Table 4.

Relationship of SEP index to age at Tanner B2 by race/ethnicity in 1,059 girls ages 6–8 years of age at entry to study with adjustment for BMI%, BCERP

White n = 371Hispanic n = 321Black n = 315Asian n = 52
TR (95% CI)TR (95% CI)TR (95% CI)TR (95% CI)
SEP indexa
 Quintile 1 (low)0.91 (0.77–1.07)0.93 (0.87–1.00)0.98 (0.91–1.06)0.84 (0.71–1.01)
 Quintile 20.93 (0.88–1.00)0.92 (0.85–0.99)0.99 (0.91–1.06)1.22 (0.95–1.58)
 Quintile 30.97 (0.93–1.00)1.00 (0.92–1.08)0.95 (0.88–1.03)0.93 (0.85–1.02)
 Quintile 40.97 (0.94–1.00)1.04 (0.96–1.14)0.95 (0.88–1.03)1.05 (0.96–1.15)
 Quintile 5 (ref)1.001.001.001.00
BMI%
 ≥850.92 (0.89–0.95)0.90 (0.87–0.93)0.84 (0.81–0.88)0.94 (0.83–1.06)
 50–850.94 (0.91–0.97)0.97 (0.93–1.01)0.92 (0.89–0.96)1.06 (0.96–1.14)
 <50 (ref)1.001.001.001.00
  • NOTE: Median at referent levels of all variables in the model = 10.25 (95% CI, 9.97–10.54). Race/ethnicity–BMI% interaction: P < 0.001; race/ethnicity–SEP interaction: P < 0.0001. SEP trend: white: P = 0.007; Hispanic: P < 0.0001; black: P = 0.33; Asian: P = 0.51.

  • Abbreviations: B2, breast stage 2; ref, referent.

  • aSEP index – Household income, mother's education, own/rent home.