Sudden Infant Death Syndrome (SIDS) in Denmark: Evaluation of the Increasing Incidence of Registered SIDS in the Period 1972 to 1983 and Results of a Prospective Study in 1987 through 1988
To investigate a reported increase, from 0.4 to 1.3 per thousand live births, in the Danish incidence of sudden infant death syndrome (SIDS), a retrospective analysis of SIDS in Denmark from 1972 to 1983 was carried out. Based on data registered with the National Board of Health, a notable regional difference in SIDS rate between the western and eastern parts of Denmark was found. This difference did not correlate with the overall postneonatal mortality by region. Danish law requires medicolegal investigation in all cases of sudden unexpected death. Medicolegal autopsies are performed only in the three forensic institutes which cover all of Denmark. Despite the law and a uniform organization of the forensic medical services, differing application of postmortem examinations and individual interpretation of the history and autopsy in cases of sudden infant death existed. Differences in reporting of respiratory infections, suffocation, and cardiac malformation were found to contribute to the increase and to regional disparities in SIDS incidence. The three Danish forensic institutes examined all cases of sudden infant deaths in Denmark 1987 and 1988. These cases were classified as explained cause of death, pure SIDS, and atypical SIDS; atypical cases were evaluated by consensus. The SIDS incidence (the number of classic SIDS and atypical SIDS per thousand live births) was 1.9 in 1987 and 1.3 in 1988, and it was identical in the eastern and western part of Denmark; however, a higher incidence both of overall postneonatal and SIDS mortality was found in the middle region of Denmark. The analysis stresses the importance of high autopsy rate and expert investigation in all cases of infant death in order to obtain reliable data for epidemiological studies. A prospective joint study of all postneonatal infant deaths in Finland, Iceland, Norway, Sweden, and Denmark will be carried out to analyze the reliability and the possible cause of reported differences in SIDS incidence in the five Nordic countries.
- Received December 5, 1990.
- Accepted June 18, 1991.
- Copyright © 1992 by the American Academy of Pediatrics