Table 3.

Associations between Patient Characteristics and EGFR and KRAS Mutations

	EGFR Mutation Status
Variable	Positive		Negative		t test P value
	#	Mean ± SE	#	Mean ± SE
Age	60	65.1 ± 1.4	303	62.9 ± 0.7	0.18
Charlson Comorbidity Index	60	5.1 ± 0.3	303	5.9 ± 0.1	0.002
Age-weighted Comorbidity Index	60	7.1 ± 0.3	303	7.9 ± 0.1	0.02

	KRAS Mutation Status
Variable	Mutant		Wild Type		t test P value
	#	Mean ± SE	#	Mean ± SE
Age	83	62.3 ± 1.1	207	62.6 ± 0.9	0.82
Charlson Comorbidity Index	83	6.0 ± 0.2	206	5.8 ± 0.1	0.31
Age-weighted Comorbidity Index	83	7.9 ± 0.2	206	7.7 ± 0.2	0.46