CLINICAL EVIDENCE CONCISE: A PUBLICATION OF BMJ PUBLISHING GROUP

Sudden Infant Death Syndrome

DAVID CREERY, M.D., and ANGELO MIKROGIANAKIS, M.D.
Children's Hospital of Eastern Ontario, Ottawa, Canada

What are the effects of interventions to reduce the risk of sudden infant death syndrome?

BENEFICIAL

Advice to Avoid Prone Sleeping. Several observational studies found that campaigns involving advice to encourage nonprone sleeping positions were followed by a reduced incidence of sudden infant death syndrome (SIDS). Randomized controlled trials (RCTs) are unlikely to be conducted.

LIKELY TO BE BENEFICIAL

Advice to Avoid Tobacco Smoke Exposure. Several observational studies found limited evidence that campaigns to reduce several risk factors for sudden infant death, which included tobacco smoke exposure, were followed by a reduced incidence of SIDS. RCTs are unlikely to be conducted.

UNKNOWN EFFECTIVENESS

Advice to Avoid Bed Sharing. One observational study found that a campaign to reduce several risk factors for sudden infant death, which included advice to avoid bed sharing, was followed by a reduced incidence of SIDS. RCTs are unlikely to be conducted.

Advice to Avoid Over Heating or Over Wrapping. Three observational studies found limited evidence that campaigns to reduce several risk factors for sudden infant death, which included over wrapping, were followed by a reduced incidence of SIDS. RCTs are unlikely to be conducted.

Advice to Avoid Soft Sleep Surfaces. We found no evidence on the effects of avoiding soft sleeping surfaces in the prevention of SIDS.

Advice to Breastfeed. One nonsystematic review of observational studies and three additional observational studies found that campaigns to reduce several risk factors for sudden infant death, which included advice to breastfeed, were followed by a reduced incidence of SIDS. In some countries, however, incidence had begun to fall before the national advice campaigns. RCTs are unlikely to be conducted.

Advice to Promote Soother Use. We found insufficient evidence on soother use in the prevention of SIDS.

Definition

SIDS is the sudden death of an infant younger than one year that remains unexplained after review of the clinical history, examination of the scene of death, and postmortem.

Incidence/Prevalence

The incidence of SIDS has varied over time and among nations (incidence per 1,000 live births of SIDS in 1996: Netherlands, 0.3; Japan, 0.4; Canada, 0.5; England and Wales, 0.7; United States, 0.8; and Australia, 0.9).¹

Etiology/Risk Factors

By definition, the cause of SIDS is not known. Observational studies have found an association between SIDS and several risk factors, including prone sleeping position,^2,3 prenatal or postnatal exposure to tobacco smoke,⁴ soft sleeping surfaces,^5,6 hyperthermia or over wrapping,^7,8 bed sharing (particularly with mothers who smoke),^9,10 lack of breastfeeding,^11,12 and soother use.^7,13

Prognosis

Although by definition prognosis is not applicable for an affected infant, the incidence of SIDS is increased in the siblings of that infant.^14,15

SEARCH DATE: March 2003

Adapted with permission from Creery D, Mikrogianakis A. Sudden infant death syndrome. Clin Evid Concise 2003;10:In press.

REFERENCES

1. Canadian Bureau of Reproductive and Child Health/Laboratory Centre for Disease Control/ Canadian Perinatal Surveillance System (CPSS); Fact sheet: www.hc-sc.gc.ca/hpb/lcdc/brch/factshts/ sids_e.html (Accessed August 28, 2003).
2. Beal SM, Finch CF. An overview of retrospective case-control studies investigating the relationship between prone sleeping position and SIDS. J Paediatr Child Health 1991;27:334-9.
3. American Academy of Pediatrics. AAP Task Force on Infant Positioning and SIDS: Positioning and SIDS. Pediatrics 1992;89(6 pt 1):1120-6.
4. Anderson HR, Cook DG. Passive smoking and sudden infant death syndrome: review of the epidemiological evidence. Thorax 1997;52:1003-9.
5. Mitchell EA, Thompson JM, Ford RP, et al. Sheepskin bedding and the sudden infant death syndrome. New Zealand Cot Death Study Group. J Pediatr 1998;133:701-4.
6. Ponsonby AL, Dwyer T, Gibbons LE, et al. Factors potentiating the risk of sudden infant death syndrome associated with the prone position. N Engl J Med 1993;329:377-82.
7. Fleming PJ, Blair PS, Bacon C, et al. Environment of infants during sleep and risk of the sudden infant death syndrome: results of the 1993-5 case-control study for confidential enquiry into stillbirths and deaths on infancy. Confidential Enquiry into Stillbirths and Deaths Regional Coordinators and Researchers. BMJ 1997;313:85-9.
8. Ponsonby AL, Dwyer T, Gibbons LE, et al. Thermal environment and sudden infant death syndrome: case-control study. BMJ 1992;304:277-82.
9. Mitchell EA, Tuohy PG, Brunt JM, et al. Risk factors for sudden infant death syndrome following the prevention campaign in New Zealand: a prospective study. Pediatrics 1997;100:835-40.
10. Scragg R, Mitchell EA, Taylor BJ, et al. Bed sharing, smoking, and alcohol in the sudden infant death syndrome. New Zealand Cot Death Study Group. BMJ 1993;307:1312-8.
11. Mitchell EA, Taylor BJ, Ford RP, et al. Four modifiable and other major risk factors for cot death: the New Zealand study. J Paediatr Child Health 1992; 28(suppl 1):S3-8.
12. Wennergren G, Alm B, Oyen N, et al. The decline in the incidence of SIDS in Scandinavia and its relation to risk-intervention campaigns. Nordic Epidemiological SIDS Study. Acta Paediatr 1997;86:963-8.
13. L'Hoir MP, Engelberts AC, van Well GT, et al. Risk and preventive factors for cot death in The Netherlands, a low-incidence country. Eur J Pediatr 1998; 157:681-8.
14. Oyen N, Skjaerven R, Irgens LM. Population-based recurrence risk of sudden infant death syndrome compared with other infant and fetal deaths. Am J Epidemiol 1996;144:300-5.
15. Guntheroth WG, Lohmann R, Spiers PS. Risk of sudden infant death syndrome in subsequent siblings. J Pediatr 1990;116:520-4.

This clinical content conforms to AAFP criteria for evidence-based continuing medical education (EB CME). EB CME is clinical content presented with practice recommendations supported by evidence that has been systematically reviewed by an AAFP-approved source. The practice recommendations in this activity are available at www.clinicalevidence.com/lpBinCE/lpext.dl?f=templates&fn=main-h.htm&2.0.

This is one in a series of chapters excerpted from Clinical Evidence Concise, published by the BMJ Publishing Group, Tavistock Square, London, United Kingdom. Clinical Evidence Concise is published in print twice a year and is updated monthly online. Each topic is revised every eight months, and users should view the most up-to-date version atwww.clinicalevidence.com. If you are interested in contributing to Clinical Evidence, please contact Claire Folkes (cfolkes@bmjgroup.com). This series is part of the AFP's CME. See "Clinical Quiz" on page 1261.