FOI reference: FOI-2025-2673
You asked
Safer sleep guidance states that the following are risk factors for Sudden Infant Death Syndrome (SIDS) (the "Risk Factors"):
- Baby not put to sleep on their back
- Baby not sleeping on their own separate surface
- Baby not on a firm surface
- Baby not on a flat surface
- Baby not on a waterproof surface
- Baby exposed to cigarette smoke
- Room temperature above 20 degrees celcius
- Baby not in the same room as parents
- Sleep surface not clear
Could you please disclose the following information relating to SIDS:
- Please provide a breakdown of how many cases of SIDS were related to each of the risk factors (e.g. Baby not on a firm surface: [number] SIDS cases). Please provide data for each year starting at 2000.
- Is it correct to say that the primary source of data about the circumstances in which SIDS occurs (e.g. what type of mattress was slept on, room temperature, sleep location, presence of soft bedding, parental drinking/smoking, etc.) is the baby's parents?
- How is this data about circumstances verified for accuracy and to what extent is information from the parents assumed to be accurate without verification?
We said
Thank you for your request.
Unfortunately we do not hold the information you have requested.
Our mortality data comes from the information collected at death registration. All the conditions mentioned on the death certificate are coded using the International Classification of Diseases, Tenth Revision (ICD-10). From all of these causes an underlying cause of death is selected using ICD-10 coding rules.
The underlying cause of death is defined by WHO as:
a) the disease or injury that initiated the train of events directly leading to death, or\ b) the circumstances of the accident or violence that produced the fatal injury
While there are ICD-10 codes indicating whether a death is due to SIDS (R95.0, R95.9 and R96.0), there are no further breakdowns within those codes to indicate SIDS due to a particular event such as baby not sleeping on their back, for example. Consequently, we are only able to produce total numbers of SIDS cases each year, which you can find in our Unexplained Deaths in Infancy release, most recently published for 2022. In Table 1 you will find counts of SIDS deaths by sex and age for each year from 2004 to 2022.
We do not hold any further information on the nature or circumstance of a death from SIDS. There are organisations other than the ONS that conduct research into SIDS, including The Lullaby Trust, Sands, and Tommy's. These organisations may collect information relevant to your query.