Twelve tips for computer-based assessment in medical education

The use of computers in education in general and in medical education in particular is nowadays well established, but the use of computer-based assessment (CBA) in higher education lags behind. In this article we explore the reasons for this situation and provide tips for teachers to guide the introduction of CBA, based on our experiences. Attention is given to benefits and drawbacks of CBA hardware solutions, the choice of software, types of test questions, security, instructing students and teachers and evaluation.     

Combining matched and unmatched control groups in case-control studies

Multiple control groups in case-control studies are used to control for different sources of confounding. For example, cases can be contrasted with matched controls to adjust for multiple genetic or unknown lifestyle factors and simultaneously contrasted with an unmatched population-based control group. Inclusion of different control groups for a single exposure analysis yields several estimates of the odds ratio, all using only part of the data. Here the authors introduce an easy way to combine odds ratios from several case-control analyses with the same cases. The approach is based upon methods used for meta-analysis but takes into account the fact that the same cases are used and that the estimated odds ratios are therefore correlated. Two ways of estimating this correlation are discussed: sandwich methodology and the bootstrap. Confidence intervals for the pooled estimates and a test for checking whether the odds ratios in the separate case-control studies differ significantly are derived. The performance of the method is studied by simulation and by applying the methods to a large study on risk factors for thrombosis, the MEGA Study (1999-2004), wherein cases with first venous thrombosis were included with a matched control group of partners and an unmatched population-based control group.     

Intra-abdominal esophageal duplication cyst: A case report and review of the literature

Intra-abdominal esophageal duplications are rare en-tities in adults. They are mostly asymptomatic, but since they can lead to complications surgical excision is advised for all duplication cysts. We present a case of a 20-year-old male with colic-like abdominal pain, mimicking symptoms of cholecystolithiasis. However after cholecystectomy the symptoms were still present. A computed tomography-scan of the abdomen and an endoscopic ultrasound revealed a cyst of the esophagus of 3.0 cm × 2.3 cm in size. Diagnostic laparoscopy was planned, during which we observed a para-esophageal cyst at the gastro-esophageal junction. Laparoscopic excision of this cyst was performed. Pathophysiological examination revealed an esophageal duplication cyst. We report a rare case of a symptomatic intra-abdominal esophageal duplication cyst in an adult. One must con-sider this diagnosis when more common diagnoses to account for the patient's symptoms are excluded. Re-moval of duplication cysts can be done laparoscopically.     

Species sensitivity distributions for suspended clays, sediment burial, and grain size change in the marine environment

Assessment of the environmental risk of discharges, containing both chemicals and suspended solids (e.g., drilling discharges to the marine environment), requires an evaluation of the effects of both toxic and nontoxic pollutants. To date, a structured evaluation scheme that can be used for prognostic risk assessments for nontoxic stress is lacking. In the present study we challenge this lack of information by the development of marine species sensitivity distributions (SSDs) for three nontoxic stressors: suspended clays, burial by sediment, and change in sediment grain size. Through a literature study, effect levels were obtained for suspended clays, as well as for burial of biota. Information on the species preference range for median grain size was used to assess the sensitivity of marine species to changes in grain size. The 50% hazardous concentrations (HC50) for suspended barite and bentonite based on 50% effect concentrations (EC50s) were 3,010 and 1,830 mg/L, respectively. For burial the 50% hazardous level (HL50) was 5.4 cm. For change in median grain size, two SSDs were constructed; one for reducing and one for increasing the median grain size. The HL50 for reducing the median grain size was 17.8 mum. For increasing the median grain size this value was 305 mum. The SSDs have been constructed by using information related to offshore oil- and gas-related activities. Nevertheless, the results of the present study may have broader implications. The hypothesis of the present study is that the SSD methodology developed for the evaluation of toxic stress can also be applied to evaluate nontoxic stressors, facilitating the incorporation of nontoxic stressors in prognostic risk assessment tools.     

Prognostic Value of Geriatric 8 and Identification of Seniors at Risk for Hospitalized Patients Screening Tools for Patients With Lung Cancer

Background

Because of the time-consuming aspect of geriatric assessments, cancer specialists are seeking shorter screening tools to distinguish fit and frail patients. We analyzed the predictive value of the Geriatric 8 (G8) and Identification of Seniors at Risk for Hospitalized Patients (ISAR-HP) in elderly patients with lung cancer.

Severely injured patients benefit from in-house attending trauma surgeons

Introduction

There is continuous drive to optimize healthcare for the most severely injured patients. Although still under debate, a possible measure is to provide 24/7 in-house (IH) coverage by trauma surgeons. The aim of this study was to compare process-related outcomes for severely injured patients before and after transition of attendance policy from an out-of-hospital (OH) on-call attending trauma surgeon to an in-house attending trauma surgeon.

Study on the relationship of serum fetuin-A concentration with aortic stiffness in patients on dialysis.

BACKGROUND: An increase in aortic stiffness, as reflected by an increase in pulse wave velocity (PWV) or aortic augmentation index (AI) is an important predictor of cardiovascular mortality in dialysis patients. Dysregulation of calcification inhibitors, such as fetuin-A, is involved in vascular pathology in dialysis patients and fetuin-A is inversely related to mortality in dialysis patients. In this study, the relation between serum fetuin-A concentration and parameters of aortic stiffness was investigated in patients with end-stage renal disease. METHODS: In a cross-sectional study we included 131 dialysis patients, aged 62+/-14 years (33 on peritoneal dialysis and 98 on haemodialysis), and 41 controls, aged 60+/-8 years. Time-averaged pre-dialysis values of serum albumin, Ca, P and intact parathyroid hormone were included in multiregression analysis, as were high-sensitivity C-reactive protein (hsCRP), fetuin-A, age, mean arterial pressure (MAP) and dialysis modality. PWV and AI were measured with the SphygmoCor device. RESULTS: Mean fetuin-A concentration in dialysis patients (0.63+/-0.16 g/l) did not differ from controls (0.63+/-0.11 g/l). Median hsCRP levels in dialysis patients were higher compared with controls (4.0 vs 1.9 mg/l; P<0.0001). PWV but not AI was higher in dialysis patients than in controls (9.9 vs 7.9 m/s; P<0.0001). In univariate analysis in dialysis patients, fetuin-A levels were inversely related to both PWV (r = - 0.25, P = 0.007) and AI (r = - 0.26, P = 0.006), respectively. However, after correction for age, gender, MAP and diabetes mellitus, this relation lost statistical significance. CONCLUSIONS: In a dialysis population with a relatively low level of inflammatory activity, the soluble calcification inhibitor fetuin-A could not be identified as an independent predictor of aortic stiffness as measured with PWV and AI.