title: Inadequate pain relief and large functional loss among patients with knee osteoarthritis: evidence from a prospective multinational longitudinal study of osteoarthritis real-world therapies.
abstract: OBJECTIVE
  To estimate the prevalence of inadequate pain relief (IPR) among patients with symptomatic knee OA prescribed analgesic therapy and to characterize patients with IPR.
  
  
  METHODS
  Patients ≥50 years old with physician-diagnosed knee OA who had taken topical or oral pain medication for at least 14 days were recruited for this prospective non-interventional study in six European countries. Pain and function were assessed using the Brief Pain Inventory (BPI) and the WOMAC; quality of life (QoL) was assessed using the 12-item short form. IPR was defined as an average pain score of >4 out of 10 on BPI question 5.
  
  
  RESULTS
  Of 1187 patients enrolled, 68% were female and the mean age was 68 years (s.d. 9); 639 (54%) met the definition of IPR. Patient responses for the BPI average pain question were well correlated with responses on the WOMAC pain subscale (Spearman r = 0.64, P < 0.001). In multivariate logistic regression, patients with IPR had greater odds of being female [adjusted odds ratio (adjOR) 1.90 (95% CI 1.46, 2.48)] and having OA in both knees [adjOR 1.48 (95% CI 1.15, 1.90)], higher BMI, longer OA duration, depression or diabetes. Patients with IPR (vs non-IPR) were more likely to have worse QoL, greater function loss and greater pain interference.
  
  
  CONCLUSIONS
  IPR is common among patients with knee OA requiring analgesics and is associated with large functional loss and impaired QoL. Patients at particular risk of IPR, as characterized in this study, may require greater attention towards their analgesic treatment options.
  
  
  BACKGROUND
  https://clinicaltrials.gov/ (NCT01294696).
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK. Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Philip G
authors.initials: PG
authors.lastname: Conaghan
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Paul M
authors.initials: PM
authors.lastname: Peloso
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Sharlette V
authors.initials: SV
authors.lastname: Everett
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Srinivasan
authors.initials: S
authors.lastname: Rajagopalan
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Christopher M
authors.initials: CM
authors.lastname: Black
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Mavros
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Nigel K
authors.initials: NK
authors.lastname: Arden
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Ceri J
authors.initials: CJ
authors.lastname: Phillips
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: François
authors.initials: F
authors.lastname: Rannou
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: Mart A F J
authors.initials: MA
authors.lastname: van de Laar
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK.
authors.forename: R Andrew
authors.initials: RA
authors.lastname: Moore
authors.affiliation: Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds, UK, Clinical Development, MRL, Merck & Co., Kenilworth, Global Health Outcomes, Merck & Co., Whitehouse Station, MedData Analytics, East Brunswick, NJ, College of Pharmacy, St Johns University, Queens, NY, USA, Nuffield Department of Orthopaedics, Rheumatology and Musculoskeletal Sciences, University of Oxford, Oxford, Centre for Health Economics, Swansea University, Swansea, UK, Cochin Hospital, Rehabilitation Department, University of Paris, Paris, France, Department of Rheumatology and Clinical Immunology, University of Twente, Enschede, The Netherlands and Pain Research & Nuffield Department of Anaesthetics, Oxford University, Oxford, UK. stephanie_taylor@merck.com.
authors.forename: Stephanie D
authors.initials: SD
authors.lastname: Taylor
mesh_terms: D000279:Administration, Cutaneous; D000284:Administration, Oral; D000368:Aged; D000700:Analgesics / Q000008:administration & dosage*; D005260:Female; D006801:Humans; D008297:Male; D059352:Musculoskeletal Pain / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D020370:Osteoarthritis, Knee / Q000150:complications* / Q000503:physiopathology; D010147:Pain Measurement / Q000379:methods; D017060:Patient Satisfaction; D011446:Prospective Studies; D011788:Quality of Life; D016896:Treatment Outcome
chemical_list: D000700:Analgesics
keywords: analgesic therapy; inadequate pain relief; knee; osteoarthritis