title: Long term use of analgesics and risk of osteoarthritis progressions and knee replacement: propensity score matched cohort analysis of data from the Osteoarthritis Initiative.
abstract: OBJECTIVE
  To determine the association between the long-term use of analgesics and progression of osteoarthritis (OA) as evidenced by up to 3-years follow-up worsening of radiographic Kellgren-Lawrence (KL) grade and incidence of knee replacement (KR).
  
  
  METHODS
  Using nearest neighbor matching of the propensity scores with caliper in the Osteoarthritis Initiative (OAI) cohort, 173 index (Analgesic +) and 173 referent (Analgesic -) subjects were included. Analgesic + and - subjects had analgesics in all and none of their visits, respectively. Analgesic + and - subjects were balanced in their demographics, baseline, first, second and third year body mass index (BMI), Western Ontario and McMaster (WOMAC) total score, Physical and Mental health summary scales (SF-12), Physical Activity Scale for the Elderly (PASE) and Charleston Comorbidity Scale. Analgesic + and - subjects were also matched for baseline radiographic KL grade. Interval increase in the KL grade and incidence of KR were defined as the outcome.
  
  
  RESULTS
  Included subjects had average 6.5 years of follow-up. By the third year, 44 subjects had an interval increase in the KL grade; 29 in Analgesic + and 15 among Analgesic - subjects (P = 0.024). By the eighth-year, 41 subjects had their first KR; 29 in Analgesic + and 12 among Analgesic - subjects (P = 0.005). Hazard Ratio (HR) of OA progression and KR for Analgesic + subjects was 1.91 (1.02-3.57) and 2.57 (1.31-5.04), respectively.
  
  
  CONCLUSIONS
  Long-term use of analgesics may be associated with radiographic progression of knee OA and increased risk of future KR.
authors.affiliation: Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD, USA. Electronic address: nhafezi1@jhmi.edu.
authors.forename: N
authors.initials: N
authors.lastname: Hafezi-Nejad
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA.
authors.forename: A
authors.initials: A
authors.lastname: Guermazi
authors.affiliation: Quantitative Imaging Center, Department of Radiology, Boston University School of Medicine, Boston, MA, USA; Department of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany.
authors.forename: F W
authors.initials: FW
authors.lastname: Roemer
authors.affiliation: Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: J
authors.initials: J
authors.lastname: Eng
authors.affiliation: Department of Orthopedic Surgery, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: B
authors.initials: B
authors.lastname: Zikria
authors.affiliation: Russell H. Morgan Department of Radiology, Johns Hopkins University, Baltimore, MD, USA.
authors.forename: S
authors.initials: S
authors.lastname: Demehri
mesh_terms: D000368:Aged; D000700:Analgesics / Q000008:administration & dosage / Q000009:adverse effects*; D019645:Arthroplasty, Replacement, Knee / Q000706:statistics & numerical data*; D015331:Cohort Studies; D018450:Disease Progression; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000139:chemically induced* / Q000150:complications / Q000000981:diagnostic imaging / Q000601:surgery; D010147:Pain Measurement / Q000379:methods; D057216:Propensity Score; D011859:Radiography; D012720:Severity of Illness Index
chemical_list: D000700:Analgesics
keywords: Analgesics; Knee replacement; Osteoarthritis progression; Propensity score matching