The Dutch Gambling Harms Question Inventory (D-GHQI-12): Development, psychometric properties and test-retest reliability

Introduction. The Netherlands lacks a standardized Dutch-language questionnaire to measure gambling harms. To address this, the current study aimed to develop and validate a set of questions spanning all gambling harms domains relevant to the Dutch context drawing on existing questionnaires. Method. First, the performance of 26 newly developed and translated items, covering eight harm domains, was evaluated. The convergent validity, test-retest stability and adequate content coverage of the item pool were evaluated. Beyond gambling product use and engagement, reference points included the Problem Gambling Severity Index, CBA-MI Reported Financial Wellbeing Scale, Australian Personal Wellbeing scale, and Mental Health Inventory (MHI-5). Secondly, the best performing items were selected for a short form scale, to support a high chance of adoption in monitoring. Results. Items performed well across multiple psychometric criteria. They demonstrated high levels of understandability, generally supportive evidence for convergent validity, and satisfactory temporal stability. These items also correlated in expected ways with participation in higher risk gambling products. Based on these results, a choice of the most suitable item from each harm domain was made, to construct the Dutch Gambling Harms Question Inventory (D-GHQI-12). Conclusion. The new 12 item Dutch gambling harms scale was constructed around explicit harm domains, verified with international experts and Dutch stakeholders, including those with lived experience of gambling harms. This ensured that most recognised domains, including crime, physical health, mental health, and financial harms, are represented by at least one item in the inventory. Taken together, the D-GHQI-12 offers a domain-balanced, Dutch-validated tool for population monitoring.