Diagnostic errors and abnormal diagnostic tests lost to follow-up: a source of needless waste and delay to treatment.

Diagnostic errors are an important and often underappreciated source of medical error, needless delays to treatment, and needlessly wasted resources. Almost 65% of diagnostic errors have an important contribution of system errors, of which many are an abnormal test result that was lost to follow-up, that is, missed results. These system problems that contribute to missed results may represent low-hanging fruit for those who wish to reduce diagnostic errors in their institution. The rate of missed results and associated treatment delay are discussed. The system factors and human factors that contribute to these errors are discussed along with strategies that can be adopted to reduce these errors.