A 13-item Health of the Nation Outcome Scale (HoNOS-13): validation by item response theory (IRT) in patients with substance use disorder.

"Declarations Ethics approval and consent to participateApproval was obtained from the Geneva Ethics Committee (ID 2017-00733). The procedures used in this study adhere to the tenets of the Declaration of Helsinki. This study used routinely collected anonymized hospital data. Therefore, the Geneva Ethics Committee did not request individual informed consent from each participant. Consent for publicationNot applicable. Competing interestsThe authors declare that they have no competing interests. Competing interests The authors declare that they have no competing interests."

"Funding Open access funding provided by University of Lausanne. No funding was obtained for this study."

"Trial registration ClinicalTrials.gov, Identifier: NCT03551301. Registered: 11.06.2018. Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03551301 ."