Development of Opioid Overdose Knowledge (OOKS) and Attitudes (OOAS) Scales for take-home naloxone training evaluation.

AIMS: To develop an Opioid Overdose Knowledge Scale (OOKS) and an Opioid Overdose Attitudes Scale (OOAS) to evaluate take-home naloxone training.

METHODS: Psychometric instrument development study conducted in England using convenience samples. Forty-five items were selected for the OOKS organised in four sub-scales (risks, signs, actions and naloxone use). The OOAS was formed initially of 32 items grouped in three sub-scales (competence, concerns and readiness). Both scales were administered to 42 friends and family members of heroin users and 56 healthcare professionals to assess internal reliability and construct validity. The Brief Overdose Recognition and Response Assessment (BORRA) and the General Self-Efficacy Scale (GSE) were also administered to family members to test concurrent validity. Family members completed the OOKS and OOAS on a second occasion to assess test-retest reliability.

RESULTS: The OOKS and OOAS were internally reliable (Cronbach's alpha=0.83 and 0.90, respectively). Retest was completed by 33 participants after 14 (SD 7) days (OOKS, ICC=0.90 and OOAS, ICC=0.82) with sub-scale item sets from each measure falling within the fair-to-excellent range (ICC=0.53-0.92). Professionals reported significantly higher scores on both scales than family members. The OOKS total score was positively correlated with the BORRA's Overdose Recognition (r=0.5, P<0.01) and Naloxone Indication sub-scales (r=0.44, P<0.05), but the total score on the OOAS was not associated with the GSE (r=0.02, NS).

CONCLUSION: The 45-item OOKS and 28-item OOAS are suitable as outcome measures of take-home naloxone training for friends and family members of opioid users.