Physical functioning and mortality in very old patients on dialysis.

BACKGROUND: Old patients with end-stage kidney disease (ESKD) represent an increasing segment of the ESKD population maintained on chronic dialysis treatment. Quality of life (QoL) is notoriously poor in ESKD but relationship between QoL and mortality has not been investigated in the old dialysis population. The objective of this study is to investigate the relationship between QoL and mortality in the old dialysis population. METHODS: Quality of Life was measured by the Rand- QoL Short Form 36 questionnaires in a multicentre, perspective cohort study including 253 very old patients (age ≥ 75 years) on chronic dialysis. Prognostic power of QoL was assessed applying C-statistics. RESULTS: In multivariate statistical models including a series of demographic and clinical variable physical function and general health maintained an independent relationship with survival (P ≤ 0.01). In analyses testing the prognostic value of these two SF36 components physical functioning was the component adding the highest explanatory power to standard demographic and clinical risk factors (+5.7%). Furthermore, the same parameter increased by 4.5% the discriminant power by the Harrell's C Index, improved risk reclassification by the 20% (P = 0.003) and model calibration by the 83%. CONCLUSIONS: In the very old dialysis population the physical function component of the SF36 is the QoL component holding the highest predictive power for mortality among the eight components of this instrument. As the discrimination power and risk reclassification ability by physical functioning is of degree relevant for clinical practice, such a measure has potential for refining prognosis and informing exercise programs in this population.

Medically unexplained physical symptoms in patients visiting the emergency department: an international multicentre retrospective study.

OBJECTIVE: The objective of this study was to assess the incidence and characteristics of patients presenting with physical symptoms that remain medically unexplained at the emergency department (ED). PATIENTS AND METHODS: A retrospective chart study was carried out in three hospitals in The Netherlands and Belgium. All patients (age > 18 years) visiting the ED in 4 selected weeks in 2013 at the Erasmus University Medical Center (Erasmus MC) in Rotterdam, The Netherlands, and 1 selected week in 2013 at the Haaglanden Medical Center, Westeinde HMC in The Hague, The Netherlands, and the University Hospital Ghent (UZG), Belgium, were included. Descriptive statistics were used for data analysis. RESULTS: A total of 2869 patients (Erasmus MC 1674, HMC 691, UZG 504) were included. Medically unexplained physical symptoms in the emergency department (EDMUPS) were present in 13.4% of all ED visits (Erasmus MC 12.5%, HMC 18.7%, UZG 9.1%). No EDMUPS were identified in trauma patients. When excluding trauma patients, EDMUPS were present in 18.5% (Erasmus MC 16.8%, HMC 26.5%, UZG 13.3%) of the visits. The characteristics of patients with and without EDMUPS differed significantly; patients with EDMUPS were more often younger, female, self-referred, frequent visitors, were prescribed less medication and more often had a psychiatric disease. Dutch and Belgian Hospital differed in the distribution of patients in triage categories and in the incidence of psychiatric illnesses. CONCLUSION: Physical symptoms remain unexplained in a significant number of patients at the time of ED assessment.

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.

The Power of Flash Mob Research: Conducting a Nationwide Observational Clinical Study on Capillary Refill Time in a Single Day.

BACKGROUND: Capillary refill time (CRT) is a clinical test used to evaluate the circulatory status of patients; various methods are available to assess CRT. Conventional clinical research often demands large numbers of patients, making it costly, labor-intensive, and time-consuming. We studied the interobserver agreement on CRT in a nationwide study by using a novel method of research called flash mob research (FMR). METHODS: Physicians in the Netherlands were recruited by using word-of-mouth referrals, conventional media, and social media to participate in a nationwide, single-day, "nine-to-five," multicenter, cross-sectional, observational study to evaluate CRT. Patients aged ≥ 18 years presenting to the ED or who were hospitalized were eligible for inclusion. CRT was measured independently (by two investigators) at the patient's sternum and distal phalanx after application of pressure for 5 s (5s) and 15 s (15s). RESULTS: On October 29, 2014, a total of 458 investigators in 38 Dutch hospitals enrolled 1,734 patients. The mean CRT measured at the distal phalanx were 2.3 s (5s, SD 1.1) and 2.4 s (15s, SD 1.3). The mean CRT measured at the sternum was 2.6 s (5s, SD 1.1) and 2.7 s (15s, SD 1.1). Interobserver agreement was higher for the distal phalanx (κ value, 0.40) than for the sternum (κ value, 0.30). CONCLUSIONS: Interobserver agreement on CRT is, at best, moderate. CRT measured at the distal phalanx yielded higher interobserver agreement compared with sternal CRT measurements. FMR proved a valuable instrument to investigate a relatively simple clinical question in an inexpensive, quick, and reliable manner.

