Weighing the Harm: Direct Elicitation of Gambling Harm Severity Through Expert Evaluation of Narrative Accounts.

This study examined whether direct expert elicitation of gambling harm severity, applied to blinded first-hand narrative accounts, produces ordered and consistent estimates with respect to quantitative self-reports. As such, this represented independent convergent validation evidence of the Gambling Harms Scales (GHS) instruments for people who gamble and affected others (AOs). Six experts with significant research or clinical expertise in the gambling field evaluated 60 transcripts from people who gamble and AOs experiencing varying levels of gambling-related harm (no-harm, low-harm, moderate-harm, and high-harm). Each transcript was evaluated using four protocols (visual analogue scale, rank ordering, time trade-off, and standard gamble). Narratives from participants with higher levels of harm (as assessed by the GHS) were associated with significantly higher expert-elicited health disutility. Disutility increased monotonically with GHS harm bands, and this pattern was consistent across all four elicitation protocols and all six expert raters. Pooled disutility estimates were 0.084 for low-harm, 0.187 for moderate-harm, and 0.221 for high-harm. Harm severity elicited by interviews and expert assessment was consistent with harm severity as assessed by the brief GHS measures. Expert evaluation of blinded narrative accounts provides independent external evidence supporting the GHS suite of instruments as measures of gambling-related harm.