A REVIEW OF QUALITY-OF-LIFE IN ALZHEIMERS-DISEASE PART 1 - ISSUES IN ASSESSING DISEASE IMPACT

There are numerous methods available for assessing patients with Alzhe imer's disease (AD) or other forms of dementia. Quality-of-life (QOL) assessment is unique among these methods, because the QOL concept itse lf includes a subjective component that is fundamental to its measurem ent. It could be argued that measuring quality of life is just as impo rtant as measuring disease severity, disease progression, symptom resp onse, cognition, behavioural disturbance and activities of daily livin g when assessing the impact of disease and intervention in dementia. T he subjective nature of quality of life provides healthcare profession als with the opportunity of incorporating the value systems of patient s and their carers into their assessments. A systematic review was car ried out to include the published data land some unpublished data) on QOL assessment tools and instruments that claim to measure quality of life in dementia. Literature for this review was identified by a thoro ugh search of computer databases (1980-1997) that included Medline, Em base, PsychLit and International Pharmaceutical Abstracts. Reports con cerning the conceptualisation, development, validation, reliability, r eproducibility, comprehensiveness, practicality and use of QOL instrum ents in dementia/AD were selected for review as well as papers documen ting clinical drug trials in this therapeutic area. A number of measur es or methods used in the literature for assessing the quality of life of patients with dementing illnesses were identified. It was decided to present the resulting review in 3 parts that correspond to the 3, m ain groups into which the instruments were categorised. The first(part I)looks at measures used to assess the impact of disease as well as i nstruments at a developmental or testing stage. The second (part 2) in cludes instruments that claim to measure quality of life in studies do cumenting the impact of a drug in this therapeutic area. There are as vet no validated methods of assessing the quality of life of both pati ents with dementia and their carers at the same time. QOL outcomes for these 2 groups is closely, if not fundamentally, linked and yet most studies identified in this review concentrate on measuring the quality of life of either the patient or the carer alone. Although some resea rchers may be getting close conceptually, an instrument has yet to sat isfy all the criteria necessary to become accepted as a gold standard for QOL assessment in dementing illness. The ideal instrument must sho w that it can reliably, reproducibly and comprehensively assess qualit y of life for patients with dementia and their carers. It should also demonstrate that it can measure quality of life effectively using a pr actical administration technique that does not place any unnecessary b urden on either informal carers, other healthcare workers involved or the patient themselves. Further cross-sectional and-longitudinal resea rch is required to psychometrically test the available instruments as well as continuing conceptual research to explore new ways of assessin g quality of life in this important area.