Table 5 Demographics of recruits by recruitment method among CHILD study participants

Maternal characteristics

Mean age (SD)

31.0 (4.3)

31.2 (4.3)

33.3 (5.5)

30.8 (4.7)

30.3 (4.9)

32.4 (5.0)

n = 267

n = 90

n = 12

n = 387

n = 26

n = 14

Above 24 weeks GA

47.43%

54.95%

68.75%

54.64%*

26.92%*

35.29%*

(129/272)

(50/91)

(11/16)

(212/388)

(7/26)

(6/17)

Mother Caucasian

85.90%

85.14%

90.00%

78.18%*

82.35%

88.24%

(195/227)

(63/74)

(9/10)

(240/307)

(14/17)

(15/17)

Mother attended post-secondary

92.63%

91.78%

90.00%

89.78%

94.44%

82.35%

(176/190)

(67/73)

(9/10)

(281/313)

(17/18)

(14/17)

Mother has or had asthma

20.26%

22.97%

30.0%

23.45%

23.53%

47.06%*

(46/227)

(17/74)

(3/10)

(72/307)

(4/17)

(8/17)

Mother smokes daily or occasionally

6.84%

1.35%

0.00%

4.23%

17.65%

5.88%

(13/190)

(1/74)

(0/10)

(13/307)

(3/17)

(1/17)

Paternal characteristics

Father born in Canada

89.23%

74.19%*

100.00%

79.75%*

88.89%

80.00%

(116/130)

(23/31)

(6/6)

(126/158)

(8/9)

(8/10)

Father attended post-secondary

86.26%

90.32%

100.00%

78.48%

88.89%

90.00%

(113/131)

(28/31)

(6/6)

(124/158)

(8/9)

(9/10)

Father has or had asthma

26.92%

25.81%

33.33%

20.89%

22.22%

10.00%

(35/130)

(8/31)

(2/6)

(33/158)

(2/9)

(1/10)

Family characteristic

Family income ≥ $40,000

95.73%

95.65%

90.00%

88.77%*

94.44%

93.33%

(202/211)

(66/69)

(9/10)

(253/285)

(17/18)

(14/15)

Married/common law

97.70%

92.31%*

100.00%

93.39%*

88.00%*

88.24%

(255/261)

(84/91)

(16/16)

(353/378)

(22/25)

(15/17)