Prevalence of reasoning error

The first step to optimal care is making the correct diagnosis, which is missed or delayed in between 5% and 14% of acute hospital admissions.1 2 Autopsy studies confirm diagnostic error rates of 10-20%,3 4 with autopsy disclosing previously undiagnosed problems in up to 25% of cases.3 Even if the diagnosis is correct, up to 45% of patients with acute or chronic medical conditions do not receive recommended evidence based care,5 while between 20% and 30% of administered investigations and drugs are potentially unnecessary.6 Clinicians are sometimes less willing to adopt new beneficial interventions than to abandon old ineffective ones.7

The extent to which these deficits relate directly to reasoning error by clinicians, rather than environmental determinants beyond their control, remains uncertain, although recent studies of adverse events in hospital patients may give some indication.8 9 A third of the identified adverse events involved errors of execution (slips, lapses, or oversights in carrying out appropriate management in correctly diagnosed patients), but almost half involved errors of reasoning or decision quality (failure to elicit, synthesise, decide, or act on clinical information). Such reasoning errors led to death or permanent disability in at least 25% of cases, and at least three quarters were deemed highly preventable.9

Of some concern is the discrepancy between prevalence of reasoning …