Table 1.

Baseline Characteristics of Participants in the Pan-Canadian Early Detection of Lung Cancer Study Overall and by Lung Cancer Status

Characteristic	No Cancer		Lung Cancer		Total		P*
	No.	%	No.	%	No.	%
Age, years							.036†
50-54	234	95.90	10	4.10	244	10.38
55-59	443	96.72	15	3.28	458	19.49
60-64	726	95.53	34	4.47	760	32.34
65-69	568	93.57	39	6.43	607	25.83
≥ 70	266	94.66	15	5.34	281	11.96
Sex							.020
Male	1,242	96.13	50	3.87	1,292	54.98
Female	995	94.05	63	5.95	1,058	45.02
BMI							.016†
Underweight (< 18.5 kg/m2)	20	95.24	1	4.76	21	0.88
Normal (18.5-24.9 kg/m2)	803	93.59	55	6.41	858	36.51
Overweight (25-29.9 kg/m2)	1,031	96.18	41	3.82	1,072	45.62
Obese (≥ 30 kg/m2)	383	95.99	16	4.01	399	16.98
Personal history of cancer							.112
No	2,095	95.36	102	4.64	2,197	93.77
Yes	135	92.47	11	7.53	146	6.23
Family history of cancer							.353
No	1,458	95.54	68	4.46	1,526	66.12
Yes	740	94.63	42	5.37	782	33.88
Pneumonia							.037
No	1,648	95.76	73	4.24	1,721	73.42
Yes	583	93.58	40	6.42	623	26.58
Emphysema							.423
No	2,091	95.26	104	4.74	2,195	93.76
Yes	137	93.84	9	6.16	146	6.24
Smoking status							.489
Former smoker	871	95.61	40	4.39	911	38.77
Current smoker	1,366	94.93	73	5.07	1,439	61.23
Race/ethnicity							.674†
White	2,175	95.14	111	4.86	2,286	97.65
Asian	22	95.65	1	4.35	23	0.98
Aboriginal	7	100	0	0	7	0.30
Black or African Canadian	12	92.31	1	7.69	13	0.56
Other	12	100	0	0.00	12	0.51
Education							.936†
8th grade or less	63	94.03	4	5.97	67	2.85
9th to 11th grade	288	94.12	18	5.88	306	13.02
High school graduate	585	96.22	23	3.78	608	25.87
Technical/vocational school	239	94.09	15	5.91	254	10.81
Associate's degree/some college	428	94.48	25	5.52	453	19.28
Bachelor's degree	401	96.63	14	3.37	415	17.66
Advanced degree	233	94.33	14	5.67	247	10.51
FEV1 ratio of predicted	2,220		111		2,331		.0034‡
Mean	0.82		0.77		0.82
SD	0.18		0.19		0.18
Median	0.83		0.77		0.83
IQR	0.71-0.94		0.67-0.86		0.71-0.94
Range	0.15-1.68		0.27-1.36		0.15-1.68
Pro-SFTPB, ng/mL	2,193		112		2,305		< .001‡
Mean	43.5		75.0		45.1
SD	42.1		64.5		43.9
Median	30.7		54.2		31.6
IQR	16.5-54.3		30.8-99.1		16.9-55.7
Range	1.2-426.9		10.0-344.4		1.2-426.9
No. of cigarettes smoked per day	2,237		113		2,350		.8943‡
Mean	24.68		24.84		24.69
SD	10.51		12.51		10.61
Median	25		25		25
IQR	20-25		20-25		20-25
Range	1-100		5-100		1-100
Smoking duration, years	2,235		112		2,347		.0012‡
Mean	43.97		45.91		44.06
SD	5.87		6.06		5.89
Median	44		46.5		44
IQR	40-48		42-50		40-48
Range	11-69		27-60		11-69
Time since quitting smoking, years	2,237		113		2,350		.9128‡
Mean	17.85		17.62		17.84
SD	21.29		21.71		21.31
Median	0		0		0
IQR	0-41		0-41		0-41
Range	0-61		0-55		0-61

Abbreviations: BMI, body mass index; FEV₁ ratio of predicted, forced expiratory volume in one second % predicted; IQR, interquartile range; pro-SFTPB, pro–surfactant protein B; SD, standard deviation.

^*Fisher's exact test.

^†Nonparametric test.

^‡Satterthwaite's unequal variance t test.