Table 1 Definitions and statistical measures of suicidal behavior outcomes

Completed suicide

Death caused by self-inflicted injurious behavior intended to end one’s own life

International classification of diseases (eighth, ninth, or tenth revisions) using diagnostic codes (E950-E950: ICD8, ICD9) or (X60-X84: ICD10)

Cox proportional hazard model

[15-21,26-28,32]

Linear regression

Logistic regression

In some studies, associations were also estimated with undetermined deaths (deaths where it was uncertain whether the cause was suicide; (E980-E989: ICD 8, ICD 10) or codes (Y10-Y34, ICD 10))

Pearson correlation (ecological analysis)

Spearman’s rank correlation (ecological analysis)

Chi-square

Wilcoxon-Mann-Whitney test

Verified using mortality registries (for example, National Death Registry, National Death Index), by next of kin and/or using pathology and medical records.

Incidence rate ratio

Attempted suicide

Potentially self-injurious behavior with a non-fatal outcome for which there is either explicit or implicit evidence that the person intended to kill him or herself [63].

Hospital Discharge Registries or Medical Records using aforementioned diagnostic codes for intentional injuries: (E950-E950: ICD8, ICD9) or (X60-X84: ICD10).

Cox proportional hazard model

[42-47]

2012 to present: [29,34,48-51]

Logistic regression

Incidence rate ratio

Self-reported using questionnaire (for example, Suicide Behaviours Questionnaire - Revised, AUDADIS, M-CIDI)

Self-reported using single-question (e.g. “How often have you already tried to take your own life”)

Suicidal ideation

Having thoughts, plans, and/or impulses for suicidal behavior, including contemplation of attempting or completing suicide.

Self-reported using questionnaire (for example, Depressive Symptom Index - Suicidality Subscale, Suicide Behaviors Questionnaire - Revised).

Logistic regression Linear regression

[42,47]

2012 to present: [48,50,52]