Preparing Residents Effectively in Emergency Skills Training With a Serious Game.

INTRODUCTION: Training emergency care skills is critical for patient safety but cost intensive. Serious games have been proposed as an engaging self-directed learning tool for complex skills. The objective of this study was to compare the cognitive skills and motivation of medical residents who only used a course manual as preparation for classroom training on emergency care with residents who used an additional serious game. METHODS: This was a quasi-experimental study with residents preparing for a rotation in the emergency department. The "reading" group received a course manual before classroom training; the "reading and game" group received this manual plus the game as preparation for the same training. Emergency skills were assessed before training (with residents who agreed to participate in an extra pretraining assessment), using validated competency scales and a global performance scale. We also measured motivation. RESULTS: All groups had comparable important characteristics (eg, experience with acute care). Before training, the reading and game group felt motivated to play the game and spent more self-study time (+2.5 hours) than the reading group. Game-playing residents showed higher scores on objectively measured and self-assessed clinical competencies but equal scores on the global performance scale and were equally motivated for training, compared with the reading group. After the 2-week training, no differences between groups existed. CONCLUSIONS: After preparing training with an additional serious game, residents showed improved clinical competencies, compared with residents who only studied course material. After a 2-week training, this advantage disappeared. Future research should study the retention of game effects in blended designs.

Oxidative Stress as Estimated by Gamma-Glutamyl Transferase Levels Amplifies the Alkaline Phosphatase-Dependent Risk for Mortality in ESKD Patients on Dialysis.

Alkaline phosphatase (Alk-Phos) is a powerful predictor of death in patients with end-stage kidney disease (ESKD) and oxidative stress is a strong inducer of Alk-Phos in various tissues. We tested the hypothesis that oxidative stress, as estimated by a robust marker of systemic oxidative stress like γ-Glutamyl-Transpeptidase (GGT) levels, may interact with Alk-Phos in the high risk of death in a cohort of 993 ESKD patients maintained on chronic dialysis. In fully adjusted analyses the HR for mortality associated with Alk-Phos (50 IU/L increase) was progressively higher across GGT quintiles, being minimal in patients in the first quintile (HR: 0.89, 95% CI: 0.77-1.03) and highest in the GGT fifth quintile (HR: 1.13, 95% CI: 1.03-1.2) (P for the effect modification = 0.02). These findings were fully confirmed in sensitivity analyses excluding patients with preexisting liver disease, excessive alcohol intake, or altered liver disease biomarkers. GGT amplifies the risk of death associated with high Alk-Phos levels in ESKD patients. This observation is compatible with the hypothesis that oxidative stress is a strong modifier of the adverse biological effects of high Alk-Phos in this population.

An experimental study on the effects of a simulation game on students' clinical cognitive skills and motivation.

