Suicide failure rates are highly associated with the method chosen. In particular, abortability, acceptability, and inherent lethality are important. Jumping, for example, is relatively lethal, but because most people fear heights many people abort before they work themselves up enough to jump.

According to a metastudy,

Based on the suicide acts that resulted in death or hospitalization, firearms were found to be the most lethal method (CFR:89.7%), followed by hanging/suffocation (84.5%), drowning (80.4%), gas poisoning (56.6%), jumping (46.7%), drug/liquid poisoning (8.0%) and cutting (4.0%).

(CFR = Case Fatality Rate)