Assessing the impact of chemotherapy-induced nausea and vomiting on patients' daily lives: A modified version of the Functional Living Index-Emesis (FLIE) with 5-day recall

Background: The Functional Living Index - Emesis (FLIE), a patient-reported outcome measure, was originally developed to assess the impact of chemotherapy-induced nausea and vomiting (CINV) on patients' daily lives over the 3 days following chemotherapy. More recent studies of CINV include assessments covering the 5 days following chemotherapy in an effort to capture information during both the acute (within 24 h) and delayed (up to 5-7 days) phases of CINV. Goals: To assess the measurement characteristics of a modified version of the FLIE with 5-day recall. Instrument reliability, validity, and missing data were assessed. Patients and methods: Data were collected from 183 patients receiving cisplatin ≥ 70 mg/m² as part of a phase IIb antiemetic trial of an NK-1 receptor antagonist (MK-0869). Patients recorded the number of vomiting episodes and nausea ratings in a 5-day daily diary. Results: The 5-day FLIE had: (1) excellent internal consistency within FLIE Nausea and Vomiting domains (Cronbach's alpha 0.77-0.78), (2) acceptable construct validity shown by FLIE item-total correlations stronger within domains (r=0.74-0.97) than across domains (r=0.52-0.76), and (3) acceptable convergent validity as shown by moderate to strong correlations between FLIE domain scores and independent endpoints of emetic episodes, nausea ratings, and use of rescue medications. The extent of missing data was within acceptable limits with less than 2% of patients missing data. Conclusion: The 5-day FLIE had adequate measurement characteristics for studying the impact of CINV on patients' daily lives during the period covering both the acute and delayed phases.