Sociodemographic and clinical characteristics of suicide methods in Denmark: A nationwide registry-based study of suicides during 2010-2020.

BACKGROUND

Suicide mortality is influenced by the lethality of the method used, making it essential for effective suicide prevention. This nationwide study examined whether suicide methods differ by sociodemographic and clinical characteristics among individuals who died by suicide in Denmark.

METHODS

We conducted a retrospective register-based cohort study including all suicide decedents in Denmark between 2010 and 2020 (n = 6257). Data were obtained from Danish national health registers. Multinomial logistic regression examined associations between individual characteristics and suicide methods, using hanging as the reference category. Statistical significance was assessed with Holm-Bonferroni-adjusted p-values.

RESULTS

Compared with hanging, self-poisoning with drugs was significantly associated with female sex (male: OR = 0.37, 95%CI [0.31-0.44]), psychotropic drug treatment (OR = 1.61, 95%CI [1.25-2.07]), and previous suicide attempts (OR = 1.46, 95%CI [1.22-1.73]). Self-poisoning with other substances was more common among individuals without known health conditions. Firearms were significantly associated with male sex (OR = 10.11, 95%CI [5.58-18.32]), and absence of psychiatric history (OR = 0.42, 95%CI [0.27-0.64]). Suicide by jumping was significantly associated with recent psychiatric admissions (OR = 2.52, 95%CI [1.87-3.40]), psychotic disorders (OR = 1.69, 95%CI [1.25-2.27]) and OCD (OR = 3.65, 95%CI [1.71-7.76]). Hanging was the most used method among individuals with a history of affective disorders.

CONCLUSIONS

Suicide methods were associated with distinct sociodemographic and clinical characteristics, indicating heterogeneity in method-specific profiles. Individuals using less lethal methods were more likely to have previous healthcare contact, indicating opportunities for targeted prevention, whereas violent methods appeared more strongly related to access to means and non-help-seeking. These findings support method-specific suicide risk assessment and prevention strategies.