87 research outputs found

    Evaluation at the Frontier: Some "Timely" Comments for Future Use

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67212/2/10.1177_109821408400500110.pd

    Reviving Preevaluative Research

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    The concept of "pre-evaluative research" is examined in the context of a museum exhibition evaluation. Preevaluation research was recommended by some of the earliest writers in the evaluation field as a way of facilitating a formal, "ultimate, "of summative evaluation. It is viewed as distinct from, and complementary to, an evaluability assessment. The exhibit preevaluative study indicates that instrumentation and imple mentation issues are likely to benefit from such activities, but that design and analysis may still suffer.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68240/2/10.1177_0193841X8701100204.pd

    Differential Attrition

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    The differential attrition of persons from comparison groups severely restricts the inferences that can be made from results of evaluative research. This problem is particularly troublesome in the evaluation of medical technologies, such as coronary artery bypass graft surgery, since a substantial percentage of medical or control patients cross over to the surgical group. A procedure using worst case assumptions is developed that allows researchers to estimate the maximum effect of differential attrition, and therefore enhance the quality of their inferences. The article first illustrates theprocedure, then concludes with a discussion of the generality of the estimation procedure to other instances in which differential attrition is a problem, and points out the limitations of the approach.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67927/2/10.1177_0193841X8300700607.pd

    Cumulating quality of life results in controlled trials of coronary artery bypass graft surgery

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    Many studies evaluating the effectiveness of coronary artery bypass graft surgery allude to the quality of life benefit resulting from surgery. However, no comprehensive empirical estimate of the absolute or relative magnitude of this benefit is currently available. This paper presents a data synthesis of the research literature on bypass surgery to derive such an estimate. It uses follow-up measures of the percent of patients who were angina-free within both the surgical and medical groups of 14 controlled trials to estimate the quality of life benefit following surgery. Results based on the longest reported follow-up period suggest that the chances are approximately 25 to 40% greater than patients will be angina-free if they receive surgery rather than medical treatment. Estimates of benefit are about 15% less in randomized controlled trials compared to controlled trials that used a matching strategy. These results are unlikely to be affected by related factors such as the percentage of patients who crossover from the medical group to the surgical group or the specific method of calculating anginal relief used in this research report. However, differential patient selection may account for the observed design effect.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25475/1/0000015.pd

    On Model-Based Systems Engineering for Design, Management, and Governance of Protective Systems

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    PresentationProtective systems failure can be catastrophic, and originates in management failure. These systems rely on a document-based approach, which involves handling disjointed artifacts that are expensive to maintain and may become inconsistent and obsolete. We propose a framework for managing process safety that pioneers the modeling of protective systems according to the tenors of model-based systems engineering (MBSE). The framework embeds management and governance, and harmonizes regulations and inconsistent industry guidelines. Potential users include enterprises and regulators in the chemical process safety industry and the energy sector. The framework starts the development of more sophisticated standards to prevent catastrophic protective systems failures

    On the Reliability of Meta-Analytic Reviews

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    The article addresses the issue of intercoder reliability in meta-analyses. The current practice of reporting a single, mean intercoder agreement score in meta-analytic research leads to systematic bias and overestimates the true reliability. An alternative approach is recommended in which average intercoder agreement scores or other reliability statistics are calculated within clusters of coded variables. These clusters form a hierarchy in which the correctness of coding decisions at a given level of the hierarchy is contingent on decisions made at higher levels. Two separate studies of intercoder agreement in meta-analysis are presented to assess the validity of the model.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/67840/2/10.1177_0193841X9301700303.pd

    Radiation Therapy Techniques and Treatment-Related Toxicity in the PORTEC-3 Trial:Comparison of 3-Dimensional Conformal Radiation Therapy Versus Intensity-Modulated Radiation Therapy

