Nulliparity enhances the risk of second primary malignancy of the breast in a cohort of women treated for thyroid cancer

Table 1 Logistic regression analysis of measured factors

Variable	Univariate analysis		Multivariate analysis
	Odds ratio (95% CI)	P value	Odds ratio (95% CI)	P value
Age at first tumor	1.06 (0.98 - 1.14)	0.14	1.07 (0.97 - 1.18)	0.16
Weight	0.96 (0.89-1.04)	0.33	0.98 (0.90-1.07)*	0.65*
Child	0.15 (0.03-0.86)	0.03	0.08 (0.01-0.94)	0.04
Smoke	5.33 (0.59-48.33)	0.72	4.79 (0.43-53.25)	0.20
Physical activity	0.32 (0.03-2.88)	0.31	0.17 (0.01-4.15)	0.28
Concurrent metabolic diseases	0.82 (0.15 - 4.40)	0.82	0.08 (0.00 - 1.56)	0.10
Family history of breast cancer	2.65 (0.49-14.41)	0.26	1.06* (0.10 - 0.88)	0.96*

The multivariate model considered as the most accurate includes as selected covariate only: age at first tumor, child, smoke, physical activity and concurrent metabolic diseases, expressed as dichotomous variables (yes/no). Weight and family history were excluded due to high p-value i.e. p > 0.6.
Hosmer Lemeshow test for goodness of fit was not statistically significant (p = 0.07), indicating a good quality of the model itself.
* the odds ratios for weight and family history of breast cancer are from the "full" model which includes all the covariates in the table.

ISSN: 1477-7819