Premature conclusions in the diagnosis of iron-deficiency anemia: cause and effect.

Case records of patients with iron-deficiency anemia were audited using a computer-based algorithm. In 24 of 35 cases, the diagnostic conclusion seemed unjustified and characteristic of premature closure, one of four recurring errors in diagnostic reasoning described previously. Premature closure appeared to originate from subjects at all levels of training, to be easily and unquestioningly accepted by other physicians, and to inappropriately condition diagnostic and therapeutic decisions. Heuristics and biases described by Tversky and Kahneman are considered as contributory factors and patient care and teaching implications are discussed.