Table 2. Multivariate logistic regression for factors predictive of IMRT utilization.

Characteristic	Odds ratio	95% confidence interval	P value
Age (years)
<55	1 (reference)	–	–
55–64	1.209	1.045–1.399	0.011
65+	1.108	0.915–1.341	0.292
Sex
Male	1 (reference)	–	–
Female	0.914	0.800-1.044	0.186
Race
White	1 (reference)	–	–
African American	1.232	0.969–1.568	0.089
Hispanic	1.521	1.065–2.172	0.021
Other/not recorded	1.306	0.798–2.136	0.288
T stage
T1	1 (reference)	–	–
T2	0.946	0.806–1.110	0.495
T3	0.816	0.677–0.984	0.034
T4	0.727	0.569–0.929	0.011
N stage
N0	1 (reference)	–	–
N+	1.404	1.226–1.608	<0.001
Charlson Deyo score
0	1 (reference)	–	–
1	0.988	0.828–1.179	0.893
2	0.952	0.681–1.330	0.772
≥3	1.198	0.824–1.742	0.343
Facility type
Non-academic	1 (reference)	–	–
Academic	1.931	1.672–2.229	<0.001
Facility location
New England	1 (reference)	–	–
Middle Atlantic	0.989	0.751–1.303	0.938
South Atlantic	1.357	1.045–1.762	0.022
East North Central	1.099	0.846–1.427	0.481
East South Central	1.294	0.932–1.796	0.124
West North Central	1.079	0.805–1.447	0.611
West South Central	1.712	1.182–2.481	0.004
Mountain	2.951	1.955–4.455	<0.001
Pacific	1.486	1.117–1.977	0.007
Income
≤$62,999	1 (reference)	–	–
$63,000+	1.100	0.956–1.266	0.182
Not recorded	0.336	0.155–0.726	0.006
Residence
Urban	1 (reference)	–
Metropolitan	0.851	0.721–1.005	0.058
Rural	0.774	0.512–1.171	0.226
Other/not recorded	1.526	0.931–2.502	0.093
Insurance
Medicaid	1 (reference)	–	–
Medicare	1.012	0.784–1.305	0.930
Private	1.018	0.816–1.272	0.872
Uninsured	0.795	0.577–1.100	0.160
Government/other	1.016	0.675–1.530	0.939

3DCRT, three-dimensional conformal radiotherapy; IMRT, intensity-modulated radiotherapy.