Table 2

Association of baseline density and type of HRT with HRT response

Variable nameCasesa (n)Controlsa (n)Unadjusted OR (95% CI)Adjusted OR (for baseline density)b (95% CI)Adjusted ORc (95% CI)
HRT
 Estrogen alone50791.00d1.00d1.00d
 Estrogen and progestin111792.27 (1.41–3.67)2.15 (1.30–3.57)1.89 (0.92–3.55)
 Combined
 Progestin alone551.64 (0.45–6.00)1.26 (0.34–4.74)1.01 (0.24–4.36)
 Missing691.02 (0.35–2.99)0.77 (0.23–2.61)0.67 (0.18–2.42)
Baseline density by qualitative Bi-Rads
 126161.00dN/Ae1.00d
 2103730.94 (0.47–1.87)1.03 (0.50–2.12)
 340710.38 (0.18–0.79)0.41 (0.19–0.89)
 43120.19 (0.05–0.77)0.17 (0.04–0.72)
Baseline density by quantitative % density
 <10.45%68431.00dN/Ae1.00d
 10.45–23.54%57430.73 (0.42–1.28)0.77 (0.43–1.38)
 23.55–33.44%29430.38 (0.19–0.74)0.40 (0.19–0.82)
 >33.44%18430.24 (0.11–0.50)0.24 (0.11–0.53)
  • a Data presented here as unmatched for descriptive purposes, but analyses were performed on matched pairs.

  • b Models adjusted for baseline density as quartiles of quantitative estimation.

  • c HRT is adjusted for baseline density as a quantitative variable and hysterectomy and/or oophorectomy status. Hysterectomy and oophorectomy status corresponds to dates preceding the initiation of HRT. Baseline density models are adjusted for HRT.

  • d Reference group.

  • e N/A, Adjustment not applicable.