Simulation games are becoming increasingly popular in education, but more insight in their critical design features is needed. This study investigated the effects of fidelity of open patient cases in adjunct to an instructional e-module on students' cognitive skills and motivation. We set up a three-group randomized post-test-only design: a control group working on an e-module; a cases group, combining the e-module with low-fidelity text-based patient cases, and a game group, combining the e-module with a high-fidelity simulation game with the same cases. Participants completed questionnaires on cognitive load and motivation. After a 4-week study period, blinded assessors rated students' cognitive emergency care skills in two mannequin-based scenarios. In total 61 students participated and were assessed; 16 control group students, 20 cases students and 25 game students. Learning time was 2 h longer for the cases and game groups than for the control group. Acquired cognitive skills did not differ between groups. The game group experienced higher intrinsic and germane cognitive load than the cases group (p = 0.03 and 0.01) and felt more engaged (p < 0.001). Students did not profit from working on open cases (in adjunct to an e-module), which nonetheless challenged them to study longer. The e-module appeared to be very effective, while the high-fidelity game, although engaging, probably distracted students and impeded learning. Medical educators designing motivating and effective skills training for novices should align case complexity and fidelity with students' proficiency level. The relation between case-fidelity, motivation and skills development is an important field for further study.

Training Medical Specialists to Communicate Better with Patients with Medically Unexplained Physical Symptoms (MUPS). A Randomized, Controlled Trial.

BACKGROUND: Patients with medically unexplained physical symptoms (MUPS) are prevalent 25-50% in general and specialist care. Medical specialists and residents often find patients without underlying pathology difficult to deal with, whereas patients sometimes don't feel understood. We developed an evidence-based communication training, aimed to improve specialists' interviewing, information-giving and planning skills in MUPS consultations, and tested its effectiveness. METHODS: The intervention group in this multi-center randomized controlled trial received a 14-hour training program to which experiential learning and feedback were essential. Using techniques from Cognitive Behavioral Therapy, they were stimulated to seek interrelating factors (symptoms, cognitions, emotions, behavior, and social environment) that reinforced a patient's symptoms. They were taught to explain MUPS understandably, reassure patients effectively and avoid unnecessary diagnostic testing. Before and after the intervention training, specialists videotaped a total of six consultations with different MUPS patients. These were evaluated to assess doctors' MUPS-focused communicating skills using an adapted version of the Four Habit Coding Scheme on five-point Likert scales. Participants evaluated the training by self-report on three-point Likert scales. Doctors in the control group received training after completion of the study. RESULTS: 123 doctors (40% specialists, 60% residents) and 478 MUPS patients from 11 specialties were included; 98 doctors completed the study (80%) and 449 videotaped consultations were assessed. Trained doctors interviewed patients more effectively than untrained ones (p < 0.001), summarized information in a more patient-centered way (p = 0.001), and better explained MUPS and the role of perpetuating factors (p < 0.05). No effects on planning skills were found. On a 3-point scale the training was evaluated with 2.79. CONCLUSION: MUPS-focused communication training increases the interviewing and information-giving skills of medical specialists. We recommend that the training is incorporated in postgraduate education for medical specialists and residents who frequently encounter patients with MUPS. TRIAL REGISTRATION: Dutch Trial Registration NTR2612.

Training specialists to write appropriate reply letters to general practitioners about patients with medically unexplained physical symptoms; A cluster-randomized trial.

OBJECTIVE: To evaluate effects of a communication training for specialists on the quality of their reply letters to general practitioners (GPs) about patients with medically unexplained physical symptoms (MUPS). METHODS: Before randomization, specialists included ≤3 MUPS patients in a multi-center cluster-randomized trial. In 14h of MUPS-specific communication training, 2.5h focused on reply letters. Letters were discussed with regard to reporting and answering GPs' referral questions and patients' questions, and to reporting findings, explaining MUPS with perpetuating factors and giving advice. After the training, all doctors again included ≤3 MUPS patients. Reply letters to GPs were assessed for quality and blindly rated on a digital scale. RESULTS: We recruited 478 MUPS patients and 123 specialists; 80% of the doctors wrote ≥1 reply letters, 285 letters were assessed. Trained doctors reported (61% versus 37%, OR=2.55, F(1281)=6.60, p(group*time)=.01) and answered (63% versus 33%, OR=3.31, F(1281)=5.36, p(group*time)=.02) patients' questions more frequently than untrained doctors. CONCLUSION: Training improves reply letters with regard to patients' questions, but not with regard to the following: GPs' referral questions, somatic findings, additional testing, explaining, and advice. PRACTICE IMPLICATIONS: Training specialists to write appropriate reply letters needs more focus on explanation and advice.

