title: Osteoarthritis and frailty in elderly individuals across six European countries: results from the European Project on OSteoArthritis (EPOSA).
abstract: BACKGROUND
  Osteoarthritis (OA) is the most common cause of disability in the elderly. Clinical frailty is associated with high mortality, but few studies have explored the relationship between OA and frailty. The objective of this study was to consider the association between OA and frailty/pre-frailty in an elderly population comprised of six European cohorts participating in the EPOSA project.
  
  
  METHODS
  Longitudinal study using baseline data and first follow-up waves, from EPOSA; 2,455 individuals aged 65-85 years were recruited from pre-existing population-based cohorts in Germany, Italy, the Netherlands, Spain, Sweden and the United Kingdom. Data were collected on clinical OA at any site (hand, knee or hip), based on the clinical classification criteria developed by the American College of Rheumatology (ACR). Frailty was defined according to Fried's criteria. The covariates considered were age, gender, educational level, obesity and country. We used multinomial logistic regression to analyse the associations between OA, frailty/pre-frailty and other covariates.
  
  
  RESULTS
  The overall prevalence of clinical OA at any site was 30.4 % (95 % CI:28.6-32.2); frailty was present in 10.2 % (95 % CI:9.0-11.4) and pre-frailty in 51.0 % (95 % CI:49.0-53.0). The odds of frailty was 2.96 (95 % CI:2.11-4.16) and pre-frailty 1.54 (95 % CI:1.24-1.91) as high among OA individuals than those without OA. The association remained when Knee OA, hip OA or hand OA were considered separately, and was stronger in those with increasing number of joints.
  
  
  CONCLUSIONS
  Clinical OA is associated with frailty and pre-frailty in older adults in European countries. This association might be considered when designing appropriate intervention strategies for OA management.
authors.affiliation: Preventive Medicine and Public Health, Unit of Primary Care and Family Medicine, Universidad Autonoma de Madrid, Madrid, Spain. mcastell.gapm05@salud.madrid.org.|IdiPAZ, Instituto de Investigacion de La PAZ, Madrid, Spain. mcastell.gapm05@salud.madrid.org.
authors.forename: Maria Victoria
authors.initials: MV
authors.lastname: Castell
authors.affiliation: EMGO Institute for Health and Care Research, Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, Netherlands. s.vanderpas@vumc.nl.
authors.forename: Suzan
authors.initials: S
authors.lastname: van der Pas
authors.affiliation: Preventive Medicine and Public Health, Unit of Primary Care and Family Medicine, Universidad Autonoma de Madrid, Madrid, Spain. angel.otero@uam.es.|IdiPAZ, Instituto de Investigacion de La PAZ, Madrid, Spain. angel.otero@uam.es.
authors.forename: Angel
authors.initials: A
authors.lastname: Otero
authors.affiliation: Medicine and Surgical Sciences. Institute of Neuroscience, University of Padova, Padua, Italy. paola.siviero@in.cnr.it.
authors.forename: Paola
authors.initials: P
authors.lastname: Siviero
authors.affiliation: MRC Epidemiology Resource Centre, University of Southampton, Southampton, UK. emd@mrc.soton.ac.uk.
authors.forename: Elaine
authors.initials: E
authors.lastname: Dennison
authors.affiliation: Bethesda Geriatric Clinic, University of Ulm, Ulm, Germany. Michael.Denkinger@bethesda-ulm.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Denkinger
authors.affiliation: Medical Epidemiology and Biostatistics, Karolinska Institutet, Stockholm, Sweden. Nancy.Pedersen@ki.se.
authors.forename: Nancy
authors.initials: N
authors.lastname: Pedersen
authors.affiliation: Preventive Medicine and Public Health, Unit of Primary Care and Family Medicine, Universidad Autonoma de Madrid, Madrid, Spain. mercedes.martinez@uam.es.|IdiPAZ, Instituto de Investigacion de La PAZ, Madrid, Spain. mercedes.martinez@uam.es.
authors.forename: Mercedes
authors.initials: M
authors.lastname: Sanchez-Martinez
authors.affiliation: IdiPAZ, Instituto de Investigacion de La PAZ, Madrid, Spain. rocio.queipo@uam.es.
authors.forename: Rocio
authors.initials: R
authors.lastname: Queipo
authors.affiliation: EMGO Institute for Health and Care Research, Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, Netherlands. nm.vanschoor@vumc.nl.
authors.forename: Natasja
authors.initials: N
authors.lastname: van Schoor
authors.affiliation: Medicine and Surgical Sciences. Institute of Neuroscience, University of Padova, Padua, Italy. sabina.zambon@unipd.it.
authors.forename: Sabina
authors.initials: S
authors.lastname: Zambon
authors.affiliation: MRC Epidemiology Resource Centre, University of Southampton, Southampton, UK. me@mrc.soton.ac.uk.
authors.forename: Mark
authors.initials: M
authors.lastname: Edwards
authors.affiliation: Bethesda Geriatric Clinic, University of Ulm, Ulm, Germany. richard.peter@uni-ulm.de.
authors.forename: Richard
authors.initials: R
authors.lastname: Peter
authors.affiliation: EMGO Institute for Health and Care Research, Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, Netherlands. l.schaap@vumc.nl.
authors.forename: Laura
authors.initials: L
authors.lastname: Schaap
authors.affiliation: EMGO Institute for Health and Care Research, Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam, Netherlands. djh.deeg@vumc.nl.
authors.forename: Dorly
authors.initials: D
authors.lastname: Deeg
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D005060:Europe / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D016330:Frail Elderly; D005858:Germany / Q000453:epidemiology; D050823:Hand Joints / Q000473:pathology*; D006801:Humans; D007558:Italy / Q000453:epidemiology; D008137:Longitudinal Studies; D008297:Male; D009426:Netherlands / Q000453:epidemiology; D015207:Osteoarthritis, Hip / Q000175:diagnosis* / Q000453:epidemiology*; D020370:Osteoarthritis, Knee / Q000175:diagnosis* / Q000453:epidemiology*; D013030:Spain / Q000453:epidemiology; D013548:Sweden / Q000453:epidemiology; D006113:United Kingdom / Q000453:epidemiology