Table 3.

Adjusted Odds Ratios of Recommending Adjuvant Radiation Therapy for Stage I Seminoma According to Year of Diagnosis, County Education Level, and Age Group Category

Covariate	No. of Patients (men)	RT Recommended (%)	Adjusted Odds Ratio†	95% CI	P
Year
1990-1994	706	85.3	1.0*		—
1995-1999	988	81.9	0.63	0.48 to 0.84	.001
2000-2004	1,431	78.7	0.49	0.37 to 0.63	< .001
Proportion of county (age > 25) with less than a high school education, quartile
4 (least educated areas)	717	77.3	1.0*		—
3	788	80.1	1.48	1.13 to 1.92	.004
2	834	81.7	1.52	1.16 to 1.98	.002
1 (most educated areas)	786	85.4	2.12	1.59 to 2.82	< .001
Age group, years
≤ 30	782	78.4	1.0*		—
> 30	2,343	82.1	1.26	1.03 to 1.55	.024

Abbreviations: RT, radiation therapy; SEER, Surveillance Epidemiology and End Results.

^*This group served as the reference group in the logistic regression analysis.

^†Odds adjusted for race, SEER region, tumor category, and tumor size.