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 to prevent or delay the onset of disability in the elderly, we conducted a systematic literature review of longitudinal studies published between 1985 and 1997 that reported statistical associations between individual base-line risk factors and subsequent functional status in community-living older persons. Functional status decline was defined as disability or physical function limitation. We used MEDLINE, PSYCINFO, SOCA, EMBASE, bibliographies and expert consultation to select the articles, 78 of which met the selection criteria. Risk factors were categorized into 14 domains and coded by two independent abstractors. Based on the methodological quality of the statistical analyses between risk factors and functional outcomes (e.g. control for base-line functional status, control for confounding, attrition rate), the strength of evidence was derived for each risk factor. The association of functional decline with medical findings was also analyzed.