TABLE 4.

: Distribution of adverse events and impact on outcome.

Variable	Distribution			PFS		OS
	CHOP‐19 (155 dogs)	CHOP‐25 (347 dogs)	P‐value	Hazard ratio	P‐value	Hazard ratio	P‐value
Vincristine (median [range])
Maximal gastrointestinal toxicity grade	1 (0‐4)	1 (0‐5)	<.001 (estimate = 0.359) *	0.99	.79	0.95	.31
Number of neutropenia events	0 (0‐6)	0 (0‐8)	<.001 (estimate = 0.521) *	0.85	<.001 *	0.86	<.001 *
Neutropenia highest grade	0 (0‐4)	0 (0‐4)	.01 (estimate = 0.346) *	0.87	.01 *	0.9	.04 *
Neutropenia score	0 (0‐8)	0 (0‐12)	<.001 (estimate = 0.384) *	0.92	.001 *	0.93	.003 *
Cyclophosphamide (median [range])
Maximal gastrointestinal toxicity grade	0 (0‐4)	0 (0‐3)	.21 (estimate = −0.177)	0.95	.36	1.01	.85
Number of neutropenia events	0 (0‐4)	0 (0‐3)	.38 (estimate = −0.124)	0.75	<.001 *	0.76	<.001 *
Neutropenia highest grade	0 (0‐4)	0 (0‐4)	.05 (estimate = −0.241)	0.85	<.001 *	0.83	<.001 *
Neutropenia score	0 (0‐13)	0 (0‐9)	<.001 (estimate = −0.394) *	0.88	<.001 *	0.88	<.001 *
Doxorubicin [median (range)]
Maximal gastrointestinal toxicity grade	0 (0‐4)	0 (0‐5)	.25 (estimate = 0.14)	0.98	.67	1.02	.7
Number of neutropenia events	0 (0‐4)	0 (0‐3)	.25 (estimate = 0.248)	0.79	.01 *	0.83	.03 *
Neutropenia highest grade	0 (0‐4)	0 (0‐4)	.47 (estimate = 0.138)	0.84	.01 *	0.86	.03 *
Neutropenia score	0 (0‐12)	0 (0‐8)	.84 (estimate = −0.033)	0.89	0.012 *	0.91	.06
Chemotherapy protocol (median [range])
Sum maximal gastrointestinal toxicity grade	2 (0‐10)	2 (0‐8)	.01 (estimate = 0.176) *	0.97	.27	0.98	.43
Number of neutropenia events	1 (0‐10)	1 (0‐13)	.003 (estimate = 0.262) *	0.87	<.001 *	0.87	<.001 *
Neutropenia score	1 (0‐18)	1 (0‐21)	.69 (estimate = 0.026)	0.92	<.001 *	0.93	<.001 *
Dogs hospitalized			.05	1.41	.003 *	1.44	.003 *
No	131 (84.5%)	265 (76.4%)
Yes	24 (15.5%)	82 (23.6%)

Abbreviations: CHOP, C = cyclophosphamide, H = hydroxydaunorubicin (Doxorubicin), O = Oncovin, P = prednisolone; PFS, progression‐free survival; OS, overall survival.

^*Significant differences (P < .05).