title: Assessment of the global trigger tool to measure, monitor and evaluate patient safety in cancer patients: reliability concerns are raised.
abstract: BACKGROUND
  Countries around the world are currently aiming to improve patient safety by means of the Institute for Healthcare Improvement global trigger tool (GTT), which is considered a valid tool for evaluating and measuring patient safety within organisations. So far, only few data on the measurement properties and utility of the GTT have been published.
  
  
  OBJECTIVE
  To determine and evaluate the effect of interrater variation between review teams on the standard outcome measures of the GTT and to assess and quantify measurement error of the GTT.
  
  
  METHODS
  Retrospective chart reviews were conducted on identical charts by two independent review teams in 2010 at a department of oncology in a university hospital. Standard GTT outcome measurements were obtained and compared between teams using statistical process control (SPC) charts. A Bland-Altman plot assessed measurement error and limits of agreement.
  
  
  RESULTS
  Only 31% of adverse events (AE) were identified by both teams, and further differences in categorisation of identical events was found. Moderate interrater agreement (κ=0.45) between teams gave rise to different conclusions on the patient safety process when monitoring using SPC charts. The Bland-Altman plot suggests little systematic error but large random error.
  
  
  CONCLUSIONS
  Review teams may identify different AE and reach different conclusions on the safety process when using the GTT on identical charts. Tracking true change in the safety level is difficult due to measurement error of the GTT. The results do not encourage further use of the GTT until additional evaluation studies on the measurement properties of the GTT have been conducted.
authors: Department of Oncology, Odense University Hospital, Odense, Denmark. thea.otto.mattsson@ouh.regionsyddanmark.dk
authors: Thea Otto
authors: TO
authors: Mattsson
authors: Janne Lehmann
authors: JL
authors: Knudsen
authors: Jens
authors: J
authors: Lauritsen
authors: Kim
authors: K
authors: Brixen
authors: Jørn
authors: J
authors: Herrstedt
mesh_terms: D003718:Denmark; D006801:Humans; D019300:Medical Errors / Q000706:statistics & numerical data*; D009369:Neoplasms; D015588:Observer Variation; D017063:Outcome Assessment, Health Care / Q000379:methods*; D061214:Patient Safety; D019984:Quality Indicators, Health Care; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: Adverse events, epidemiology and detection; Patient safety; Performance measures; Statistical process control; Trigger tools