The script concordance test for clinical reasoning: re-examining its utility and potential weakness.

CONTEXT: The script concordance test (SCT) assesses clinical reasoning under conditions of uncertainty. Relatively little information exists on Z-score (standard deviation [SD]) cut-offs for distinguishing more experienced from less experienced trainees, and whether scores depend on factual knowledge. Additionally, a recent review highlighted the finding that the SCT is potentially weakened by the fact that the mere avoidance of extreme responses may greatly increase test scores. OBJECTIVES: This study was conducted in order to elucidate the best cut-off Z-scores, to correlate SCT scores with scores on a separate medical knowledge examination (MKE), and to investigate potential solutions to the weakness of the SCT. METHODS: An analysis of scores on pulmonary and critical care medicine tests undertaken during July and August 2013 was performed. Clinical reasoning was tested using 1-hour SCTs (Question Sets 1 or 2). Medical knowledge was tested using a 3-hour, computer-adapted, multiple-choice question examination. RESULTS: The expert panel was composed of 16 attending physicians. The SCTs were completed by 16 fellows and 10 residents. Fourteen fellows completed the MKE. Test reliability was acceptable for both Question Sets 1 and 2 (Cronbach's alphas of 0.79 and 0.89, respectively). Z-scores of - 2.91 and - 1.76 best separated the scores of residents from those of fellows, and the scores of fellows from those of attending physicians, respectively. Scores on the SCT and MKE were poorly correlated. Simply avoiding extreme answers boosted the Z-scores of the lowest 10 scorers on both Question Sets 1 and 2 by ≥ 1 SD. Increasing the proportion of questions with extreme modal answers to 50%, and using hypothetical question sets created from Question Set 1 overcame this problem, but consensus scoring did not. CONCLUSIONS: The SCT was able to differentiate between test subjects of varying levels of competence, and results were not associated with medical knowledge. However, the test was vulnerable to responses that intentionally avoided extreme values. Increasing the proportion of questions with extreme modal answers may attenuate the effect of candidates exploiting the test weakness related to extreme responses.

The use of a blood conservation device to reduce red blood cell transfusion requirements: a before and after study.

INTRODUCTION: Anaemia and the associated need for packed red blood cell (PRBC) transfusions are common in patients admitted to the intensive care unit (ICU). Among many causes, blood losses from repeated diagnostic tests are contributory. METHODS: This is a before and after study in a medical ICU of a university hospital. We used a closed blood conservation device (Venous Arterial blood Management Protection, VAMP, Edwards Lifesciences, Irvine, CA, USA) to decrease PRBC transfusion requirements. We included all adult (> or =18 years) patients admitted to the ICU with indwelling arterial catheters, who were expected to stay more than 24 hours and were not admitted for active gastrointestinal or any other bleeding. We collected data for six months without VAMP (control group) immediately followed by nine months (active group) with VAMP. A restrictive transfusion strategy in which clinicians were strongly discouraged from any routine transfusions when haemoglobin (Hb) levels were above 7.5 g/dL was adopted during both periods. RESULTS: Eighty (mean age 61.6 years, 49 male) and 170 patients (mean age 60.5 years, 101 male) were included in the control and active groups respectively. The groups were comparable for age, gender, Acute Physiology and Chronic Health Evaluation (APACHE) II score, need for renal replacement therapy, length of stay, and Hb levels on discharge and at transfusion. The control group had higher Hb levels on admission (12.4 +/- 2.5 vs. 11.58 +/- 2.8 gm/dL, P = 0.02). Use of a blood conservation device was significantly associated with decreased requirements for PRBC transfusion (control group 0.131 unit vs. active group 0.068 unit PRBC/patient/day, P = 0.02) on multiple linear regression analysis. The control group also had a greater decline in Hb levels (2.13 +/- 2.32 vs. 1.44 +/- 2.08 gm/dL, P = 0.02) at discharge. CONCLUSIONS: The use of a blood conservation device is associated with 1) reduced PRBC transfusion requirements and 2) a smaller decrease in Hb levels in the ICU.

Identification of concurrent bacterial infection in adult patients with dengue.

We aim to construct a diagnostic model for bacterial coinfection in dengue patients (Dengue Dual Infection Score [DDIS]); 2,065 adult dengue patients (mean age = 41.9 ± 17.2 years, 58.4% male, 83 patients with bacterial coinfection) seen at a university hospital from January of 2005 to February of 2010 were studied. The DDIS was created by assigning one point to each of five risk factors for bacterial coinfection: pulse rate ≥ 90 beats/minute, total white cell count ≥ 6 × 10(9)/L, hematocrit < 40%, serum sodium < 135 mmol/L, and serum urea ≥ 5 mmol/L. The DDIS identified bacterial coinfection (derivation set area under the curve = 0.793, 95% confidence interval = 0.732-0.854; validation set area under the curve = 0.761, 95% confidence interval = 0.637-0.886). A DDIS of ≥ 4 had a specificity of 94.4%, whereas a DDIS of ≥ 1 had a sensitivity of 94.4% for bacterial coinfection. The DDIS can help to select dengue patients for early bacterial cultures and empirical antibiotics.

Mild illness associated with severe acute respiratory syndrome coronavirus infection: lessons from a prospective seroepidemiologic study of health-care workers in a teaching hospital in Singapore.

BACKGROUND: Severe acute respiratory syndrome (SARS) is a newly recognized infectious disease that has recently emerged in East Asia and North America. Although the clinical features of acute infection have been well described, mildly symptomatic or asymptomatic infections have not been well characterized. OBJECTIVE: To assess the spectrum of illness in health-care workers (HCWs). METHODS: A prospective seroepidemiologic cohort study was conducted on 372 HCWs in a large teaching hospital in Singapore who were both exposed and not exposed to patients with SARS. Participating HCWs completed a questionnaire and provided paired serum samples, which were analyzed by 2 different laboratories blinded to clinical data, by use of an enzyme-linked immunosorbent assay based on a protocol developed by the Centers for Disease Control and Prevention and a dot-blot immunoassay, with confirmation by a viral neutralization assay. RESULTS: A total of 21 patients with SARS were treated at our hospital. They were associated with transmission to 14 staff members, patients, and visitors in our hospital. Of the 372 HCWs participating in the present study, 8 were found to have positive antibodies to the SARS coronavirus in both samples by use of both test methods, and 6 had pneumonia and had been hospitalized for either probable or suspected SARS infection, whereas 2 had fever but did not have changes on chest radiographs. All seropositive HCWs had been exposed either directly or indirectly to patients with SARS. No asymptomatic, nonexposed staff members were found to be seropositive. There was a trend towards protection for HCWs who, while fully protected, had had contact with patients with SARS. CONCLUSIONS: Although the majority of cases of SARS are associated with pneumonia, a small number of mildly symptomatic individuals do seroconvert. HCWs who are exposed to patients with SARS can be infected with SARS, regardless of the intensity of exposure. This has implications for surveillance and infection control planning, in the event that SARS returns next winter.