Table 1.

Response rates by age and gender for the NFAS-4 and the NFAS-5 (N = 3325)

	NFAS-4		NFAS-5
	N (%)	Response rate %	N (%)	Response rate %
Females	905 (55.9)	60.0	919 (53.9)	58.8
Males	715 (44.1)	48.0	786 (46.1)	50.8
All	1620	54.0	1705	54.8
Age:
24–26	150 (9.3)	33.3	169 (9.9)	37.6
34–36	429 (26.5)	49.9	521 (30.6)	53.7
44–46	301 (18.6)	54.2	301 (17.7)	54.2
54–56	358 (22.1)	68.4	327 (19.2)	62.5
64–66	219 (13.5)	66.2	239 (14.0)	72.2
74–76	132 (8.1)	66.8	120 (7.0)	60.8
84–86	31 (1.9)	37.8	28 (1.6)	34.1