No abstract

Case-based teaching is regarded as a superior instructional method compared with lectures in promoting a learner's critical thinking skills. While much is known about the role a discussion facilitator plays in case-based teaching, the debate on the influence of the format and structure of cases on learning is controversial. We sought to identify strategies for constructing cases based on studies from multiple disciplines, which report the development and use of cases in teaching and learning. The purpose was to offer the medical and other educational communities a conceptual framework that can be examined in future research. Based on a review of 100 studies, we synthesised 17 strategies around 5 core attributes of cases: relevant (level of learner, goals and objectives, setting of case narrative); realistic (authenticity, distractors, gradual disclosure of content); engaging (rich content, multiple perspectives, branching of content); challenging (difficulty, unusual cases, case structure, multiple cases), and instructional (build upon prior knowledge, assessment, feedback, and teaching aids). Despite the wide use of cases in disparate disciplines, there has been no overarching study that synthesises strategies of case development or tests these strategies in research settings. The framework we developed can serve as a menu of case development options that educators and researchers can pilot and evaluate in their local settings.

OBJECTIVE To describe vertebral left atrial size (VLAS), a quantitative method to estimate left atrial (LA) size radiographically, and to determine its diagnostic value for prediction of echocardiographic LA enlargement in dogs with myxomatous mitral valve disease (MMVD) of varying severity. DESIGN Prospective observational study. ANIMALS 103 client-owned dogs with a left-sided systolic murmur. PROCEDURES For each dog, 3-view thoracic radiographs were obtained within 24 hours of an echocardiographic examination. The VLAS was measured on right and left lateral thoracic radiographs and compared with the left atrium-to-aortic root ratio acquired from short-axis (LA:AoSx) and long-axis (LA:AoLx) echocardiographic images. Left atrial enlargement was defined as an LA:AoLx ≥ 2.6 or LA:AoSx ≥ 1.6. Dogs were allocated to 4 groups on the basis of MMVD severity. RESULTS Of the 103 dogs, 15, 40, 26, and 22 were assigned to the control (no echocardiographic abnormalities), stage B1 (hemodynamically irrelevant MMVD), B2 (hemodynamically relevant MMVD), and C-D (MMVD with congestive heart failure) groups, respectively. Median VLAS, LA:AoSx, and LA:AoLx for the stage B2 and C-D groups were significantly greater than the corresponding medians for the control and stage B1 groups. There was a moderate positive correlation between VLAS and both LA:AoSx and LA:AoLx. Receiver operating characteristic analyses revealed that a VLAS ≥ 2.3 vertebrae was a useful predictor of LA enlargement. Intraobserver and interobserver agreements for VLAS measurements were high. CONCLUSIONS AND CLINICAL RELEVANCE Results indicated VLAS was a repeatable and useful radiographic measurement for prediction of LA enlargement in dogs with MMVD.

No abstract

No abstract