Variation in expert opinion in medical malpractice review

Background: Expert opinion in medical malpractice is a form of implicit assessment, based on unstated individual opinion. This contrasts with explicit assessment processes, which are characterized by criteria specified and stated before the assessment. Although sources of bias that might hinder the objectivity of expert witnesses have been identified, the effect of the implicit nature of expert review has not been firmly established. Methods: Pairs of anesthesiologist-reviewers independently assessed the appropriateness of care in anesthesia malpractice claims. With potential sources of bias eliminated or held constant, the level of agreement was measured. Results: Thirty anesthesiologists reviewed 103 claims. Reviewers agreed on 62% of claims and disagreed on 38%. They agreed that care was appropriate in 27% and less than appropriate in 32%. Chance-corrected levels of agreement were in the poor-good range (kappa = 0.37; 95% CI = 0.23 to 0.51). Conclusions: Divergent opinion stemming from the implicit nature of expert review may be common among objective medical experts reviewing malpractice claims.