title: Change in Pain and Physical Function Following Bariatric Surgery for Severe Obesity.
abstract: OBJECTIVE
  The variability and durability of improvements in pain and physical function following Roux-en-Y gastric bypass (RYGB) or laparoscopic adjustable gastric banding (LAGB) are not well described.
  
  
  OBJECTIVE
  To report changes in pain and physical function in the first 3 years following bariatric surgery, and to identify factors associated with improvement.
  
  
  METHODS
  The Longitudinal Assessment of Bariatric Surgery-2 is an observational cohort study at 10 US hospitals. Adults with severe obesity undergoing bariatric surgery were recruited between February 2005 and February 2009. Research assessments were conducted prior to surgery and annually thereafter. Three-year follow-up through October 2012 is reported.
  
  
  METHODS
  Bariatric surgery as clinical care.
  
  
  METHODS
  Primary outcomes were clinically meaningful presurgery to postsurgery improvements in pain and function using scores from the Medical Outcomes Study 36-Item Short-Form Health Survey (SF-36) (ie, improvement of ≥5 points on the norm-based score [range, 0-100]) and 400-meter walk time (ie, improvement of ≥24 seconds) using established thresholds. The secondary outcome was clinically meaningful improvement using the Western Ontario McMaster Osteoarthritis Index (ie, improvement of ≥9.7 pain points and ≥9.3 function points on the transformed score [range, 0-100]).
  
  
  RESULTS
  Of 2458 participants, 2221 completed baseline and follow-up assessments (1743 [78.5%] were women; median age was 47 years; median body mass index [BMI] was 45.9; 70.4% underwent RYGB; 25.0% underwent LAGB). At year 1, clinically meaningful improvements were shown in 57.6% (95% CI, 55.3%-59.9%) of participants for bodily pain, 76.5% (95% CI, 74.6%-78.5%) for physical function, and 59.5% (95% CI, 56.4%-62.7%) for walk time. Additionally, among participants with severe knee or disability (633), or hip pain or disability (500) at baseline, approximately three-fourths experienced joint-specific improvements in knee pain (77.1% [95% CI, 73.5%-80.7%]) and in hip function (79.2% [95% CI, 75.3%-83.1%]). Between year 1 and year 3, rates of improvement significantly decreased to 48.6% (95% CI, 46.0%-51.1%) for bodily pain and to 70.2% (95% CI, 67.8%-72.5%) for physical function, but improvement rates for walk time, knee and hip pain, and knee and hip function did not (P for all ≥.05). Younger age, male sex, higher income, lower BMI, and fewer depressive symptoms presurgery; no diabetes and no venous edema with ulcerations postsurgery (either no history or remission); and presurgery-to-postsurgery reductions in weight and depressive symptoms were associated with presurgery-to-postsurgery improvements in multiple outcomes at years 1, 2, and 3.
  
  
  CONCLUSIONS
  Among a cohort of participants with severe obesity undergoing bariatric surgery, a large percentage experienced improvement, compared with baseline, in pain, physical function, and walk time over 3 years, but the percentage with improvement in pain and physical function decreased between year 1 and year 3.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT00465829.
authors.affiliation: University of Pittsburgh, Graduate School of Public Health, Pittsburgh, Pennsylvania.
authors.forename: Wendy C
authors.initials: WC
authors.lastname: King
authors.affiliation: University of Pittsburgh, Graduate School of Public Health, Pittsburgh, Pennsylvania.
authors.forename: Jia-Yuh
authors.initials: JY
authors.lastname: Chen
authors.affiliation: University of Pittsburgh, Graduate School of Public Health, Pittsburgh, Pennsylvania.
authors.forename: Steven H
authors.initials: SH
authors.lastname: Belle
authors.affiliation: University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania.
authors.forename: Anita P
authors.initials: AP
authors.lastname: Courcoulas
authors.affiliation: Weill Cornell Medical Center, New York, New York.
authors.forename: Gregory F
authors.initials: GF
authors.lastname: Dakin
authors.affiliation: Oregon Health and Science University, Portland5Now with Pacific University, Forest Grove, Oregon, and the Oregon Health and Science University, Portland.
authors.forename: Katherine A
authors.initials: KA
authors.lastname: Elder
authors.affiliation: University of Washington, Seattle.
authors.forename: David R
authors.initials: DR
authors.lastname: Flum
authors.affiliation: University of Washington, Seattle.
authors.forename: Marcelo W
authors.initials: MW
authors.lastname: Hinojosa
authors.affiliation: Neuropsychiatric Research Institute, Fargo, North Dakota.
authors.forename: James E
authors.initials: JE
authors.lastname: Mitchell
authors.affiliation: Brody School of Medicine, East Carolina University, Greenville, North Carolina.
authors.forename: Walter J
authors.initials: WJ
authors.lastname: Pories
authors.affiliation: Oregon Health and Science University, Portland.
authors.forename: Bruce M
authors.initials: BM
authors.lastname: Wolfe
authors.affiliation: National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda, Maryland.
authors.forename: Susan Z
authors.initials: SZ
authors.lastname: Yanovski
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D018771:Arthralgia / Q000209:etiology / Q000601:surgery*; D050110:Bariatric Surgery; D015331:Cohort Studies; D003863:Depression; D005260:Female; D005500:Follow-Up Studies; D015390:Gastric Bypass; D006621:Hip Joint / Q000503:physiopathology; D006801:Humans; D007719:Knee Joint / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009767:Obesity, Morbid / Q000150:complications / Q000503:physiopathology* / Q000523:psychology / Q000601:surgery*; D012737:Sex Factors; D013997:Time Factors; D016896:Treatment Outcome; D016138:Walking / Q000502:physiology