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    Purpose Radiation therapy techniques have developed from 3-dimensional conformal radiation therapy (3DCRT) to intensity modulated radiation therapy (IMRT), with better sparing of the surrounding normal tissues. The current analysis aimed to investigate whether IMRT, compared to 3DCRT, resulted in fewer adverse events (AEs) and patient-reported symptoms in the randomized PORTEC-3 trial for high-risk endometrial cancer. Methods and Materials Data on AEs and patient-reported quality of life (QoL) of the PORTEC-3 trial were available for analysis. Physician-reported AEs were graded using Common Terminology Criteria for Adverse Events v3.0. QoL was assessed by the European Organisation for Research and Treatment of Cancer QLQC30, CX24, and OV28 questionnaires. Data were compared between 3DCRT and IMRT. A P value of ≤ .01 was considered statistically significant due to the risk of multiple testing. For QoL, combined scores 1 to 2 (“not at all” and “a little”) versus 3 to 4 (“quite a bit” and “very much”) were compared between the techniques. Results Of 658 evaluable patients, 559 received 3DCRT and 99 IMRT. Median follow-up was 74.6 months. During treatment no significant differences were observed, with a trend for more grade ≥3 AEs, mostly hematologic and gastrointestinal, after 3DCRT (37.7% vs 26.3%, P = .03). During follow-up, 15.4% (vs 4%) had grade ≥2 diarrhea, and 26.1% (vs 13.1%) had grade ≥2 hematologic AEs after 3DCRT (vs IMRT) (both P < .01). Among 574 (87%) patients evaluable for QoL, 494 received 3DCRT and 80 IMRT. During treatment, 37.5% (vs 28.6%) reported diarrhea after 3DCRT (vs IMRT) (P = .125); 22.1% (versus 10.0%) bowel urgency (P = 0039), and 18.2% and 8.6% abdominal cramps (P = .058). Other QoL scores showed no differences. Conclusions IMRT resulted in fewer grade ≥3 AEs during treatment and significantly lower rates of grade ≥2 diarrhea and hematologic AEs during follow-up. Trends toward fewer patient-reported bowel urgency and abdominal cramps were observed after IMRT compared to 3DCRT

    Structure of the germline genome of Tetrahymena thermophila and relationship to the massively rearranged somatic genome

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    The germline genome of the binucleated ciliate Tetrahymena thermophila undergoes programmed chromosome breakage and massive DNA elimination to generate the somatic genome. Here, we present a complete sequence assembly of the germline genome and analyze multiple features of its structure and its relationship to the somatic genome, shedding light on the mechanisms of genome rearrangement as well as the evolutionary history of this remarkable germline/soma differentiation. Our results strengthen the notion that a complex, dynamic, and ongoing interplay between mobile DNA elements and the host genome have shaped Tetrahymena chromosome structure, locally and globally. Non-standard outcomes of rearrangement events, including the generation of short-lived somatic chromosomes and excision of DNA interrupting protein-coding regions, may represent novel forms of developmental gene regulation. We also compare Tetrahymenas germline/soma differentiation to that of other characterized ciliates, illustrating the wide diversity of adaptations that have occurred within this phylum.</p

    A framework for human microbiome research

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    A variety of microbial communities and their genes (the microbiome) exist throughout the human body, with fundamental roles in human health and disease. The National Institutes of Health (NIH)-funded Human Microbiome Project Consortium has established a population-scale framework to develop metagenomic protocols, resulting in a broad range of quality-controlled resources and data including standardized methods for creating, processing and interpreting distinct types of high-throughput metagenomic data available to the scientific community. Here we present resources from a population of 242 healthy adults sampled at 15 or 18 body sites up to three times, which have generated 5,177 microbial taxonomic profiles from 16S ribosomal RNA genes and over 3.5 terabases of metagenomic sequence so far. In parallel, approximately 800 reference strains isolated from the human body have been sequenced. Collectively, these data represent the largest resource describing the abundance and variety of the human microbiome, while providing a framework for current and future studies
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