Table 1.

Characteristics of pedigrees to map susceptibility loci for smoking rate.

Category	Mean ± SEM (Range)	Sample SizeA
No. of subjects per pedigree	8.25 ± 0.31 (3–53)	313
No. of smokers per pedigree	3.92 ± 0.16 (1–25)	313
Age of subjects	43.76 ± .34 (9–83)	2583
Male subjects	42.92 ± 0.49 (11–82)	1242
Female subjects	44.54 ± 0.46 (9–83)	1341
Age of smokers	39.23 ± 0.39 (13–80)	1228
Male smokers	38.73 ± 0.54 (15–79)	614
Female smokers	39.73 ± 0.56 (13–80)	614
Self-reported cigarettes per day, 1970–1971	20.73 ± 0.35 (1–90)	1228
Male smokers	23.51 ± 0.53 (1–90)	614
Female smokers	17.95 ± 0.43 (1–60)	614

^AThe unit of measurement is number of pedigrees for the first two and number of individual subjects for all other rows.