title: Association between adherence to concomitant proton pump inhibitor therapy in current NSAID users and upper gastrointestinal complications.
abstract: BACKGROUND
  Proton pump inhibitors (PPIs) play a well-documented role as a gastroprotective agent among NSAID users at an increased risk of peptic ulcer and bleeding. Observational studies have, however, suggested that the clinical efficacy of PPI therapy may be reduced because of poor adherence.
  
  
  OBJECTIVE
  To study the association between adherence to concomitant PPI in current NSAID users and the risk of peptic ulcer and bleeding.
  
  
  METHODS
  Case-control study linking nationwide data from the Swedish Patient Registry with the Swedish Drug Prescription Database. The study population included patients admitted for a first-time peptic ulcer or bleeding and who were incident users of NSAID. Each case was matched on age, sex, NSAID duration, and calendar month with five controls. PPI adherence was calculated as the proportion of NSAID days being covered by PPI therapy. Matched and adjusted odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using conditional logistic regression.
  
  
  RESULTS
  A total of 3649 cases were identified. Patients with poor adherence (<20% PPI coverage) had a significantly increased risk of upper gastrointestinal complications (OR=1.88, 95% CI 1.22-2.88) compared with fully adherent patients (≥80% PPI coverage). As a continuous variable, the risk of an event increased with 6% points for every 10% decrease in PPI adherence (OR=1.06, 95% CI 1.03-1.10).
  
  
  CONCLUSIONS
  The gastroprotective effect of PPI in NSAID users is highly dependent on adherence, with about twice the risk in patients with poor adherence. Efforts to increase adherence should be an integrated part of clinical practice.
authors.affiliation: Institute of Medicine, University of Bergen, Bergen, Norway. christian.jonasson@med.uib.no
authors.forename: Christian
authors.initials: C
authors.lastname: Jonasson
authors.forename: Jan G
authors.initials: JG
authors.lastname: Hatlebakk
authors.forename: Lars
authors.initials: L
authors.lastname: Lundell
authors.forename: Jukka P
authors.initials: JP
authors.lastname: Kouri
authors.forename: Morten
authors.initials: M
authors.lastname: Andersen
authors.forename: Fredrik
authors.initials: F
authors.lastname: Granath
mesh_terms: D000368:Aged; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000008:administration & dosage / Q000009:adverse effects*; D000897:Anti-Ulcer Agents / Q000008:administration & dosage* / Q000627:therapeutic use; D016022:Case-Control Studies; D004334:Drug Administration Schedule; D015987:Effect Modifier, Epidemiologic; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000139:chemically induced* / Q000453:epidemiology / Q000517:prevention & control; D006801:Humans; D008297:Male; D008875:Middle Aged; D010437:Peptic Ulcer / Q000139:chemically induced* / Q000453:epidemiology / Q000517:prevention & control; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000627:therapeutic use; D018570:Risk Assessment / Q000379:methods; D013548:Sweden / Q000453:epidemiology; D016903:Drug Monitoring
chemical_list: D000894:Anti-Inflammatory Agents, Non-Steroidal; D000897:Anti-Ulcer Agents; D054328:Proton Pump Inhibitors