Validation of the Structured Assessment of Gastrointestinal Symptoms Scale to Support Standardized Evaluation and Follow-up.

OBJECTIVES: Patient-reported outcome measures facilitate evaluation of patients and allow to better assess treatment effects. Validated tools are lacking for pediatric gastroenterological patients. We thus aimed to adapt and validate for pediatric populations a self-administered Structured Assessment of Gastrointestinal Symptoms (SAGIS) tool that previously has been validated in adult cohorts. METHODS: Each item of the original SAGIS instrument was thoroughly reviewed for its relevance in the pediatric population. The resulting pediatric (p)SAGIS was utilized over a 35 months' period in consecutive patients in a pediatric outpatient GI clinic. Principal component analysis (PCA) followed by varimax rotation and confirmatory factor analysis (CFA) was performed in derivation and validation samples. Responsiveness to change was assessed in 32 children with inflammatory bowel disease (IBD) after 12 months of therapy. RESULTS: The final pediatric SAGIS (pSAGIS) consisted of 21 GI-related Likert-type questions, 8 dichotomous questions assessing extra-intestinal symptoms, and 2 most bothersome symptoms; 1153 children/adolescents completed a total of 2647 questionnaires. Cronbach alpha was 0.89, indicating good internal consistency. PCA supported a 5-factor model (symptom groups: abdominal pain, dyspepsia, diarrhea, constipation, dysphagia/nausea) and CFA showed good model fit (comparative fit index: 0.96, root-mean-square error of approximation: 0.075). The initial mean total GI symptom score in IBD patients (8.7 ± 10.3) decreased to 3.6 ± 7.7 after 1 year of therapy ( P < 0.01), and 4 of 5 symptom group scores decreased significantly upon treatment ( P < 0.05). CONCLUSIONS: The pSAGIS is a novel, easy to use, self-administered instrument for GI-symptom assessment in children/adolescents with excellent psychometric properties. It may standardize GI-symptom assessment and may enable uniform clinical analysis of treatment outcomes.

Significance of validated symptom assessment versus breath testing for malabsorption after lactose load in children.

BACKGROUND AND OBJECTIVES: Lactose malabsorption and lactose-induced symptoms are poorly correlated, as shown by breath tests and various symptom assessment methods. Validated assessment is the key to overcome the limitations of biased symptom measurements. We characterized lactose-induced symptoms with the population-specific, validated paediatric carbohydrate perception questionnaire (pCPQ) and their correlation with the history of symptoms (HoS). METHODS: A total of 130 patients with functional gastrointestinal symptoms underwent a lactose hydrogen breath and tolerance test (LBTT) allowing for a diagnosis of malabsorption (M+) and lactose sensitivity (S+). HoS indicative of lactose-induced symptoms (abdominal pain, nausea, bloating, flatulence, diarrhoea) in the 4 weeks preceding the test was determined using a validated questionnaire. The pCPQ was used to score lactose-induced symptoms. MAIN RESULTS: The LBTT revealed 41 children (31.5%) with lactose malabsorption (M+), 56 (43.1%) with lactose sensitivity (S+) and 24 (18.5%) were M+/S+. Sensitivity correlated with HoS (P < 0.001), regardless of whether malabsorption was detectable. Malabsorption status did not correlate with HoS (NS). The odds of lactose sensitivity significantly increased when abdominal pain [odds ratio (OR) 3.5, confidence interval (CI) 1.6-7.8], nausea (OR 2.3, CI, 1.1-4.9) and flatulence (OR 3.1, CI 1.4-6.8) were reported in the 4 weeks preceding the LBTT. Symptoms after the lactose load were similar for M+/S+ and M-/S+, except for flatulence, which was more frequent in malabsorbers (P < 0.01). CONCLUSION: Our findings fit well with the emerging view of the important role of a validated symptom assessment after a lactose load. The determination of symptoms may be more relevant than malabsorption for the clinical outcomes of paediatric patients with lactose-related gastrointestinal symptoms.

Development and validation of the paediatric Carbohydrate Perception Questionnaire (pCPQ), an instrument for the assessment of carbohydrate-induced gastrointestinal symptoms in the paediatric population.

BACKGROUND: There is an unmet need for a validated, test-specific symptom questionnaire to evaluate carbohydrate perception during breath tests. Our aim was to develop and validate a questionnaire for the assessment of symptoms after a provocative carbohydrate load. METHODS: After a literature search and initial focus group-style interviews, five relevant complaints were identified. Responses were given on a Likert-type faces scale with a language children use and understand. Reliability, validity and responsiveness to change were established by the implementation of the questionnaire during breath tests in 215 pediatric subjects. Correlation between the questionnaire and a medical interview by a pediatrician who was blinded to the results of the questionnaire (n = 19) was determined. KEY RESULTS: The questionnaire had good face and content validity (Lawshe ratio = 1). Intraclass correlation coefficients for test-retest reliability (n = 116) demonstrated good repeatability (P < .001), and effect sizes were small (Cohen's d < 0.15 for all symptoms). Convergent validity and discriminant validity were supported according to the multitrait-multimethod matrix method. The results obtained by the questionnaire correlated highly with the result of the medical interview (P < .001; Fisher's exact test). Cronbach's alpha was 0.81. Responsiveness was verified for the whole patient group and subgroups with medium to high effect sizes. CONCLUSIONS AND INFERENCES: The paediatric Carbohydrate Perception Questionnaire (pCPQ) is a simple, test-specific questionnaire for a pediatric population. It is a valid instrument with excellent psychometric properties to assess gastrointestinal symptoms after carbohydrate ingestion. The pCPQ can replace non-validated symptom assessment during carbohydrate breath tests and allows a standardized diagnosis of carbohydrate intolerance.

Valid Assessment of Carbohydrate Intolerance and the Need for a Distinction to Carbohydrate Malabsorption. Comment on "Roles of Lactose and Fructose Malabsorption and Dietary Outcomes in Children Presenting with Chronic Abdominal Pain.", Nutrients, 2019, 11, 3063.

We have read with interest the recent paper by Posovszky and Roesler et al [1] that reports, based on the doctoral thesis by Dr. Roesler [2] [...].