Table 3.

Adjusted risk estimates of overall survival

Multivariate analysis
Parity groupa	Number of cases	Adjusted HRb,c	95 % CI	p	5-Year survival (%)
PABC <5	N = 86	2.65	1.09–6.42	0.03	65.8
Parous ≥5	N = 172	1.52	0.71–3.28	0.28	77.5
Nulliparous	N = 76	1.0	–	–	98.0

Hazard ratios and 95 % confidence intervals for all covariates included in the final model are described in Table 7 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 3.0 ± 2.9 years. Mean followup time for nulliparous was 3.6 ± 3.6 years and 3.9 ± 3.7 years for cases diagnosed ≥5

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

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