Understanding context specificity:the effect of contextual factors on clinical reasoning

Background: Situated cognition theory argues that thinking is inextricably situated in a context. In clinical reasoning, this can lead to context specificity: a physician arriving at two different diagnoses for two patients with the same symptoms, findings, and diagnosis but different contextual factors (something beyond case content potentially influencing reasoning). This paper experimentally investigates the presence of and mechanisms behind context specificity by measuring differences in clinical reasoning performance in cases with and without contextual factors. Methods: An experimental study was conducted in 2018-2019 with 39 resident and attending physicians in internal medicine. Participants viewed two outpatient clinic video cases (unstable angina and diabetes mellitus), one with distracting contextual factors and one without. After viewing each case, participants responded to six open-ended diagnostic items (e.g. problem list, leading diagnosis) and rated their cognitive load. Results: Multivariate analysis of covariance (MANCOVA) results revealed significant differences in angina case performance with and without contextual factors [Pillai's trace = 0.72, F=12.4, df=(6, 29), p Conclusions: Using typical presentations of common diagnoses, and contextual factors typical for clinical practice, we provide ecologically valid evidence for the theoretically predicted negative effects of context specificity (i.e. for the angina case), with large effect sizes, offering insight into the persistence of diagnostic error

Exploring implications of context specificity and cognitive load in residents

Introduction: Context specificity (CS) refers to the variability in clinical reasoning across different presentations of the same diagnosis. Cognitive load (CL) refers to limitations in working memory that may impact clinicians’ clinical reasoning. CL might be one of the factors that lead to CS. Although CL during clinical reasoning would be expected to be higher in internal medicine residents, CL’s effect on CS in residents has not been studied. Methods: Internal medicine residents watched a series of three cases portrayed on videos. Following each case, participants filled out a post-encounter form and completed a validated measure of CL. Results: Fourteen residents completed all three cases. Across cases, self-reported CL was relatively high and there were small to moderate correlations between CL and performance in clinical reasoning (r’s = .43, -.33, -.23). In terms of changing CL across cases, the correlations between change in CL and change in total performance were statistically significantly only in moving from case 1 to case 2 (r = -.54, p =.05). Discussion and Conclusion: Residents self-reported measurements of CL were relatively high across cases. However, higher CL was not consistently associated with poorer performance. We did observe the expected associations when looking at case-to-case change in CL. This relationship warrants further study

Contextual factors and clinical reasoning: differences in diagnostic and therapeutic reasoning in board certified versus resident physicians

This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background The impact of context on the complex process of clinical reasoning is not well understood. Using situated cognition as the theoretical framework and videos to provide the same contextual “stimulus” to all participants, we examined the relationship between specific contextual factors on diagnostic and therapeutic reasoning accuracy in board certified internists versus resident physicians. Methods Each participant viewed three videotaped clinical encounters portraying common diagnoses in internal medicine. We explicitly modified the context to assess its impact on performance (patient and physician contextual factors). Patient contextual factors, including English as a second language and emotional volatility, were portrayed in the videos. Physician participant contextual factors were self-rated sleepiness and burnout.. The accuracy of diagnostic and therapeutic reasoning was compared with covariates using Fisher Exact, Mann-Whitney U tests and Spearman Rho’s correlations as appropriate. Results Fifteen board certified internists and 10 resident physicians participated from 2013 to 2014. Accuracy of diagnostic and therapeutic reasoning did not differ between groups despite residents reporting significantly higher rates of sleepiness (mean rank 20.45 vs 8.03, U = 0.5, p < .001) and burnout (mean rank 20.50 vs 8.00, U = 0.0, p < .001). Accuracy of diagnosis and treatment were uncorrelated (r = 0.17, p = .65). In both groups, the proportion scoring correct responses for treatment was higher than the proportion scoring correct responses for diagnosis. Conclusions This study underscores that specific contextual factors appear to impact clinical reasoning performance. Further, the processes of diagnostic and therapeutic reasoning, although related, may not be interchangeable. This raises important questions about the impact that contextual factors have on clinical reasoning and provides insight into how clinical reasoning processes in more authentic settings may be explained by situated cognition theory

Antiplatelet therapy with aspirin, clopidogrel, and dipyridamole versus clopidogrel alone or aspirin and dipyridamole in patients with acute cerebral ischaemia (TARDIS): a randomised, open-label, phase 3 superiority trial

