Sudden unexpected death in infancy in Denmark

Figures & data

Figure 1. Flowchart of the review of death certificates in Denmark during a seven-year period (2000–2006) in infants below age one year.

Table I. Characteristics of the 192 Danish SUDI cases and comparisons between the 167 autopsied and 25 non-autopsied cases during 2000–2006.

SUDI	Total (n = 192)	Autopsied (n = 167)	Non autopsied (n = 25)	p-value
Previous medical history, n (%)	17 (9%)	9 (5%)	8 (32%)	<0.0001
Gender, male/female (% male)	116/76 (60%)	106/61 (63%)	10/15 (40%)	0.025
Median age at death	64 days	59 days	72 days	ns
SUDI autopsies
Forensic autopsy	147 (77%)
Hospital autopsy	20 (10%)
No autopsy	25 (13%)
Autopsy ratio overall	87%
Incidence rate, SUDI	0.42/1000 births

Abbreviation: SUDI = sudden unexpected death in infancy.

Table II. Causes of death after autopsy in the 167 autopsied SUDI cases in Denmark 2000–2006, categorized in major groups.

Cause of death, autopsied SUDI cases (n = 167)	n	Cardiac disease diagnosed prior to death, n
SIDS	82
Congenital heart malformations	29
Coarctation of the aorta	6
Transposition of the great arteries	5	1
Malformation of cardiac chambers, unclassified	4	1
Truncus arterious communis	3
Hypoplastic left ventricle	3	2
Single ventricle	3
Ebsteins anomaly	1
Valvular disease	2	1
Malformation of coronary artery	1
Aneurysm of pulmonal artery	1
Other heart diseases	11
HCM	2
Endocardial Fibroelastosis	2
Left ventricular hypertrophy	2
Endocarditis	1
Myocarditis	1
Benign tumor, heart	1	1
ARVC	1
Other cardiomyopathy	1
Infectious disease	28
Pneumonia	13
Sepsis	9
Meningitis	4
Epiglottitis	1
Encephalitis	1
Cerebral disease	4
Intestinal volvolus	2
Asphyxia	2
Metabolic disease	1
Other causes	8
Conclusion after autopsy
SUDI, cardiac cause	40 (24%)
SUDI, non cardiac cause	45 (27%)
SIDS	82 (49%)

Abbreviations: HCM = Hypertrophic Cardiomyopathy, ARVC = Arrhythmogenic Right Ventricular Cardiomyopathy, SUDI = sudden unexpected death in infancy, SIDS = sudden infant death syndrome.

Table III. Death circumstances in the 98 Danish SIDS cases and comparisons between the 82 autopsied and the 16 non-autopsied cases during 2000–2006.

SIDS and USID	Total (n = 98)	SIDS (n = 82)	USID (n = 16)	p-value
Median age at death	70 days	69 days	72 days	ns
Gender, male/female (% male)	55/43 (56%)	49/33 (60%)	6/10 (38%)	ns
Sleep status
Awake	10 (10%)	8 (10%)	2 (13%)	ns
Sleeping alone	46 (47%)	34 (41%)	12 (75%)	0.026
Sleeping with parents/siblings	42 (43%)	40 (49%)	2 (13%)	0.011
Event place (found)
Home, inside	88 (90%)	75 (91%)	13 (81%)	ns
Other family, inside	3 (3%)	3 (4%)	0 (0%)	ns
Outside, babycarriage	3 (3%)	0 (0%)	3 (19%)	0.004
Hospital	4 (4%)	4 (5%)	0 (0%)	ns
Position found (sleep)
Back	26 (30%)	20 (27%)	6 (43%)	ns
Prone	19 (22%)	17 (23%)	2 (14%)	ns
Side	9 (10%)	9 (12%)	0 (0%)	ns
Not stated	34 (39%)	28 (38%)	6 (43%)	ns
Time of day found (intervals of 3 hours)				0.024
00:01–03:00	13 (13%)	12 (15%)	1 (6%)
03:01–06:00	12 (12%)	12 (15%)	0 (0%)
06:01–09:00	38 (39%)	33 (40%)	5 (31%)
09:01–12:00	16 (16%)	13 (16%)	3 (19%)
12:01–15:00	6 (6%)	5 (6%)	1 (6%)
15:01–18:00	3 (3%)	1 (1%)	2 (13%)
18:01–21:00	8 (8%)	4 (5%)	4 (25%)
21:01–00:00	2 (2%)	2 (2%)	0 (0%)
Incidence rates
Incidence rate SIDS (autopsy negative, death during sleep)	0.16/1000 births
Incidence rate SIDS (autopsy negative)	0.18/1000 births
Incidence rate SIDS (including USID cases)	0.22/1000 births

Abbreviations: SUDI = sudden unexpected death in infancy, USID = unclassified sudden infant death.