title: Predictive validity of a frailty measure (GFI) and a case complexity measure (IM-E-SA) on healthcare costs in an elderly population.
abstract: OBJECTIVE
  Measures of frailty (Groningen Frailty Indicator, GFI) and case complexity (INTERMED for the Elderly, IM-E-SA) may assist healthcare professionals to allocate healthcare resources. Both instruments have been evaluated with good psychometric properties. Limited evidence has been published about their predictive validity. Thus, our aim is to evaluate the predictive validity of both instruments on healthcare costs.
  
  
  METHODS
  Multivariate linear regression models were developed to estimate associations between the predictors frailty (GFI) and/or case complexity (IM-E-SA) and the healthcare costs (in € log transformed) in the following year. All models were adjusted for demographics and the presence of morbidity.
  
  
  RESULTS
  In the multivariate regression analyses the continuous scores of the GFI and IM-E-SA remained significant predictors for total healthcare costs. Adjusted βs for GFI and IM-E-SA were respectively 0.14 (95% CI 0.10-0.18) and 0.06 (95% CI 0.04-0.07). The corresponding explained variance (R(2)) for both models was 0.40. Frailty remained a significant predictor of long-term care costs (adjusted β 0.13 [95% CI 0.09-0.16]), while case complexity was a significant predictor of curative care costs (adjusted β 0.03 [95% CI 0.02-0.05]).
  
  
  CONCLUSIONS
  The GFI and IM-E-SA both accurately predict total healthcare costs in the following year.
authors.affiliation: University of Groningen, University Medical Centre Groningen, Department of Epidemiology, Unit HTA, The Netherlands. Electronic address: L.L.Peters@umcg.nl.
authors.forename: Lilian L
authors.initials: LL
authors.lastname: Peters
authors.affiliation: University of Groningen, University Medical Centre Groningen, Department of Epidemiology, Unit Medical Statistics, The Netherlands.
authors.forename: Johannes G M
authors.initials: JG
authors.lastname: Burgerhof
authors.affiliation: University of Groningen, University Medical Centre Groningen, Department of Epidemiology, Trial Coordination Center, The Netherlands.
authors.forename: Han
authors.initials: H
authors.lastname: Boter
authors.affiliation: Medical University Hospital Heidelberg, Department of General Internal Medicine and Psychosomatics, Germany.
authors.forename: Beate
authors.initials: B
authors.lastname: Wild
authors.affiliation: University of Groningen, University Medical Centre Groningen, Department of Epidemiology, Unit HTA, The Netherlands.
authors.forename: Erik
authors.initials: E
authors.lastname: Buskens
authors.affiliation: University of Groningen, University Medical Centre Groningen, Department of Geriatric Medicine, The Netherlands.
authors.forename: Joris P J
authors.initials: JP
authors.lastname: Slaets
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D004522:Educational Status; D005260:Female; D016330:Frail Elderly / Q000706:statistics & numerical data*; D015577:Geriatric Assessment / Q000379:methods*; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006801:Humans; D008019:Life Style; D008134:Long-Term Care / Q000191:economics; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012959:Socioeconomic Factors
keywords: Case complexity; Curative care costs; Frailty; Healthcare costs; Long-term care costs; Predictive validity