Table 3.

Hazard ratios for death by treatment group (unadjusted and multivariable models)

Treatment group	Model 1 (n=637)	Model 2 (n=637)	Model 3 (n=555)	Model 4 (n=555)	Model 5 (n=478)
Neither radiation nor systemic therapy	1.00 (ref)	1.00 (ref)	1.00 (ref)	1.00 (ref)	1.00 (ref)
Radiation therapy only	0.78 (0.50–1.22)	0.79 (0.51–1.24)	0.74 (0.45–1.23)	0.84 (0.50–1.39)	0.74 (0.43–1.28)
Systemic therapy only	0.43 (0.36–0.52)	0.43 (0.36–0.52)	0.42 (0.34–0.51)	0.44 (0.36–0.54)	0.42 (0.34–0.53)
Both radiation and systemic therapy	0.42 (0.32–0.56)	0.42 (0.32–0.56)	0.45 (0.32–0.62)	0.49 (0.35–0.69)	0.44 (0.30–0.63)

Abbreviations as in Table 1.

Values in parentheses are 95% confidence intervals. Model 1: No covariates. Model 2: Controlling for time to progression. Model 3: Controlling for age at diagnosis, RPA, and cycles of adjuvant treatment. Model 4: Controlling for age at diagnosis, RPA, cycles of adjuvant treatment, surgery at progression, and time to progression. Model 5: Controlling for all measure confounders (assigned treatment group, MGMT methylation status, gender, RPA, KPS at randomization, neurologic function at randomization, prior surgery, surgery at progression, reason for radiation therapy termination, reason for adjuvant termination, time to progression, age at diagnosis, and cycles of adjuvant therapy).