Multiple regression analysis of risk factors related to radiation pneumonitis

Table 1 Comparison of general data between the two groups [n (%)]

General information		Control group (n = 141)	Study group (n = 93)	χ2	P
Sex	Male	70 (49.65)	56 (60.22)	2.519	0.112
	Female	71 (50.35)	37 (39.78)
Age (years)	< 60	80 (56.74)	36 (38.71)	7.286	0.007
	≥ 60	61 (43.26)	57 (61.29)
Smoking	Yes	48 (34.04)	39 (41.94)	1.495	0.221
	No	93 (65.96)	54 (58.06)
Tumor type	lung cancer	52 (36.88)	69 (74.19)	36.127	< 0.001
	Mammary cancer	52 (36.88)	21 (22.58)
	Esophageal cancer	37 (26.24)	3 (2.23)
TNM stage	II	43 (30.50)	39 (41.94)	5.065	0.079
	III	54 (38.30)	36 (38.71)
	IV	44 (31.20)	18 (19.35)
History of chemotherapy	Yes	36 (25.53)	57 (61.29)	29.921	< 0.001
	No	105 (74.47)	36 (38.71)
Operation	Yes	47 (33.33)	39 (41.94)	1.784	0.182
	No	94 (66.67)	54 (58.06)