Exploring the Implications of Analysing Time-to-Event Outcomes as Binary in Meta-analysis

Systematic reviews and meta-analysis of time-to-event outcomes can be analysed on the hazard ratio (HR) scale but are very often dichotomised and analysed as binary using effect measures such as odds ratios (OR). This thesis investigates the impact of using these different scales by re-analysing meta-analyses from the Cochrane Database of Systematic Reviews (CDSR), using individual participant data (IPD) and a comprehensive simulation study. For the CDSR and IPD, the pooled HR estimates were closer to 1 than the OR estimates in most meta-analyses. Important differences in between-study heterogeneity between the HR and OR analyses were observed. These caused discrepant conclusions between the OR and HR scales in some meta-analyses. Situations under which the clog-log link outperformed the logit link and vice versa were apparent, indicating that the correct method choice does matter. Differences between scales occurred mainly when event probability was high and could occur via differences in between-study heterogeneity or via increased within-study standard error in OR relative to HR analyses. In many simulation scenarios, analysing time-to-event data as binary using the logit link did not substantially affect bias and coverage apart from those where large percentage random censoring and long follow-up time was present. The method though lacks precision particularly for small meta-analyses. Analysing the data as binary using the clog-log link consistently produced more bias, low coverage and low power. If a HR estimate cannot be obtained per trial to perform a meta-analysis of time-to-event data, a meta-analysis using the OR scale (using the logit link) could be conducted but with awareness that this would provide less precise estimates in the analysis. Investigators should avoid performing meta-analyses on the OR scale in the presence of high event probability, large percentage random censoring and therefore longer follow-up times assuming of large event rates of the trials included

Sistem Pembelajaran Berbicara Berbasis Web Di Program Studi Bahasa Inggris

Pembelajaran speaking sangat penting bagi pelajar dan mahasiswa, karena bahasa inggris adalah salah satu bahasa internasional, juga untuk melatih agar mempersiapkan diri pada dunia kerja yang sangat dibutuhkan nya pandai dalam berbicara terutama berbicara dalam bahasa inggris. berbicara dalam bahasa inggris masih sangat kurang dikalangan pelajar dan mahasiswa karena takut, dan kurang nya kebiasaan berbicara bahasa inggris, dan dibutuhkan untuk mengimprove skill bahasa inggris yang dimiliki oleh pelajar dan mahasiswa. Pada penelitian ini dibuat sebuah web based yang dapat dimanfaatkan dan berguna bagi pelajar dan mahasiswa dalam belajar  membaca bahasa inggri

EVALUATION OF IN VITRO ANTI-UROLITHIATIC ACTIVITY OF METHANOLIC EXTRACT OF CUCUMIS MELO SEEDS ON CALCIUM OXALATE CRYSTALS

Objective: This in vitro study was carried out to evaluate the anti-urolithiatic activity of the methanolic extract of the Cucumismelo seeds on experimentally prepared calcium oxalate crystals which was prepared by the homogeneous precipitation method in the laboratory.Methods: The crude extract was prepared by the soxhlet extraction method and the extraction was done until all the compounds get extracted into the solution and solvent was evaporated by rotary evaporator. Extracts were stored in an airtight light-resistant container at 4 °C in a refrigerator for further analysis.Results: Seed extract of Cucumismelo showed maximum efficiencies in the dissolution of the calcium oxalate crystals. Cystone drug was used as the standard. This in vitro study has shown that the methanolic extract of the seeds of Cucumismelo has the potential anti-urolithiatic activity when compared with the standard.Conclusion: This in vitro study has given the primary evidence that the extract of seeds of Cucumismelo has the anti-urolithiatic activity. In vivo studies can be carried out on the seed extract of Cucumismelo for further investigations

Action Research in Teacher Education: Classroom Inquiry, Reflection, and Data-Driven Decision Making

One of the growing interests in teacher education lies in how and what teachers learn across time and space in the complex ecologies and technologies of today’s society. Teacher research has been implemented in teacher education programs as a powerful, exploratory tool for teacher candidates to inquire about educational problems and to improve their knowledge of teaching practice. This article presents insights gained from review of 18 action research projects completed by classroom teachers enrolled in a graduate reading methods course. To better understand what teachers learned through the action research process and how their self-study impacted teaching and learning in their classrooms, qualitative research methods were used to analyze the teachers’ projects. The data revealed action research impacted literacy instruction, teachers struggled with how to make their literacy instruction explicit, projects focused on specific literacy topics, teachers used a range of resources for their selected intervention and shared information with each other and with colleagues in their respective contexts

Which Came First: Literacy or Social Studies? How Primary Sources Can Bridge the Divide

Due to the implementation of No Child Left Behind and the Common Core State Standards, disciplinary literacy has become a vital component of social studies instruction in middle and secondary classrooms. This paper determines the degree to which nine middle and high school social studies teachers were successful in designing integrated learning experiences for their students after attending professional development. Data from semi-structured interviews, teachers’ instructional units, workshop surveys and field notes were collected and analyzed for the qualitative study. The study considers how teachers’ instructional units incorporated primary sources to support students’ foundational literacy skills, scaffolded disciplinary understanding, historical analysis, and highlighted community issues that connected their lived experiences to broader social concerns

Engaging Students in the Research Process: Comparing Approaches Used with Diverse Learners in Two Urban High School Classrooms

This paper describes instructional choices used by two high school teachers to engage students in the research process. Working with diverse learners in large urban high schools, the teachers used different approaches to support students’ through the research process. The teachers’ intentional teaching helped to engage students through structured and semi-structured explorations of real-world issues

