System-related factors contributing to diagnostic errors.

Several studies in primary care, internal medicine, and emergency departments show that rates of errors in test requests and result interpretations are unacceptably high and translate into missed, delayed, or erroneous diagnoses. Ineffective follow-up of diagnostic test results could lead to patient harm if appropriate therapeutic interventions are not delivered in a timely manner. The frequency of system-related factors that contribute directly to diagnostic errors depends on the types and sources of errors involved. Recent studies reveal that the errors and patient harm in the diagnostic testing loop have occurred mainly at the pre- and post-analytic phases, which are directed primarily by clinicians who may have limited expertise in the rapidly expanding field of clinical pathology. These errors may include inappropriate test requests, failure/delay in receiving results, and erroneous interpretation and application of test results to patient care. Efforts to address system-related factors often focus on technical errors in laboratory testing or failures in delivery of intended treatment. System-improvement strategies related to diagnostic errors tend to focus on technical aspects of laboratory medicine or delivery of treatment after completion of the diagnostic process. System failures and cognitive errors, more often than not, coexist and together contribute to the incidents of errors in diagnostic process and in laboratory testing. The use of highly structured hand-off procedures and pre-planned follow-up for any diagnostic test could improve efficiency and reliability of the follow-up process. Many feedback pathways should be established so that providers can learn if or when a diagnosis is changed. Patients can participate in the effort to reduce diagnostic errors. Providers should educate their patients about diagnostic probabilities and uncertainties. The patient-safety strategies focusing on the interface between diagnostic system and therapeutic intervention are strategies that involve both processes to facilitate appropriate follow-up and structural changes, such as the use of electronic tracking systems and patient navigation programs.