Performance of "standardized examinees" in a standardized-patient examination of clinical skills

PURPOSE: As a first step in testing the utility of using trained "standardized examinees" (SEs) as a quality-assurance measure for the scoring process in a standardized-patient (SP) examination, to test whether medical residents could simulate students in an SP examination and perform consistently to specified levels under test conditions. METHOD: Fourth-year students from the Baltimore-Washington Consortium for SPs participated in a National Board of Medical Examiners Prototype Examination of clinical skills consisting of twelve 15-minute student-patient encounters in 1994-95. For this examination, internal medicine residents were trained to act as ordinary candidates and to achieve target scores by performing to a set level on specific checklist items used by SPs for recording interviewing, physical-examination, and communication skills. The "strong SEs" were trained to score 80% correct on six of the examination's 12 cases (study cases), and the "weak SEs" were trained to score 40% correct on the same six cases. The strong and weak SEs' checklist scores on the study cases were compared through independent, two-tailed t-tests. When there was less than 85% agreement on specific checklist items in each case between the SE training and the SP recording, videotapes of the cases were reviewed; in such cases an SE's performance was the final score agreed upon after review. RESULTS: Seven SEs took the SP examination and were not detected by the SPs. There was a total of 84 discrepancies between predicted and recorded checklist scores across 659 checklist items in 40 encounters scored by the SPs. After correcting the discrepancies based on videotape review, the estimated actual mean score was 77.3% for the strong SEs and 44.0% for the weak SEs, and was higher for the strong SEs in each study case. The overall fidelity of the SEs to their training was estimated to be 97%, and the overall SP accuracy was estimated to be 91%. The videotape review revealed 47 training-scoring discrepancies, most in the area of communication skills. CONCLUSION: This study suggests that SEs can be trained to specific performance levels and may be an effective internal control for a high-stakes SP examination. They may also provide a mechanism for refining scoring checklists and for exploring the validity of SP examinations.     

Preventing sleep problems in infants: a randomized controlled trial

In the pre-school years sleep problems are one of the most common subjects on which parents seek advice from health professionals. In the majority of cases a sleepless child causes significant stress within the family, and if parents do not obtain sufficient sleep this can have a detrimental effect on their physical and emotional well-being. In a small number of cases a child who wakes frequently and will not settle back to sleep may be at risk of physical abuse. In recent years it has been suggested that it may be possible to prevent sleep problems developing by providing parents with advice in the post-natal period. Parents have stated that they find this type of intervention helpful, however, there has been no attempt to establish whether a preventive approach is effective. The aim of this research was to evaluate the efficacy of health education in reducing the incidence of sleep problems. Adopting an experimental approach, participants were randomly allocated to a control group or an intervention group. Parental knowledge of sleep and settling behaviour was manipulated when the children in the intervention group were 3 months old. The sleeping behaviour of the infants in both groups was compared 6 months later, when the children were 9 months old. Data was collected from 86 families in the intervention group and 83 families in the control group. A comprehensive analysis of the sleeping behaviour demonstrated that a significantly smaller percentage of babies in the intervention group had settling and night-waking difficulties than in the control group.     

Effects of carbon dioxide pneumoperitoneum, air pneumoperitoneum, and gasless laparoscopy on body weight and tumor growth

