHANES-based estimates of the US population prevalence of a skin test ≥10 mm with a bias analysis that considered the influence of non-US birth distributions and within-household skin test results, reclassified borderline-positive results, and adjusted for TST item nonresponse. RESULTS: The weighted non-US birth distribution among NHANES participants was similar to that in the overall US population; further adjustment was unnecessary. We found no evidence of bias due to sampling multiple participants per household. Prevalence estimates changed 0.3% with reclassification of borderline-positive TST results and 0.2%-0.3% with adjustment for item nonresponse. CONCLUSIONS: For estimating the national prevalence of a TST ≥10 mm during these three survey cycles, a conventional NHANES analysis using the standard participant weights and masked design parameters that are provided in the public-use datasets appears robust. See video abstract at, http://links.lww.com/EDE/B636.