Measuring quality of life for patients with terminal illness: the Missoula–VITAS® quality of life index

Abstract

Quality of life (QOL) is an important outcome measure in caring for terminally ill patients. The Missoula–VITAS® Quality of Life index (MVQOLI) has been developed to provide a measure of quality of life that is meaningful to both clinicians and patients. Unique features of the instrument include its focus on the terminal phase of life, the item structure and a scoring system that allows the weighting of each dimension of QOL by the respondent, and the subjective wording of the items that allows respondents to interpret the measured elements according to their own experience. The validity and reliability of the patient-reported survey instrument were tested by administering the 25-item questionnaire to 257 patients in 10 communitybased hospices. Participants were incurably ill with predicted survival of six months or less. Exclusion criteria included inability to communicate, dementia, or psychological symptoms that might be intensified by completing the index. Reliability and validity of the new index were examined using standard statistical and psychometric analyses. The MVQOLI demonstrated internal consistency (Cronbach's alpha = 0.77). MVQOLI total scores were correlated with scores on the Multidimensional Quality of Life Scale–Cancer 2 and with patient-reported global QOL ratings. MVQOLI scores did not correlate with observer-rated functional status scores indicating divergent validity. The MVQOLI could be completed by patients of varied educational level, age, functional status, and length of time with a terminal illness. The instrument is designed to contribute to the task of planning care by evaluating patient-identified sources of distress, strength and satisfaction, including issues of life closure. This information contributes to crafting highly specific interventions. Further studies are necessary to determine the usefulness of the instrument in measuring outcomes of end-of-life care in nonhospice settings, and for racial and diagnostic groups under-represented in this sample.