Comparison of pulmonary embolism (PE)-positive and PE-negative groups
| All | PE positive | PE negative | p-value | |
| Subjects n | 135 | 32 | 103 | |
| Males | 94 (70) | 26 (81) | 68 (66) | 0.103 |
| Age years | 64 (54–76) | 70 (59–77) | 63 (52–75) | 0.207 |
| D-dimer µg·L−1 | 1600 (1010–3644) | 9841 (2921–10 000) | 1285 (891–2742) | <0.001 |
| Days since symptom onset | 8 (5–12) | 7 (5–14) | 8 (5–11) | 0.597 |
| Hospitalisation days | 5 (4–8) | 7 (3–11) | 5 (4–8) | 0.239 |
| CTPA for clinical deterioration | 72 (53) | 17 (53) | 55 (53) | 0.979 |
| Disease extent increase compared to previous CT¶ | 43 (81) | 5 (50) | 38 (88) | 0.009 |
| Disease extent | 0.146# | |||
| Low <25% | 19 (14) | 3 (9) | 16 (16) | |
| Moderate 25–50% | 47 (35) | 9 (28) | 38 (37) | |
| Severe >50% | 69 (51) | 20 (63) | 49 (47) | |
| ICU | 24 (18) | 12 (38) | 12 (12) | 0.001 |
| Mechanical ventilation | 18 (13) | 10 (31) | 8 (8) | 0.001 |
Categorical variables are presented as n (%) and comparisons between the two groups were made using the Chi-squared test. Continuous variables are presented as median (interquartile range) and comparisons between the two groups were made using the Mann–Whitney U-test. Bold indicates statistical significance. CTPA: computed tomography pulmonary angiography; CT: computed tomography; ICU: intensive care unit. ¶: Cochran–Armitage trend test; #: only 53 of the 72 inpatients had a previous CT.