INTRODUCTION: Research has shown that nutritional status is related to more stable lung function and fewer exacerbations (Stephenson AL, et al. Am J Clin Nutr 2013;97:872-2) among cystic fibrosis (CF) patients. Published studies suggest that individuals with CF have challenges meeting their caloric goals and often do not take their pancreatic enzyme replacement therapy (PERT) as prescribed (Barker DH, Quittner AL. Pediatrics 2016;137:e20152296). A recent, open-ended study of 30 adolescents and adults with CF highlighted some of the nutritional challenges. The study reported that patients continued to have difficulties with eating, or stay adherent to PERT therapy and also showed that symptoms such as abdominal pain and stools were related to impaired daily functioning and health-related quality of life (HRQoL).The Gastrointestinal (GI) Symptom Tracker has been designed to standardize assessment of GI and nutritional issues, and provide a communication tool for clinical practice. During the development phase, cognitive interviews were conducted to ensure all relevant content was captured and to refine item wording. This resulted in 4 key domains: 1) Abdominal Pain (e.g., cramping); 2) Stools (e.g., constipation); 3) Eating Challenges (e.g., appetite); and 4) Adherence Challenges (e.g., forgetting enzymes, antacids). Scores were proposed for these domains using a standardized 0 to 100 scale, with higher scores indicating greater severity
OBJECTIVE: To perform a psychometric evaluation of the GI Symptom Tracker at 10 CF centers across the US
METHODS: Patients with CF were screened to determine eligibility and completed the GI Symptom Tracker, Cystic Fibrosis Questionnaire-Revised (CFQ-R), enzyme replacement questions and a global status question at a routine clinic visit, administered using an iPad in the CF center. A subset of patients completed a second clinic visit to obtain test-retest data. The psychometric evaluation included confirmation of the scale structure, reliability (internal consistency and test-retest), construct validity, and known groups validity.
RESULTS: More than 175 patients (mix of adults and adolescents) with CF at 10 centers participated. A subset of those patients completed the GI Symptom Tracker, global status question and enzyme replacement ques-tions a second time 10-14 days later to evaluate test-retest reliability. Participants were able to complete the survey easily, with minimal missing data for the tracker.
CONCLUSIONS: The GI Symptom Tracker is easy for patients to complete and demonstrates good content validity based on CF patient-reported experiences of their GI symptoms. This tool will enable clinicians to unobtrusively measure patient-reported GI and nutritional problems and facilitates collaborative patient-provider discussions and decision-making.
