Surrogate outcomes in quality-of-life research: where will we end up?

Quality of Life Assessment of Randomized Controlled Trials

Aims and Background

According to the USA Food and Drug Administration, quality of life (QOL) and/or survival are a priority for new anticancer drug approval. This study was performed to review approaches to QOL in randomized controlled clinical trials (RCCTs) and to survey the use of such measures in trials.

Material and Methods

A literature survey was carried out using the Medline/Medscape, Embase, Cochrane Library, and Ovid databases. Included in the survey were all publications in the set period (from 1966 to June 2005) with “quality of life” in the title or in the abstract in the field of “randomized, controlled clinical trials”. Each trial was evaluated according to the level of importance of QOL as a measure of outcome (primary, important and secondary) and was analyzed using the quality scoring system reported by Nicolucci et al. with some items regarding QOL.

Results

Four hundred and five RCCT articles in the oncology setting were found. Fifty-six of the 405 (13.8%) publications had QOL as primary end point. The overall quality score of these trials ranged from 40% to 100%, with a median overall score of 80%. The overall score was correlated with the year of publication (P = 0.007), the type of journal (P = 0.05), the presence of a biostatistician among the authors (P = 0.001), and the number of participating institutions (P = 0.009).

Conclusions

More attention to QOL in all components of RCCTs (design, choice of instruments, data management and processing) is required from both clinicians and statisticians.

Outcome research in palliative care: could it represent a new dimension of clinical research or clinical practice?

Outcome research is a new dimension of clinical research, and all fields of clinical medicine are involved in this kind of analysis. Overall survival and quality of life are the main outcomes identified in clinical oncology. The former must be the main outcome whenever possible; the latter has to be the main outcome when an improvement of overall survival cannot be expected. It follows that quality of life is the main outcome of palliative care, in which the patient instead of the disease represents the target of the clinical approach. In our critical paper, we review the meaning of clinical outcomes in palliative care, classifying the outcomes as main and surrogate outcomes, and the results of the trials as indexes of activity and efficacy of a treatment. We also review the main randomized clinical trials on the treatment of cancer cachexia, trying to define the role of the treatments in cachexia-related symptom control and quality of life improvement. Strictly related to outcome analysis is the dimension of pharmacoeconomic evaluation. The models of the different designs of pharmacoeconomic analysis are revisited in an attempt to conjugate the pharmacoeconomic evaluation with the particular dimension of palliative care.