Odds ratios IIBMJ 2010; 341 doi: https://doi.org/10.1136/bmj.c4971 (Published 15 September 2010) Cite this as: BMJ 2010;341:c4971
- Philip Sedgwick, senior lecturer in medical statistics
- 1Centre for Medical and Healthcare Education, St George’s, University of London, Tooting, London
Researchers conducted a case-control study to investigate whether sleeping environment was associated with sudden infant death syndrome.1 The researchers aimed to include all cases of sudden unexpected death for infants aged between 7 and 364 days from five regions of England with a combined population of more than 17 million people. A total of 325 cases were identified through registers. For every case, four controls matched for age, locality, and time of sleep were included. Interviews were undertaken with the parents of all cases and controls to ascertain past sleeping environment.
Infant’s typical sleeping environment in relation to their parents was classified as usual room sleeper (shared room but not bed), usual solitary sleeper (slept in room separate from parents), or usual bed sharer (shared bed with parents for more than two nights per week). The results are presented in the table, which shows the odds ratios of sudden unexpected death for the categories of the infants’ usual sleeping environment.⇓