Disturbed Serotonergic Neurotransmission and Oxidative Stress in Elderly Patients with Delirium.

BACKGROUND: Oxidative stress and disturbances in serotonergic and dopaminergic neurotransmission may play a role in the pathophysiology of delirium. AIMS: In this study, we investigated levels of amino acids, amino acid ratios and levels of homovanillic acid (HVA) as indicators for oxidative stress and disturbances in neurotransmission. METHODS: Plasma levels of amino acids, amino acid ratios and HVA were determined in acutely ill patients aged ≥65 years admitted to the wards of Internal Medicine and Geriatrics of the Erasmus University Medical Center and the ward of Geriatrics of the Havenziekenhuis, Rotterdam, The Netherlands. Differences in the biochemical parameters between patients with and without delirium were investigated by analysis of variance in models adjusted for age, gender and comorbidities. RESULTS: Of the 86 patients included, 23 had delirium. In adjusted models, higher mean phenylalanine/tyrosine ratios (1.34 vs. 1.14, p = 0.028), lower mean tryptophan/large neutral amino acids ratios (4.90 vs. 6.12, p = 0.021) and lower mean arginine levels (34.8 vs. 45.2 µmol/l, p = 0.022) were found in patients with delirium when compared to those without. No differences were found in HVA levels between patients with and without delirium. CONCLUSION: The findings of this study suggest disturbed serotonergic neurotransmission and an increased status of oxidative stress in patients with delirium.

Assessing the assessment in emergency care training.

OBJECTIVE: Each year over 1.5 million health care professionals attend emergency care courses. Despite high stakes for patients and extensive resources involved, little evidence exists on the quality of assessment. The aim of this study was to evaluate the validity and reliability of commonly used formats in assessing emergency care skills. METHODS: Residents were assessed at the end of a 2-week emergency course; a subgroup was videotaped. Psychometric analyses were conducted to assess the validity and inter-rater reliability of the assessment instrument, which included a checklist, a 9-item competency scale and a global performance scale. RESULTS: A group of 144 residents and 12 raters participated in the study; 22 residents were videotaped and re-assessed by 8 raters. The checklists showed limited validity and poor inter-rater reliability for the dimensions "correct" and "timely" (ICC = .30 and.39 resp.). The competency scale had good construct validity, consisting of a clinical and a communication subscale. The internal consistency of the (sub)scales was high (α = .93/.91/.86). The inter-rater reliability was moderate for the clinical competency subscale (.49) and the global performance scale (.50), but poor for the communication subscale (.27). A generalizability study showed that for a reliable assessment 5-13 raters are needed when using checklists, and four when using the clinical competency scale or the global performance scale. CONCLUSIONS: This study shows poor validity and reliability for assessing emergency skills with checklists but good validity and moderate reliability with clinical competency or global performance scales. Involving more raters can improve the reliability substantially. Recommendations are made to improve this high stakes skill assessment.

Snoring amplifies the risk of heart failure and mortality in dialysis patients.

BACKGROUND: Snoring, an indicator of sleep-disordered breathing (SDB), associates with all-cause and cardiovascular (CV) mortality in high-risk conditions such as chronic heart failure (HF). Because SDB and HF are exceedingly frequent in end-stage kidney disease (ESKD), we hypothesized that SDB as detected by snoring may impact upon the relationship between chronic HF and all-cause and CV mortality in these patients. METHODS: We tested this hypothesis in a cohort of 827 ESKD patients, followed up for 2.3 years. RESULTS: In this population, snoring was a strong modifier of the risk of chronic HF for all-cause and CV death. In fully adjusted Cox models, the hazard ratio (HR) associated to chronic HF for the study outcomes was highest in heavy snorers [all-cause death: HR 2.6 (95% CI 1.6-4.3, p < 0.001); CV death: HR 4.0 (95% CI 2.1-7.6, p < 0.001)], intermediate in moderate snorers [all-cause death: HR 1.6 (95% CI 1.1-2.2, p = 0.01); CV death: HR 1.8 (95% CI 1.2-2.8, p = 0.01)], and lowest and not significant in non-snorers [all-cause death: HR 0.9 (95% CI 0.6-1.6, p = NS); CV death: HR 0.8 (95% CI 0.4-1.6, p = NS)]. CONCLUSIONS: Snoring is a strong and independent effect modifier of the relationship between chronic HF and all-cause and CV mortality in ESKD. Since SDB and snoring are in part attributable to reversible pharyngeal oedema, intensified surveillance and treatment of chronic HF snorers on dialysis may translate into better clinical outcomes in this very high-risk population, an issue which remains to be tested in specifically designed clinical trials.

