Measuring fatigue in medically unwell and distressed patients

Fatigue is now recognized as part of the phenotype of an increasing number of physical disorders and may be caused by a number of direct and indirect mechanisms. Fatigue may have a significant impact on health-related quality of life (HRQL) and therefore there has been increased interest in its meas urement. Fatigue may be measured as part of a generic HRQL assessment scale (e.g. the SF-36) or symptom specific rating scales. A large number of thes e scales have recently been developed although the majority of these have b een used only in a limited range of situations. Much research has concentra ted on cancer-related fatigue, which is one of the commonest and most distr essing symptoms experienced by patients with malignancies. At least eight s eparate fatigue assessment scales have been designed for use in such patien ts, although several of these have been reported in single studies only. Fa tigue has been studied to a lesser extent in neurological, liver and cardio respiratory disorders and disease specific scales have been developed. Furt her development work is necessary to establish the generalisability of thes e scales so that they may be incorporated into routine clinical assessment and the therapeutic trials. (C) 2001 Lippincott Williams & Wilkins.