Using Primary Sources in Content Areas to Increase Disciplinary Literacy Instruction

This paper describes how a three-day summer workshop on using primary sources helped teachers increase the emphasis placed on disciplinary literacy when teaching social studies and history. Two specific issues in teacher education and practice are addressed. First, increasing teachers’ content knowledge of history topics can help them plan lessons that connect local and global events. Second, content area reading requires literacy practices, which are unique to disciplines. Therefore, teachers need to apply historical inquiry and disciplinary literacy methods in the curriculum

Influence of Hospital Volume on Nephrectomy Mortality and Complications: A Systematic Review and Meta-analysis Stratified by Surgical Type

Objectives The provision of complex surgery is increasingly centralised to high volume specialist hospitals. Evidence to support nephrectomy centralisation however has been inconsistent. We conducted a systematic review and meta-analysis to determine the association between hospital case volumes and perioperative outcomes in radical nephrectomy, partial nephrectomy and nephrectomy with venous thrombectomy. Methods Medline, Embase and the Cochrane Library were searched for relevant studies published between 1990 and 2016. Pooled effect estimates for nephrectomy mortality and complications were calculated for each nephrectomy type using the DerSimonian and Laird random-effects model. Sensitivity analyses were performed to examine the effects of heterogeneity on the pooled effect estimates by excluding studies with the heaviest weighting, lowest methodological score, and most likely to introduce bias from misclassification of standardised hospital volume. Results Some 226,372 patients from sixteen publications were included in our review and meta-analysis. Considerable between-study heterogeneity was noted and only a few reported volume-outcome relationships specifically in partial nephrectomy or nephrectomy with venous thrombectomy. High volume hospitals were correlated with a 26% and 52% reduction in mortality for radical nephrectomy (OR 0.74, 95% CI 0.61-0.90, p<0.01) and nephrectomy with venous thrombectomy (OR 0.48, 95% CI 0.29-0.81, p<0.01) respectively. In addition, radical nephrectomy in high volume hospitals was associated with an 18% reduction in complications (OR 0.82, 95% CI 0.73-0.92, p<0.01). No significant volume-outcome relationship in mortality (OR 0.84, 95% CI 0.31-2.26, p=0.73) or complications (OR 0.85, 95% CI 0.55-1.30, p=0.44) was observed for partial nephrectomy. Conclusions Our findings suggest that patients undergoing radical nephrectomy have improved outcomes when treated by high volume hospitals. Evidence of this in partial nephrectomy and nephrectomy with venous thrombectomy is however not yet clear and could be secondary to the low number of studies included and the small patient number in our analyses. Further investigation is warranted to establish the full potential of nephrectomy centralisation particularly as existing evidence is of low quality with significant heterogeneity.This work was supported by Addenbrooke’s Charitable Trust, the Royal College of Surgeons of England and the Urology Foundation. Cancer Research UK Advanced Clinician Scientist Fellowship award (No. C18081/A18180) has supported GL and TS

Pre-Service Teachers’ Use of Multicultural Literature

This qualitative study examines how pre-service teachers in urban elementary classrooms develop student literacy with multicultural literature. By evaluating the action research reports of three pre-service teacher candidates, the authors determine how reading experiences with texts align to Bloom’s Taxonomy and expectations for Common Core State Standards. Findings indicate that multicultural literature engages students with authentic connections to learning. Results also show that teachers relied on guided questioning to measure reading comprehension, though the types of questions varied. The implications of this study for teachers to consider are: how to incorporate multicultural texts into the curriculum to encourage critical thinking, and the types of questions that promote text analysis

Implications of analysing time-to-event outcomes as binary in meta-analysis: empirical evidence from the Cochrane Database of Systematic Reviews

BACKGROUND: Systematic reviews and meta-analysis of time-to-event outcomes are frequently published within the Cochrane Database of Systematic Reviews (CDSR). However, these outcomes are handled differently across meta-analyses. They can be analysed on the hazard ratio (HR) scale or can be dichotomized and analysed as binary outcomes using effect measures such as odds ratios (OR) or risk ratios (RR). We investigated the impact of reanalysing meta-analyses from the CDSR that used these different effect measures. METHODS: We extracted two types of meta-analysis data from the CDSR: either recorded in a binary form only ("binary"), or in binary form together with observed minus expected and variance statistics ("OEV"). We explored how results for time-to-event outcomes originally analysed as "binary" change when analysed using the complementary log-log (clog-log) link on a HR scale. For the data originally analysed as HRs ("OEV"), we compared these results to analysing them as binary on a HR scale using the clog-log link or using a logit link on an OR scale. RESULTS: The pooled HR estimates were closer to 1 than the OR estimates in the majority of meta-analyses. Important differences in between-study heterogeneity between the HR and OR analyses were also observed. These changes led to discrepant conclusions between the OR and HR scales in some meta-analyses. Situations under which the clog-log link performed better than logit link and vice versa were apparent, indicating that the correct choice of the method does matter. Differences between scales arise mainly when event probability is high and may occur via differences in between-study heterogeneity or via increased within-study standard error in the OR relative to the HR analyses. CONCLUSIONS: We identified that dichotomising time-to-event outcomes may be adequate for low event probabilities but not for high event probabilities. In meta-analyses where only binary data are available, the complementary log-log link may be a useful alternative when analysing time-to-event outcomes as binary, however the exact conditions need further exploration. These findings provide guidance on the appropriate methodology that should be used when conducting such meta-analyses