title: Effect of Comorbid Knee and Hip Osteoarthritis on Longitudinal Clinical and Health Care Use Outcomes in Older Adults With New Visits for Back Pain.
abstract: To examine if a comorbid diagnosis of knee or hip osteoarthritis (OA) in older adults with new back pain visits is associated with long-term patient-reported outcomes and back-related health care use.
  
  
  
  Prospective cohort study.
  
  
  
  Three integrated health systems forming the Back pain Outcomes using Longitudinal Data cohort.
  
  
  
  Participants (N=5155) were older adults (≥65y) with a new visit for back pain and a complete electronic health record data.
  
  
  
  Not applicable; we obtained OA diagnoses using diagnostic codes in the electronic health record 12 months prior to the new back pain visit.
  
  
  
  The Roland-Morris Disability Questionnaire (RDQ) and the EuroQol-5D (EQ-5D) were key patient-reported outcomes. Health care use, measured by relative-value units (RVUs), was summed for the 12 months after the initial visit. We used linear mixed-effects models to model patient-reported outcomes. We also used generalized linear models to test the association between comorbid knee or hip OA and total back-related RVUs.
  
  
  
  Of the 5155 participants, 368 (7.1%) had a comorbid knee OA diagnosis, and 94 (1.8%) had a hip OA diagnosis. Of the participants, 4711 (91.4%) had neither knee nor hip OA. In adjusted models, the 12-month RDQ score was 1.23 points higher (95% confidence interval [CI], 0.72-1.74) for patients with knee OA and 1.26 points higher (95% CI, 0.24-2.27) for those with hip OA than those without knee or hip OA, respectively. A lower EQ-5D score was found among participants with knee OA (.02 lower; 95% CI, -.04 to -.01) and hip OA diagnoses (.03 lower; 95% CI, -.05 to -.01) compared with those without knee or hip OA, respectively. Comorbid knee or hip OA was not significantly associated with total 12-month back-related resource use.
  
  
  
  Comorbid knee or hip OA in older adults with a new back pain visit was associated with modestly worse long-term disability and health-related quality of life.
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA; Comparative Effectiveness, Cost, and Outcomes Research Center, University of Washington, Seattle, WA. Electronic address: srundell@uw.edu.
authors: Sean D
authors: SD
authors: Rundell
authors: Department of Orthopaedics, Duke University, Durham, NC.
authors: Adam P
authors: AP
authors: Goode
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA; Comparative Effectiveness, Cost, and Outcomes Research Center, University of Washington, Seattle, WA; VA Puget Sound Health Care System, Seattle, WA.
authors: Pradeep
authors: P
authors: Suri
authors: Center for Biomedical Statistics, University of Washington, Seattle, WA.
authors: Patrick J
authors: PJ
authors: Heagerty
authors: Center for Biomedical Statistics, University of Washington, Seattle, WA.
authors: Bryan A
authors: BA
authors: Comstock
authors: Department of Rehabilitation Medicine, University of Washington, Seattle, WA; Comparative Effectiveness, Cost, and Outcomes Research Center, University of Washington, Seattle, WA.
authors: Janna L
authors: JL
authors: Friedly
authors: Comparative Effectiveness, Cost, and Outcomes Research Center, University of Washington, Seattle, WA; Department of Radiology, University of Washington, Seattle, WA.
authors: Laura S
authors: LS
authors: Gold
authors: Comparative Effectiveness, Cost, and Outcomes Research Center, University of Washington, Seattle, WA; Department of Radiology, University of Washington, Seattle, WA.
authors: Zoya
authors: Z
authors: Bauer
authors: Division of Research, Kaiser Permanente Northern California, Oakland, CA.
authors: Andrew L
authors: AL
authors: Avins
authors: Department of Anesthesiology, Perioperative and Pain Medicine, Brigham and Women's Hospital, and Spine Unit, Harvard Vanguard Medical Associates, Boston, MA.
authors: Srdjan S
authors: SS
authors: Nedeljkovic
authors: Neuroscience Institute, Henry Ford Hospital, Detroit, MI.
authors: David R
authors: DR
authors: Nerenz
authors: Department of Health Services, University of Washington, Seattle, WA.
authors: Larry
authors: L
authors: Kessler
authors: Comparative Effectiveness, Cost, and Outcomes Research Center, University of Washington, Seattle, WA; Department of Radiology, University of Washington, Seattle, WA; Department of Health Services, University of Washington, Seattle, WA; Department of Neurological Surgery, University of Washington, Seattle, WA.
authors: Jeffrey G
authors: JG
authors: Jarvik
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001416:Back Pain / Q000453:epidemiology* / Q000628:therapy*; D015897:Comorbidity; D004185:Disability Evaluation; D005260:Female; D006296:Health Services / Q000706:statistics & numerical data*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D009819:Office Visits / Q000706:statistics & numerical data; D015207:Osteoarthritis, Hip / Q000175:diagnosis / Q000453:epidemiology*; D020370:Osteoarthritis, Knee / Q000175:diagnosis / Q000453:epidemiology*; D000071066:Patient Reported Outcome Measures; D011446:Prospective Studies; D011788:Quality of Life; D011795:Surveys and Questionnaires
keywords: Back pain; Comorbidity; Osteoarthritis; Patient outcome assessment; Rehabilitation