BACKGROUND: Suicide is a major public health issue, and a priority requirement 
is accurately identifying high-risk individuals. The SAD PERSONS suicide risk 
assessment scale is widely implemented in clinical settings despite limited 
supporting evidence. This article aims to determine the ability of the SAD 
PERSONS scale (SPS) to predict future suicide in the emergency department.
METHODS: Five thousand four hundred sixty-two consecutive adults were seen by 
psychiatry consultation teams in two tertiary emergency departments with linkage 
to population-based administrative data to determine suicide deaths within 6 
months, 1, and 5 years.
RESULTS: Seventy-seven (1.4%) individuals died by suicide during the study 
period. When predicting suicide at 12 months, medium- and high-risk scores on 
SPS had a sensitivity of 49% and a specificity of 60%; the positive and negative 
predictive values were 0.9 and 99%, respectively. Half of the suicides at both 
6- and 12-month intervals were classified as low risk by SPS at index visit. The 
area under the curve at 12 months for the Modified SPS was 0.59 (95% confidence 
interval [CI] range 0.51-0.67). High-risk scores (compared to low risk) were 
significantly associated with death by suicide over the 5-year study period 
using the SPS (hazard ratio 2.49; 95% CI 1.34-4.61) and modified version (hazard 
ratio 2.29; 95% CI 1.24-2.29).
CONCLUSIONS: Although widely used in educational and clinical settings, these 
findings do not support the use of the SPS and Modified SPS to predict suicide 
in adults seen by psychiatric services in the emergency department.