Presentation W P20

W P20 (Poster Presentation):
Independent Medical Evaluations: A systematic review of North American empirical evidence

Presented by: Shanil Ebrahim


Busse JW1, Ebrahim S1, Riva JJ1, Bance S2, Guyatt GH1, Bagby M2, Kunz R3

  1. McMaster University, Hamilton, Ontario, Canada
  2. University of Toronto, Toronto, Ontario, Canada
  3. Swiss Academy Insurance Medicine, University Hospital Basel, Basel, Switzerland



Independent medical evaluations (IMEs) are often used to determine whether patients receive compensation for an injury or illness. To inform the evidence-base underlying IMEs, we conducted a systematic review of all primary studies conducted in North America.


We searched electronic databases and other sources for studies published through to Sept. 20, 2011. We included all primary literature reporting empirical findings on the topic of IMEs. Teams of reviewers performed assessment for study inclusion and risk-of-bias, and extracted data. Using an individual patient data meta-analysis, we explored the association between reference standard strength for classifying symptom exaggeration and the prevalence of symptom exaggeration.


We included 51 observational studies, most of moderate quality. Most reported on neuropsychological testing and focussed on the rate of symptom exaggeration among IME examinees, which ranged from 16% to 62%. We found a significant association between stronger reference standards and a higher prevalence of symptom exaggeration (p=0.003). The rate among examinees with external incentive when investigators used a rigorous reference system ranged from 41% to 62%. Inferences are limited by patient selection (only those referred for neuropsychological testing), absence of a definitive reference standard, and poor inter-rater reliability. Examinees were largely dissatisfied with the assessment process and outcomes.


Symptom exaggeration is common among examinees with external incentives and should be formally evaluated by IME assessors. Research to establish standards for IME assessment and reporting is urgently needed to ensure greater reliability and validity of this common adjudicative process.

Schedule Details

Wednesday October 1
13:00 - 14:00 Poster Viewing
Session: Varia