title: [A hazard scale for severe interactions: a tool for establishing prioritising strategies to improve the safety of the prescription in family medicine].
abstract: OBJECTIVE
  To effectively locate the drugs most implicated in severe interactions as a basis of designing actions to improve patient safety in Primary Care.
  
  
  METHODS
  Cross-sectional study of prescriptions using the Primary Care computerised medical records database (OMI-PC).
  
  
  METHODS
  Murcia (Spain) Health Areas I, VI, VII and IX (723,664 inhabitants).
  
  
  METHODS
  There are 362,271 patients over 14 years-old available in the OMI-PC and are assigned to a doctor who uses the OMI-PC regularly.
  
  
  METHODS
  We analysed the drugs that each patient could be taking, looking for severe interactions. We constructed a severe interaction hazard scale (e-PIG) calculating [1] the probability that a non-selected patient may be taking a particular drug and [2] the probability that a drug may produce a severe interaction. With this, we estimated the risk of producing a severe interaction for each drug, which was converted into a 5 point logarithmic scale.
  
  
  RESULTS
  We found 83,138 patients (22.9%) at risk (they took 2 or more drugs). We identified 466,940 prescriptions providing 939 drugs and 5,597 severe interactions (prevalence 5.8%). In these, 167 drugs were involved, of which e-PIG identified 5 (3%) with an extreme value: omeprazole, diazepam, acenocoumarol, ibuprofen and calcium.
  
  
  CONCLUSIONS
  e-PIG is a logarithmic expression of the risk that prescribing a particular drug may produce a severe interaction in a determined setting and time. Its monitoring could become a prioritisation element that may assist the design of strategies for improving the safety of the use of drugs.
authors.affiliation: Médico de Familia, Dirección General de Asistencia Sanitaria, Servicio Murciano de Salud, Murcia, España. julioj.lopez-picazo@carm.es
authors.forename: Julio J
authors.initials: JJ
authors.lastname: López-Picazo
authors.forename: Juan C
authors.initials: JC
authors.lastname: Ruiz
authors.forename: José F
authors.initials: JF
authors.lastname: Sánchez
authors.forename: Angeles
authors.initials: A
authors.lastname: Ariza
authors.forename: Belén
authors.initials: B
authors.lastname: Aguilera
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D004347:Drug Interactions; D011307:Drug Prescriptions / Q000592:standards*; D005194:Family Practice; D005260:Female; D006801:Humans; D008297:Male; D011320:Primary Health Care; D012449:Safety; D012984:Software