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Arri Coomarasamy

Publications and source records attributed to Arri Coomarasamy.

8 recordsLinked to original sources
PubMed2006

A hierarchy of effective teaching and learning to acquire competence in evidenced-based medicine.

BACKGROUND: A variety of methods exists for teaching and learning evidence-based medicine (EBM). However, there is much debate about the effectiveness of various EBM teaching and learning activities, resulting in a lack of consensus as to what methods constitute the best educational practice. There is a need for a clear hierarchy of educational activities to effectively impart and acquire competence in EBM skills. This paper develops such a hierarchy based on current empirical and theoretical evidence. DISCUSSION: EBM requires that health care decisions be based on the best available valid and relevant evidence. To achieve this, teachers delivering EBM curricula need to inculcate amongst learners the skills to gain, assess, apply, integrate and communicate new knowledge in clinical decision-making. Empirical and theoretical evidence suggests that there is a hierarchy of teaching and learning activities in terms of their educational effectiveness: Level 1, interactive and clinically integrated activities; Level 2(a), interactive but classroom based activities; Level 2(b), didactic but clinically integrated activities; and Level 3, didactic, classroom or standalone teaching. SUMMARY: All health care professionals need to understand and implement the principles of EBM to improve care of their patients. Interactive and clinically integrated teaching and learning activities provide the basis for the best educational practice in this field.

Competency-Based Education↗
PubMed2006

Meta-DiSc: a software for meta-analysis of test accuracy data.

BACKGROUND: Systematic reviews and meta-analyses of test accuracy studies are increasingly being recognised as central in guiding clinical practice. However, there is currently no dedicated and comprehensive software for meta-analysis of diagnostic data. In this article, we present Meta-DiSc, a Windows-based, user-friendly, freely available (for academic use) software that we have developed, piloted, and validated to perform diagnostic meta-analysis. RESULTS: Meta-DiSc a) allows exploration of heterogeneity, with a variety of statistics including chi-square, I-squared and Spearman correlation tests, b) implements meta-regression techniques to explore the relationships between study characteristics and accuracy estimates, c) performs statistical pooling of sensitivities, specificities, likelihood ratios and diagnostic odds ratios using fixed and random effects models, both overall and in subgroups and d) produces high quality figures, including forest plots and summary receiver operating characteristic curves that can be exported for use in manuscripts for publication. All computational algorithms have been validated through comparison with different statistical tools and published meta-analyses. Meta-DiSc has a Graphical User Interface with roll-down menus, dialog boxes, and online help facilities. CONCLUSION: Meta-DiSc is a comprehensive and dedicated test accuracy meta-analysis software. It has already been used and cited in several meta-analyses published in high-ranking journals. The software is publicly available at http://www.hrc.es/investigacion/metadisc_en.htm.

Clinical Laboratory Techniques↗
PubMed2006

Value of ovarian reserve testing before IVF: a clinical decision analysis.

BACKGROUND: To assess the value of testing for ovarian reserve prior to a first cycle IVF incorporating patient and doctor valuation of mismatches between test results and treatment outcome. METHODS: A decision model was developed for couples who were considering participation in an IVF programme. Three strategies were evaluated: (I) withholding IVF without prior testing, (II) testing for ovarian reserve, and then deciding on IVF treatment if ovarian reserve was estimated to be sufficient, and (III) treatment with IVF without prior ovarian reserve testing. The outcome considered was the birth of a child. The valuation of the combination of the strategy conducted and the outcome accomplished was expressed on a distress scale in units of 'IVF cycles that were performed in vain'. Correct treatment with IVF and correct withholding of IVF were considered to bring no distress. The distress of withholding IVF in case pregnancy occurred is consequently specified by the ratio of the expected distress after incorrect withholding IVF to the expected distress after incorrect performing IVF (distress ratio). We interviewed both patients and doctors to determine realistic estimates for this distress ratio. RESULTS: The value of testing for ovarian reserve depends strongly on the expected pregnancy rate after IVF as well as on the valuation of the incorrect decisions from testing. For realistic ranges of the success rate after IVF and for distress ranges as were measured, treatment of all couples without testing was found to generate less distress than testing for ovarian reserve. The sensitivity and specificity of testing for ovarian reserve has to improve to 50 and 96% respectively, to make testing a valuable strategy. CONCLUSION: Based on the decision analysis, where current test accuracy and preference inventory among patients and physicians were used, testing for ovarian reserve seems not useful for current IVF programmes.

Attitude↗
PubMed2005

Accuracy of ultrasound biometry in the prediction of macrosomia: a systematic quantitative review.

OBJECTIVE: To determine the accuracy of ultrasonographically estimated fetal weight (EFW) and abdominal circumference (AC) in the prediction of macrosomia. DESIGN: Systematic quantitative review. METHODS: Studies were identified without language restrictions from MEDLINE (1966-2003), EMBASE (1980-2003), Cochrane Library (2003:4), SCISEARCH (1974-2003) and manual searching of bibliographies of known primary and review articles. Studies were selected if accuracy of ultrasonographically EFW or AC was evaluated for predicting macrosomia using birthweight as the reference standard. Data were extracted on study characteristics, quality and accuracy. Data were pooled to produce summary receiver operating characteristic curves (sROC) for studies with various test thresholds. Summary likelihood ratios for positive (LR+) and negative (LR-) test results were generated for an EFW of 4000 g and an AC of 36 cm for predicting birthweight of over 4000 g. MAIN OUTCOME MEASURES: Birthweight over various thresholds. RESULTS: There were 36 primary articles consisting of 63 accuracy studies (51 evaluating the accuracy of EFW, and 12 accuracy of fetal AC), including a total of 19,117 women. The sROC area for EFW was not different from the area for fetal AC (0.87 vs 0.85, P= 0.91). For predicting a birthweight of over 4000 g, the summary LRs were 5.7 (95% CI: 4.3 to 7.6) for a positive test and 0.48 (95% CI: 0.38 to 0.60) for a negative test, using Hadlock's method of ultrasonographically estimating fetal weight. For ultrasound fetal AC of 36 cm, the respective LRs for predicting a birthweight over 4000 g were 6.9 (95% CI: 5.2 to 9.0) and 0.37 (0.30-0.45). CONCLUSION: There is no difference in accuracy between ultrasonographically EFW and AC in the prediction of a macrosomic baby at birth. A positive test result is more accurate for ruling in macrosomia than a negative test result for ruling it out.

Abdomen↗
PubMed2004

What is the evidence that postgraduate teaching in evidence based medicine changes anything? A systematic review.

OBJECTIVE: To evaluate the effects of standalone versus clinically integrated teaching in evidence based medicine on various outcomes in postgraduates. DESIGN: Systematic review of randomised and non-randomised controlled trials and before and after comparison studies. DATA SOURCES: Medline, Embase, ERIC, Cochrane Library, DARE, HTA database, Best Evidence, BEME, and SCI. STUDY SELECTION: 23 studies: four randomised trials, seven non-randomised controlled studies, and 12 before and after comparison studies. 18 studies (including two randomised trials) evaluated a standalone teaching method, and five studies (including two randomised trials) evaluated a clinically integrated teaching method. MAIN OUTCOME MEASURES: Knowledge, critical appraisal skills, attitudes, and behaviour. RESULTS: Standalone teaching improved knowledge but not skills, attitudes, or behaviour. Clinically integrated teaching improved knowledge, skills, attitudes, and behaviour. CONCLUSION: Teaching of evidence based medicine should be moved from classrooms to clinical practice to achieve improvements in substantial outcomes.

Clinical Competence↗