Table 2.

The association between childhood cognitive ability and long-term sickness absence in three British birth cohorts

	Model 1: unadjusted		Model 2: adjusted for sex, paternal social class		Model 2 + adult social class		Model 2 + educational attainment		Model 2 + depression		Adjusted for all covariables
	OR (95% CI)	p Value	OR (95% CI)	p Value	OR (95% CI)	p Value	OR (95% CI)	p Value	OR (95% CI)	p Value	OR (95% CI)	p Value
1946 cohort
Cognition	0.66 (0.53 to 0.82)	<0.001	0.70 (0.56 to 0.86)	0.001	0.78 (0.63 to 0.98)	0.04	0.80 (0.63 to 1.02)	0.07	0.69 (0.56 to 0.86)	0.001	0.84 (0.66 to 1.07)	0.15
Quartile 1 (least able)	1		1		1		1		1		1
Quartile 2	0.77 (0.46 to 1.29)	0.32	0.84 (0.50 to 1.42)	0.52	0.98 (0.57 to 1.67)	0.93	0.95 (0.56 to 1.61)	0.84	0.84 (0.50 to 1.41)	0.51	1.02 (0.60 to 1.74)	0.94
Quartile 3	0.49 (0.27 to 0.88)	0.02	0.54 (0.30 to 0.96)	0.04	0.65 (0.36 to 1.19)	0.17	0.67 (0.36 to 1.24)	0.21	0.52 (0.29 to 0.95)	0.03	0.71 (0.38 to 1.33)	0.29
Quartile 4 (most able)	0.26 (0.11 to 0.58)	0.001	0.31 (0.13 to 0.70)	0.005	0.44 (0.18 to 1.05)	0.06	0.45 (0.18 to 1.11)	0.09	0.30 (0.13 to 0.69)	0.005	0.53 (0.21 to 1.33)	0.17
1958 cohort
Cognition	0.68 (0.60 to 0.76)	<0.001	0.69 (0.61 to 0.77)	<0.001	0.69 (0.61 to 0.78)	<0.001	0.77 (0.67 to 0.90)	0.001	0.72 (0.64 to 0.81)	<0.001	0.79 (0.68 to 0.92)	0.002
Quartile 1 (least able)	1		1		1		1		1		1
Quartile 2	0.67 (0.51 to 0.88)	0.004	0.68 (0.52 to 0.89)	0.005	0.68 (0.52 to 0.90)	0.006	0.78 (0.59 to 1.03)	0.09	0.72 (0.54 to 0.94)	0.02	0.81 (0.61 to 1.07)	0.13
Quartile 3	0.43 (0.31 to 0.59)	<0.001	0.44 (0.32 to 0.61)	<0.001	0.45 (0.33 to 0.62)	<0.001	0.56 (0.40 to 0.79)	0.001	0.49 (0.35 to 0.68)	<0.001	0.60 (0.42 to 0.84)	0.003
Quartile 4 (most able)	0.32 (0.22 to 0.48)	<0.001	0.35 (0.24 to 0.52)	<0.001	0.36 (0.24 to 0.54)	<0.001	0.49 (0.30 to 0.81)	0.005	0.39 (0.26 to 0.59)	<0.001	0.53 (0.32 to 0.86)	0.01
1970 cohort
Cognition	0.78 (0.64 to 0.94)	0.01	0.80 (0.66 to 0.97)	0.03	0.84 (0.69 to 1.03)	0.1	0.85 (0.70 to 1.02)	0.08	0.80 (0.66 to 0.98)	0.03	0.87 (0.72 to 1.05)	0.15
Quartile 1 (least able	1		1		1		1		1		1
Quartile 2	0.94 (0.48 to 1.82)	0.85	0.97 (0.50 to 1.88)	0.93	1.03 (0.52 to 2.03)	0.93	1.0 (0.51 to 1.94)	0.99	0.97 (0.50 to 1.87)	0.92	1.03 (0.52 to 2.02)	0.93
Quartile 3	0.71 (0.44 to 1.15)	0.17	0.74 (0.46 to 1.21)	0.24	0.82 (0.50 to 1.34)	0.43	0.80 (0.50 to 1.29)	0.37	0.75 (0.46 to 1.22)	0.24	0.82 (0.50 to 1.34)	0.43
Quartile 4 (most able)	0.44 (0.21 to 0.90)	0.03	0.48 (0.24 to 0.98)	0.04	0.56 (0.26 to 1.19)	0.13	0.57 (0.28 to 1.12)	0.10	0.48 (0.24 to 0.98)	0.04	0.56 (0.26 to 1.19)	0.13