Table 2.

Unadjusted associations (TRs and 95% CIs) of SEP index, BMI%, and race/ethnicity to age at first signs of breast development (B2) or pubic hair development (PH2) in 1,235 girls ages 6–8 years at baseline, BCERP

Age at breast stage B2 (n = 1,235)Age at pubic hair stage PH2 (n = 1,230)
Variable(No.) TR (95% CI)(No.) TR (95% CI)
SEP indexa1,0591,054
Median age (y)9.74 (9.54–9.94)10.45 (10.23–10.67)
Quintile 1 (lowest)0.94 (0.91–0.97)0.95 (0.92–0.97)
Quintile 20.93 (0.91–0.96)0.90 (0.87–0.93)
Quintile 30.96 (0.93–0.98)0.93 (0.90–0.96)
Quintile 40.98 (0.95–1.00)0.96 (0.93–0.99)
Quintile 5 (ref)1.001.00
BMI%1,2331,228
Mediana9.83 (9.69–9.98)10.44 (10.27–10.61)
 >85th0.89 (0.87–0.91)0.90 (0.88–0.92)
 50–85th0.95 (0.94–0.97)0.94 (0.92–0.96)
 <50th (ref)1.001.00
Race/ethnicity1,2351,230
 Mediana9.58 (9.44–9.72)10.27 (10.11–10.43)
 Black0.93 (0.92–0.95)0.90 (0.88–0.92)
 Hispanic0.98 (0.96–1.00)0.96 (0.94–0.99)
 Asian1.04 (1.00–1.08)1.08 (1.04–1.13)
 White (ref)1.001.00
  • aMedian of referent group

  • Abbreviation: ref, referent.