Distribution of variables according to LC risk category (as calculated by PLCOM2012)
| Variable | PLCOM2012 score | |||||||
| <1.51% | 1.51%–2% | 2%–3% | 3%–4% | 4%–6% | 6%–9% | ≥10% | P value for trend | |
| No participants (%) | 1112 | 265 (19) | 294 (21) | 233 (16) | 263 (18) | 221 (16) | 153 (11) | – |
| No screened (%) | n/a | 263 (19) | 291 (21) | 231 (16) | 256 (18) | 218 (16) | 151 (11) | – |
| % with LC (n) (%M/F) | – | 1.5 (4) (1.5/1.6) | 1.4 (4) (1.5/1.3) | 3.0 (7) (2.6/3.4) | 5.5 (14) (3.2/7.6) | 7.8 (17) (6.6/9.4) | 10.6 (16) (10.8/10.4) | <0.0001 |
| NNS to detect 1 LC within each individual risk group (M/F) | – | 66 (67/65) | 73 (66/80) | 33 (38/29) | 18 (31/13) | 13 (15/11) | 9 (9/10) | – |
| NNS to detect 1 LC at or above risk score (M/F) | – | 23 (26/20) | 20 (23/18) | 16 (19/14) | 13 (16/11) | 11 (12/10) | 9 (9/10) | – |
| Mean age (±SD) | 63.4±5.5 | 62.4±5.6 | 63.4±5.4 | 64.1±5.2 | 65.0±4.8 | 66.1±4.5 | 69.7±3.6 | <0.0001 |
| Sex % F (n) | 52 (573) | 49 (130) | 55 (162) | 51 (118) | 52 (136) | 44 (98) | 52 (79) | 0.388 |
| Age start smoking (±SD) | 17.6±6.3 | 16.3±5.1 | 16.2±4.3 | 16.0±4.0 | 15.8±4.0 | 15.3±4.0 | 15.0±3.1 | <0.0001 |
| Current smokers % (n) | 12 (137) | 39 (104) | 41 (121) | 51 (118) | 57 (149) | 66 (145) | 77 (117) | <0.0001 |
| Mean years smoked (±SD) | 22.8±12.6 | 37.5±8.0 | 40.2±6.8 | 42.6±6.9 | 45.7±5.6 | 48.5±6.0 | 53.5±4.6 | <0.0001 |
| Mean cigs/day (±SD) | 16±12 | 21±10 | 22±11 | 24±12 | 26±17 | 26±12 | 27±14 | <0.0001 |
| LC relative* % yes (n) | 15 (161) | 17 (45) | 24 (70) | 19 (45) | 30 (80) | 39 (85) | 44 (67) | <0.0001 |
| MRC dyspnoea scale 1 % (n) | 78 (871) | 63 (168) | 72 (211) | 70 (70) | 66 (174) | 57 (125) | 52 (80) | <0.0001 |
| Symptomatic† % yes (n) | 38 | 52 (136) | 51 (149) | 55 (129) | 62 (163) | 73 (162) | 76 (116) | <0.0001 |
| FEV1 (±SD) | 2.6±0.8 | 2.4±0.7 | 2.3±0.7 | 2.2±0.7 | 2.0±0.7 | 2.0±0.7 | 1.7±0.6 | <0.0001 |
| % pred FEV1 (±SD) | 98±24 | 91±23 | 90±22 | 86±26 | 81±23 | 78±25 | 73±23 | <0.0001 |
| FVC (±SD) | 3.4±1 | 3.3±0.9 | 3.2±0.9 | 3.2±0.9 | 3.0±1.0 | 3.1±1.0 | 2.9±0.9 | <0.0001 |
| % pred FVC (±SD) | 107±25 | 102±25 | 103±22 | 101±27 | 97±24 | 95±24 | 96±24 | <0.0001 |
| FEV1: FVC ratio (±SD) | 75±9 | 72±9 | 70±10 | 68±10 | 67±11 | 64±11 | 61±12 | <0.0001 |
| Airflow obstn % yes (n) | 21 (232) | 28 (75) | 39 (114) | 50 (114) | 58 (152) | 68 (149) | 74 (112) | <0.0001 |
| Emphysema % yes (n) | – | 54 (142) | 60 (171) | 64 (146) | 65 (164) | 69 (146) | 77 (114) | <0.0001 |
| CVD % yes (n) | – | 17.8 (33) | 17.0 (35) | 24.8 (38) | 18.2 (31) | 31.1 (42) | 30.0 (27) | 0.005 |
| QRISK2 score‡ %±SD | – | 21±11 | 22±12 | 23±11 | 24±10 | 27±13 | 31±12 | <0.0001 |
| CAC% (n) | ||||||||
| None | – | 34 (81) | 26 (66) | 27 (52) | 29 (62) | 23 (42) | 20 (25) | – |
| Mild | – | 54 (80) | 40 (103) | 38 (72) | 37 (81) | 39 (71) | 39 (49) | |
| Moderate-severe | – | 12 (75) | 35 (90) | 35 (67) | 34 (74) | 39 (71) | 41 (52) | |
*LC diagnosed in a first degree relative.
†Defined as the presence of ≥1 symptom at baseline, including: breathlessness (MRC dyspnoea scale ≥2), cough ≥6 weeks in duration, sputum production ≥teaspoon/day.
‡QRISK2 score calculated in the second screening round only in those with no prior history of CVD.
CAC, coronary artery calcification; CVD, cardiovascular disease; FEV1, forced expiratory volume in 1 s; FVC, forced vital capacity; LC, lung cancer; NNS, number needed to screen.