Do patients' disruptive behaviours influence the accuracy of a doctor's diagnosis? A randomised experiment.

BACKGROUND: Literature suggests that patients who display disruptive behaviours in the consulting room fuel negative emotions in doctors. These emotions, in turn, are said to cause diagnostic errors. Evidence substantiating this claim is however lacking. The purpose of the present experiment was to study the effect of such difficult patients' behaviours on doctors' diagnostic performance. METHODS: We created six vignettes in which patients were depicted as difficult (displaying distressing behaviours) or neutral. Three clinical cases were deemed to be diagnostically simple and three deemed diagnostically complex. Sixty-three family practice residents were asked to evaluate the vignettes and make the patient's diagnosis quickly and then through deliberate reflection. In addition, amount of time needed to arrive at a diagnosis was measured. Finally, the participants rated the patient's likability. RESULTS: Mean diagnostic accuracy scores (range 0-1) were significantly lower for difficult than for neutral patients (0.54 vs 0.64; p=0.017). Overall diagnostic accuracy was higher for simple than for complex cases. Deliberate reflection upon the case improved initial diagnostic, regardless of case complexity and of patient behaviours (0.60 vs 0.68, p=0.002). Amount of time needed to diagnose the case was similar regardless of the patient's behaviour. Finally, average likability ratings were lower for difficult than for neutral-patient cases. CONCLUSIONS: Disruptive behaviours displayed by patients seem to induce doctors to make diagnostic errors. Interestingly, the confrontation with difficult patients does however not cause the doctor to spend less time on such case. Time can therefore not be considered an intermediary between the way the patient is perceived, his or her likability and diagnostic performance.

Why patients' disruptive behaviours impair diagnostic reasoning: a randomised experiment.

BACKGROUND: Patients who display disruptive behaviours in the clinical encounter (the so-called 'difficult patients') may negatively affect doctors' diagnostic reasoning, thereby causing diagnostic errors. The present study aimed at investigating the mechanisms underlying the negative influence of difficult patients' behaviours on doctors' diagnostic performance. METHODS: A randomised experiment with 74 internal medicine residents. Doctors diagnosed eight written clinical vignettes that were exactly the same except for the patients' behaviours (either difficult or neutral). Each participant diagnosed half of the vignettes in a difficult patient version and the other half in a neutral version in a counterbalanced design. After diagnosing each vignette, participants were asked to recall the patient's clinical findings and behaviours. Main measurements were: diagnostic accuracy scores; time spent on diagnosis, and amount of information recalled from patients' clinical findings and behaviours. RESULTS: Mean diagnostic accuracy scores (range 0-1) were significantly lower for difficult than neutral patients' vignettes (0.41 vs 0.51; p<0.01). Time spent on diagnosing was similar. Participants recalled fewer clinical findings (mean=29.82% vs mean=32.52%; p<0.001) and more behaviours (mean=25.51% vs mean=17.89%; p<0.001) from difficult than from neutral patients. CONCLUSIONS: Difficult patients' behaviours induce doctors to make diagnostic errors, apparently because doctors spend part of their mental resources on dealing with the difficult patients' behaviours, impeding adequate processing of clinical findings. Efforts should be made to increase doctors' awareness of the potential negative influence of difficult patients' behaviours on diagnostic decisions and their ability to counteract such influence.

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.

Exposure to media information about a disease can cause doctors to misdiagnose similar-looking clinical cases.

PURPOSE: Anecdotal evidence indicates that exposure to media-distributed disease information, such as news about an outbreak, can lead physicians to errors; influenced by an availability bias, they misdiagnose patients with similar-looking but different diseases. The authors investigated whether exposure to media-provided disease information causes diagnostic errors and whether reflection (systematic review of findings) counteracts bias. METHOD: In 2010, 38 internal medicine residents first read the Wikipedia entry about one or another of two diseases (Phase 1). Six hours later, in a seemingly unrelated study, they diagnosed eight clinical cases (Phase 2). Two cases superficially resembled the disease in the Wikipedia entry they had read (bias expected), two cases resembled the other disease they had not read about (bias not expected), and four were filler cases. In Phase 3, they diagnosed the bias-expected cases again, using reflective reasoning. RESULTS: Mean diagnostic accuracy scores (Phase 2; range: 0-1) were significantly lower on bias-expected cases than on bias-not-expected cases (0.56 versus 0.70, P = .016) because participants misdiagnosed cases that looked similar to a Wikipedia description of a disease more often when they had read the Wikipedia description (mean = 0.61) than when they had not (mean = 0.29). Deliberate reflection (Phase 3) restored performance on bias-expected cases to pre-bias levels (mean = 0.71). CONCLUSIONS: Availability bias may arise simply from exposure to media-provided information about a disease, causing diagnostic errors. The bias's effect can be substantial. It is apparently associated with nonanalytical reasoning and can be counteracted by reflection.

Cognitive diagnostic error in internal medicine.

