Rate, Risk Factors, and Outcomes of Nonadherence in Pediatric Patients With Celiac Disease: A Systematic Review

BACKGROUND AND AIMS:The only treatment for celiac disease is strict adherence to a gluten-free diet (GFD). We performed a systematic review to investigate the rate of adherence to a GFD in children with celiac disease, risk factors that affect adherence, and outcomes of non-adherence. METHODS:We searched PubMed, Cochrane Library, EBSCO, and Scopus for studies through January 2019. We included observational studies of ≥50 children diagnosed with celiac disease and recommended for placement on a GFD. We collected data on adherence assessment (self-report, serology tests, structured dietary interview, biopsies, or assays for gluten immunogenic peptides), risk factors, and outcomes related to adherence. Findings were presented with medians, range, and a narrative synthesis. RESULTS:We identified 703 studies; of these, 167 were eligible for full-text assessment and 49 were included in the final analysis, comprising 7850 children. Rates of adherence to a GFD ranged from 23% to 98%. Comparable rates (median rates of adherence, 75%-87%) were found irrespective of how assessments were performed. Adolescents were at risk of non-adherence and children whose parents had good knowledge about celiac disease adhered more strictly. Non-adherence associated with patient growth, symptoms, and quality of life. CONCLUSION:In a systematic review of 49 studies of children with celiac disease, we found substantial variation in adherence to a GFD among patients. Rate of adherence was not associated with method of adherence measurement, so all methods appear to be useful, with lack of consensus on the ideal metric. Studies are needed to determine the best method to ensure adherence and effects on long-term health.