The General Self-Efficacy Scale in a population planned for bariatric surgery in Sweden: a psychometric evaluation study

ObjectivesThis study psychometrically evaluated General Self-Efficacy (GSE) Scale in patients planned for bariatric surgery in Sweden.DesignA cross-sectional psychometric study. The psychometric evaluation was guided by the COnsensus-based Standards for the selection of health status Measurement Instruments checklist for health-related reported-patient outcomes.SettingThree bariatric centres in Sweden.ParticipantsAdult patients≥18 years old scheduled for primary bariatric surgery (with sleeve gastrectomy or Roux-en-Y gastric bypass).Primary and secondary measuresPsychometric properties of the GSE.ResultsIn total, 704 patients were included in the analysis. Mean values for GSE items were 2.9–3.4 and the mean GSE sum score was 31.4 (SD 4.7). There were no floor or ceiling effects. Cronbach’s alpha was 0.89. Men reported a higher mean GSE than did women, that is, 31.2 (SD 4.8) for women versus 32.1 (SD 4.3) for men, p=0.03. Correlation coefficients were weak or negligible: GSE and mental component summary score of 36-Item Short Form Health Survey (SF-36)/RAND 36, r=0.18 (p