Acute care of pediatric patients with sickle cell disease: a simulation performance assessment.

BACKGROUND: Sickle cell disease (SCD) is a rare disorder with cardinal features including hospitalization for vaso-occlusive pain episodes, acute pulmonary injury, and increased infection rates. For physician-trainees, learning optimal SCD management is challenging because of limited exposure to life threatening complications requiring timely interventions. PROCEDURE: To create, demonstrate reliability, and validate simulation-based, acute care SCD scenarios for physician-trainees, seven scenarios were derived from SCD patient cases. For each scenario, participants had 5 minutes to complete diagnostic and treatment interventions. Participants were divided into two groups based on clinical experience: interns or residents/fellows. Two raters scored performances using diagnostic and therapeutic checklists--indicating whether specific actions were performed and a global, 1 (poor) to 9 (excellent), rating. Scenario scores were calculated by averaging rater scores on each metric. Reliability was defined through uniformity in rater scoring and consistency of participant performance over scenarios. Validity was demonstrated by the performance gradient where the more experienced trainees outperform those early in training. RESULTS: Twenty-eight pediatric residents and hematology fellows took part in the study. Reliability for assessment scores overall was moderate. Performance on all but one scenario was moderately predictive of overall performance. Senior resident/fellows performed significantly better than interns. Positive associations existed between overall performance scores (P < 0.01) and months of postgraduate training (P < 0.01). CONCLUSIONS: Mannequin-based simulation is a novel method for teaching pediatric residents SCD-specific acute care skills. The assessment provided reliable and valid measures of trainees' performance. Further studies are needed to determine simulation's utility in education and evaluation.

Precision and accuracy of DXA and pQCT for densitometry of the rat femur.

Measurements of bone mineral density and bone mineral content are key data in the study of osteoporosis and pathologic skeletal disease. Dual-energy X-ray absorptiometry and peripheral quantitative computed tomography are used in human and small animal studies. The purpose of this study was to evaluate the precision, accuracy, and systematic bias of measurement of the rat femur. Comparing machine-measured parameters with standard, nonradiographic measurements, we assessed validation of relative and absolute accuracy. Regression analysis and calculations of percent difference from standard values were used to determine the accuracy of each densitometry technique. Machine-specific and subject-specific precision was evaluated for each densitometer using repeated scans to calculate coefficients of variation. Each of the methods of densitometry examined in this study produced comparable results and was sensitive to small changes following experimental stimuli. Further, our assessment of the precision and accuracy observed between methods of scanning excised rat femurs validates our data acquisition method and serves as a foundation for future densitometry studies.