Forecasting the impact of means restriction on the suicide mortality rate in the Region of the Americas: an ecological modeling study.

Background: The suicide mortality rate has been increasing in Region of the Americas, despite decreasing in all other World Health Organization (WHO) regions. Means restriction is an effective evidence-based intervention for suicide prevention. The objective of the current study was to estimate the impact of implementing national-level means restriction policies (i.e., firearm and pesticide restrictions) on the suicide mortality rate in the Region of the Americas. Methods: In this ecological modeling study, two counterfactual scenarios were investigated using sex-specific suicide mortality data from the WHO Global Health Estimates database for 2000 to 2019. Forecasted sex-specific age-standardized suicide mortality rates were then estimated for each country for 2020 to 2030. Counterfactual scenario 1 involved modeling the impact of a firearm or pesticide restriction implemented in 2020 for those countries where the respective means accounted for 40% or more of all suicides for at least one sex in 2019, while in counterfactual scenario 2 this threshold was reduced to 20% or more. Findings: It was estimated that if a firearm or pesticide restriction had been implemented in 2020 in those countries where the respective means accounted for 40% or more of all suicides for at least one sex in 2019, by 2030 the male and female suicide mortality rate in the Region of the Americas would be 20.5% (from 14.5 [95% Confidence Interval [CI]: 14.1, 15.0] per 100,000 males to 11.5 [95% CI: 11.1, 12.0] per 100,000 males) and 11.1% (from 4.5 [95% CI: 4.4, 4.7] per 100,000 females to 4.0 [95% CI: 3.9, 4.2] per 100,000 females) lower than the rate if no such restrictions were implemented, respectively. When the threshold was reduced to 20% or more, minimal additional gains in terms of number of suicides avoided and suicide mortality rate reduction would be achieved. Interpretation: The implementation of a firearm or pesticide restriction policy in countries where the respective means account for a large proportion of suicides (e.g., at least 40%) could aid the Region of the Americas in achieving the WHO target of a one third reduction in the suicide mortality rate by 2030. Funding: This work received no funding.