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Table 1 Questionnaire response rates by early life factors

From: Early life factors, childhood cognition and postal questionnaire response rate in middle age: the Aberdeen Children of the 1950sstudy

 

Male

Female

 

Number

Response rate (%)

Odds ratio

(95% CI)

Number

Response rate (%)

Odds ratio

(95% CI)

Sex

        

Male

5,742

59.8

1.00

     

Female

5,540

67.7

1.41

(1.31 to 1.52)

    

Birth weight (lbs)

        

<6.5

1,118

58.7

1.00

 

1,451

65.0

1.00*

 

6.5–7.5

1,874

588

1.00

(0.86 to 1.17)

2,061

68.3

1.16

(1.01 to 1.34)

7.5–8.5

1,809

60.7

1.09

(0.93 to 1.27)

1,480

69.6

1.23

(1.06 to 1.44)

≥8.5

929

61.0

1.10

(0.92 to 1.32)

539

68.3

1.16

(0.94 to 1.43)

Missing†

12

83.3

  

9

22.2

  

Mother's marital status at birth

        

Single/widowed/divorced

175

52.0

1.00

 

190

50.5

1.00

 

Married

5,564

60.0

1.39

(1.02 to 1.87)

5,349

68.3

2.11

(1.58 to 2.83)

Missing†

3

66.7

  

1

0.0

  

Father's social class at birth

        

Unemployed/disabled/deceased

297

52.9

1.00*

 

336

56.9

1.00*

 

IV/V

1,765

55.9

1.13

(0.88 to 1.45)

1,633

63.4

1.32

(1.04 to 1.67)

III Manual

2,486

59.7

1.32

(1.04 to 1.68)

2,442

68.4

1.64

(1.30 to 2.07)

III Non-manual

633

65.9

1.72

(1.30 to 2.29)

613

73.9

2.15

(1.62 to 2.86)

I/II

561

69.2

2.00

(1.49 to 2.68)

515

77.9

2.67

(1.96 to 3.63)

Missing†

0

   

1

0.0

  

Father's social class in 1962

        

Unemployed/disabled/deceased

341

46.6

1.00*

 

357

53.5

1.00*

 

IV/V

1,424

55.4

1.42

(1.12 to 1.80)

1,419

64.3

1.57

(1.24 to 1.98)

III Manual

2,419

60.0

1.72

(1.36 to 2.16)

2,291

68.0

1.84

(1.47 to 2.31)

III Non-manual

701

67.3

2.36

(1.80 to 3.09)

630

73.2

2.37

(1.79 to 3.13)

I/II

776

67.8

2.41

(1.85 to 3.14)

781

76.6

2.84

(2.16 to 3.73)

Missing

81

43.2

0.87

(0.54 to 1.42)

62

50.0

0.87

(0.51 to 1.48)

Number of siblings in 1962

        

5 or more

1,041

50.4

1.00*

 

946

59.2

1.00*

 

4

938

57.7

1.34

(1.12 to 1.60)

942

65.2

1.29

(1.07 to 1.56)

3

1,424

61.5

1.57

(1.34 to 1.85)

1,420

70.9

1.67

(1.41 to 1.99)

2

1,749

64.2

1.76

(1.50 to 2.06)

1,677

71.3

1.71

(1.45 to 2.03)

1

545

64.6

1.79

(1.45 to 2.22)

510

68.8

1.52

(1.21 to 1.91)

Missing

45

35.6

0.54

(0.29 to 1.00)

45

53.3

0.79

(0.44 to 1.42)

Height for age at 1st medical exam 1962

≤-1

734

54.4

1.00*

 

872

62.3

1.00*

 

-1 to 0

1,882

57.1

1.12

(0.94 to 1.33)

1,969

66.0

1.17

(1.00 to 1.39)

0 to 1

2,139

62.3

1.39

(1.17 to 1.65)

1,775

69.9

1.40

(1.18 to 1.67)

≥1

737

66.9

1.70

(1.37 to 2.10)

723

73.7

1.70

(1.37 to 2.11)

Missing

250

52.8

0.94

(0.70 to 1.25)

201

67.7

1.27

(0.92 to 1.75)

Weight for age at 1st medical exam (SD)

≤-1

870

56.7

1.00*

 

795

63.9

1.00*

 

-1 to 0

2,045

59.5

1.12

(0.96 to 1.32)

2,109

65.5

1.07

(0.91 to 1.27)

0 to 1

1,810

59.2

1.11

(0.94 to 1.31)

1,667

70.0

1.32

(1.10 to 1.58)

≥1

767

67.8

1.61

(1.31 to 1.97)

769

72.7

1.50

(1.21 to 1.87)

Missing

250

52.8

0.86

(0.65 to 1.13)

200

67.5

1.17

(0.84 to 1.63)

Rutter B behavioral score

        

9+

595

47.4

1.00*

 

320

57.2

1.00*

 

3–8

1,736

56.2

1.42

(1.18 to 1.72)

1,448

61.5

1.19

(0.93 to 1.53)

1–2

1,517

63.8

1.96

(1.61 to 2.38)

1,637

69.6

1.72

(1.34 to 2.20)

0

1,720

65.7

2.13

(1.75 to 2.58)

1,990

73.3

2.06

(1.61 to 2.63)

Missing

174

44.3

0.88

(0.63 to 1.24)

145

54.5

0.90

(0.60 to 1.33)

  1. * p < 0.05 for the score test for trend (missings were not included).
  2. † We did not calculate odds ratio and 95% confidence interval due to small sample size.
  3. ‡ p < 0.05 for the interaction with sex tested by using likelihood ratio test in logistic regression.