Table 3.
Frequency of symptom combinations for headache and cognitive features in 1 or 6 months before diagnosis
| Brain tumour status | PPV††(%) | PLR (95% CI) | ||||
| Case (n=8184) | Control (n=28 110) | |||||
| Number with symptoms | Sensitivity | Number with symptoms | Specificity | |||
| Headache | ||||||
| Headache plus (1 month) | 476 | (5.8) | 81 | (99.7) | 0.7 | 18.1 (16.6 to 19.8) |
| Headache only (1 month) | 687 | (8.4) | 437 | (98.4) | 0.1 | 3.92 (3.65 to 4.21) |
| Headache plus (6 months) | 569 | (7.0) | 116 | (99.6) | 0.6 | 16.3 (15.0 to 17.6) |
| Headache only (6 months) | 594 | (7.3) | 402 | (98.6) | 0.1 | 3.57 (3.30 to 3.86) |
| Headache +depression (6 months) | 83 | (1.0) | 32 | (99.9) | 0.4 | 9.90 (7.99 to 12.3) |
| Headache +cognition (6 months) | 47 | (0.6) | 2 | (100.0) | 5.9 | 165 (123 to 221) |
| Headache +weakness (6 months) | 35 | (0.4) | 1 | (100.0) | 4.4 | 122 (87 to 171) |
| Headache +nausea (6 months) | 167 | (2.0) | 11 | (100.0) | 2.0 | 55 (47 to 64) |
| Cognitive* | ||||||
| Cognitive plus (1 month) | 325 | (4.0) | 48 | (99.8) | 1.5 | 39 (35 to 44) |
| Cognitive only (1 month) | 435 | (5.3) | 140 | (99.5) | 0.7 | 18.9 (17.2 to 20.7) |
| Cognitive plus (6 months) | 379 | (4.6) | 69 | (99.8) | 1.2 | 32.0 (29.0 to 35.3) |
| Cognitive only (6 months) | 381 | (4.7) | 119 | (99.6) | 0.7 | 19.6 (17.8 to 21.7) |
| Cognitive +depression (6 months) | 62 | (0.8) | 20 | (99.9) | 0.5 | 12.9 (10.1 to 16.6) |
| Cognitive +headache (6 months) | 111 | (1.4) | 4 | (100.0) | 7.2 | 205 (169 to 249) |
| Cognitive +weakness (6 months) | 19 | (0.2) | 1 | (100.0) | 9.6 | 282 (176 to 451) |
| Cognitive +nausea (6 months) | 60 | (0.7) | 5 | (100.0) | 3.5 | 96 (74 to 124) |
*This cognitive variable is a composite of cognition, concentration and confusion symptoms.
† Calculated after weighting for population sampling.
PLR, positive likelihood ratio; PPV, positive predictive value.