Augmented Reality-Supported Cognitive Behavioral Therapy for Children With Cancer: A Three-Arm Randomized Controlled Trial

Background and rationale. Childhood cancer is among the leading causes of disease burden in children worldwide, with more than 400,000 children and adolescents estimated to develop cancer each year. Although survival has improved markedly in higher-resource settings, the diagnosis and subsequent treatment impose a profound and often traumatic psychological burden. Repeated hospitalizations, an unfamiliar and frequently frightening medical environment, and disruption of everyday routines contribute to clinically meaningful anxiety, low mood, and substantial impairment in health-related quality of life that can persist into survivorship. Left unaddressed, these difficulties are associated with poorer treatment adherence, prolonged adjustment problems, and elevated rates of post-traumatic stress and internalizing symptoms extending well beyond the acute treatment period.

Two features of pediatric cancer care are particularly distressing for children. First, children repeatedly undergo invasive procedures, including venipuncture, central line or port access, and painful diagnostic evaluations, that provoke fear, pain, and anticipatory distress with each subsequent encounter. Second, prolonged chemotherapy produces aversive symptoms such as nausea, vomiting, and fatigue that frequently become conditioned and anticipatory over the course of treatment, further eroding wellbeing and treatment tolerance. Psychosocial standards of care in pediatric oncology designate evidence-based psychological support as an essential, rather than optional, component of comprehensive cancer care, and cognitive behavioral therapy (CBT) has the strongest evidence base among psychosocial interventions for reducing distress and improving adjustment in children facing serious illness.

In practice, access to trained pediatric mental health specialists is severely constrained, particularly in low- and middle-resource settings, and conventional face-to-face therapy places additional burden on children who are already fatigued and immunosuppressed. Digital delivery offers one route to scalability, and app-based interventions have been shown to reduce anxiety and depressive symptoms in youth more broadly. Immersive technologies are especially promising in this context: virtual reality (VR) reliably reduces procedural pain and anxiety in pediatric patients, including children with cancer. Augmented reality (AR), which overlays interactive digital content onto the real environment rather than replacing it, has been used for pediatric health education and, increasingly, for mental health applications, but had not previously been combined with a structured, manualized psychotherapeutic framework in pediatric oncology. Prior digital and play-based interventions in this population have been largely limited to distraction or education without an explicit therapeutic model, and resilience-focused programs have most often targeted parents, adolescents, or young adults rather than school-aged children (6 to 12 years) -- a group old enough to experience and voice fear, yet too young for most adolescent- or parent-directed programs, and who typically benefit from concrete, play-based, developmentally tailored delivery rather than verbal therapy alone.

To address this gap, the investigators developed "Hospital Buddy Ida" ("Hastane Arkadaşım İda"), an augmented reality-supported, manualized CBT program in which a three-dimensional virtual companion guides children through psychoeducation, emotion-regulation, and coping modules integrated with Child Life principles. This trial was designed to evaluate the efficacy, feasibility, and acceptability of this AR-supported CBT program (AR-CBT) relative to an identical CBT program delivered without the AR application (standard CBT), and relative to usual oncologic care, so as to isolate the incremental contribution of the augmented reality delivery layer from the therapeutic content itself.

Development context and reporting. This trial was conducted as the efficacy-testing phase of a multi-phase intervention development program that progressed sequentially from user-experience research and application prototyping, through pilot feasibility testing, to the present three-arm randomized controlled trial. Reporting follows the CONSORT statement and its extension for e-health interventions (CONSORT-EHEALTH), and participant sex and sociodemographic characteristics are reported in accordance with the Sex and Gender Equity in Research (SAGER) guidelines. The trial was conducted across multiple pediatric oncology centers spanning university, training-and-research, and private hospital settings in Istanbul and Antalya, Türkiye. Written informed consent was obtained from caregivers and assent was obtained from children; study data were anonymized by protocol number.