Medical error poses an important healthcare burden and a challenge for physicians and policy makers worldwide. Diagnostic error accounts for a substantial fraction of all medical mistakes. Most diagnostic errors have been associated with flaws in clinical reasoning. Empirical evidence on the cognitive mechanisms underlying such flaws and effectiveness of strategies to counteract them is scarce. Recent experimental studies, reviewed in this article, have increased our understanding of the relationship between cognitive factors and diagnostic mistakes. These studies have explored the role of cognitive biases, such as confirmation and availability bias, in diagnostic mistakes. They have suggested that confirmation bias and availability bias may indeed cause diagnostic errors. The latter bias seems to be associated with non-analytical reasoning, and was neutralized by analytical, or reflective, reasoning. Although non-analytical reasoning is a hallmark of clinical expertise, reflective reasoning was shown to improve diagnoses when cases are complex. Research on cognitive diagnostic mistakes remains a quite novel line of investigation. Follow-up studies that shine more light on the cognitive roots of, and cure for, diagnostic errors are needed.

Accepting diagnostic suggestions by residents: a potential cause of diagnostic error in medicine.

BACKGROUND: Psychological research has shown that people tend toward accepting rather than refuting hypotheses. Diagnostic suggestions may evoke such confirmatory tendencies in physicians, which may lead to diagnostic errors. PURPOSE: This study investigated the influence of a suggested diagnosis on physicians' diagnostic decisions on written clinical cases. It was hypothesized that physicians would tend to go along with the suggestions and therefore would have more difficulty rejecting incorrect suggestions than accepting correct suggestions. METHODS: Residents (N = 24) had to accept or reject suggested diagnoses on 6 cases. Three of those suggested diagnoses were correct, and 3 were incorrect. RESULTS: Results showed the mean correct evaluation score on cases with a correct suggested diagnosis (M = 2.21, SD = 0.88) was significantly higher than the score on cases with an incorrect suggested diagnosis (M = 1.42, SD = 0.97), meaning physicians indeed found it easier to accept correct diagnoses than to reject incorrect diagnoses, t(23) = 2.74, p < .05, d = .85, despite equal experience with the diagnoses. CONCLUSION: These findings indicate that suggested diagnoses may evoke confirmatory tendencies and consequently may lead to diagnostic errors.

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, η p (2) = 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.

Effect of availability bias and reflective reasoning on diagnostic accuracy among internal medicine residents.

CONTEXT: Diagnostic errors have been associated with bias in clinical reasoning. Empirical evidence on the cognitive mechanisms underlying biases and effectiveness of educational strategies to counteract them is lacking. OBJECTIVES: To investigate whether recent experience with clinical problems provokes availability bias (overestimation of the likelihood of a diagnosis based on the ease with which it comes to mind) resulting in diagnostic errors and whether reflection (structured reanalysis of the case findings) counteracts this bias. DESIGN, SETTING, AND PARTICIPANTS: Experimental study conducted in 2009 at the Erasmus Medical Centre, Rotterdam, with 18 first-year and 18 second-year internal medicine residents. Participants first evaluated diagnoses of 6 clinical cases (phase 1). Subsequently, they diagnosed 8 different cases through nonanalytical reasoning, 4 of which had findings similar to previously evaluated cases but different diagnoses (phase 2). These 4 cases were subsequently diagnosed again through reflective reasoning (phase 3). MAIN OUTCOME MEASURES: Mean diagnostic accuracy scores (perfect score, 4.0) on cases solved with or without previous exposure to similar problems through nonanalytical (phase 2) or reflective (phase 3) reasoning and frequency that a potentially biased (ie, phase 1) diagnosis was given. RESULTS: There were no main effects, but there was a significant interaction effect between "years of training" and "recent experiences with similar problems." Results consistent with an availability bias occurred for the second-year residents, who scored lower on the cases similar to those previously encountered (1.55; 95% confidence interval [CI], 1.15-1.96) than on the other cases (2.19; 95% CI, 1.73-2.66; P =.03). This pattern was not seen among the first-year residents (2.03; 95% CI, 1.55-2.51 vs 1.42; 95% CI, 0.92-1.92; P =.046). Second-year residents provided the phase 1 diagnosis more frequently for phase 2 cases they had previously encountered than for those they had not (mean frequency per resident, 1.44; 95% CI, 0.93-1.96 vs 0.72; 95% CI, 0.28-1.17; P =.04). A significant main effect of reasoning mode was found: reflection improved the diagnoses of the similar cases compared with nonanalytical reasoning for the second-year residents (2.03; 95% CI, 1.49-2.57) and the first-year residents (2.31; 95% CI, 1.89-2.73; P =.006). CONCLUSION: When faced with cases similar to previous ones and using nonanalytic reasoning, second-year residents made errors consistent with the availability bias. Subsequent application of diagnostic reflection tended to counter this bias; it improved diagnostic accuracy in both first- and second-year residents.