Creating and evaluating the score to assess overdose: the OD score.

"Declarations Ethics approval and consent to participateThe Teikyo University Medical Research Ethics Committee approved this retrospective study (approval number: 22–077). All methods were carried out in accordance with the declaration of Helsinki. This was an observational study that added no extra intervention to the usual care of patients. Therefore, the requirement for informed consent was waived by Teikyo University Medical Research Ethics Committee. The use of research data that did not include personal information was announced on the Teikyo University website, which provided the subjects with the opportunity to opt out of the study. Consent for publicationNot applicable. Competing interestsThe authors declare no competing interests. Competing interests The authors declare no competing interests."

"Funding This work was supported by Innovative Research Program on Suicide Countermeasure Grant Number JPSCIRS20220304 (for KN)."