Nonresponse was slightly higher in the Northeast (32%) compared with the West (25%), Midwest (21%), and South (24%), and the poststratification sampling weights adjusted for this differential nonresponse. An additional 7.89% of Wave III respondents refused to provide a urine specimen. 43 We performed sensitivity analyses to assess the total effect of nonresponse combined with imperfect sensitivity and specificity of the PCR assay (Table 3 ). If non-response was random, a modest drop in specificity (specificity = 0.995) would lead to a sizeable reduction in prevalence (corrected PR = 0.6%; 95% CI = 0, 1.07). When specificity was set at 0.99 or higher, prevalence among all subgroups, except Blacks, was 0% (data not shown). Читать далее →