title: Analgesic use and risk of recurrent falls in participants with or at risk of knee osteoarthritis: data from the Osteoarthritis Initiative.
abstract: Few studies have compared the risk of recurrent falls across different types of analgesic use, and with limited adjustment for potential confounders (e.g., pain/depression severity). We assessed analgesic use and the subsequent risk of recurrent falls, among participants with or at risk of knee osteoarthritis (OA).
  
  
  
  A longitudinal analysis included 4231 participants aged 45-79 years at baseline with 4-year follow-up from the Osteoarthritis Initiative (OAI) cohort study. We grouped participants into six mutually exclusive subgroups based on annually assessed analgesic use in the following hierarchical order of analgesic/central nervous system (CNS) potency: use of (1) opioids, (2) antidepressants, (3) other prescription pain medications, (4) over-the-counter (OTC) pain medications, (5) nutraceuticals, and (6) no analgesics. We used multivariable modified Poisson regression models with a robust error variance to estimate the effect of analgesic use on the risk of recurrent falls (≥2) in the following year, adjusted for demographics and health status/behavior factors.
  
  
  
  Opioid use increased from 2.7% at baseline to 3.6% at the 36-month visit (>80% using other analgesics/nutraceuticals), while other prescription pain medication use decreased from 16.7% to 11.9% over this time period. Approximately 15% of participants reported recurrent falls. Compared to those not using analgesics, participants who used opioids and/or antidepressants had a 22-25% increased risk of recurrent falls (opioids: RRadjusted= 1.22, 95% CI = 1.04-1.45; antidepressants: RRadjusted= 1.25, 95% CI = 1.10-1.41).
  
  
  
  Participants with or at risk of knee OA who used opioids and antidepressants with/without other analgesics/nutraceuticals may have an increased risk of recurrent falls after adjusting for potential confounders. Use of opioids and antidepressants warrants caution.
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ 85719, USA. Electronic address: lociganic@pharmacy.arizona.edu.
authors.forename: W-H
authors.initials: WH
authors.lastname: Lo-Ciganic
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ 85719, USA. Electronic address: libbyford@gmail.com.
authors.forename: L
authors.initials: L
authors.lastname: Floden
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ 85719, USA. Electronic address: jlee@pharmacy.arizona.edu.
authors.forename: J K
authors.initials: JK
authors.lastname: Lee
authors.affiliation: University of Arizona Arthritis Center, College of Medicine, University of Arizona, Tucson, AZ, USA. Electronic address: eashbeck@arthritis.arizona.edu.
authors.forename: E L
authors.initials: EL
authors.lastname: Ashbeck
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ 85719, USA. Electronic address: lilizhou@pharmacy.arizona.edu.
authors.forename: L
authors.initials: L
authors.lastname: Zhou
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ 85719, USA. Electronic address: chinthammit@pharmacy.arizona.edu.
authors.forename: C
authors.initials: C
authors.lastname: Chinthammit
authors.affiliation: Department of Pharmacy, Practice and Science, College of Pharmacy, University of Arizona, Tucson, AZ 85719, USA. Electronic address: apurdy@email.arizona.edu.
authors.forename: A W
authors.initials: AW
authors.lastname: Purdy
authors.affiliation: University of Arizona Arthritis Center, College of Medicine, University of Arizona, Tucson, AZ, USA; Department of Medicine, Division of Rheumatology, University of Arizona, Tucson, AZ, USA. Electronic address: ckwoh@arthritis.arizona.edu.
authors.forename: C K
authors.initials: CK
authors.lastname: Kwoh
mesh_terms: D000058:Accidental Falls / Q000706:statistics & numerical data*; D000368:Aged; D000700:Analgesics / Q000009:adverse effects*; D000701:Analgesics, Opioid / Q000009:adverse effects; D000928:Antidepressive Agents / Q000009:adverse effects; D015986:Confounding Factors, Epidemiologic; D004363:Drug Utilization / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000188:drug therapy* / Q000453:epidemiology; D012008:Recurrence; D018570:Risk Assessment / Q000379:methods; D012307:Risk Factors; D012720:Severity of Illness Index; D014481:United States / Q000453:epidemiology
chemical_list: D000700:Analgesics; D000701:Analgesics, Opioid; D000928:Antidepressive Agents
keywords: Analgesics; Antidepressants; Falls; Knee osteoarthritis; Non-steroidal anti-inflammatory drugs; Opioids