Evidence for longitudinal ambulatory care rotations: a review of the literature.

PURPOSE: Block ambulatory rotations and longitudinal ambulatory care experiences are now common in U.S. medical schools, but little is known about their efficacy. Through a structured review of the medical literature from 1966 through March 2000, the authors summarize the characteristics of, the evidence for, and the evaluation of longitudinal ambulatory care rotations. METHOD: The authors searched Medline using the terms "outpatients," "continuity of patient care," "ambulatory care," "mentors," "preceptorship," "graduate medical education," "curriculum," and "clinical clerkship" cross-matched to "medical students" and "internship and residency" for literature published from 1966 through March 2000. They narrowed the list to only articles containing empirical outcome data focusing on medical students' experiences in longitudinal ambulatory care rotations. Each study was scored to assess its strengths and weaknesses. RESULTS: Seven articles met the search criteria. The articles identified the benefits of longitudinal ambulatory care experiences, including developing effective patient interactions and understanding chronic diseases. There were little or no differences in the students' overall knowledge acquisition when those with longitudinal experiences were compared with those in block rotations. DISCUSSION: Although longitudinal ambulatory care experiences are now common in medical schools, evidence supporting their widespread implementation is sparse. Few studies employ rigorous methods to evaluate educational outcomes. Research to identify benefits and costs, improve the quality and consistency of the students' experiences, and develop other innovative ways of teaching and learning ambulatory care is needed.     

Understanding the accuracy of tests with cutting scores: the sensitivity, specificity, and predictive value model

While researchers usually are concerned about psychometric properties of psychological tests estimated using large samples, most clinical decision-makers must evaluate the accuracy of test results for individuals. This is particularly true as regards tests that have cutting scores to determine, for example, whether to assign a particular diagnosis or accept an applicant into a training program. This paper reviews a conceptual model that may foster improved understanding of test outcomes for individuals. The terms "sensitivity," "specificity," and "predictive value" are defined, and the relations of positive and negative predictive values to population base rates are emphasized. Examples from the psychological literature are presented to illustrate the utility of these concepts in clinical decision-making with psychological tests. Implications for test users, test developers, and instructors are discussed.     

Pearson's Test, Trend Test, and MAX Are All Trend Tests with Different Types of Scores

Pearson's test is one of the most commonly used statistics for testing genetic association of case-control data. The trend test is another one which assumes a dose-response model between the risk of the disease and genotypes. To apply the trend test, a set of ordered scores is assigned a priori based on the underlying genetic model. Pearson's test is model-free and robust, but is less powerful for common genetic models. MAX is another robust test statistic, which takes the maximum of the trend tests over a family of scientifically plausible genetic models. We show that the three test statistics are all trend tests but with different types of scores; whether the scores are prespecified or data-driven, or whether the scores are ordered (restricted) or not ordered (unrestricted). We then provide insights into power performance of the three tests when the underlying genetic model is unknown and discuss which test to use for the analyses of case-control genetic association studies.     

Chance guessing in a forced-choice recognition task and the detection of malingering

Guessing occurs on forced-choice (FC) tests for which responses cannot be based on relevant knowledge. Its importance is in inverse relation to the level of knowledge being measured, so that it becomes an increasing component of test scores as the level of knowledge decreases. It is also used as a benchmark to detect simulated impairment. This investigation examined the role of guessing in a 2-alternative FC face recognition test. Chance groups shown only the test items were asked to guess which were the targets, to measure the variation in scores likely to be found with pure guessing. Controls performed normally, and two simulation groups tried to fake amnesia. Results suggested that simple guessing in the chance group produced variable scores that overlapped both low genuine and "malingering" performance. Low control scores were hidden by the guessing "chance bonus," which ameliorated the apparent level of decline in memory. Simulators told of their role at the outset (before presentation of the target items) produced more convincing "amnesic" scores than those told only just before the test, who produced the expected below-chance level of score. It is suggested that guessing variability should be taken into account in interpreting FC scores.     

