Table 1

Sample characteristics at the first and fifth wave of English Longitudinal Study of Ageing

	Wave 1 (2002) Cohort (based on age in 2002)
	All (N=11 220)		50–54 (1966)		55–59 (2164)		60–64 (1666)		65–69 (1687)		70–74 (1452)		75–79 (1078)		80+ (1207)
	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD
Frailty Index	0.16	0.12	0.12	0.11	0.14	0.11	0.15	0.11	0.16	0.11	0.18	0.11	0.20	0.12	0.24	0.12
Age	65	10	52	1	57	1	62	1	67	1	72	1	77	1	84	4
Female	54%	50	55%	50	53%	50	52%	50	53%	0.50	54%	0.50	54%	50	62%	49
Poorest tertile	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47
Middle wealth tertile	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47
Richest wealth tertile	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47	33%	47

	Wave 5 (2010) Cohort (based on age in 2002)
	All (N=6237)		50–54 (1298)		55–59 (1409)		60–64 (1307)		65–69 (1030)		70–74 (727)		75–79 (451)		80+ (284)
	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD	M/%	SD
Frailty Index	0.18	0.13	0.13	0.11	0.15	0.11	0.17	0.12	0.19	0.12	0.23	0.13	0.27	0.14	0.34	0.16
Age	71	9	61	1	65	2	70	2	75	1	80	1	85	2	91	2
Female	56%	49	56%	50	54%	50	55%	50	56%	50	57%	50	59%	49	68%	46
Poorest tertile	28%	45	30%	46	28%	45	28%	45	27%	45	28%	45	25%	44	24%	43
Middle wealth tertile	34%	47	32%	47	36%	48	34%	47	35%	48	35%	48	34%	47	32%	47
Richest wealth tertile	38%	48	37%	48	36%	48	38%	49	37%	48	37%	48	41%	49	44%	50