Assessment Question Characteristics Predict Medical Student Performance in General Pathology.

CONTEXT.­: Evaluation of medical curricula includes appraisal of student assessments in order to encourage deeper learning approaches. General pathology is our institution's 4-week, first-year course covering universal disease concepts (inflammation, neoplasia, etc). OBJECTIVE.­: To compare types of assessment questions and determine which characteristics may predict student scores, degree of difficulty, and item discrimination. DESIGN.­: Item-level analysis was employed to categorize questions along the following variables: type (multiple choice question or matching answer), presence of clinical vignette (if so, whether simple or complex), presence of specimen image, information depth (simple recall or interpretation), knowledge density (first or second order), Bloom taxonomy level (1-3), and, for the final, subject familiarity (repeated concept and, if so, whether verbatim). RESULTS.­: Assessments comprised 3 quizzes and 1 final exam (total 125 questions), scored during a 3-year period, (total 417 students) for a total 52 125 graded attempts. Overall, 44 890 attempts (86.1%) were correct. In multivariate analysis, question type emerged as the most significant predictor of student performance, degree of difficulty, and item discrimination, with multiple choice questions being significantly associated with lower mean scores (P = .004) and higher degree of difficulty (P = .02), but also, paradoxically, poorer discrimination (P = .002). The presence of a specimen image was significantly associated with better discrimination (P = .04), and questions requiring data interpretation (versus simple recall) were significantly associated with lower mean scores (P = .003) and a higher degree of difficulty (P = .046). CONCLUSIONS.­: Assessments in medical education should comprise combinations of questions with various characteristics in order to encourage better student performance, but also obtain optimal degrees of difficulty and levels of item discrimination.

Low-Cost High-Resolution Microendoscopy for the Detection of Esophageal Squamous Cell Neoplasia: An International Trial.

BACKGROUND & AIMS: Esophageal squamous cell neoplasia has a high mortality rate as a result of late detection. In high-risk regions such as China, screening is performed by Lugol's chromoendoscopy (LCE). LCE has low specificity, resulting in unnecessary tissue biopsy with a subsequent increase in procedure cost and risk. The purpose of this study was to evaluate the accuracy of a novel, low-cost, high-resolution microendoscope (HRME) as an adjunct to LCE. METHODS: In this prospective trial, 147 consecutive high-risk patients were enrolled from 2 US and 2 Chinese tertiary centers. Three expert and 4 novice endoscopists performed white-light endoscopy followed by LCE and HRME. All optical images were compared with the gold standard of histopathology. RESULTS: By using a per-biopsy analysis, the sensitivity of LCE vs LCE + HRME was 96% vs 91% (P = .0832), specificity was 48% vs 88% (P < .001), positive predictive value was 22% vs 45% (P < .0001), negative predictive value was 98% vs 98% (P = .3551), and overall accuracy was 57% vs 90% (P < .001), respectively. By using a per-patient analysis, the sensitivity of LCE vs LCE + HRME was 100% vs 95% (P = .16), specificity was 29% vs 79% (P < .001), positive predictive value was 32% vs 60%, 100% vs 98%, and accuracy was 47% vs 83% (P < .001). With the use of HRME, 136 biopsies (60%; 95% confidence interval, 53%-66%) could have been spared, and 55 patients (48%; 95% confidence interval, 38%-57%) could have been spared any biopsy. CONCLUSIONS: In this trial, HRME improved the accuracy of LCE for esophageal squamous cell neoplasia screening and surveillance. HRME may be a cost-effective optical biopsy adjunct to LCE, potentially reducing unnecessary biopsies and facilitating real-time decision making in globally underserved regions. ClinicalTrials.gov, NCT 01384708.

High-resolution microendoscopy for esophageal cancer screening in China: A cost-effectiveness analysis.

AIM: To study the cost-effectiveness of high-resolution microendoscopy (HRME) in an esophageal squamous cell carcinoma (ESCC) screening program in China. METHODS: A decision analytic Markov model of ESCC was developed. Separate model analyses were conducted for cohorts consisting of an average-risk population or a high-risk population in China. Hypothetical 50-year-old individuals were followed until age 80 or death. We compared three different strategies for both cohorts: (1) no screening; (2) standard endoscopic screening with Lugol's iodine staining; and (3) endoscopic screening with Lugol's iodine staining and an HRME. Model parameters were estimated from the literature as well as from GLOBOCAN, the Cancer Incidence and Mortality Worldwide cancer database. Health states in the model included non-neoplasia, mild dysplasia, moderate dysplasia, high-grade dysplasia, intramucosal carcinoma, operable cancer, inoperable cancer, and death. Separate ESCC incidence transition rates were generated for the average-risk and high-risk populations. Costs in Chinese currency were converted to international dollars (I$) and were adjusted to 2012 dollars using the Consumer Price Index. RESULTS: The main outcome measurements for this study were quality-adjusted life years (QALYs) and incremental cost-effectiveness ratio (ICER). For the average-risk population, the HRME screening strategy produced 0.043 more QALYs than the no screening strategy at an additional cost of I$646, resulting in an ICER of I$11808 per QALY gained. Standard endoscopic screening was weakly dominated. Among the high-risk population, when the HRME screening strategy was compared with the standard screening strategy, the ICER was I$8173 per QALY. For both the high-risk and average-risk screening populations, the HRME screening strategy appeared to be the most cost-effective strategy, producing ICERs below the willingness-to-pay threshold, I$23500 per QALY. One-way sensitivity analysis showed that, for the average-risk population, higher specificity of Lugol's iodine (> 40%) and lower specificity of HRME (< 70%) could make Lugol's iodine screening cost-effective. For the high-risk population, the results of the model were not substantially affected by varying the follow-up rate after Lugol's iodine screening, Lugol's iodine test characteristics (sensitivity and specificity), or HRME specificity. CONCLUSION: The incorporation of HRME into an ESCC screening program could be cost-effective in China. Larger studies of HRME performance are needed to confirm these findings.

Molecular tumor testing for Lynch syndrome in patients with colorectal cancer.

Lynch syndrome (LS) is the most common hereditary colon cancer syndrome, and accounts for 2% to 3% of all colorectal cancers. These tumors are caused by germline mutations of DNA mismatch repair genes, which result in microsatellite instability. Colonic and extracolonic malignancies can occur at a young age, and are often diagnosed at a late stage because of underrecognition of the syndrome. Identifying individuals with LS before the development of these malignancies decreases mortality because of frequent screening and surveillance of colonic and extracolonic cancers. Moreover, family members of these individuals can be tested and begin screening at a young age if appropriate. Classically, Amsterdam criteria and Bethesda guidelines have been used to identify at-risk individuals; however, these tools miss a significant number of cases. As the molecular basis for LS has been clarified, more sophisticated strategies have emerged. Testing all colorectal cancers for loss of mismatch repair proteins, known as universal screening, is a strategy used to identify individuals at risk for LS. This approach has been shown to be more sensitive than previous methods that rely on family history. Implementation of universal tumor testing necessitates a systematic approach to positive results in order to have maximal effect, and could prove to be the most cost-effective approach to reducing cancer mortality in patients with LS.