title: Reliability of the assessment of preventable adverse drug events in daily clinical practice.
abstract: OBJECTIVE
  To determine the reliability of the assessment of preventable adverse drug events (ADEs) in daily practice and to explore the impact of the assessors' professional background and the case characteristics on reliability.
  
  
  METHODS
  We used a combination of the simplified Yale algorithm and the National Coordinating Council for Medication Error Reporting and Prevention (NCC MERP) scheme to assess on the one hand the causal relationship between medication errors (MEs) and adverse events in hospitalised patients and on the other hand the severity of the clinical consequence of MEs. Five pharmacists and five physicians applied this algorithm to 30 potential MEs. After individual assessment, the pharmacists reached consensus and so did the physicians. Outcome was both MEs' severity (ordinal scale, NCC MERP categories A-I) and the occurrence of preventable harm (binary outcome, NCC MERP categories A-D vs. E-I). Kappa statistics was used to assess agreement.
  
  
  RESULTS
  The overall agreement on MEs' severity was fair for the pharmacists (kappa = 0.34) as well as for the physicians (kappa = 0.25). Overall agreement for the 10 raters was fair (kappa = 0.25) as well as the agreement between both consensus outcomes (kappa = 0.30). Agreement on the occurrence of preventable harm was higher, ranging from kappa = 0.36 for the physicians through kappa = 0.49 for the pharmacists. Overall agreement for the 10 raters was fair (kappa = 0.36). The agreement between both consensus outcomes was moderate (kappa = 0.47). None of the included case characteristics had a significant impact on agreement.
  
  
  CONCLUSIONS
  Individual assessment of preventable ADEs in real patients is difficult, possibly because of the difficult assessment of contextual information. Best approach seems to be a consensus method including both pharmacists and physicians.
authors.affiliation: Department of Clinical Pharmacy, University of Groningen and University Medical Center Groningen, Groningen, The Netherlands. j.e.van.doormaal@apoth.umcg.nl
authors.forename: Jasperien E
authors.initials: JE
authors.lastname: van Doormaal
authors.forename: Peter G M
authors.initials: PG
authors.lastname: Mol
authors.forename: Patricia M L A
authors.initials: PM
authors.lastname: van den Bemt
authors.forename: Rianne J
authors.initials: RJ
authors.lastname: Zaal
authors.forename: Antoine C G
authors.initials: AC
authors.lastname: Egberts
authors.forename: Jos G W
authors.initials: JG
authors.lastname: Kosterink
authors.forename: Flora M
authors.initials: FM
authors.lastname: Haaijer-Ruskamp
mesh_terms: D016907:Adverse Drug Reaction Reporting Systems; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D003625:Data Collection / Q000379:methods; D003627:Data Interpretation, Statistical; D003657:Decision Making; D005260:Female; D006801:Humans; D008297:Male; D008508:Medication Errors / Q000145:classification* / Q000706:statistics & numerical data; D008875:Middle Aged; D015588:Observer Variation; D010595:Pharmacists; D010820:Physicians; D015203:Reproducibility of Results; D012720:Severity of Illness Index