Self-efficacy in Pathological Gambling Treatment Outcome: Development of a Gambling Abstinence Self-efficacy Scale (GASS)

A 21-item measure of gambling abstinence self-efficacy (GASS) was developed. Principal component analyses of 101 pathological gamblers supported the use of a total score that showed good internal (a = .93) and retest reliability (ICC (n = 35) = .86) as well as four subscales: 1) winning/external situations (6 items, a = .91); 2) negative emotions (9 items, a = .87); 3) positive mood/testing/urges (3 items, a = .70); and 4) social factors (3 items, a = .81). The total and subscales showed moderate relationships with single item ratings of confidence to abstain from gambling and weak or nonsignificance relationships with demographic and gambling-related variables. The total score and three of the subscales showed evidence of predictive validity for gamblers not currently involved with treatment. Higher self-efficacy was related to fewer days of gambling over a 12-month period. These results provide preliminary support for the reliability and validity of the GASS.