Table 3. Association between case characteristics and type of initial imaging (univariate analysis).

	Patients undergoing CXR (%)	OR (95% CI) for CXR	Overall P value
Age
≤65 years	58	1.05 (0.70–1.58)	0.81
>65 years	57	Reference
Gender
Male	61	1.39 (0.93–2.09)	0.11
Female	53	Reference
Race
White	55	Reference	0.11
Non-white	63	1.43 (0.92–2.23)
Insurance
Private	62	Reference
Medicare	53	0.69 (0.43–1.11)	0.13
Indigenta	66	1.18 (0.59–2.35)
Smoking status
Current	63	Reference	0.03
Former/never	51	0.61 (0.39–0.96)
Imaging reason
Symptoms	70	Reference	<0.001
Other	40	0.28 (0.18–0.46)
Year of diagnosis
2000–2004	67	2.14 (1.41–3.23)	<0.001
2005–2009	49	Reference
Histology
Adenocarcinoma	57	Reference
Squamous cell	61	1.17 (0.74–1.86)	0.39
Other	51	0.77 (0.45–1.33)
Clinical stage
1	54	Reference	0.005
2	71	2.16 (1.26–3.69)

OR >1: more likely to have CXR than other modalities as initial imaging study.

^aIncludes Medicaid, county health plan, and no insurance.

CI, confidence interval; CXR, chest x-ray; OR, odds ratio.