Influence of clinical parameters on quality of life during chemotherapy in patients with advanced non-small cell lung cancer: Application of a general linear model

Objective: The aim of this study was to determine the relative influence of physician-assessed clinical parameters, including non-hematological adverse events and performance status, on quality of life (QOL) during chemotherapy. Methods: QOL questionnaires consisting of four domains (functional, physical, mental and psychosocial) were self-administered every week during chemotherapy by patients with advanced non-small cell lung cancer in two phase III clinical trials; 377 patients who completed the questionnaires at baseline and at least once during the first course of therapy were analyzed. A general linear model was applied, where the four domains and the clinical parameters (nausea/vomiting, anorexia, diarrhea, fever, peripheral neuropathy and performance status) were used as the response and explanatory variables, respectively. In this model, the multidimensional and longitudinal aspects of QOL data were taken into account. Results: All four domains were significantly affected by the occurrence of nausea/vomiting, anorexia and diarrhea. No influence of peripheral neuropathy on the domains was detected. Performance status was significantly related to the domains (except the psychosocial domain). Conclusion: This study revealed, by examination of multi-dimensional repeated QOL data, that clinical parameters had significant effects on QOL in patients undergoing chemotherapy. Our findings suggest that supportive care to control non-hernatological adverse events, especially gastrointestinal, could maintain overall QOL in cancer patients in an earlier phase of chemotherapy.