Symptoms, blood investigations and number of general practice consultations recorded among cases and controls in the 4–12 and 13–24 month periods prior to lung cancer diagnosis
| Variable in GP record | Cases n (%) N=12074 | Controls n (%) N=120731 | Unadjusted OR for lung cancer | 95% CI | p Value* |
|---|---|---|---|---|---|
| Cough | |||||
| 4–12 months | 1938 (16.05) | 7088 (5.87) | 3.07 | 2.90 to 3.24 | <0.001 |
| 13–24 months | 1774 (14.69) | 9087 (7.53) | 2.12 | 2.00 to 2.24 | <0.001 |
| Haemoptysis | |||||
| 4–12 months | 247 (2.05) | 125 (0.10) | 20.15 | 16.24 to 25.01 | <0.001 |
| 13–24 months | 133 (1.10) | 191 (0.16) | 7.03 | 5.63 to 8.78 | <0.001 |
| Chest/shoulder pain | |||||
| 4–12 months | 1002 (8.30) | 4880 (4.04) | 2.15 | 2.00 to 2.31 | <0.001 |
| 13–24 months | 959 (7.94) | 6540 (5.42) | 1.51 | 1.40 to 1.62 | <0.001 |
| Voice hoarseness | |||||
| 4–12 months | 66 (0.55) | 219 (0.18) | 3.02 | 2.30 to 3.99 | <0.001 |
| 13–24 months | 56 (0.46) | 326 (0.27) | 1.72 | 1.30 to 2.29 | <0.001 |
| Dyspnoea | |||||
| 4–12 months | 1091 (9.04) | 2479 (2.05) | 4.74 | 4.40 to 5.10 | <0.001 |
| 13–24 months | 992 (8.22) | 3,047 (2.52) | 3.46 | 3.21 to 3.72 | <0.001 |
| Weight loss | |||||
| 4–12 months | 197 (1.63) | 323 (0.27) | 6.18 | 5.17 to 7.39 | <0.001 |
| 13–24 months | 139 (1.15) | 416 (0.34) | 3.37 | 2.78 to 4.09 | <0.001 |
| Constipation | |||||
| 4–12 months | 423 (3.50) | 1469 (1.22) | 2.95 | 2.64 to 3.29 | <0.001 |
| 13–24 months | 421 (3.49) | 1848 (1.53) | 2.32 | 2.09 to 2.59 | <0.001 |
| Depressive disorders | |||||
| 4–12 months | 365 (3.02) | 3365 (2.79) | 1.09 | 0.97 to 1.21 | 0.135 |
| 13–24 months | 449 (3.72) | 4705 (3.90) | 0.95 | 0.86 to 1.05 | 0.333 |
| URTI | |||||
| 4–12 months | 426 (3.53) | 3082 (2.55) | 1.40 | 1.26 to 1.55 | <0.001 |
| 13–24 months | 497 (4.12) | 4274 (3.54) | 1.17 | 1.06 to 1.29 | <0.001 |
| LRTI | |||||
| 4–12 months | 516 (4.27) | 1585 (1.31) | 3.36 | 3.03 to 3.71 | <0.001 |
| 13–24 months | 566 (4.69) | 2218 (1.84) | 2.63 | 2.39 to 2.89 | <0.001 |
| Non-specific chest infections | |||||
| 4–12 months | 1398 (11.58) | 4350 (3.60) | 3.50 | 3.29 to 3.73 | <0.001 |
| 13–24 months | 1356 (11.23) | 5856 (4.85) | 2.48 | 2.33 to 2.64 | <0.001 |
| COPD | |||||
| 4–12 months | 978 (8.10) | 1349 (1.12) | 7.80 | 7.17 to 8.49 | <0.001 |
| 13–24 months | 1024 (8.48) | 1553 (1.29) | 7.11 | 6.56 to 7.71 | <0.001 |
| Outcome of blood tests | |||||
| 4–12 months | |||||
| No blood test record | 6406 (53.06) | 84997 (70.40) | 1.00 | ||
| Test without results | 5431 (44.98) | 34295 (28.41) | 2.10 | 2.02 to 2.18 | |
| Abnormal | 107 (0.89) | 528 (0.44) | 2.69 | 2.18 to 3.31 | <0.001 |
| Normal | 130 (1.08) | 911 (0.75) | 1.89 | 1.57 to 2.28 | |
| 13–24 months | |||||
| No blood test record | 6136 (50.82) | 79446 (65.80) | 1.00 | ||
| Test without results | 5632 (46.65) | 39255 (32.51) | 1.86 | 1.79 to 1.93 | |
| Abnormal | 127 (1.05) | 752 (0.62) | 2.19 | 1.81 to 2.64 | <0.001 |
| Normal | 179 (1.48) | 1278 (1.06) | 1.81 | 1.55 to 2.13 | |
| Number of GP consultations | |||||
| 4–12 months | |||||
| 0–10 | 4316 (35.75) | 77720 (64.37) | 1.00 | ||
| 11–20 | 4373 (36.22) | 29327 (24.29) | 2.69 | 2.57 to 2.81 | <0.001 |
| 21 or more | 3385 (28.04) | 13684 (11.33) | 4.45 | 4.24 to 4.68 | |
| 13–24 months | |||||
| 0–10 | 3491 (28.91) | 64881 (53.74) | 1.00 | ||
| 11–20 | 3492 (28.92) | 29296 (24.27) | 2.22 | 2.11 to 2.33 | <0.001 |
| 21 or more | 5091 (42.16) | 26554 (21.99) | 3.56 | 3.41 to 3.73 | |
*p Values for binary variables were obtained using Wald's test of significance. In variables with more than two categories, p values were obtained from the likelihood ratio test.
COPD, chronic obstructive pulmonary disease; GP, general practitioner; LRTI, Lower respiratory tract infections; URTI, upper respiratory tract infections.