Evaluating the reliability and validity of the short gambling harm screen: Are binary scales worse than Likert scales at capturing gambling harm?

Gambling-related harm has become a key metric for measuring the adverse consequences of gambling on a population level. Yet, despite this renewed understanding in contemporary research, little exploration has been conducted to evaluate which instrument is best suited to capture the harmful consequences of gambling. This study was designed with the aim of determining whether Likert scales were better suited to capture gambling harm than binary scales. We hypothesized that the Short Gambling Harm Screen (SGHS), initially scored using a binary scale, would perform similarly to the alternate form that was Likertized for the purpose of this study. A corresponding comparison in the reverse direction was executed for the Problem Gambling Severity Index. The SGHS’s performance was assessed via a repeated-measures design in combination with three other measures of validity administered at the conclusion of the survey. In the end, we found that changing the scoring format (i.e., from binary to Likert) had negligible impact on the SGHS’s psychometric performance. We conclude that the original scoring method of the SGHS is not only appropriate but also no less suitable than Likert scales in measuring gambling harm.