Reliability of suicide statistics: key considerationsfor suicide research in Ontario, Canada

Suicides tend to be under-reported (by 10 to 38% in Canada) since many suicides are ‘hidden’ and considered ‘undetermined death’ or ‘accidental death’ through poisoning or drowning. 

Three key issues identified during designing suicide studies on the general population in Ontario are:

1.   Limitations of coronial method in differentiating suicides from deaths from drug self-intoxication;

2.  Selection of ICD codes in suicide research excludes undetermined deaths; and

3.  MAID (Medical assistance in dying) deaths are not counted as suicides. As the criteria for MAID are further expanded, even more suicides may be hidden by being counted as a ‘natural death’ albeit by MAID.

The reliability of suicide statistics depends on the way a jurisdiction determines what is counted as a suicide.

The Ontario approach of coronial determination and the standard ICD-code inclusions for suicide, mean that suicide counts often exclude suicides from injuries or poisoning.

Suicide mortality statistics are likely being impacted as a result of legal and administrative changes from MAID, particularly as the criteria for MAID have, and will likely be further, expanded.