Table 2. Multivariate analysis of factors affecting grade 2 radiation pneumonitis.

			95% confidence interval for HR
Factor	p-value	HR	Lower	Upper
Gender	0.032	5.895	1.160	29.961
Operability	0.169	2.600	0.666	10.150
FEV1	0.018	5.760	1.343	24.701
ITV	0.264	1.030	0.978	1.084
V15	0.035	1.275	1.017	1.599

FEV1, forced expiratory volume in 1 s; HR, hazard ratio; ITV, internal target volume; V15, lung volumes treated with doses >15 Gy.