Development and validation of the Comprehensive Quality of Life Outcome (CoQoLo) inventory for patients with advanced cancer.

Background The purpose of this study was to develop a scale capable of measuring comprehensive quality of life (QOL) outcomes based on the concept of a good death for patients with advanced cancer. Methods We conducted an anonymous cross-sectional questionnaire survey on inpatients being treated at the Oncology Clinic in Saitama Medical University International Medical Center and seven palliative units throughout Japan. Results A total of 405 patients with cancer participated in this study. Factor analysis of scores on the Comprehensive Quality of Life Outcome (CoQoLo) inventory revealed 28 items and the following 10 subscales: physical and psychological comfort; staying in a favourite place; maintaining hope and pleasure; good relationships with medical staff; not being a burden to others; good relationships with family; independence; environmental comfort; being respected as an individual; and having a fulfilling life. The total CoQoLo score was moderately correlated with satisfaction (r=0.34) and overall QOL (r=0.34), and moderately correlated with feelings of support and security regarding cancer care (r=0.44). Cronbach's a and the intraclass correlation coefficient of the total score were 0.90 and 0.79, respectively. No significant correlation was found between the total CoQoLo score and self-reported Eastern Cooperative Oncology Group performance status (r=-0.01). Conclusions These results suggest that the CoQoLo has sufficient reliability and validity and therefore provides an accurate measure of QOL outcomes independent of the general physical condition of the patient.