Construct validity of the Quality of Life in Life-Threatening Illness-Patient questionnaire (QOLLTI-P) in cancer patients

Quality of life (QOL) optimization is an important issue during the process of care for patients suffering from a life-threatening illness such as cancer. The Quality of Life in Life-Threatening Illness-Patient questionnaire (QOLLTI-P) is a self-administered questionnaire based on the McGill Quality of Life questionnaire (MQOL) with domains added to enhance content validity. This study's main objective was to assess the construct validity of QOLLTI-P in cancer patients. Cancer outpatients were asked to complete a set of questionnaires including QOLLTI-P and the Functional Assessment of Chronic Illness Therapy- Spiritual well-being scale (FACIT-Sp). An 8-factor structure was suggested for QOLLTI-P. In general, QOLLTI-P Total and subscale scores are highly correlated with their corresponding FACIT-Sp scores. In conclusion, QOLLTI-P is a valid instrument to assess the QOL of cancer patients.