TABLE 1

Patient characteristics of 885 806 hospitalisations with acute pulmonary embolism (PE) stratified by seasons

WinterSpringSummerAutumnp-value for difference between summer and winter
Temperature
 Median temperature# in Germany1.1 (−0.5–3.6)8.7 (5.7–12.4)17.2 (16.1–18.2)9.1 (6.8–12.8)<0.001
Incidence, total numbers and length of stay
 3-month incidence of PE per 100 000 citizens25.524.123.725.30.021
 Number of PE events229 379 (25.9%)216 420 (24.4%)212 595 (24.0%)227 412 (25.7%)0.021
 In-hospital stay days10 (6–16)10 (6–17)10 (6–16)10 (6–16)0.001
Patients' characteristics and comorbidities
 Age at event years72.0 (61.0–80.0)72.0 (61.0–80.0)72.0 (60.0–80.0)72.0 (60.0–80.0)<0.001
 Age >70 years124 578 (54.3%)117 899 (54.5%)114 166 (53.7%)122 950 (54.1%)<0.001
 Female sex (n=885 770)124 150 (54.1%)117 827 (54.4%)113 473 (53.4%)123 428 (54.3%)<0.001
 Obesity21 224 (9.3%)20 936 (9.7%)21 162 (10.0%)21 961 (9.7%)<0.001
 Diabetes mellitus42 018 (18.3%)40 781 (18.8%)40 720 (19.2%)42 233 (18.6%)<0.001
 Hyperlipidaemia25 882 (11.3%)24 649 (11.4%)24 472 (11.5%)27 035 (11.9%)0.017
 Essential arterial hypertension96 860 (42.2%)91 899 (42.5%)89 806 (42.2%)97 545 (42.9%)0.916
 Coronary artery disease31 183 (13.6%)30 406 (14.0%)29 801 (14.0%)31 448 (13.8%)<0.001
 Heart failure47 476 (20.7%)46 496 (21.5%)45 372 (21.3%)47 783 (21.0%)<0.001
 Atrial fibrillation/flutter35 256 (15.4%)34 420 (15.9%)33 288 (15.7%)34 647 (15.2%)0.008
 Cancer43 596 (19.0%)43 227 (20.0%)44 066 (20.7%)45 344 (19.9%)<0.001
 COPD24 313 (10.6%)23 513 (10.9%)21 756 (10.2%)23 076 (10.1%)<0.001
 Stroke6099 (2.7%)5887 (2.7%)5921 (2.8%)5909 (2.6%)0.010
 Acute and chronic kidney disease44 862 (19.6%)43 408 (20.1%)43 633 (20.5%)45 340 (19.9%)<0.001
Bleeding events during hospitalisation
 Gastro-intestinal bleeding3127 (1.4%)2939 (1.4%)2961 (1.4%)3120 (1.4%)0.400
 Subarachnoid bleeding305 (0.1%)318 (0.1%)354 (0.2%)341 (0.1%)0.004
 Intracerebral bleeding1274 (0.6%)1273 (0.6%)1265 (0.6%)1248 (0.5%)0.082
 Transfusion of erythrocyte concentrates25 428 (11.1%)25 681 (11.9%)26 432 (12.4%)26 286 (11.6%)<0.001
Reperfusion treatments
 Surgical embolectomy351 (0.2%)322 (0.1%)346 (0.2%)375 (0.2%)0.415
 Systemic thrombolysis9791 (4.3%)8858 (4.1%)8812 (4.1%)9456 (4.2%)0.041
Risk stratification and deep vein thrombosis
 Deep vein thrombosis or thrombophlebitis83 757 (36.5%)76 093 (35.2%)75 469 (35.5%)82 669 (36.4%)<0.001
 Tachycardia4099 (1.8%)3947 (1.8%)4038 (1.9%)4211 (1.9%)0.005
 Syncope5459 (2.4%)5057 (2.3%)5006 (2.4%)5356 (2.4%)0.582
 Haemodynamic instability20 549 (9.0%)19 478 (9.0%)19 032 (9.0%)19 584 (8.6%)0.942
 Shock7848 (3.4%)7668 (3.5%)7582 (3.6%)7841 (3.4%)0.009
Primary outcome
 CPR15 949 (7.0%)15 002 (6.9%)14 486 (6.8%)15 082 (6.6%)0.068
 In-hospital death38 921 (17.0%)37 115 (17.1%)35 439 (16.7%)35 759 (15.7%)0.008

Data are presented as n (%) or median (interquartile range), unless otherwise stated. CPR: cardiopulmonary resuscitation. #: Median temperature in the different seasons during the observational timeframe (2005–2015); : Obesity was defined according to the World Health Organization (body mass index ≥30 kg·m−2). Bold text indicates p<0.05.