METHODS: The present study was a cross-sectional survey conducted from September to November 2001. Schoolchildren were recruited from primary schools that were selected randomly from a list of all primary schools in Petaling Jaya, Malaysia, using random sampling numbers. Information concerning recurrent abdominal pain, socio-economic status, life events, demographic and other details was obtained using a combination of questionnaires and interviews. Academic achievement was assessed using a score based on the Malaysian Primary School Achievement Examination. An overall score at or above the mean was taken to indicate high academic achievement while a score below the mean indicated poor academic achievement.
RESULTS: A total of 1971 children were studied (958 boys and 1013 girls: 1047 Malays, 513 Chinese and 411 Indians). Of these children, 456 (23.1%) fulfilled the criteria for recurrent abdominal pain. Using the method of binary logistic regression analysis, the following factors were found to be independently associated with poor academic performance: a low socio-economic status (odds ratio (OR) 1.30; 95% confidence interval (CI) 1.25-1.35); male sex (OR 1.61; 95% CI 1.26-2.05); the death of a close relative (OR 2.22; 95% CI 1.73-2.85); the divorce or separation of parents (OR 3.05; 95% CI 1.73-5.40); the commencement of work by the mother (OR 1.34; 95% CI 1.02-1.76); hospitalization of the child in the 12 months prior to the study (OR 1.83; 95% CI 1.12-3.01); lack of health-care consultation (OR 1.80; 95% CI 1.36-2.36); missing breakfast (OR 1.47; 95% CI 1.07-2.02); and lack of kindergarten education (OR 1.35; 95% CI 1.04-1.75).
CONCLUSIONS: Many factors, such as socio-economic status and recent life events, were associated with poor academic performance. Recurrent abdominal pain did not correlate directly to academic performance. Stress may be a means by which various factors cause children to struggle academically.
METHODOLOGY: Twenty-four children referred consecutively to the University of Malaya Medical Centre who fulfilled Apley's criteria (at least three episodes of abdominal pain severe enough to affect normal activity over a period longer than 3 months) were tested for lactase deficiency using a pocket breath test analyser (BreatH2 meter; Europa Scientific, Cheshire, England). Lactulose was used to check for hydrogen-producing capacity.
RESULTS: There were 14 males and 10 females in the study, consisting of five Malays, 14 Chinese and five Indians. Mean age was 9.9 years. Seventeen of the 24 children (70.8%) with recurrent abdominal pain who underwent the breath hydrogen test had a positive result. In those with a negative result, subsequent lactulose administration resulted in a positive rise in breath hydrogen. None of the 24 children developed abdominal pain during the test. All the Indian subjects, 71.4% of the Chinese subjects and 40% of the Malay subjects with recurrent abdominal pain had lactase deficiency. The proportion of boys and girls with lactase deficiency was similar (71.4 vs 70.0%, respectively). There was no significant difference between lactase sufficient and deficient children with recurrent abdominal pain with regard to sex, age, ethnic group and clinical features. Following a lactose-free diet, none of the children in the breath hydrogen positive and negative groups reported any appreciable difference in pain symptoms.
CONCLUSIONS: The prevalence of lactase deficiency among this group of Malaysian children with recurrent abdominal pain was high, but lactase deficiency did not appear to play an important role in causing the symptoms.