Quality-of-Life measurements for patients taking which drugs? The clinical PCASEE perspective.

Abstract

Of the many publications on quality of life in medicine over the last 2 decades, only a minor fraction have been devoted to drug trials. The most frequently investigated are classes of drugs within cancer disorders, hypertension and depressive illness. Health-related quality-of-life (QOL) measurements are typically applied in chronic or subchronic disorders where the balance between effectiveness (disease-modifying drug effects) and safety (adverse drug reactions) are assessed by patients in terms of subjective well-being. In this context, quality of life is an attempt to help the doctor to listen to his or her patient. The components of QOL measurements are to be found within the PCASEE model where: P = physical indicators; C = cognitive indicators; A = affective indicators; S = social indicators; E = economic-social stressors or negative life events; and E = ego function or personality problems. Most variance in QOL measurements arises through operating in the cognitive (e.g. lack of control, concentration difficulties) or affective (e.g. depressed mood or anxiety) components. The most specific component is, of course, adverse drug reactions, which are typically gastrointestinal symptoms in cancer therapies, and circulatory symptoms and sexual function with antihypertensive drugs. However, the affective and cognitive components also have different weights within subclasses of drugs, such as antihypertensive agents. Thus, angiotensin converting enzyme inhibitors act on the affective component (depression and anxiety) and calcium channel blockers on the cognitive component (neurasthenia). In general, patients with cancer or hypertension give more reliable assessments of their cognitive and affective symptoms than their doctors do, while patients with primary depression are less reliable than their doctors or relatives in measuring changes in the affective components of their illness when they are ill. Health-related QOL measurements have not only an impact on the doctor-patient relationship but also involve a holistic approach to drug treatment, by checking all the PCASEE components.