Table 1

Overview over baseline characteristics of the study population overall and stratified by endpoints

Variable	Time period considered	Total (N=26 262)		All-cause mortality					Mechanical ventilation/ECLS/resuscitation/death
Variable	Time period considered	Total (N=26 262)		Deceased (n=2241)		Alive (n=24 021)		P value	EP+ (n=4716)		EP− (n=21 546)		P value
Age (median (Q1–Q3)), years	At admission	31 (1–74)		76 (64–84)		12 (1–70)		<0.001	67 (48–79)		7 (1–70)		<0.001
No of previous viral pneumonias	At admission							0.008					<0.001
None		24 980	95.1%	2111	94.2%	22 869	95.2%		4355	92.3%	20 625	95.7%
1		1102	4.2%	120	5.4%	982	4.1%		308	6.5%	794	3.7%
2		180	0.7%	10	0.4%	170	0.7%		53	1.1%	127	0.6%
Female gender		12 793	48.7%	1059	47.3%	11 734	48.8%	0.15	2234	47.4%	10 559	49.0%	0.04
CHD complexity								<0.001					<0.001
0—No CHD		25 082	95.5%	2211	98.7%	22 871	95.2%		4490	95.2%	20 592	95.6%
1—Simple defect		831	3.2%	17	0.8%	814	3.4%		128	2.7%	703	3.3%
2—Moderate complexity		197	0.8%	6	0.3%	191	0.8%		44	0.9%	153	0.7%
3—Complex CHD		152	0.6%	7	0.3%	145	0.6%		54	1.1%	98	0.5%
Chromosomal anomaly	Prior to admission	343	1.3%	20	0.9%	323	1.3%	0.08	83	1.8%	260	1.2%	0.004
History of cerebral infarction	Prior to admission	1564	6.0%	328	14.6%	1236	5.1%	<0.001	478	10.1%	1086	5.0%	<0.001
History of myocardial infarction	Prior to admission	702	2.7%	126	5.6%	576	2.4%	<0.001	224	4.7%	478	2.2%	<0.001
Diagnosis of heart failure	Prior to admission	948	3.6%	191	8.5%	757	3.2%	<0.001	304	6.4%	644	3.0%	<0.001
History of cancer	Prior to admission	4690	17.9%	972	43.4%	3718	15.5%	<0.001	1447	30.7%	3243	15.1%	<0.001
Immune disease	Prior to admission	1066	4.1%	116	5.2%	950	4.0%	0.007	223	4.7%	843	3.9%	0.012
History of diabetes	Prior to admission	4350	16.6%	773	34.5%	3577	14.9%	<0.001	1364	28.9%	2986	13.9%	<0.001
Obesity	Prior to admission	3323	12.7%	485	21.6%	2838	11.8%	<0.001	1006	21.3%	2317	10.8%	<0.001
Smoking history	Prior to admission	1737	6.6%	272	12.1%	1465	6.1%	<0.001	621	13.2%	1116	5.2%	<0.001
History of alcohol abuse	Prior to admission	800	3.0%	156	7.0%	644	2.7%	<0.001	301	6.4%	499	2.3%	<0.001
Severe renal dysfunction	Prior to admission	425	1.6%	76	3.4%	349	1.5%	<0.001	147	3.1%	278	1.3%	<0.001
History of arrhythmia	Prior to admission	3561	13.6%	635	28.3%	2926	12.2%	<0.001	1036	22.0%	2525	11.7%	<0.001
Arterial hypertension	Prior to admission	8663	33.0%	1533	68.4%	7130	29.7%	<0.001	2624	55.6%	6039	28.0%	<0.001
Chronic lung disease	Prior to admission	7816	29.8%	777	34.7%	7039	29.3%	<0.001	1612	34.2%	6204	28.8%	<0.001
Documented vaccination
Influenza	1 year prior	4199	16.0%	647	28.9%	3552	14.8%	<0.001	1157	24.5%	3042	14.1%	<0.001
Pneumococcal disease	5 years prior	1757	6.7%	248	11.1%	1509	6.3%	<0.001	481	10.2%	1276	5.9%	<0.001
Prescription medication
Cardiac medication	1 year prior	10 063	38.3%	1741	77.7%	8322	34.6%	<0.001	3012	63.9%	7051	32.7%	<0.001
Antidepressant or antipsychotic drugs	1 year prior	3768	14.3%	720	32.1%	3048	12.7%	<0.001	1172	24.9%	2596	12.0%	<0.001
Anticonvulsives	1 year prior	2212	8.4%	357	15.9%	1855	7.7%	<0.001	690	14.6%	1522	7.1%	<0.001
NSAIDs	1 year prior	9062	34.5%	658	29.4%	8404	35.0%	<0.001	1416	30.0%	7646	35.5%	<0.001
Antidiabetics	1 year prior	2790	10.6%	490	21.9%	2300	9.6%	<0.001	911	19.3%	1879	8.7%	<0.001
Pulmonary hypertension drugs	1 year prior	69	0.3%	11	0.5%	58	0.2%	0.047	24	0.5%	45	0.2%	0.001
Anticoagulation vitamin K antagonists	1 year prior	1425	5.4%	249	11.1%	1176	4.9%	<0.001	429	9.1%	996	4.6%	<0.001
Novel oral anticoagulants	1 year prior	1244	4.7%	263	11.7%	981	4.1%	<0.001	407	8.6%	837	3.9%	<0.001
Antiplatelet drugs	1 year prior	2432	9.3%	474	21.2%	1958	8.2%	<0.001	745	15.8%	1687	7.8%	<0.001
Immunosuppressant medication	1 year prior	6073	23.1%	706	31.5%	5367	22.3%	<0.001	1313	27.8%	4760	22.1%	<0.001

P-values represent comparisons between endpoint positive and negative groups. Significant values are given in bold.
CHD, congenital heart disease; ECLS, extracorporeal lung support; ; EP, endpoint; NSAIDS, non-steroidal anti-inflammatory drugs; Q1–Q3, first and third quartiles.