title: Underreporting of recognized adverse drug reactions by primary care physicians: an exploratory study.
abstract: OBJECTIVE
  This study evaluated the magnitude of underreporting of adverse drug reactions (ADRs) and investigated possible reporting patterns according to patient characteristics and the type of reaction based on the integration of information obtained from primary care electronic medical records (EMRs) and the Spanish Pharmacovigilance System.
  
  
  METHODS
  This investigation was a descriptive retrospective study analysing ADRs recorded in 2005 in the EMRs from six health centers in Zaragoza (Aragon, Spain) with a covered population of 126,838 subjects. The associations between the probability of reporting and the reaction and drug type were studied using logistic regression models adjusted by age and sex.
  
  
  RESULTS
  The total number of ADRs recorded in the EMRs was 543, of which 65.7% were reported to the Spanish Pharmacovigilance System. Positive associations were found between the probability of reporting an ADR and advanced age of patients (OR for ≥76 years = 2.0; 95%CI 1.1-3.6), involvement of the reproductive system (OR = 7.9; 95%CI 1.02-60.2) and involvement of psychiatric disorders (OR = 4.0; 95%CI 1.4-11.6). Negative associations were found between reporting an ADR and early age of patients (OR for 0-14 years = 0.2; 95%CI 0.1-0.6) and the use of antimicrobial drugs (OR = 0.6; 95%CI 0.4-0.9).
  
  
  CONCLUSIONS
  This study tackles an important public health problem directly related to patients' safety and highlights the utility of EMRs for investigating the current significance of ADR underreporting. It also makes us think that primary care physicians seem to have selective reporting patterns based on their familiarity with the reaction type and the drug causing the reaction as well as on the age of patients.
authors.affiliation: Instituto Aragonés de Ciencias de la Salud-I+CS, Instituto de Investigación Sanitaria Aragón (IIS Aragón), Zaragoza, Spain.
authors.forename: Francisca
authors.initials: F
authors.lastname: González-Rubio
authors.forename: Amaia
authors.initials: A
authors.lastname: Calderón-Larrañaga
authors.forename: Beatriz
authors.initials: B
authors.lastname: Poblador-Plou
authors.forename: Cristina
authors.initials: C
authors.lastname: Navarro-Pemán
authors.forename: Anselmo
authors.initials: A
authors.lastname: López-Cabañas
authors.forename: Alexandra
authors.initials: A
authors.lastname: Prados-Torres
mesh_terms: D000293:Adolescent; D000328:Adult; D016907:Adverse Drug Reaction Reporting Systems / Q000706:statistics & numerical data*; D000367:Age Factors; D000368:Aged; D002648:Child; D002675:Child, Preschool; D057286:Electronic Health Records / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D060735:Pharmacovigilance; D058007:Physicians, Primary Care / Q000706:statistics & numerical data*; D012189:Retrospective Studies; D013030:Spain; D055815:Young Adult