Abstract
Pediatric functional abdominal pain disorders (FAPDs) are common and associated with impairment. Internet cognitive behavioral therapy (ICBT) has shown effectiveness in reducing symptoms and impairments, whereas the role of parents is not fully understood. A particular objective of the present study was therefore to assess parental factors as predictors of effect and adherence.Youth aged 8-17 years with FAPDs (n = 87) and parents were recruited by pediatricians to therapist-guided ICBT. Primary youth outcomes were gastrointestinal symptoms and pain intensity. Secondary outcomes: quality of life, gastrointestinal-anxiety, behavioral responses, somatic and psychological symptom burden, illness-related cognitions, and pain acceptance. Parental factors: emotional distress, health anxiety (HA) by proxy, monitoring and protective symptom-related behaviors. Linear models evaluated treatment effects from baseline to 12-week follow-up and explored associations between baseline parental factors and youth primary outcomes.Youth improved significantly from baseline to 12-week follow-up in gastrointestinal symptoms (SMD = 1.17, 95% CI 0.83;1.51) pain intensity (SMD = 0.94, 95% CI 0.61;1.27), and most secondary outcomes.Parents improved in HA by proxy (SMD = 0.99, 95% CI 0.66;1.32), monitoring (SMD = 1.31, 95% CI 0.97;1.65), protective behaviors (SMD = 0.66, 95% CI 0.34;0.98), not emotional distress (SMD = 0.03, 95% CI -0.28;0.34). Higher baseline HA by proxy predicted more youth gastrointestinal symptoms and higher pain intensity while higher baseline monitoring predicted lower pain intensity at 12-week follow-up.Therapist-guided ICBT provided significant improvements in youth outcomes and parental factors. Findings highlight the relevance of assessing and targeting parental HA by proxy, and monitoring behaviors to enhance treatment effectiveness. CLINICAL TRIAL REGISTRATION: i-CBT Functional Gastrointestinal Disorders in Youth: the Impact of Negative Illness Understanding and Parental Illness Worries, (ID: NCT05486585) (ClinicalTrials.gov).