Table 3.

Mean clinical attachment loss, mean difference, and mean ratio^a estimates for selected sociodemographic characteristics in U.S. adults 20 years of age and older: NHANES III (1988–1994) and NHANES 1999–2004

^aMeans (SEs) for CAL for adults 20 years of age and older

^bMean difference and ratio compare NHANES 1999–2004 with NHANES III (1988–1994).

^cSEs for ratios calculated using the delta method from estimates obtained from SUDAAN

^dp<0.01 for t-test assessing the difference between the prevalence of each level of the characteristic and the level assigned as the reference

^ep<0.05 for t-test assessing the difference between the prevalence of each level of the characteristic and the level assigned as the reference

^fLow, medium, and high categories for income were <$14,999, $15,000–$24,999, and ≥$25,000 in NHANES III and <$19,999, $20,000–$44,999, and ≥$45,000 in NHANES 1999–2004, respectively.

NHANES = National Health and Nutrition Examination Survey

CAL = clinical attachment loss

mm = millimeters

SE = standard error

CI = confidence interval

NA = not applicable