Common cognitive biases often contribute to diagnostic errors and can result in preventable harm to patients, states the author of a commentary from the June 2015 edition of the Agency for Healthcare Research and Quality's (AHRQ) online case study review, WebM&M. In the spotlight case, a 61-year-old man who presented to his primary care physician complaining of burning pain and numbness in his left foot was diagnosed with peripheral neuropathy and referred to a podiatrist. He returned four more times over a two-month period with the same complaint and was referred to podiatry each time because he never went to any of the previous appointments. His complaint was repeatedly attributed to his initial diagnosis of peripheral neuropathy without any further physical examination. Ultimately, the patient's worsening symptoms caused him to present to an emergency department, where a computed tomography angiogram revealed the source of the complaint to be complete occlusion of the left superficial femoral artery secondary to atherosclerotic peripheral arterial disease. According to the commentary's author, the case provides an opportunity to discuss diagnostic reasoning and focus on interventions that can be taken to prevent diagnostic errors. He notes that premature closure can be exacerbated by anchoring (the tendency for clinicians to stick with the initial impression even as new information becomes available), which is in turn fed by several biases, including confirmation bias, anchoring bias, and status quo bias. To combat these, he recommends that clinicians improve their awareness of cognitive biases through education and teamwork; explicitly consider base rates (prior probabilities), sensitivity, and specificity of diagnostic tests and maneuvers when diagnosing common clinical conditions; actively seek information that could refute the current provisional diagnosis; frame diagnostic thinking to avoid premature diagnostic labeling and share uncertainty; and use system-based interventions, including structured diagnostic assessments, diagnostic decision support, or computerized expert diagnostic systems. Other case studies in the June 2015 issue of WebM&M discuss unintended patient harm related to urinary catheters and the confusion of Crohn disease symptoms with Clostridium difficile infection.

HRC Recommends: Risk managers should investigate ways to incorporate reporting of diagnostic errors into the organization's event reporting system and promote an environment that supports reporting. Strategies that may be used to help prevent diagnostic errors include use of electronic health records, optimization of test result communication, standardized handoffs, postdischarge follow-up, audits (e.g., retrospective chart reviews), mandatory second opinions on error-prone diagnoses, educational case studies, clinical decision support, electronic access to reference material (e.g., medical reference books, journals), promotion of clinical guidelines and algorithms, diagnostic checklists, feedback to physicians, and reduction of distractions and fatigue.