Table 3.

Variability in contralateral prophylactic mastectomy use (compared to BCS) explained by patient, disease and area characteristics

Characteristic	% of variation explained
Young age	32
Breast reconstruction	29
Stage 0 (DCIS)	5
Lobular histology	4
Race	4
Tumor size	4
Facility location	3

Percent of variation explained by each characteristic based on change in logistic regression pseudo-R2, with and without each characteristic. Only variables that changed the pseudo R² by ≥2% are shown here. The full model included all characteristics shown in Table 3, and had a pseudo R² of 0.1274, c-statistic 0.75, n=1,149,395.