Measurement of Quality of Life in Clinical Trials of Therapy

Abstract

This article discusses some of the issues involved in the use of quality of life methods to evaluate treatment, primarily in trials of cardiovascular disease. The choice of aspects to measure is influenced by the severity and nature of the disease, the expected benefits and adverse effects of treatment and pragmatic considerations such as the length of the trial, and availability of the methods. The choice of specific instruments should take account of good measurement criteria such as validity and reliability, and, most importantly, sensitivity to the effects of treatment. The advantages and disadvantages of interviewer and self-completed questionnaires are discussed. The choice of respondent is primarily the patient. In some circumstances it may be appropriate to also include family members, either for their views on the patient, or for an assessment of their own quality of life as this may also be disrupted. Withdrawals are a major problem in the analysis of all trial results. The inclusion of a Health Index is one method of obtaining quality of life scores from patients who withdraw or die. The interpretation of quality of life results from trials is not simple, for example, the benefit of trial inclusion needs to be distinguished from the effect of treatment. Moreover, changes in quality of life scores should correspond to changes in the patients’ own experiences of their daily lives.

Long‐Term Quality of Life After Hepatic Resection: Health Is not Simply the Absence of Disease

“…For example, there is the potential for patients to rate their QoL better than reality when answering a QoL questionnaire. Self-administered questionnaires can be a disadvantage to patients with limited literacy and the information gathered may be incomplete [35]. Because the ''need to please'' is likely to affect all patients similarly, artificial differences within the subgroup analyses seem unlikely.…”

Self‐rated menopausal status and quality of life in women aged 40‐63 years

“…The majority of previous studies fail to include women over the age of 55 years, so that little information exists about the end of the climacteric at a time when women may be still coming to terms with physical, social, cultural and psychological changes associated with the menopause and ageing. In this study we have chosen to de ne QOL as 'the extent to which the physical, emotional and social aspects of a person's life are intact' (Fletcher & Bulpitt, 1987). The advantage of using this de nition is that the biological, social or psychological variables that may be responsible for the adverse impact upon women's lives become a secondary consideration, and the focus is placed squarely upon a woman's experiences, her interpretation of the menopause and the impact she believes it has on her QOL.…”

Assessing quality of life after pulmonary embolism: Comparing results from the PEmb‐QoL with semistructured interviews

“…QoL captures patients’ lived experiences of the impact of disease and treatment on patients’ physical, psychological, and social functioning and well‐being. 1 , 2 , 3 , 4 QoL can be assessed by general QoL instruments that score standardized responses to standardized questions (eg, the Short Form 36 [SF‐36]). 5 , 6 , 7 These general instruments are designed to sample a broad spectrum of function, disability, and distress that is relevant to QoL.…”