title: Factors contributing to frailty: literature review.
abstract: OBJECTIVE
  This paper presents a review of theoretical and research literature in order to identify the factors contributing to frailty.
  
  
  BACKGROUND
  Frailty is a multifaceted gerontological concept that lacks a clear definition, but may result from an identifiable homogeneous cluster of bio-psycho-social-spiritual factors.
  
  
  METHODS
  A total of 134 articles were identified through a search of the MEDLINE (1966 to July 2004), CINAHL (1982 to July 2004), PsychInfo (1985 to July 2004) and Ageline (1995 to July 2004) databases. Each article was reviewed to determine its fit with inclusion/exclusion criteria. Seven research and 11 theoretical articles were retained and further reviewed for methodological quality using a validity tool.
  
  
  RESULTS
  Seventeen different definitions of frailty were identified. Regardless of the differing definitions, common contributing factors could be identified. Physical, cognitive/psychological, nutritional and social factors, as well as ageing and disease, were evident in both the theoretical and research literature.
  
  
  CONCLUSIONS
  Although there is strong agreement that a relationship exists between a cluster of factors and frailty, designation of the factors as contributors or outcomes of frailty differs. Without a clear explanatory theory of the path from contributors to frailty to outcomes, research will continue to produce confusing results. A theoretical framework that includes bio-psycho-social-spiritual factors as contributors to frailty is recommended as the most useful framework for gerontological nursing.
authors.affiliation: Vancouver Island Health Authority, Centre on Aging, University of Victoria, Victoria, British Columbia, Canada. merry-jo.levers@viha.ca
authors.forename: Merry-Jo
authors.initials: MJ
authors.lastname: Levers
authors.forename: Carole A
authors.initials: CA
authors.lastname: Estabrooks
authors.forename: Janet C
authors.initials: JC
authors.lastname: Ross Kerr
mesh_terms: D000367:Age Factors; D000368:Aged; D000375:Aging; D035843:Biomedical Research; D016330:Frail Elderly; D005853:Geriatrics; D006801:Humans; D008962:Models, Theoretical; D009017:Morbidity