Table 2—

Results of Cox proportional hazards regression modeling used to identify potential associations between variables of interest and a shorter PFI or OST for the 70 dogs described in Table 1.

Outcome	Variable	No. of dogs	Initial models*		Multivariable models with 3 CBC variables†		Multivariable models with all variables‡
			HR (95% CI)	P value	HR (95% CI)	P value	HR (95% CI)	P value
PFI		65
	Tumor stage
	1	7	1.35 (0.59–3.08)	0.482	2.07 (0.82–5.24)	0.125	1.91 (0.27–13.35)	0.516
	2	51	Referent		Referent		Referent
	3	7	6.98 (2.69–18.09)	< 0.001	7.65 (2.87–20.40)	< 0.001	7.51 (2.65–21.34)	< 0.001
	Treatment group
	SRCBST1	19	0.76 (0.42–1.39)	0.377	0.82 (0.43–1.58)	0.559	1.17 (0.55–2.47)	0.680
	SRCBST2	16	1.53 (0.79–2.96)	0.205	1.50 (0.71–3.17)	0.291	2.14 (0.90–5.11)	0.086
	Control	30	Referent		Referent		Referent
	Age (+1 SD)§	65	1.15 (0.88–1.51)	0.314	—	—	1.19 (0.87–1.62)	0.276
	Sex
	Male	32	1.12 (0.65–1.91)	0.690	—	—	1.27 (0.70–2.30)	0.428
	Female	33	Referent		—	—	Referent
	BSA (+1 SD)§	65	0.91 (0.71–1.18)	0.489	—	—	1.04 (0.73–1.46)	0.839
	Hemoabdomen
	Yes	56	1.69 (0.39–7.37)	0.483	—	—	1.05 (0.19–5.80)	0.956
	No	9	Referent		—	—	Referent
	Transfusion
	Yes	35	1.46 (0.81–2.64)	0.204	—	—	1.48 (0.78–2.79)	0.226
	No	30	Referent		—	—	Referent
	Treatment facility
	UMNVMC	37	1.24 (0.71–2.18)	0.450	—	—	1.34 (0.72–2.49)	0.363
	Other	28	Referent		—	—	Referent
	Anemia
	Yes	48	1.83 (0.96–3.49)	0.065	1.01 (0.40–2.56)	0.977	0.92 (0.34–2.53)	0.878
	No	17	Referent		Referent		Referent
	Leukocytosis
	Yes	31	0.93 (0.55–1.57)	0.775	1.01 (0.59–1.72)	0.983	0.99 (0.52–1.90)	0.985
	No	34	Referent		Referent		Referent
	Thrombocytopenia
	Yes	46	2.22 (1.18–4.15)	0.013	2.20 (0.89–5.45)	0.090	2.34 (0.85–6.45)	0.102
	No	19	Referent		Referent		Referent
OST		70
	Stage
	1	8	0.87 (0.41–1.86)	0.724	1.59 (0.66–3.82)	0.302	1.68 (0.27–10.24)	0.576
	2	55	Referent		Referent		Referent
	3	7	4.42 (1.85–10.52)	< 0.001	6.37 (2.44–16.64)	< 0.001	9.35 (3.07–28.48)	<0.001
	Treatment group
	SRCBST1	21	0.72 (0.41–1.29)	0.271	0.79 (0.42–1.47)	0.452	0.97 (0.50–1.89)	0.924
	SRCBST2	18	1.22 (0.66–2.26)	0.516	1.28 (0.65–2.52)	0.469	1.73 (0.82–3.68)	0.153
	Control	31	Referent		Referent		Referent
	Age (+1 SD)§	70	1.22 (0.95–1.58)	0.119	—	—	1.34 (0.99–1.79)	0.056
	Sex
	Male	36	0.91 (0.54–1.53)	0.714	—	—	0.84 (0.47–1.52)	0.570
	Female	34	Referent		—	—	Referent
	BSA (+1 SD)§	70	1.00 (0.79–1.26)	0.995	—	—	1.15 (0.84–1.57)	0.381
	Hemoabdomen
	Yes	60	1.55 (0.35–6.77)	0.560	—	—	1.38 (0.25–7.56)	0.713
	No	10	Referent		—	—	Referent
	Transfusion
	Yes	37	1.22 (0.72–2.07)	0.455	—	—	1.28 (0.69–2.39)	0.432
	No	33	Referent		—	—	Referent
	Treatment facility
	UMNVMC	39	1.34 (0.77–2.32)	0.303	—	—	1.09 (0.61–1.93)	0.771
	Other	31	Referent		—	—	Referent
	Anemia
	Yes	52	1.13 (0.64–2.00)	0.672	0.55 (0.25–1.22)	0.142	0.44 (0.19–1.01)	0.052
	No	18	Referent		Referent		Referent
	Leukocytosis
	Yes	32	1.16 (0.68–1.97)	0.595	1.19 (0.69–2.03)	0.536	1.17 (0.60–2.30)	0.638
	No	38	Referent		Referent		Referent
	Thrombocytopenia
	Yes	50	2.04 (1.09–3.81)	0.026	3.09 (1.32–7.23)	0.009	3.50 (1.43–8.55)	0.006
	No	20	Referent		Referent		Referent

^*Initial models were fit for each CBC and physical examination variable separately, with HSA stage and treatment as covariates.

^†Multivariable models that refit the initial models to include all 3 CBC variables (Hct, WBC count, and platelet count) and with HSA stage and treatment as covariates.

^‡Multivariable models that refit the initial models to include all CBC and physical examination variables of interest and with HSA stage and treatment as covariates.

^§For continuous variables (age and BSA), the standardized HR associated with an increase of 1 SD in the value of the variable is shown.

^{— =}Not assessed in the model.