A procedure that differentiates unintentional from intentional overdose in opioid abusers

ObjectiveThe purpose of this study is to develop a procedure for assessing unintentional overdose (OD) in opiate abusers that differentiates it from intentional OD, and provides reliable information about the incident.MethodsA sample of 121 patients in a methadone maintenance program at an urban university hospital completed a baseline assessment. A total of 70 participants completed an identical assessment at least 14 days later. The ability of an OD item to differentiate unintentional OD from intentional OD was tested, as was the test-retest reliability of questions assessing symptoms and treatment of OD.ResultsThe procedure is reliable and differentiated unintentional OD from intentional OD. Questions assessing symptoms of OD were endorsed in almost every unintentional OD incident, although reliability was affected by loss of consciousness. The reliability of questions assessing emergency treatment and Narcan administration was outstanding.ConclusionsOur procedure for assessing OD differentiates unintentional OD from intentional OD. The use of follow-up questions assessing acute treatment for OD is recommended. Items concerning symptoms of OD are not needed to confirm the presence of an OD, but may be used to clarify whether an event was an OD.

► We examined if a procedure could differentiate unintentional from intentional overdose (OD).
► We examined the test-retest reliability of items assessing OD symptoms and emergency treatment.
► The procedure differentiated unintentional from intentional OD.
► OD symptoms were valid as an aggregate, but reliability was affected by loss of consciousness.
► The emergency treatment items had outstanding reliability.