Development and psychometric evaluation of a 10-item short form inventory of gambling situations

The Inventory of Gambling Situations (IGS-63; Turner and Littman-Sharp, Inventory of gambling situations users guide, 2006) is a 63-item measure of high-risk gambling situations. It assesses gambling across 10 situational subscales that load onto two higher-order factors: negative and positive situations (Stewart et al. Psychology of Addictive Behaviors, 22:257-268, 2008). While the IGS-63 has excellent psychometric properties (Littman-Sharp et al., The Inventory of Gambling Situations: Reliability, factor structure, and validity (IGS Technical Manual), in press) its length may preclude its use in time-limited contexts. The purpose of this study was to develop and validate a 10-item short-form of the IGS (IGS-10). Each IGS-10 item reflects one of the ten subscale categories from the IGS-63, with two items from the original subscales included as examples for each IGS-10 item. The IGS-10 was administered to 180 undergraduate gamblers along with the IGS-63 and the Problem Gambling Severity Index (PGSI; Ferris and Wynne, Canadian Problem Gambling Index: Final report, 2001). IGS-10 items showed convergent validity with the corresponding IGS-63 subscales (r's = .60-.73). Principal components analysis of the IGS-10 revealed two factors: negative (α = .84) and positive (α = .85). PGSI scores correlated significantly with all IGS-10 items (r's = .33-.58) and with both IGS-10 higher-order subscales (r's = .66 [negative] and .49 [positive]), supporting the criterion validity of the IGS-10. Since minimal information is lost when using the IGS-10, the short form may prove particularly useful when respondent burden prevents using the full IGS-63.