title: Screening for frailty in primary care: a systematic review of the psychometric properties of the frailty index in community-dwelling older people.
abstract: BACKGROUND
  To better accommodate for the complex care needs of frail, older people, general practitioners must be capable of easily identifying frailty in daily clinical practice, for example, by using the frailty index (FI). To explore whether the FI is a valid and adequate screening instrument for primary care, we conducted a systematic review of its psychometric properties.
  
  
  METHODS
  We searched the Cochrane, PubMed and Embase databases and included original studies focusing on the criterion validity, construct validity and responsiveness of the FI when applied in community-dwelling older people. We evaluated the quality of the studies included using the Quality in Prognosis Studies (QUIPS) tool. This systematic review was conducted based on the PRISMA statement.
  
  
  RESULTS
  Of the twenty studies identified, eighteen reported on FIs derived from research data, one reported upon an FI derived from an administrative database of home-care clients, and one reported upon an FI derived from routine primary care data. In general, the FI showed good criterion and construct validity but lacked studies on responsiveness. When compared with studies that used data gathered for research purposes, there are indications that the FI mean score and range might be different in datasets using routine primary care data; however, this finding needs further investigation.
  
  
  CONCLUSIONS
  Our results suggest that the FI is a valid frailty screening instrument. However, further research using routine Electronic Medical Record data is necessary to investigate whether the psychometric properties of the FI are generalizable to a primary care setting and to facilitate its interpretation and implementation in daily clinical practice.
  
  
  BACKGROUND
  PROSPERO systematic review register number: CRD42013003737.
authors.affiliation: Department of General Practice, Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Str, 6,131, Universiteitsweg 100, 3584 CG, Utrecht, the Netherlands. i.drubbel@umcutrecht.nl.
authors.forename: Irene
authors.initials: I
authors.lastname: Drubbel
authors.forename: Mattijs E
authors.initials: ME
authors.lastname: Numans
authors.forename: Guido
authors.initials: G
authors.lastname: Kranenburg
authors.forename: Nienke
authors.initials: N
authors.lastname: Bleijenberg
authors.forename: Niek J
authors.initials: NJ
authors.lastname: de Wit
authors.forename: Marieke J
authors.initials: MJ
authors.lastname: Schuurmans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016330:Frail Elderly; D015577:Geriatric Assessment / Q000379:methods*; D006801:Humans; D011320:Primary Health Care / Q000379:methods* / Q000592:standards; D011594:Psychometrics / Q000379:methods* / Q000592:standards; D012111:Residence Characteristics