Reliability of the DSS-Swe Questionnaire

Background Symptomatic postbariatric hypoglycemia (PBH) is a known complication that can occur a few years after Roux-en-Y gastric bypass (RYGB). There is currently no established rating scale for PBH-associated symptoms developed for use in Swedish populations. The aim of the study was to translate an already existing questionnaire into Swedish and to test its reliability. Methods The study included forward and backward translations of the original Dumping Severity Scale (DSS) questionnaire with 8 items regarding symptoms of early dumping and 6 items regarding hypoglycemia, with each item graded on a 4-point Likert scale. The reliability of the Swedish translated questionnaire (DSS-Swe) was estimated using internal consistency and test–retest methods. Results A total of 200 patients were included in the study. Good internal consistency was demonstrated regarding the items related to early dumping symptoms, with a Cronbach’s alpha coefficient of 0.82, and very good agreement in terms of test–retest reliability, with an overall intraclass correlation coefficient (ICC) of 0.91 (95% CI 0.88–0.93). The items related to hypoglycemia yielded a good Cronbach’s alpha coefficient of 0.76 and an ICC of 0.89 (95% CI 0.85–0.91). Conclusion The DSS-Swe questionnaire shows good reliability regarding both internal consistency and test–retest performance for use in Swedish populations. Graphical Abstract