Objective: The Functional Living Index-Emesis (FLIE) instrument is a validated nausea and vomiting specific quality of life (QOL) tool originally created as a 3-day test of the impact of chemotherapy-induced nausea and vomiting on cancer patients' daily life. The primary objective of the present study was to retrospectively explore the use of the FLIE from data obtained in a previously published study of patients with gastrointestinal radiation-induced nausea and vomiting (RINV) and compare the extracted symptom clusters on a weekly basis for the entirety of gastrointestinal cancer patients' radiotherapy treatments.
Methods: QOL was assessed on a weekly basis using the 18-item FLIE questionnaire for patients' radiotherapy treatments. A principal component analysis with varimax rotation was performed at each visit. The internal consistency and reliability of the derived clusters was assessed with Cronbach's alpha. Robust relationship and correlation among symptoms was displayed with biplot graphics.
Results: A total of 460 FLIE assessments were completed for the 86 gastrointestinal patients who underwent radiotherapy. Two components were consistently identified except for week 5 where only one component was identified. Component 1 contained the items "Q10-Q18" which included all vomiting items. Component 2 included all nausea items from "Q1 to Q9". All the variables were well accounted for by two components for most weeks of treatment with excellent internal consistency. Biplots indicate that the two symptom clusters were evident at each week, with the exception of the first week of treatment. Strong correlations were seen between the effect of nausea on patients' ability to make meals, patients' ability to do tasks within the home, and patients' willingness to spend time with family and friends.
Conclusion: The high internal consistency at all timepoints indicates that the FLIE QOL instrument is useful for the RINV population.