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.

Post-graduate education for medical specialists focused on patients with medically unexplained physical symptoms; development of a communication skills training programme.

OBJECTIVE: Stepwise description of the development of a post-graduate communication skills training programme for medical specialists focused on patients with medically unexplained physical symptoms (MUPS) to improve specialist interaction with MUPS patients. METHODS: Using the 'intervention mapping approach' we accomplished a needs assessment (literature study and pilot) to formulate intervention objectives and identify methods and techniques for a MUPS-focused communication skills training programme for medical specialists. RESULTS: A 14-h training programme which consists of experiential learning, role-play and feedback. Using skills from Cognitive Behavioural Therapy, medical specialists are stimulated to explore interrelating factors that reinforce symptoms, to reassure patients effectively and to provide plausible and understandable explanations for MUPS. Dealing with complex referrals and informing GPs properly are also practiced. CONCLUSION: By applying the 'intervention mapping approach' we were able to create a feasible and promising intervention to improve specialist interaction with MUPS patients. Intervention effects are currently being assessed in a randomized controlled trial. PRACTICE IMPLICATIONS: If the RCT demonstrates sufficient effectiveness and efficiency of the MUPS focused communication skills training programme for medical specialists the intervention could be embedded in post-graduate education of medical specialists and residents.

Encounters between medical specialists and patients with medically unexplained physical symptoms; influences of communication on patient outcomes and use of health care: a literature overview.

Medically unexplained physical symptoms (MUPS) burden patients and health services due to large quantities of consultations and medical interventions. The aim of this study is to determine which elements of communication in non-psychiatric specialist MUPS care influence health outcomes. Systematic search in PubMed, PsycINFO and Embase. Data extraction comprising study design, patient characteristics, number of patients, communication strategies, outcome measures and results. Elements of doctor-patient communication were framed according to symptoms, health anxiety, satisfaction, daily functioning and use of health care. Eight included studies. Two studies described the effect of communication on patient outcome in physical symptoms, three studies on health anxiety and patient satisfaction and one study on daily functioning. Two studies contained research on use of health care. Qualitative synthesis of findings was conducted. Communication matters in non-psychiatric MUPS specialist care. Perceiving patients' expectations correctly enables specialists to influence patients' cognitions, to reduce patients' anxiety and improve patients' satisfaction. Patients report less symptoms and health anxiety when symptoms are properly explained. Positive interaction and feedback reduces use of health care and improves coping. Development of communication skills focused on MUPS patients should be part of postgraduate education for medical specialists.

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.

A case of primary aldosteronism revealed after renal transplantation.

BACKGROUND: A 57-year-old woman was referred to a nephrology clinic because of chronic hypokalemia. She had a history of polycystic kidney disease, resistant hypertension, atrial fibrillation, type 2 diabetes, stroke, and end-stage renal disease, and had received a kidney transplant from a deceased donor at the age of 48 years. At presentation, the patient described symptoms of chronic fatigue and muscle aches, but she did not report pareses. Her medications included four antihypertensive agents, glucose-lowering drugs, immunosuppressants, digoxin, a coumarin derivative, and potassium chloride. INVESTIGATIONS: Full history, physical examination, laboratory testing of blood and urine, including aldosterone-torenin ratio, and a saline infusion test. DIAGNOSIS: Primary aldosteronism. MANAGEMENT: Treatment with spironolactone resulted in prompt control of hypertension and hypokalemia, allowing discontinuation of potassium chloride and reduction in antihypertensive medication.

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.