Table 1

Mean (SD) age of patients at disease onset (in years) in familial male and female RA groups

	Males [n]	Females [n]	p
All	46.6 (13.1) [45]	40.4 (14.3) [119]	0.0044
RF^1-150 positive patients	46.7 (13.2) [44]	39.2 (13.1) [98]	0.0019
RF negative patients	45.0 [1]	46.4 (18.9) [19]	NS
DR4 positive	47.2 (13.1) [31]	39.7 (14.9) [75]	0.0057
DR4 negative	45.5 (13.5) [14]	41.6 (13.3) [44]	NS

↵1-150 RF = rheumatoid factor.