TABLE 1.
Demographic and baseline clinical characteristics of the intervention arm of the Yorkshire Lung Screening Trial stratified by nonresponse or response (contacted telephone triage line) following invitation
| Intervention group | Nonresponders | Responders | p-value | |
| Subjects | 44 943 (100) | 22 128 (49.2) | 22 815 (50.8) | |
| Age, years | 66.1±7.2 | 64.8±7.1 | 67.3±7.1 | |
| Age group, years | <0.001 | |||
| <60 | 11 809 (26.3) | 7244 (32.7) | 4565 (20.0) | |
| 60–64 | 9936 (22.1) | 5329 (24.1) | 4607 (20.2) | |
| 65–69 | 8619 (19.2) | 3745 (16.9) | 4874 (21.4) | |
| 70–74 | 8149 (18.1) | 3317 (15.0) | 4832 (21.2) | |
| ≥75 | 6430 (14.3) | 2493 (11.3) | 3937 (17.3) | |
| Gender | <0.001 | |||
| Female | 21 446 (47.7) | 9969 (45.1) | 11 477 (50.3) | |
| Male | 23 496 (52.3) | 12 158 (54.9) | 11 338 (49.7) | |
| Indeterminate | 1 (<0.1) | 1 (<0.1) | 0 | |
| IMD rank | 15 050 (4014–23 016) |
11 508 (3091–21 681) |
17 272 (6658–23 723) |
<0.001 |
| IMD quintile | <0.001 | |||
| 1 (most deprived) | 13 641 (30.4) | 8102 (36.6) | 5539 (24.3) | |
| 2 | 7184 (16.0) | 3709 (16.8) | 3475 (15.2) | |
| 3 | 7621 (17.0) | 3537 (16.0) | 4084 (17.9) | |
| 4 | 9638 (21.4) | 4012 (18.1) | 5626 (24.7) | |
| 5 (least deprived) | 6811 (15.2) | 2744 (12.4) | 4067 (17.8) | |
| Missing | 48 (0.1) | 24 (0.1) | 24 (0.1) | |
| Ethnicity (derived )# | <0.001 | |||
| White | 22 500 (50.1) | 10 524 (47.6) | 11 958 (52.4) | |
| Black or Black British | 690 (1.5) | 415 (1.9) | 275 (1.2) | |
| Asian or Asian British | 932 (2.1) | 544 (2.5) | 388 (1.7) | |
| Mixed | 18 339 (40.8) | 9102 (41.1) | 9237 (40.5) | |
| Other | 486 (1.1) | 291 (1.3) | 195 (0.9) | |
| Unclear | 357 (0.8) | 190 (0.8) | ||
| Not stated | 1639 (3.7) | 1067 (4.8) | 572 (2.5) | |
| COPD code | 4364 (9.7) | 2219 (10.0) | 2145 (9.4) | 0.16 |
| Smoking status (derived)# | <0.001 | |||
| Currently smoking | 13 435 (29.9) | 8907 (40.3) | 4528 (19.9) | |
| Previously smoked | 31 036 (69.1) | 12 990 (58.7) | 18 046 (79.1) | |
| Never smoked | 13 (<0.1) | 5 (<0.1) | 8 (<0.1) | |
| Noninformative code | 459 (1.0) | 226 (1.0) | 233 (1.02) |
Data are presented as n (%), mean±sd or median (interquartile range), unless otherwise stated. IMD: Index of Multiple Deprivation; COPD: chronic obstructive pulmonary disease. #: general practice electronic record codes used to derive ethnicity and smoking status.