title: Gastroprotection in low-dose aspirin users for primary and secondary prevention of ACS: results of a cost-effectiveness analysis including compliance.
abstract: OBJECTIVE
  Low-dose aspirin (ASA) increases the risk of upper gastrointestinal (GI) complications. Proton pump inhibitors (PPIs) reduce these upper GI side effects, yet patient compliance to PPIs is low. We determined the cost-effectiveness of gastroprotective strategies in low-dose ASA users considering ASA and PPI compliance.
  
  
  METHODS
  Using a Markov model we compared four strategies: no medication, ASA monotherapy, ASA+PPI co-therapy and a fixed combination of ASA and PPI for primary and secondary prevention of ACS. The risk of acute coronary syndrome (ACS), upper GI bleeding and dyspepsia was modeled as a function of compliance and the relative risk of developing these events while using medication. Costs, quality adjusted life years and number of ACS events were evaluated, applying a variable risk of upper GI bleeding. Probabilistic sensitivity analyses were performed.
  
  
  RESULTS
  For our base case patients using ASA for primary prevention of ACS no medication was superior to ASA monotherapy. PPI co-therapy was cost-effective (incremental cost-effectiveness ratio [ICER] €10,314) compared to no medication. In secondary prevention, PPI co-therapy was cost-effective (ICER €563) while the fixed combination yielded an ICER < €20,000 only in a population with elevated risk for upper GI bleeding or moderate PPI compliance. PPI co-therapy had the highest probability to be cost-effective in all scenarios. PPI use lowered the overall number of ACS.
  
  
  CONCLUSIONS
  Considering compliance, PPI co-therapy is likely to be cost-effective in patients taking low dose ASA for primary and secondary prevention of ACS, given low PPI prices. In secondary prevention, a fixed combination seems cost-effective in patients with elevated risk for upper GI bleeding or in those with moderate PPI compliance. Both strategies reduced the number of ACS compared to ASA monotherapy.
authors: Department Gastroenterology and Hepatology, University Medical Center Utrecht, PO Box (85500 internal code F02.618), 3508 GA Utrecht, The Netherlands. n.l.degroot-3@umcutrecht.nl
authors: N L
authors: NL
authors: de Groot
authors: H G M
authors: HG
authors: van Haalen
authors: B M R
authors: BM
authors: Spiegel
authors: L
authors: L
authors: Laine
authors: A
authors: A
authors: Lanas
authors: J Jaspers
authors: JJ
authors: Focks
authors: P D
authors: PD
authors: Siersema
authors: M G H
authors: MG
authors: van Oijen
mesh_terms: D054058:Acute Coronary Syndrome / Q000191:economics / Q000517:prevention & control*; D001241:Aspirin / Q000008:administration & dosage* / Q000191:economics; D003362:Cost-Benefit Analysis; D004359:Drug Therapy, Combination; D006471:Gastrointestinal Hemorrhage / Q000191:economics / Q000517:prevention & control*; D017048:Health Care Costs; D006801:Humans; D008297:Male; D008875:Middle Aged; D008962:Models, Theoretical; D010349:Patient Compliance; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage* / Q000191:economics; D011322:Primary Prevention; D054328:Proton Pump Inhibitors / Q000008:administration & dosage* / Q000191:economics; D019057:Quality-Adjusted Life Years; D055502:Secondary Prevention
chemical_list: D010975:Platelet Aggregation Inhibitors; D054328:Proton Pump Inhibitors; D001241:Aspirin