Competing risks of death in younger and older postmenopausal breast cancer patients

Table 2 Competing risks assessment of factors associated with death

Factor	Association with death		Association by type of death
	χ21	P-value	χ22	P-value
Treatment (TAM, TAM + OCT)	0.52	0.77
Age (yr)	7.90	0.02	4.73	0.03
Race (white, other)	1.85	0.40
ECOG performance status (0, other)	0.56	0.75
Tumour size (T1, ≥ T2, unknown)	10.55	0.01	4.22	0.04
Nodal status (N0, N1, N2, Nx)	12.79	0.002	0.38	0.543
Surgery (segmental mastectomy, other)	0.04	0.98
IGF-1 (continuous)	1.17	0.56
IGFBP-3 (continuous)	0.19	0.91
C-peptide (continuous)	3.86	0.15
Weight (kg)	0.27	0.88
BMI (continuous)	1.38	0.50
Vitamin D (continuous)	1.05	0.59
Number of positive nodes
(0, Nx, 1-3+, ≥ 4+)	19.43	< 0.0001	0.02	0.893
Hormone receptor status (ER-PR-,
unknown, ER+ and/or PR+)	5.11	0.08	4.19	0.04
Adjuvant chemotherapy (no, yes)	2.39	0.30

¹Hypothesis H1: Factor does not affect type or time to death. Test criterion was the likelihood ratio criterion that has an approximately chi-square distribution on 2 df (- X²²). Only factors with an indication of statistical significance were considered in H2; ²Hypothesis H2: Factor effect is the same for two causes of death. Test criterion was the likelihood ratio criterion that has an approximately chi-square distribution on 1 df (- Χ²¹);

³Hypothesis H3: As H2 was not rejected, there is evidence of a common effect on both types of death, or on all cause mortality, which was tested by the third hypothesis, H3. H3 is that the factor has no effect on time of death. Test criterion was the likelihood ratio criterion that has an approximately chi-square distribution on 1 df (- Χ²¹). H3 P-value for nodal status and for number of positive nodes was < 0.0001.