Measuring chemotherapy-induced nausea and emesis - Psychometric properties of a quality of life questionnaire

BACKGROUND. Chemotherapy-induced nausea and emesis (CINE) is one of the most dreaded side effects of cancer therapy. To investigate the influence of these symptoms on a patient's quality of life (QOL), a validated tool measuring many domains is needed. METHODS. A QOL questionnaire consisting of scales from the European Organization for Research and Treatment of Cancer QLQ-C30, the Morrow Assessment of Nausea and Emesis, the Osoba Nausea and Emesis Module, and new items specific to nausea, emesis, and retching was constructed and administered daily for 7-9 days to outpatients receiving emetogenic chemotherapy. RESULTS. Test-retest and internal consistency reliabilities ranged from 0.44 to 0.84 and from 0.59 to 0.85, respectively. Item and scale correlations indicated good convergent and discriminant validity. Scales and items measuring similar factors (e.g., severity of emesis and severity of nausea) had strong correlations than did scales measuring dissimilar factors (e.g., cognitive functioning and physical functioning). The validity of known groups was demonstrated by significant differences (P < 0.01) in patients' QOL scores between days with no episodes of nausea, emesis, or retching, days with I or 2 episodes, and days with more than 3 episodes. Patients' QOL significantly decreased as the number of episodes per day increased (P < 0.001). CONCLUSIONS. A CINE QOL questionnaire that successfully measures the short-term impact of nausea, emesis, and retching on patients receiving emetogenic chemotherapy has been developed, largely as a battery of preexisting questionnaires. The psychometric properties of the new questionnaire show adequate reliability and validity to warrant its use in clinical trials and outcomes studies. CINE adversely affects many domains within a patient's QOL. (C) 2003 American Cancer Society.