Table 3.

Gamel Boag log-normal multivariate regression model parameters.

Covariate	Beta Coefficient	p-value
Intercept	5.7053	<0.001
age	−0.0276	0.018
age′	−0.0347	0.286
age″	0.2145	0.123
sex=male	0.0445	0.525
race=African-American	−0.3267	0.003
race=Asian/Pacific Islander	−0.0502	0.611
race=American Indian/Alaskan	−0.3163	0.305
T stage=T2	−0.4292	<0.001
T stage=T3	−0.8574	<0.001
T stage=T4	−1.4002	<0.001
N stage=N1	−0.2779	0.002
N stage=N2	−0.1842	0.469
lymphadenectomy	0.6584	<0.001
CRT	−1.0881	<0.001
T2 * CRT	1.8257	<0.001
T3 * CRT	1.2955	<0.001
T4 * CRT	1.1025	<0.001
N1 * CRT	0.6856	<0.001
N2 * CRT	−0.2175	0.633
lymphadenectomy * CRT	−1.7721	<0.001
Log(sigma)	−0.1581	<0.001

Abbreviations: CRT=chemoradiotherapy

Age was modeled using a restricted cubic spline function with 4 knots, requiring 3 independent coefficients: age, age′, age″.