Measuring Exposure to the Hazardous Drinking of Others and Perceived Opportunity to Intervene as a Bystander.

Objective: Excessive alcohol use is very prevalent among young adults, and consequences of drinking are often observed by witnesses. Understanding the circumstances under which witnesses of risky alcohol use help others and whether they perceive these circumstances as an opportunity to engage in bystander intervention are important, but valid measures of these constructs are needed. The current study is a psychometric evaluation of the Exposure to Hazardous Drinking in Others (EHDO) scale and a single-item indicator of Perceived Alcohol-Related Bystander Opportunity (PARBO).

Method: Young adults ( = 1,011; 46.0% women) who reported being around someone who showed signs of alcohol intoxication in the past 3 months were recruited via Qualtrics Panels. The initial item set for the EHDO was developed through qualitative methods and reflected observed or reported risks or consequences. Factor analyses and Item Response Theory analyses were used to reduce and categorize EHDO items, and construct validity was assessed for the EHDO and the PARBO item.

Results: An initial set of 33 EHDO items was reduced to 21, representing two factors: Situational Risk Signs and Problematic Pattern. Both factors demonstrated good model fit, internal consistency, and evidence of convergent validity. The PARBO item showed good construct validity but was distinct from the EHDO.

Conclusions: These instruments are useful for measuring secondhand alcohol risks in a community and are particularly applicable for evaluating bystander intervention for alcohol risk.