Development and validation of the Gambling Follow-up Scale, Self-Report version: an outcome measure in the treatment of pathological gambling.

Objective: To validate the Gambling Follow-up Scale, Self-Report version (GFS-SR), a 10-item scale designed to assess gambling frequency, time and money spent on gambling, gambling craving, debts, emotional distress, family relationships, autonomy, and frequency of and satisfaction with leisure activities in individuals diagnosed with gambling disorder according to the DSM-5 criteria. Methods: One hundred and twenty treatment-seeking gamblers were evaluated, 84 of whom proceeded to treatment. Fifty-two relatives provided collateral informant reports at baseline. Six months later, the 50 patients who completed the program were reassessed. Results: The GFS-SR showed good inter-rater agreement and internal consistency. Factor analysis presented a three-factor solution: gambling behavior (factor 1); social life (factor 2); and personal hardship (factor 3). There was a high degree of convergence between GFS-SR scores and those of reference scales. The GFS-SR scores showed excellent sensitivity to change (factor 1), predictive validity for treatment response (factor 2), and ability to distinguish recovered from unrecovered patients after treatment (factor 3). A cutoff score of 33 was found to have 87% sensitivity and 80% specificity for gambling recovery. Conclusion: The GFS-SR is well suited to providing reliable follow-up of gamblers under treatment and assessing the efficacy of their treatment.