. Author manuscript; available in PMC: 2014 Nov 15.

Published in final edited form as: Cancer. 2013 Aug 26;119(22):3976–3983. doi: 10.1002/cncr.28326

Table 2.

Lung Cancer and Overall Mortality Rates by Major Covariates, with Interaction Analysis

	Arm	# Lung Cancer Deaths \| Death Rate ¹	Risk Ratio ²	p-value for interaction³	# Total Deaths \| Death Rate ¹	Risk Ratio ²	p-value for interaction³
Subset
All	LDCT	469 \| 280	0.84		1912 \| 1141	0.931
All	CXR	552 \| 332	Referent		2039 \|1225	Referent
Women	LDCT	158 \| 228	0.73		574 \|828	0.921
Women	CXR	215 \| 312	Referent		619 \|899	Referent
Men	LDCT	311 \| 316	0.92		1338 \|1361	0.936
Men	CXR	337 \| 345	Referent	0.08	1420 \| 1454	Referent	0.84
Age < 65	LDCT	253 \| 205	0.82		1059 \| 856	0.942
Age < 65	CXR	307 \| 250	Referent		1117 \| 909	Referent
Age >=65	LDCT	216 \| 491	0.87		853 \| 1943	0.918
Age >=65	CXR	245 \| 562	Referent	0.60	922 \| 2116	Referent	0.67
Current Smoker	LDCT	294 \| 369	0.81		1146 \|1437	0.944
Current Smoker	CXR	360 \| 455	Referent		1206 \| 1523	Referent
Former Smoker	LDCT	175 \| 199	0.91		766 \| 872	0.914
Former Smoker	CXR	192 \| 220	Referent	0.40	833 \| 954	Referent	0.61

. Per 100,000 PY.

. Risk ratio of LDCT versus CXR arm within covariate category.

. Interaction of Risk Ratio with given covariate.