Predictors of abdominal pain in schoolchildren: a 4-year population-based prospective study

Background: Chronic abdominal pain (CAP) is common among schoolchildren, but risk factors for its onset are still largely unknown. Aims: To determine the frequency of onset of CAP in schoolchildren and investigate risk factors for its development. Methods: 1411 schoolchildren aged 11-14 years were recruited from schools in North West England. Information was collected on recent pain symptoms and potential risk factors for developing CAP. Participants were followed up 1 and 4 years later and new episodes of CAP were identified. Results: 22% reported new-onset abdominal pain at 1-year follow-up which persisted at 4-year follow-up (CAP). CAP was almost three times higher in girls than boys (34% vs 13%; chi(2): 26.0; p<0.001). In girls, reporting headache at baseline was the only predictive factor for CAP onset: those reporting headaches experienced a doubling in the risk of symptom onset (relative risk: 2.1; 95% confidence interval: 0.95 to 4.7). In contrast, in boys, development of CAP was independently predicted by daytime tiredness (3.0; 1.2 to 7.6), lack of school enjoyment (2.0; 0.95 to 4.2), adverse psychosocial exposures (2.3; 1.2 to 4.5) and taller stature (1.9; 0.8 to 4.5). Conclusion: Our results suggest that over 20% of adolescent schoolchildren experience new-onset non-self-limiting abdominal pain over a 1-year period. Future abdominal pain is predicted by previous somatic symptom reporting in girls and both somatic symptom reporting and psychosocial factors in boys. These risk factors indicate a possible mechanism for understanding the development of CAP, and might have important implications for both primary and secondary preventive strategies.