title: Does age modify the relationship between adherence to secondary prevention medications and mortality after acute myocardial infarction? A nested case-control study.
abstract: OBJECTIVE
  Clinical trials have shown that evidence-based secondary prevention medications reduce mortality after acute myocardial infarction (AMI). Yet, these medications are generally underused in daily practice, and older people are often excluded from drug trials. The purpose of this study was to examine whether the relationship between adherence to evidence-based drugs and post-AMI mortality varies with increasing age.
  
  
  METHODS
  The study population was defined as all residents in the Local Health Authority of Bologna (Italy) hospitalized for AMI between January 1, 2008 and June 30, 2011, and followed up until December 31, 2012. Medication adherence was calculated as the proportion of days covered (PDC) for filled prescriptions of angiotensin-converting enzyme inhibitors/angiotensin receptor blockers, β-blockers, antiplatelet drugs, and statins; patients were classified as adherent (PDC ≥75 %) or nonadherent (PDC <75 %). We used incidence density sampling, and the moderating effect of age on the relationship between adherence and mortality was investigated through conditional multiple logistic regression analysis.
  
  
  RESULTS
  The study population comprised 3963 patients. During the 5-year study period, 1085 deaths (27.4 %) were observed. For both younger and older patients, adherence to polytherapy (three or four medications) was associated with lower mortality (adj. rate ratio = 0.41; P < 0.001). A significant inverse relationship was found between adherence to each of the four medications and mortality, although the risk reduction associated with antiplatelet therapy declined after the age of 70-75.
  
  
  CONCLUSIONS
  The beneficial effect of evidence-based polytherapy on mortality following AMI is observed also in older populations. Nevertheless, the risk-benefit ratio associated with antiplatelet therapy is less favorable with increasing age.
authors.affiliation: Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum-University of Bologna, Via San Giacomo 12, 40126, Bologna, Italy, jacopo.lenzi2@unibo.it.
authors.forename: Jacopo
authors.initials: J
authors.lastname: Lenzi
authors.forename: Paola
authors.initials: P
authors.lastname: Rucci
authors.forename: Ilaria
authors.initials: I
authors.lastname: Castaldini
authors.forename: Adalgisa
authors.initials: A
authors.lastname: Protonotari
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Di Pasquale
authors.forename: Mirko
authors.initials: M
authors.lastname: Di Martino
authors.forename: Enrica
authors.initials: E
authors.lastname: Perrone
authors.forename: Paola
authors.initials: P
authors.lastname: Forti
authors.forename: Maria Pia
authors.initials: MP
authors.lastname: Fantini
mesh_terms: D018674:Adrenergic Antagonists / Q000627:therapeutic use; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000401:mortality*; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use; D055502:Secondary Prevention; D016903:Drug Monitoring
chemical_list: D018674:Adrenergic Antagonists; D000806:Angiotensin-Converting Enzyme Inhibitors; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010975:Platelet Aggregation Inhibitors