Cognitive metaphors of expertise and knowledge: prospects and limitations for medical education

CONTEXT: Many approaches to the study of expertise in medical education have their roots most strongly established in the traditional cognitive psychology literature. As such, they take a common approach to the construction of expertise and frame their questions in a common way. This paper reflects on a few of the paradigmatic assumptions that have 'come along for the ride' with the traditional cognitive approach, and explores what might have been left out as a consequence. METHODS: We examine the operational definition of 'expert' as it has evolved using the traditional cognitive paradigm and we explore some alternative definitions and constructions of expert performance that have arisen in parallel education research paradigms. We address 3 inter-related aspects of expertise as manifested in the traditional cognitive approach: the construction of the expert as a (routine) diagnostician; the construction of the developmental process as the (automatic and un-reflective) accrual of resources through experience, and the construction of accrued knowledge as a relatively static resource that is subsequently used and built upon with further experience. CONCLUSIONS: We hope that, by highlighting these issues, we may begin to marry the strengths of the traditional cognitive paradigm with the strengths of these other paradigms and expand the scope of cognitive research in medical expertise.     

Spondylometaphyseal dysplasia, corner fracture type: a heritable condition associated with coxa vara

The authors present the radiographic features of a previously incompletely delineated bone dysplasia, which they call spondylometaphyseal dysplasia, corner fracture type. This is a dominant heritable condition associated with short stature and developmental coxa vara. The progressive hip deformity usually causes significant disability requiring surgical correction. Developmental coxa vara, simulated corner fractures of long tubular bones, and vertebral body abnormalities result in a diagnostic constellation. Knowledge of these distinctive radiologic features allows accurate diagnosis, which in turn should lead to appropriate genetic counseling and possibly to earlier, more efficacious surgical treatment of the coxa vara.     

A comparison of polymerase chain reaction and an infectivity assay for human immunodeficiency virus type 1 titration during virus inactivation of blood components

Three examples of human plasma-derived concentrates, intermediate- purity factors VIII and IX, and fibrinogen were spiked with tissue culture-grown human immunodeficiency virus type 1 (HIV-1) strain RF. All examples were freeze-dried and heated at 80 degrees C for 72 hours by using validated production process models. HIV-1 infectivity was measured by a syncytial infectivity assay in C8166 cells and then compared with levels determined by nested HIV polymerase chain reaction (PCR). The infectivity assay demonstrated a reduction index of at least 4.5 log10, while PCR showed an average 1.7 log10. Large amounts of HIV- 1 RNA (10(5)) were still detectable by PCR in samples in which infectivity assays failed to detect any HIV-1. These data suggest that HIV-1 PCR levels do not parallel HIV-1 infectivity levels during virus- inactivation procedures involved in coagulation factor concentrate production. PCR was able to detect the RNA associated with inactivated HIV-1 particles in the factor concentrates, which allows the conclusion that PCR is not a useful test with which to monitor virus-inactivation procedures such as heating at 80 degrees C for 72 hours. This judgment contrasts with the more definite and sensitive role of PCR in diagnosing HIV-1 infection in patients in whom a positive HIV-1 PCR result correlates with active HIV-1 infection and with PCR's usefulness in monitoring virus removal.     

Predictive Validity of the Global Assessment Form Used in a Final-year Undergraduate Rotation in Emergency Medicine

OBJECTIVES: To determine whether the predictive validity of Global Assessment Form (GAF) knowledge subdomain marks exceeds that of the overall GAF marks with respect to written examination marks for an undergraduate rotation in emergency medicine, and to determine the interdependence between subdomain marks on the GAF. METHODS: Final-year clinical clerks completing a four-week rotation through the emergency departments of a university teaching center were evaluated using both a ten-subdomain GAF for clinical performance and an independent written examination. The GAF and examination marks were prospectively obtained for clinical clerks over a two-year period. Pearson correlations were calculated between examination marks and both the GAF knowledge subdomain and the GAF overall mark. Olkin's Z score was calculated to determine the significance of the difference between correlations. Interdependencies between subdomains of the GAF were calculated using an alpha coefficient and inter-item correlations. RESULTS: Data sets were reviewed for 347 clinical clerks. Nine sets of data were excluded (incomplete evaluations); 338 sets were analyzed. Means for overall clinical mark and examination mark were 80.11% (SD = 4.375) and 81 (SD = 7.66). Among subdomains, knowledge had the highest correlation with the examination mark (0.19). Overall clinical marks had lower correlation with the examination marks (0.169); the difference was not significant (Olkin's Z = 0.40). The correlation of the examination marks with the average marks of all subdomains excluding knowledge was even lower (0.12). The tenitem alpha for the GAF was 0.92. CONCLUSIONS: Clinical GAF assessments of knowledge, as measured by written examination, do not appear to be any more predictive than overall clinical impression. There is substantial consistency between subdomain scores, suggesting that assessors are not effectively discriminating between them when assigning marks.     

Does posttraumatic stress disorder (PTSD) affect performance?

Research has increasingly identified alarming levels of traumatic stress symptoms in individuals working in emergency services and other high stress jobs. This study examined the effects of prior critical incident exposure and current posttraumatic symptoms on the performance of a nonpatient population, police recruits, during an acutely stressful event. A stressful policing situation was created through the use of a video simulator room that was responsive to actions of participants. The performance of participants to the simulated emergency was evaluated by 3 independent blinded raters. Prior exposure to critical incidents was measured using the Critical Incident History Questionnaire and current level of traumatic stress symptoms was measured using the Impact of Events Scale-Revised. Neither previous exposure to critical incidents nor trauma symptoms correlated with performance level. Recruits with high or severe levels of trauma symptoms did not demonstrate impairments in judgment, communication, or situation control compared with their colleagues with lesser or no trauma symptoms. On the basis of these findings, there is no reason to believe that police recruits with PTSD are prone to making errors of communication or judgment that would place them or others at increased risk.     

Evaluating Teamwork in a Simulated Obstetric Environment

Background: The National Confidential Enquiry into Maternal Deaths identified "lack of communication and teamwork" as a leading cause of substandard obstetric care. The authors used high-fidelity simulation to present obstetric scenarios for team assessment.

Methods: Obstetric nurses, physicians, and resident physicians were repeatedly assigned to teams of five or six, each team managing one of four scenarios. Each person participated in two or three scenarios with differently constructed teams. Participants and nine external raters rated the teams' performances using a Human Factors Rating Scale (HFRS) and a Global Rating Scale (GRS). Interrater reliability was determined using intraclass correlations and the Cronbach [alpha]. Analyses of variance were used to determine the reliability of the two measures, and effects of both scenario and rater profession (R.N. vs. M.D.) on scores. Pearson product-moment correlations were used to compare external with self-generated assessments.

Results: The average of nine external rater scores showed good reliability for both HFRS and GRS; however, the intraclass correlation coefficients for a single rater was low. There was some effect of rater profession on self-generated HFRS but not on GRS. An analysis of profession-specific subscores on the HFRS revealed no interaction between profession of rater and profession being rated. There was low correlation between externally and self-generated team assessments.