The McGill Quality of Life Questionnaire: a measure of quality of life appropriate for people with advanced disease. A preliminary study of validity and acceptability

TLDR

The MQOL differs from most quality‑of‑life instruments by measuring an existential domain, giving weight to physical symptoms without dominance, and capturing positive contributions to life. This study reports the first evaluation of the McGill Quality of Life Questionnaire for patients with life‑threatening illness across all disease stages. The authors conducted the study in a palliative care setting and established construct validity by correlating the four MQOL subscales with items from the Spitzer Quality of Life Index. Principal component analysis identified four subscales—physical symptoms, psychological symptoms, outlook on life, and meaningful existence—and only the meaningful existence subscale correlated significantly with overall quality of life ratings, underscoring the importance of the existential domain.

Abstract

This is the first report on the McGill Quality of Life Questionnaire (MQOL), a questionnaire relevant to all phases of the disease trajectory for people with a life-threatening illness. This questionnaire differs from most others in three ways: the existential domain is measured; the physical domain is important but not predominant; positive contributions to quality of life are measured. This study was conducted in a palliative care setting. Principal components analysis suggests four subscales: physical symptoms, psychological symptoms, outlook on life, and meaningful existence. Construct validity of the subscales is demonstrated through the pattern of correlations with the items from the Spitzer Quality of Life Index. The importance of measuring the existential domain is highlighted by the finding that, of all the MQOL subscales and Spitzer items, only the meaningful existence subscale correlated significantly with a single item scale rating overall quality of life.