Table 3

Risk ratios for asthma-like outcomes in late childhood by income and education at baseline using adjusted multivariate regression (weighted)

ExposureGenR
(Netherlands)
LSAC B
(Australia)
ABIS
(Sweden)
MCS
(UK)
QLSCD
(Quebec)
NLSCY
(Canada)
USNLSY
(USA)
Asthma (ever)
Risk ratio (95% CI)
Maternal education
 HighReferenceReferenceReferenceReferenceReferenceReferenceReference
 Middle1.06 (0.83 to 1.34)1.18 (0.98 to 1.41)1.10 (0.93 to 1.31)1.04 (0.94 to 1.16)1.05 (0.80 to 1.38)1.13 (0.74 to 1.72)0.96 (0.65 to 1.41)
 Low1.52 (1.15 to 1.99)1.38 (1.06 to 1.79)1.18 (0.80 to 1.75)1.20 (1.06 to 1.37)1.11 (0.79 1.57)1.14 (0.70 to 1.87)1.12 (0.65 to 1.91)
Household income
 HighReferenceReferenceReferenceReferenceReferenceReferenceReference
 Middle0.92 (0.68 to 1.23)1.16 (0.94 to 1.43)1.10 (0.90 to 1.34)1.10 (0.97 to 1.25)0.98 (0.73 to 1.31)1.32 (0.86 to 2.03)0.95 (0.58 to 1.55)
 Low1.31 (0.92 to 1.87)1.39 (1.05 to 1.83)1.04 (0.79 to 1.38)1.33 (1.14 to 1.56)1.28 (0.84 to 1.94)1.35 (0.67 to 2.71)1.29 (0.72 to 2.32)
Wheezing or asthma attack (past year)
Risk ratio (95% CI)
Maternal education
 HighReferenceReferenceReferenceReferenceReferenceReferenceReference
 Middle1.61 (1.16 to 2.23)1.17 (0.98 to 1.41)1.08 (0.80 to 1.17)0.96 (0.84 to 1.09)0.79 (0.34 to 1.85)1.12 (0.70 to 1.78)1.11 (0.80 to 1.53)
 Low1.47 (0.94 to 2.29)1.38 (1.06 to 1.80)0.86 (0.52 to 1.42)1.01 (0.86 to 1.19)1.03 (0.46 to 2.30)1.25 (0.69 to 2.26)1.14 (0.72 to 1.81)
Household income
 HighReferenceReferenceReferenceReferenceReferenceReferenceReference
 Middle1.11 (0.71 to 1.76)1.62 (0.94 to 1.43)1.21 (0.96 to 1.52)0.98 (0.85 to 1.15)1.16 (0.50 to 2.70)1.23 (0.78 to 1.94)1.75 (1.09 to 2.83)
 Low1.52 (0.89 to 2.60)1.39 (1.05 to 1.83)0.90 (0.64 to 1.26)1.11 (0.91 to 1.35)1.45 (0.53 to 3.98)1.75 (0.86 to 3.58)1.42 (0.80 to 2.51)
Asthma medication control (past year)*
Risk ratio (95% CI)
Maternal education
 HighReferenceReferenceReferenceReferenceReferenceReference
 Middle1.09 (0.78 to 1.52)N/A0.87 (0.64 to 1.18)0.87 (0.69 to 1.09)0.90 (0.60 to 1.35)1.23 (0.62 to 2.43)0.90 (0.52 to 1.56)
 Low1.46 (0.99 to 2.16)1.00 (0.49 to 2.05)1.13 (0.87 to 1.48)1.05 (0.65 to 1.70)1.21 (0.48 to 3.05)0.89 (0.38 to 2.07)
Household income
 HighReferenceReferenceReferenceReferenceReferenceReference
 Middle0.76 (0.52 to 1.11)N/A1.27 (0.88 to 1.83)1.07 (0.83 to 1.38)0.93 (0.61 to 1.41)2.08 (1.02 to 4.22)1.11 (0.54 to 2.29)
 Low1.16 (0.72 to 1.86)0.94 (0.55 to 1.62)1.30 (0.94 to 1.81)1.23 (0.69 to 2.20)4.33 (1.55 to 12.1)1.14 (0.45 to 2.88)
  • Risk ratios adjusted for child age, child sex, maternal ethnicity, maternal age at birth for all cohorts. Sample sizes may differ from baseline N reported in online supplemental table 2 or table 2 due to missing data for SES exposure in early childhood or asthma in late childhood or cohort attrition.

  • Bold typeface indicates statistical significance at P<0.05.

  • Values for 95% CIs vary slightly versus those in the pooled forest plots due to rounding.

  • *In USNLSY (USA), medication use information was collected regarding last 30 days.

  • ABIS, All Babies in Southeast Sweden; LSAC, Longitudinal Study of Australian Children B-Cohort; MCS, Millennium Cohort Study; N/A, not available; NLSCY, National Longitudinal Survey of Children and Youth; QLSCD, Québec Longitudinal Study of Child Development; SES, socioeconomic status; USNLSY, US National Longitudinal Survey of Youth, Children and Young Adults.