A healthy patient with positive mantoux test but negative quantiferon Gold assay and no evidence of risk factors - to treat or not to treat?

A 56-year-old woman who vaccinated as a child with the Bacillus Calmette-Guerin (BCG), now tests positive to the tuberculin skin test (TST) but test negative to the Quantiferon Gold assay. She has no history of tuberculosis contact and is asymptomatic. This dilemma now is, should be treated for tuberculosis or not, based only on the TST results? To prevent these falsepositive results with TST and avoid treatment with isoniazid (INH) it may be helpful to use interferon-gamma release assay (IGRA) instead, which unlike the TB skin test is not affected by prior BCG vaccination.

Tutor assessment of PBL process: does tutor variability affect objectivity and reliability?

BACKGROUND: Ensuring objectivity and maintaining reliability are necessary in order to consider any form of assessment valid. Evaluation of students in Problem-Based Learning (PBL) tutorials by the tutors has drawn the attention of critiques citing many challenges and limitations. The aim of this study was to determine the extent of tutor variability in assessing the PBL process in the Faculty of Medical Sciences, The University of the West Indies, St Augustine Campus, Trinidad and Tobago. METHOD: All 181 students of year 3 MBBS were assigned randomly to 14 PBL groups. Out of 18 tutors, 12 had an opportunity to assess three groups: one assessed 2 groups and 4 tutors assessed one group each; at the end each group had been assessed three times by different tutors. The tutors used a PBL assessment rating scale of 12 different criteria on a six-point scale to assess each PBL Group. To test the stated hypotheses, independent t-test, one-way ANOVA followed by post-hoc Bonferroni test, Intra Class Correlation, and Pearson product moment correlations were performed. RESULT: The analysis revealed significant differences between the highest- and lowest-rated groups (t-ratio = 12.64; p < 0.05) and between the most lenient and most stringent raters (t-ratio = 27.96; p < 0.05). ANOVA and post-hoc analysis for highest and lowest rated groups revealed that lenient- and stringent-raters significantly contribute (p < 0.01) in diluting the score in their respective category. The intra class correlations (ICC) among rating of different tutors for different groups showed low agreement among various ratings except three groups (Groups 6, 8 and 13) (r = 0.40). The correlation between tutors' PBL experiences and their mean ratings was found to be moderately significant (r = 0.52; p > 0.05). CONCLUSION: Leniency and stringency factors amongst raters affect objectivity and reliability to a great extent as is evident from the present study. Thus, more rigorous training in the areas of principles of assessment for the tutors are recommended. Moreover, putting that knowledge into practice to overcome the leniency and stringency factors is essential.

A comparison of clinical-scenario (case cluster) versus stand-alone multiple choice questions in a problem-based learning environment in undergraduate medicine.

OBJECTIVES: To compare stand-alone multiple choice questions (MCQs) and integrated clinical-scenario (case cluster) multiple choice questions (CS-MCQs) in a problem-based learning (PBL) environment. METHODS: A retrospective descriptive analysis of MCQ examinations was conducted in a course that integrates the subspecialties of anatomical pathology, chemical pathology, hematology, immunology, microbiology and pharmacology. The MCQ items were analyzed for their reliability (Kuder-Richardson-20, KR-20), level of difficulty (Pi), discrimination index (Di), item distractors and student performances. The statistical analysis of the results was extracted from the integrity online item-analysis programme. The results of the standard stand-alone and CS multiple choice questions were compared. RESULTS: KR-20 for the CS-MCQs and stand-alone MCQs was consistently high. KR-20 and Pi were higher for the CS-MCQs. There was no significant difference between the CS-MCQs and stand-alone MCQs in Pi and Di. A range of difficulty levels was found based on Bloom's taxonomy. The mean scores for the class were higher for the CS-MCQ examination. The compilation of the CS-MCQ examination was more challenging. CONCLUSIONS: CS-MCQs compare favorably to stand-alone MCQs and provide opportunities for the integration of sub-specialties and assessment in keeping with PBL. They assess students' cognitive skills and are reliable and practical. Different levels of item difficulty promote multi-logical and critical thinking. Students' scores were higher for the CS-MCQ examination, which may suggest better understanding of the material and/or better question clarity. The scenarios have to flow logically. Increasing the number of scenarios ensures the examination of more course content.

Evaluation of the effectiveness of progressive disclosure questions as an assessment tool for knowledge and skills in a problem based learning setting among third year medical students at The University of The West Indies, Trinidad and Tobago.

BACKGROUND: At the University of the West Indies, Trinidad and Tobago, third year undergraduate teaching is a hybrid of problem-based learning (PBL) and didactic lectures. PBL discourages students from simply getting basic factual knowledge but encourages them to integrate these basic facts with clinical knowledge and skills. Recently progressive disclosure questions (PDQ) also known as modified essay questions (MEQs) were introduced as an assessment tool which is reported to be in keeping with the PBL philosophy. OBJECTIVE: To describe the effectiveness of the PDQ as an assessment tool in a course that integrates the sub-specialties of Anatomical Pathology, Chemical Pathology, Haematology, Immunology, Microbiology, Pharmacology and Public Health. METHODS: A descriptive analysis of examination questions in PDQs, and the students' performance in these examinations was performed for the academic years 2011-2012, 2012-2013, and 2013-2014 in one-third year course that integrates Anatomical Pathology, Chemical Pathology, Haematology, Immunology, Microbiology, Pharmacology and Public Health. RESULTS: The PDQs reflected real life scenarios and were composed of questions of different levels of difficulty by Blooms' Taxonomy, from basic recall through more difficult questions requiring analytical, interpretative and problem solving skills. The integrated PDQs in the years 2011-2012, 2012-2013, 2013-2014 respectively was 52.9, 52.5, 58% simple recall of facts. By sub-specialty this ranged from 26.7 to 100%, 18.8 to 70%, and 23.1 to 100% in the 3 years respectively. The rest required higher order cognitive skills. For some sub-specialties, students' performance was better where the examination was mostly basic recall, and was poorer where there were more higher-order questions. The different sub-specialties had different percentages of contribution in the integrated examinations ranging from 4% in Public health to 22.9% in Anatomical Pathology. CONCLUSION: The PDQ asked students questions in an integrated fashion in keeping with the PBL process. More care should be taken to ensure appropriate questions are included in the examinations to assess higher order cognitive skills. However in an integrated course, some sub-specialties may not have content requiring higher cognitive level questions in certain clinical cases. More care should be taken in choosing clinical cases that integrate all the sub-specialties.