Table 2. Association between case characteristics and reason for imaging (univariate analysis).

	Patients undergoing imaging to evaluate symptoms (%)	OR (95% CI) for imaging performed to evaluate symptoms	Overall P value
Age
≤65 years	54	1.25 (0.79–1.95)	0.34
>65 years	49	Reference
Gender
Male	51	0.98 (0.63–1.52)	0.91
Female	51	Reference
Race
White	44	Reference	<0.001
Non-white	65	2.43 (1.48–3.98)
Insurance
Private	55	Reference
Medicare	44	0.64 (0.37–1.08)	0.005
Indigenta	71	1.95 (0.89–4.27)
Smoking status
Current	54	Reference	0.06
Former/never	43	0.64 (0.39–1.03)
Imaging type
CXR	64	Reference	<0.001
Other	34	0.28 (0.18–0.46)
Year of diagnosis
2000–2004	55	1.25 (0.79–1.98)	0.35
2005–2009	49	Reference
Histology
Adenocarcinoma	52	Reference
Squamous cell	51	0.96 (0.58–1.61)	0.89
Other	48	0.87 (0.42–1.57)
Clinical stage
1	43	Reference	<0.001
2	79	5.05 (2.66–9.59)

OR >1: More likely to have imaging performed for evaluation of symptoms than for other reasons.

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

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