Risk factors for functional status decline in community-living elderly people: a systematic literature review

To lay the groundwork for devising, improving and implementing strategies t o prevent or delay the onset of disability in the elderly, we conducted a s ystematic literature review of longitudinal studies published between 1985 and 1997 that reported statistical associations between individual base-lin e risk factors and subsequent functional status in community-living older p ersons. Functional status decline was defined as disability or physical fun ction limitation. We used MEDLINE, PSYCINFO, SOCA, EMBASE, bibliographies a nd expert consultation to select the articles, 78 of which met the selectio n criteria. Risk factors were categorized into 14 domains and coded by two independent abstractors. Based on the methodological quality of the statist ical analyses between risk factors and functional outcomes (e.g, control fo r base-line functional status, control for confounding. attrition rate), th e strength of evidence was derived for each risk factor. The association of functional decline with medical findings was also analyzed. The highest strength of evidence for an increased risk in functional status decline was found for (alphabetical order) cognitive impairment, depressio n. disease burden (comorbidity), increased and decreased body mass index, l ower extremity functional limitation, low frequency of social contacts. low level of physical activity, no alcohol use compared to moderate use. poor self-perceived health, smoking and vision impairment. The review revealed t hat some risk factors (e.g. nutrition, physical environment) have been negl ected in past research. This review will help investigators set priorities for future research of the Disablement Process, plan health and social serv ices for elderly persons and develop more cost-effective programs for preve nting disability among them. (C) 1998 Elsevier Science Ltd. All rights rese rved.