BACKGROUND: The oncologic consequences of intraperitoneal carbon dioxide (CO2) insufflation during the laparoscopic resection of cancer are under debate. The effect of other insufflating gases or gasless laparoscopy on cancer requires study. OBJECTIVE: To study body weight and tumor growth in rats after CO2 pneumoperitoneum, air pneumoperitoneum, and gasless laparoscopy. METHODS: On day 1, an 8-mg bolus of ROS-1 tumor was placed under the renal capsule of both kidneys in rats. In experiment A, rats had either CO2 insufflation (n=10) or a gasless laparoscopic bowel resection (n=10) on day 3 and were humanely killed after 7 days. In experiment B, rats had either a laparoscopic bowel resection with CO2 insufflation (n=11) or insufflation with air (n=11) on day 3 and were killed after 7 days. In both experiments, postoperative weight loss and tumor growth were measured, and the differences were tested with an analysis of covariance. RESULTS: Renal subcapsular tumor growth in the group having gasless laparoscopy was less than that in the group having CO2 pneumoperitoneum (P=.04). Postoperative weight loss in these groups showed no differences (P=.55). No differences in tumor growth or weight loss were found between rats having insufflation with CO2 and those having insufflation with air (P=.61 and P=.68, respectively). CONCLUSIONS: The restoration of body weight after a laparoscopic surgical procedure was similar with CO2, air, or gasless laparoscopy. Gasless laparoscopy was associated with less renal subcapsular tumor growth than was insufflation with CO2. Therefore, the application of gasless techniques in laparoscopic oncologic surgical treatment demands further study.     

Studies on the effect of intratesticular administration of opioid peptides, naloxone or N-acetyl beta-endorphin antiserum on some testicular parameters in rats

Substrate specificity and other properties of a fatty acid monooxygenase system in kidney microsomes of the Japanese house musk shrew (Suncus murinus) were examined. The suncus kidney microsomes catalyzed the hydroxylation of various saturated and unsaturated fatty acids to the omega- and (omega-1)-hydroxy derivatives. Laurate was most effectively hydroxylated among saturated and unsaturated fatty acids. The specific activity (53.79 +/- 5.59 [mean +/- SD, n = 6] nmol/nmol cytochrome P450/min) of laurate in suncus kidney microsomes was very high compared with that in liver and kidney microsomes of other species. C18 unsaturated fatty acids were converted to epoxides by a cytochrome P450-dependent fatty acid monooxygenase system in suncus kidney microsomes, in addition to omega- and (omega-1)-hydroxylation products. The monooxygenase system metabolized arachidonic acid only to omega- and (omega-1)-hydroxylation products, not to epoxidation products.     

Extreme lateral transcondylar approach: technical improvements and lessons learned

An extreme lateral transcondylar or extreme lateral transfacetal surgical approach was used to treat 22 patients with complex lesions over a 22-month period. The lesions included basilar invagination with vertebral artery pathology, giant aneurysm or arteriovenous fistula of the vertebral artery, meningioma, chordoma, chondrosarcoma, and paraganglioma. The approach was used alone or in combination with a presigmoid petrosal or subtemporal-infratemporal approach. Refinements of the operative technique, treatment strategies for complex lesions, and the avoidance of complications are discussed. Complications included cerebrospinal fluid leakage, meningitis, pseudomeningocele, hemiparesis or quadriparesis, lower cranial nerve deficits, and vertebral artery injury requiring repair. With treatment, major neurological deficits resolved completely in three patients and partially in two. There was no operative mortality, but four patients died during the follow-up period. For the 18 surviving patients, the mean preoperative and postoperative Karnofsky scores were 81 and 93, respectively. For the four who died, the mean preoperative Karnofsky score was 73 and the mean postoperative score was 63.     

Prolongation of the QT interval related to cisapride-diltiazem interaction

A liquid chromatographic method was developed for the determination of nanogram quantities of 5 broad-spectrum structurally related beta-lactam antibiotics (cefazolin, cefadroxil, cephalexin, cephradine, and ampicillin) in solution. The method uses a C18 reversed-phase column, UV absorption (240 nm) detection, and an aqueous mobile phase containing isopropyl alcohol and acetic acid. Relative resolution between the antibiotic peaks ranged from 1.7 to 5.9 for all peaks. Chromatographic retention times were 2.97, 3.92, 4.57, 5.37, and 6.56 min for cefazolin, cefadroxil, cephalexin, ampicillin, and cephradine, respectively. Accuracy, precision, linearity, and long term analytical reproducibility were determined by statistical analysis. Use of the proposed method to evaluate the degradation of cephradine solutions stored at room temperature illustrated its potential as a stability-indicating assay.