Table 3.

Relationship of SEP index to age at Tanner breast stage B2 and Tanner stage PH2 adjusted for BMI%, race/ethnicity, and BMI%-race/ethnicity interaction in 1,059 girls ages 6–8 years of age at baseline, BCERP

Age at B2 (n = 1,059)Age at PH2 (n = 1,054)
VariableTR (95% CI)TR (95% CI)
SEP index
 Mediana10.19 (9.92–10.46)10.87 (10.58–11.18)
 Quintile 1 (lowest)0.94 (0.91–0.97)1.00 (0.97–1.04)
 Quintile 20.95 (0.92–0.98)0.96 (0.93–1.00)
 Quintile 30.96 (0.94–0.99)0.97 (0.94–1.00)
 Quintile 40.98 (0.96–1.01)0.98 (0.95–1.01)
 Quintile 5 (ref)1.001.00
BMI%: White (ref)
 ≥85th0.92 (0.89–0.95)0.94 (0.90–0.97)
 50–85th0.94 (0.91–0.97)0.94 (0.90–0.97)
 <50th (ref)1.001.00
Race/ethnicity
BMI% ≥ 85th:
 Black0.91 (0.87–0.95)0.88 (0.84–0.92)
 Hispanic1.00 (0.96–1.04)0.97 (0.93–1.01)
 Asian0.99 (0.88–1.11)0.99 (0.88–1.12)
 White (ref)1.001.00
BMI% 50–85th:
 Black0.98 (0.94–1.02)0.91 (0.88–0.95)
 Hispanic1.05 (1.01–1.09)0.99 (0.95–1.03)
 Asian1.10 (1.03–1.17)1.11 (1.04–1.19)
 White (ref)1.001.00
BMI% < 50th:
 Black1.00 (0.96–1.04)0.92 (0.89–0.96)
 Hispanic1.02 (0.98–1.06)0.97 (0.93–1.01)
 Asian0.99 (0.94–1.04)1.05 (0.99–1.11)
 White (ref)1.001.00
  • NOTE: Race/ethnicity–BMI% interaction: P < 0.001 (B2), P = 0.31 (PH2). SEP trend: P = 0.0002 (B2); P = 0.8633 (PH2).

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

  • aMedian of referent group for all variables in model.