title: Convergent validity of the interRAI-HC for societal costs estimates in comparison with the RUD Lite instrument in community dwelling older adults.
abstract: The interRAI-Home Care (interRAI-HC) instrument is commonly used in routine care to assess care and service needs, resource utilisation and health outcomes of community dwelling home care clients. Potentially, the interRAI-HC can also be used to calculate societal costs in economic evaluations. The purpose of this study was to assess the convergent validity of the interRAI-HC instrument in comparison with the RUD Lite instrument for the calculation of societal costs among care-dependent community dwelling older adults.
  
  
  
  A within-subject design was used. Participants were 65 years and older and received professional community care in five countries. The RUD Lite was administered by trained (research) nurses or self-reports within 4 weeks after the interRAI-HC assessment. Agreement between the interRAI-HC and RUD Lite estimates was assessed using Spearman's correlation coefficients. We hypothesised that there was strong correlation (Spearman's ρ > 0.5) between resource utilisation estimates, costs of care estimates and total societal cost estimates derived from both instruments.
  
  
  
  Strong correlation was found between RUD Lite and interRAI-HC resource utilisation assessments for eight out of ten resource utilisation items. Total societal costs according to the RUD Lite were statistically significantly lower than according to the interRAI-HC (mean difference €-804, 95 % CI -1340; -269). The correlation between the instruments for total societal costs and all six cost categories was strong.
  
  
  
  The interRAI-HC has good convergent validity as compared with the RUD-Lite instrument to estimate societal cost of resource utilisation in community dwelling older adults. Since interRAI-HC assessments are part of routine care in many community care organisations and countries already, this finding may increase the feasibility of performing economic evaluations among community dwelling older adults.
authors: Department of General Practice and Elderly Care Medicine and EMGO+ Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands. l.vanlier@vumc.nl.
authors: Lisanne I
authors: 0000-0001-5707-2345
authors: LI
authors: van Lier
authors: Department of General Practice and Elderly Care Medicine and EMGO+ Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors: Henriëtte G
authors: HG
authors: van der Roest
authors: Department of General Practice and Elderly Care Medicine and EMGO+ Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors: Hein P J
authors: HP
authors: van Hout
authors: LUCAS, Centre for Care Research and Consultancy KU Leuven (University of Leuven), Minderbroederstraat 8, box 5310, B-3000, Leuven, Belgium.
authors: Liza
authors: L
authors: van Eenoo
authors: LUCAS, Centre for Care Research and Consultancy KU Leuven (University of Leuven), Minderbroederstraat 8, box 5310, B-3000, Leuven, Belgium.
authors: Anja
authors: A
authors: Declercq
authors: HTW Berlin, FB III-Economics, Treskowallee 8, D-10318, Berlin, Germany.
authors: Vjenka
authors: V
authors: Garms-Homolová
authors: Department of Geriatrics, Università Cattolica del Sacro, Largo F. Vito 1, 00168, Rome, Italy.
authors: Graziano
authors: G
authors: Onder
authors: Department of Wellbeing, National Institute for Health and Wellbeing, P.O. BOX 30, FI-00271, Helsinki, Finland.
authors: Harriet
authors: H
authors: Finne-Soveri
authors: Department of Geriatrics, Landspitali National University Hospital and Faculty of Medicine, University of Iceland, Landakot, 101, Reykjavik, Iceland.
authors: Pálmi V
authors: PV
authors: Jónsson
authors: Department of General Practice and Elderly Care Medicine and EMGO+ Institute for Health and Care Research, VU University Medical Center, Van der Boechorststraat 7, 1081 BT, Amsterdam, The Netherlands.
authors: Cees M P M
authors: CM
authors: Hertogh
authors: Department of Health Sciences and EMGO+ Institute of Health and Care Research, Faculty of Earth and Life Sciences, VU University, De Boelelaan 1085, 1081 HV, Amsterdam, The Netherlands.
authors: Judith E
authors: JE
authors: Bosmans
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003695:Delivery of Health Care / Q000191:economics / Q000706:statistics & numerical data; D005060:Europe; D005260:Female; D015577:Geriatric Assessment; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006295:Health Resources; D006699:Home Care Services / Q000191:economics*; D006801:Humans; D057187:Independent Living / Q000191:economics*; D008297:Male; D018803:Models, Economic; D057566:Self Report
keywords: Community care; Convergent validity; Correlation; Costs of care; InterRAI-HC; Older adults; RUD Lite; Resource utilisation; Routine care assessment; Societal costs