. Author manuscript; available in PMC: 2015 May 1.

Published in final edited form as: J Allergy Clin Immunol. 2014 Mar 14;133(5):1484–1487.e5. doi: 10.1016/j.jaci.2014.01.028

Table 1.

Demographic characteristics of NHEFS participants at Baseline (1971-74).

	Full Cohort n=l3,042	Sub-cohort n=5,132
Age 25-34, % 35-44, % 45-54, % 55-64, % 65-75,%	26.6 21.7 16.1 12.1 23.3	25.9 19.3 23.6 17.4 13.6
Race White, % African American, % Other, %	83.6 15.2 1.2	89.2 10.8 --
Sex Male, % Female, %	39.6 60.4	45.3 54.7
Education <10^th grade/ special school, % 11^th - 12^th grade, % college/graduate, % Missing, %	37.3 38.5 23.5 0.6	30.7 41.8 27.2 0.2
Income (annual) <$5,000, % $5,000-<$10,000, % ≥$10,000-<$l 5,000, % ≥$15,000 Missing, %	25.5 29.3 20.9 20.4 3.7	18.9 26.424.0 27.1 3.5
Smoking Status^* Never, % Ever, % Current, % Former, % Missing, %	38.2 46.4 -- -- 15.4	38.0 -- 19.6 42.2 0.01
Pack years category^* 0,% <30, % 30-60, % >60, % Missing, %	n/a	41.4 31.5 15.6 7.5 3.9

The full cohort includes all NHEFS who met inclusion/exclusion criteria. The sub-cohort includes all NHEFS participants who had additional spirometry performed and further information obtained on smoking history. For the full cohort, smoking status (never/ever) was obtained at the 1982-1984 survey. For the sub-cohort, smoking status (never/ever/current) and pack years smoked were obtained at baseline. A smoking history was not obtained on all subjects at baseline. Please see Appendix for methods and variable definitions.