title: Can physician laboratory-test requests be influenced by interventions?
abstract: BACKGROUND
  Laboratory tests affect healthcare costs and unnecessary test requests can thus be a concern. We studied whether it was possible to influence physician laboratory-test requests using four structured interventions: introduction of clinical guidelines, education, feedback, and reminder letters. The interventions occurred at different times at Landspítali University Hospital, Reykjavik, Iceland. Akureyri Hospital, northern Iceland, was used as a control, since no formal interventions were introduced there.
  
  
  METHODS
  Six types of laboratory tests were analyzed. The relative risk of a laboratory test being conducted at Landspítali University Hospital compared to Akureyri Hospital was calculated for various points in time, as well as the associated 95% confidence intervals. The primary estimates compare the pre- and post-intervention periods (2007-2009 vs. 2010-2013), but also on a monthly basis in order to observe the trends in greater detail.
  
  
  RESULTS
  Interventions at Landspítali University Hospital led to a significant reduction in the average number of laboratory tests (12-52%, p < 0.001) compared with Akureyri Hospital. Relative risk coefficients of laboratory tests at Landspítali University Hospital (LUH) compared to Akureyri Hospital (AH) were calculated pre- and post-guidelines, the relative risk for ASAT, CRP and GGT fell markedly, while ALAT and ALP tests did not show a significant decrease. Relative risk for a blood culture test in the period after the guidelines was statistically significantly increased.
  
  
  CONCLUSIONS
  It is possible to influence physician laboratory-test requests using multifaceted interventions that include continuous monitoring and follow-up.
authors.affiliation: Department of Economics, University of Iceland , Reykjavik , Iceland.
authors.forename: Helga
authors.initials: H
authors.lastname: Erlingsdóttir
authors.forename: Ari
authors.initials: A
authors.lastname: Jóhannesson
authors.forename: Tinna L
authors.initials: TL
authors.lastname: Ásgeirsdóttir
mesh_terms: D000066491:Clinical Decision-Making; D003955:Diagnostic Tests, Routine / Q000706:statistics & numerical data*; D019468:Disease Management; D017048:Health Care Costs; D006785:Hospitals, University; D006801:Humans; D010820:Physicians; D010818:Practice Patterns, Physicians'; D012189:Retrospective Studies; D012621:Seasons
keywords: Clinical chemistry tests; diagnostic tests; feedback; guideline adherence; iceland; practice guidelines; reminder systems; routine; unnecessary procedures