Table 2.

Adjusted risk estimates of distant recurrence

Multivariate analysis
Parity groupa	Number of cases	Adjusted HRb,c	95 % CI	p	5-Year distant recurrence probability (%)
PABC <5	N = 84	2.80	1.12–6.57	0.02	31.3
Parous ≥5	N = 168	1.01	0.48–2.15	0.97	19.9
Nulliparous	N = 74	1.0	–	–	14.8

Hazard ratios and 95 % confidence intervals for all covariates included in the final model are described in Table 6 in the supplemental material. Clinical characteristics of the collapsed Parous ≥5 group can be viewed in Table 8 in the supplemental material

Parous ≥5, cases diagnosed five years or later from last childbirth

^aPABC <5 cases had a mean followup time of 2.7 ± 2.7 years. Mean followup time for nulliparous was 3.2 ± 3.2 years and 3.5 ± 3.6 years for cases diagnosed ≥5

^bAdjusted for tumor biologic subtype, clinical stage, year of diagnosis, and local recurrence

^cHistologic subtype and grade were not univariately significant and were thus not included in the final multivariate models