Background: Intensive antiplatelet therapy with three agents might be more effective than guideline treatment for preventing recurrent events in patients with acute cerebral ischaemia. We aimed to compare the safety and efficacy of intensive antiplatelet therapy (combined aspirin, clopidogrel, and dipyridamole) with that of guideline-based antiplatelet therapy. Methods: We did an international, prospective, randomised, open-label, blinded-endpoint trial in adult participants with ischaemic stroke or transient ischaemic attack (TIA) within 48 h of onset. Participants were assigned in a 1:1 ratio using computer randomisation to receive loading doses and then 30 days of intensive antiplatelet therapy (combined aspirin 75 mg, clopidogrel 75 mg, and dipyridamole 200 mg twice daily) or guideline-based therapy (comprising either clopidogrel alone or combined aspirin and dipyridamole). Randomisation was stratified by country and index event, and minimised with prognostic baseline factors, medication use, time to randomisation, stroke-related factors, and thrombolysis. The ordinal primary outcome was the combined incidence and severity of any recurrent stroke (ischaemic or haemorrhagic; assessed using the modified Rankin Scale) or TIA within 90 days, as assessed by central telephone follow-up with masking to treatment assignment, and analysed by intention to treat. This trial is registered with the ISRCTN registry, number ISRCTN47823388. Findings: 3096 participants (1556 in the intensive antiplatelet therapy group, 1540 in the guideline antiplatelet therapy group) were recruited from 106 hospitals in four countries between April 7, 2009, and March 18, 2016. The trial was stopped early on the recommendation of the data monitoring committee. The incidence and severity of recurrent stroke or TIA did not differ between intensive and guideline therapy (93 [6%] participants vs 105 [7%]; adjusted common odds ratio [cOR] 0·90, 95% CI 0·67–1·20, p=0·47). By contrast, intensive antiplatelet therapy was associated with more, and more severe, bleeding (adjusted cOR 2·54, 95% CI 2·05–3·16, p<0·0001). Interpretation: Among patients with recent cerebral ischaemia, intensive antiplatelet therapy did not reduce the incidence and severity of recurrent stroke or TIA, but did significantly increase the risk of major bleeding. Triple antiplatelet therapy should not be used in routine clinical practice

The status of the world's land and marine mammals: diversity, threat, and knowledge

Knowledge of mammalian diversity is still surprisingly disparate, both regionally and taxonomically. Here, we present a comprehensive assessment of the conservation status and distribution of the world's mammals. Data, compiled by 1700+ experts, cover all 5487 species, including marine mammals. Global macroecological patterns are very different for land and marine species but suggest common mechanisms driving diversity and endemism across systems. Compared with land species, threat levels are higher among marine mammals, driven by different processes (accidental mortality and pollution, rather than habitat loss), and are spatially distinct (peaking in northern oceans, rather than in Southeast Asia). Marine mammals are also disproportionately poorly known. These data are made freely available to support further scientific developments and conservation action

Search for supersymmetry in final states with charm jets and missing transverse momentum in 13 TeV pp collisions with the ATLAS detector

A search for supersymmetric partners of top quarks decaying as t ~ 1 →cχ ~ 0 1 and supersymmetric partners of charm quarks decaying as c ~ 1 →cχ ~ 0 1, where χ ~ 0 1 is the lightest neutralino, is presented. The search uses 36.1 fb −1 pp collision data at a centre-of-mass energy of 13 TeV collected by the ATLAS experiment at the Large Hadron Collider and is performed in final states with jets identified as containing charm hadrons. Assuming a 100% branching ratio to cχ ~ 0 1, top and charm squarks with masses up to 850 GeV are excluded at 95% confidence level for a massless lightest neutralino. For m t ~ 1 ,c ~ 1 −m χ ~ 0 1 < 100 GeV, top and charm squark masses up to 500 GeV are excluded

Measurements of b-jet tagging efficiency with the ATLAS detector using tt ¯ events at √s =13 TeV

The efficiency to identify jets containing b -hadrons (b -jets) is measured using a high purity sample of dileptonic top quark-antiquark pairs (tt ¯ ) selected from the 36.1 fb −1 of data collected by the ATLAS detector in 2015 and 2016 from proton-proton collisions produced by the Large Hadron Collider at a centre-of-mass energy s √ =13 TeV. Two methods are used to extract the efficiency from tt ¯ events, a combinatorial likelihood approach and a tag-and-probe method. A boosted decision tree, not using b -tagging information, is used to select events in which two b -jets are present, which reduces the dominant uncertainty in the modelling of the flavour of the jets. The efficiency is extracted for jets in a transverse momentum range from 20 to 300 GeV, with data-to-simulation scale factors calculated by comparing the efficiency measured using collision data to that predicted by the simulation. The two methods give compatible results, and achieve a similar level of precision, measuring data-to-simulation scale factors close to unity with uncertainties ranging from 2% to 12% depending on the jet transverse momentum

Search for photonic signatures of gauge-mediated supersymmetry in 13 TeV pp collisions with the ATLAS detector

A search is presented for photonic signatures, motivated by generalized models of gauge-mediated supersymmetry breaking. This search makes use of proton-proton collision data at √s = 13 TeV corresponding to an integrated luminosity of 36.1 fb −1 recorded by the ATLAS detector at the LHC, and it explores models dominated by both strong and electroweak production of supersymmetric partner states. Experimental signatures incorporating an isolated photon and significant missing transverse momentum are explored. These signatures include events with an additional photon or additional jet activity not associated with any specific underlying quark flavor. No significant excess of events is observed above the Standard Model prediction, and 95% confidence-level upper limits of between 0.083 fb and 0.32 fb are set on the visible cross section of contributions from physics beyond the Standard Model. These results are interpreted in terms of lower limits on the masses of gluinos, squarks, and gauginos in the context of generalized models of gauge-mediated supersymmetry, which reach as high as 2.3 TeV for strongly produced and 1.3 TeV for weakly produced supersymmetric partner pairs