Abstract / Summary
Abstract Background Internet-based cognitive behavioral therapy (iCBT) has demonstrated efficacy across a range of mental health and chronic somatic conditions. However, treatment dropout remains a common challenge, and the factors contributing to premature discontinuation are not yet fully understood. Research examining dropout from iCBT for endometriosis is particularly limited. Therefore, the present study pursued two main objectives: (1) to examine whether demographic, medical, and psychological characteristics were associated with dropout from a guided iCBT intervention for endometriosis (Ed.iTh), and (2) to explore participants’ subjective reasons for treatment discontinuation. Methods This mixed-methods study was conducted in the context of a randomized controlled trial evaluating the Ed.iTh intervention. Quantitative analyses included 149 participants, of whom 95 completed the intervention and 54 discontinued before completing all eight modules. Baseline characteristics were compared between completers and dropouts using Welch’s analyses of variance, chi-squared tests, and Fisher’s exact tests, as appropriate. Factors associated with dropout were further examined using multiple binary logistic regression with data-driven predictor selection. In addition, semi-structured interviews were conducted with ten participants who had discontinued the intervention. Interview data were analyzed using content-structuring qualitative content analysis according to Kuckartz and Rädiker [1], combining deductive and inductive category development. Results The overall dropout rate was 36.2%. Baseline comparisons revealed no significant differences between dropouts and completers in demographic, medical, or psychological characteristics, except for painkiller use, which was more frequent among completers. In the final logistic regression model, painkiller use was associated with lower odds of dropout (OR = 0.41, 95% CI [0.20, 0.81], p = .012), whereas time since laparoscopy was not significantly associated with dropout. Qualitative analysis resulted in five overarching themes reflecting reasons for dropout or barriers to continued participation: time-related barriers, technical and usability barriers, intervention design and implementation, perceived lack of relevance, and emotional difficulties. Conclusions Quantitative baseline characteristics provided limited insight into treatment dropout, whereas qualitative findings highlighted individual, contextual, and intervention-related barriers to continued participation. Increasing flexibility, optimizing platform usability, aligning intervention design with participants’ needs and expectations, and considering the emotional demands of treatment may help improve engagement and retention in guided iCBT interventions for endometriosis.