Opioid overdose risk during and after drug treatment for heroin dependence: an incidence 1 density case-control study nested in the VEdeTTE cohort

Fabrizio Faggiano, Federica Mathis, Roberto Diecidue, Federica Vigna-Taglianti, Maria Paola Caria, Samantha Colledge*, Matt Hickman, Annamaria Bargagli, Marina Davoli

*Corresponding author for this work

Research output: Contribution to journalArticle (Academic Journal)peer-review

Abstract

Aims: To corroborate protective effects of a range of drug treatment modalities against overdose mortality risk. Design & Methods: Nested case-control study, with incidence density sampling, selecting controls retrospectively at each case event. Cases and controls came from a sub-cohort of opioid dependent patients (N=4,444) from two Italian regions (Lazio and Piedmont). From 1998 to 2005, there were 91 overdose deaths (cases) matched to 352 controls. The primary outcome was overdose mortality and the primary exposure was drug treatment: opioid agonist treatment (OAT), opioid detoxification, residential community, psychosocial, and other pharmacological treatment. Conditional logistic regression models generated intervention effects comparing mortality risk in and out of treatment, adjusting for confounding variables. Results: Overall, drug treatment reduced overdose mortality risk by 80% (adjusted odds ratio [AOR]: 0.18, 95%CI: 0.10-0.33, p<0.001) compared to being out of treatment. There was a particularly strong protective effect of OAT on overdose mortality (AOR: 0.08, 95%CI: 0.03-0.23, p<0.001) compared to being out of treatment. There was evidence of a substantially elevated risk of overdose in the first month of leaving treatment (AOR=23.50, 95%CI: 7.84-70.19, p<0.001) compared to being in treatment. Discussion & Conclusions: The nested case-control design strengthened earlier findings that OAT in Italy has strong protective effects on overdose mortality risk, much stronger than has been previously seen in other Western European settings.
Original languageEnglish
Number of pages6
JournalDrug and Alcohol Review
Volume(2020)
DOIs
Publication statusPublished - 23 Sep 2020

Keywords

  • Opioid agonist treatment
  • heroin dependence
  • drug treatment
  • methadone maintenance
  • overdose mortality

Fingerprint Dive into the research topics of 'Opioid overdose risk during and after drug treatment for heroin dependence: an incidence 1 density case-control study nested in the VEdeTTE cohort'. Together they form a unique fingerprint.

Cite this