Cognitive Diagnostic Error in Internal Medicine

This thesis focuses on the subject of cognitive diagnostic error in internal medicine; mistakes resulting from flaws in physicians’ reasoning processes. More specifically, this thesis addresses errors caused by confirmation and availability bias. Recently, the potential of cognitive factors to cause faults in diagnosis caught the attention of authors and policy-makers, and the topic is pursued in several position papers. Nonetheless, little empirical evidence supporting a relationship between cognitive factors and medical error exists. In this doctoral thesis, five experimental studies will be presented that focus on this theme

Consistency in diagnostic suggestions does not influence the tendency to accept them

Background: Studies suggest that residents tend to accept diagnostic suggestions, which could lead to diagnostic errors if the suggestion is incorrect. Those studies did not take into account that physicians in clinical practice will mainly encounter correct suggestions. The present study investigated residents’ diagnostic performance if they would first encounter a number of correct suggestions followed by a number of incorrect suggestions, and vice versa. It was hypothesized that more incorrect suggestions would be accepted if participants had first evaluated a series of correct suggestions. Method: Residents (n = 38) evaluated suggested diagnoses on eight written clinical cases. Half of the participants first evaluated four correct suggestions and then evaluated four incorrect suggestions (C/I-condition). The other half started with the four incorrect suggestions followed by the correct suggestions (I/C-condition). Results: Our findings show that the evaluation score in the C/I condition (M = 2.87, MSE = 0.14) equaled that in the I/C condition (M = 2.66, MSE = 0.14), F(1,36) = 1.09, p = 0.30, ns, meaning that consistency in preceding suggested diagnoses did not influence the tendency to accept subsequent diagnostic suggestions. There was, however, a significant interaction effect between case order and phase, F(1,36) = 11.82, p = 0.001, ηp2 = 0.25, demonstrating that the score on cases with correct suggestions was higher than the score on cases with incorrect suggestions. Conclusion: These findings indicate that consistency in preceding correct or incorrect diagnostic suggestions did not influence the tendency to accept or reject subsequent suggestions. However, overall residents still showed a tendency to accept diagnostic suggestions, which may lead to diagnostic errors if the suggestion is incorrect

A symptom-based algorithm for calcium management after thyroid surgery: a prospective multicenter study

Objective: Evidence-based treatment guidelines for the management of postthyroidectomy hypocalcemia are absent. The aim of this study was to evaluate a newly developed symptom-based treatment algorithm including a protocolized attempt to phase out supplementation. Methods: In a prospective multicenter study, patients were treated according to the new algorithm and compared to a historical cohort of patients treated with a biochemically based approach. The primary outcome was the proportion of patients receiving calcium and/or alfacalcidol supplementation. Secondary outcomes were calcium-related complications and predictors for supplementation. Results: One hundred thirty-four patients were included prospectively, and compared to 392 historical patients. The new algorithm significantly reduced the proportion of patients treated with calcium and/or alfacalcidol during the first postoperative year (odds ratio (OR): 0.36 (95% CI: 0.23–0.54), P < 0.001), and persistently at 12 months follow-up (OR: 0.51 (95% CI: 0.28–0.90), P < 0.05). No severe calcium-related complications occurred, even though calcium-related visits to the emergency department and readmissions increased (OR: 11.5 (95% CI: 4.51–29.3), P <0.001) and (OR: 3.46 (95% CI: 1.58–7.57), P < 0.05), respectively. The proportional change in pre- to post operative parathyroid hormone (PTH) was an independent predictor for supplementation (OR: 1.04 (95% CI: 1.02–1.07), P < 0.05). Conclusions: Symptom-based management of postthyroidectomy hypocalcemia and a protocolized attempt to phase out supplementation safely reduce d the proportion of patients receiving supplementation, although the number of calcium-related hospital visits increased. For the future, we envision a more individualized treatment approach for patients at risk for delayed symptomatic hypocalcemia, including the proportional change in pre- to post- operative PTH

Why do doctors make mistakes? A study of the role of salient distracting clinical features

PURPOSE: Diagnostic errors have been attributed to faulty reasoning and cognitive biases, but minimizing errors requires understanding the mechanisms underlying biases. The authors investigated whether salient distracting features (SDFs) - case findings that tend to grab physicians' attention because they are strongly associated with a particular disease, but are indeed unrelated to the problem - misdirect diagnostic reasoning, causing errors. METHOD: In a 2012 study conducted at Erasmus Medical Centre, Rotterdam, 72 internal medicine residents diagnosed 12 clinical cases (6 simple, 6 complex) in three different formats: without a SDF, with a SDF in the beginning, and with a SDF at the end. In a within-subjects design, each participant solved 2 simple cases and 2 complex cases in each format. Proportions of correct diagnoses in each case type were compared by performing repeated-measures analysis of variance (ANOVA). RESULTS: There was a significant main effect of SDFs and a significant interaction effect between SDFs and case complexity. The presence of SDFs in the beginning of complex cases caused errors decreasing the proportion of correct diagnoses in comparison both with cases without SDFs (0.18, 95% CI, 0.13-0.23 versus 0.43, 95% CI, 0.35-0.51; P < .001) or with SDFs at the end (0.18, 95% CI, 0.13-0.23 versus 0.36, 95% CI, 0.29-0.43; P < .001). SDFs did not affect performance when presented near the end of cases. CONCLUSIONS: SDFs early in a case are apparently an important source of diagnostic errors. Physicians should be aware of the need to overcome their influence

Preventive implantable cardioverter defibrillator therapy in contemporary clinical practice

While the efficacy of the intracardiac defibrillators (ICDs) for primary prevention is not disputed, the relevant studies were carried out a long time ago. Most pertinent trials, including MADIT-II, SCD-Heft, and DEFINITE, recruited patients more than 20 years ago. Since then, improved therapeutic modalities including, in addition to cardiac resynchronization therapy, mineralocorticoid receptor antagonists, angiotensin receptor-neprilysin inhibitors, and, most recently, inhibitors of sodium-glucose cotransporter 2, have lowered present-day rates of mortality and of sudden cardiac death. Thus, nowadays, ICD therapy may be less effective than previously reported, and not as beneficial as many people currently believe. However, criteria for ICD im