Table 1.

Estimates from the Cox model, the fixed effects model, the gamma and log-normal frailty models.

		Cox model				Fixed Effects			Gamma frailty			Log-normal frailty
		Coef	SE	Robust SE		Coef	SE		Coef	SE		Coef	SE
Type of surgery	Mastectomy with RT
	Mastectomy without RT	0.25	0.11	0.17		0.16	0.13		0.16	0.12		0.16	0.12
	Breast conserving	−0.07	0.10	0.10		−0.09	0.10		−0.08	0.10		−0.08	0.10
Tumor size	<2 cm
	2–5 cm	0.35	0.10	0.10		0.35	0.10		0.35	0.10		0.35	0.10
	>5 cm	0.89	0.15	0.16		0.83	0.16		0.84	0.16		0.84	0.16
Nodal status	Node negative
	Node positive	0.97	0.11	0.26		0.77	0.11		0.79	0.11		0.78	0.11
Age	$\le$50
	>50	0.01	0.10	0.12		0.10	0.10		0.09	0.10		0.09	0.10
Adjuvant chemo	No
	Yes	−0.38	0.13	0.35		−0.15	0.14		−0.17	0.13		−0.17	0.14
Tamoxifen	No
	Yes	−0.17	0.12	0.31		0.12	0.13		0.08	0.12		0.08	0.12
Perioperative chemo	No
	Yes	−0.12	0.07	0.06		−0.13	0.07		−0.13	0.07		−0.13	0.07
Frailty variance									0.122			0.132

Note: Estimated center effects of the fixed effects model have been omitted from the table.