Personality profiles of the morbidly obese

Personality characteristics of 150 morbidly obese patients (100 pounds or more over ideal weight) were investigated. The patients were given the Minnesota Multiphasic Personality Inventory (MMPI) and a new, self-report personality disorder inventory. The study attempted to determine whether particular personality variables could predict success or failure at weight loss six months post-surgery. Multivariate analyses of variance revealed no significant differences on any of the personality variables when the patients were divided into "good," "fair," and "poor" success categories. Rank order MMPI scale profiles and personality disorder profiles are presented and implications discussed.     

SVSI: Fast and Powerful Set‐Valued System Identification Approach to Identifying Rare Variants in Sequencing Studies for Ordered Categorical Traits

In genetic association studies of an ordered categorical phenotype, it is usual to either regroup multiple categories of the phenotype into two categories and then apply the logistic regression (LG) , or apply ordered logistic (oLG) , or ordered probit (oPRB) regression, which accounts for the ordinal nature of the phenotype. However, they may lose statistical power or may not control type I error due to their model assumption and/or instable parameter estimation algorithm when the genetic variant is rare or sample size is limited. To solve this problem, we propose a set‐valued (SV) system model to identify genetic variants associated with an ordinal categorical phenotype. We couple this model with a SV system identification algorithm to identify all the key system parameters. Simulations and two real data analyses show that SV and LG accurately controlled the Type I error rate even at a significance level of 10^?6 but not oLG and oPRB in some cases. LG had significantly less power than the other three methods due to disregarding of the ordinal nature of the phenotype, and SV had similar or greater power than oLG and oPRB . We argue that SV should be employed in genetic association studies for ordered categorical phenotype.     

液晶复合膜的表面形貌特征及其血液相容性研究

目的:模仿生物膜的表面结构形态,制备液晶/聚氨酯复合膜,作为抗凝血生物材料;材料和方法:将胆甾醇液晶引入到聚合物中,制成液晶复合材料,利用偏光显微镜观察复合材料的表面形貌特征,并通过溶血率测试,动态凝血试验及血小板粘附试验探究液晶/PU复合膜的血液相溶性;结果:在聚合物基材中加入亲水性的胆甾醇液晶可使复合材料表面呈现有液晶微区的有序结构特征,复合膜表面的抗凝血性能提高;结论:胆甾醇液晶能明显改善材料的血液相容性,改善的程度与液晶的组成及复合膜中液晶的含量相关.     

Interpersonal style differences among drug abusers

Interpersonal style differences among drug abusers were explored using Ryan's (1977) typological system of FIRO-B interpretation. One hundred eleven male veteran drug abusers were administered the FIRO-B, along with a battery of psychological tests and a structured interview. The drug abusers were more likely to be categorized as "loners," "rebels," and "pessimists" than was the general population sample. The categories within each FIRO-B dimension (inclusion, control, and affection) were collapsed into three larger subtypes based on general patterns of "expressed" and "wanted" scores within each dimension. The construct validity of the Ryan schema was tested by comparing the three larger groups for each dimension on a series of preselected variables for which differences would be hypothesized from FIRO theory. The results of these analyses were consistent with Ryan's (1977) and Schutz's (1978) theories about interpersonal orientation. The findings of the study provide information about the commonality and heterogeneity of interpersonal style among drug abusers. The findings also support the construct validity of Ryan's typological schema for the FIRO-B.     

Guidelines for cognitively efficient multimedia learning tools: educational strategies, cognitive load, and interface design.

The field of medical education has consistently embraced new technologies in an attempt to improve the training process of our nation's doctors. There are thousands of available multimedia learning tools (MMLTs), but no quantitative scale exists to assess their efficiency and overall educational value. The authors review existing literature and suggest guidelines for creating cognitively efficient medical MMLTs. In 2004, the authors searched PubMed to identify articles regarding mutimedia learning, including educational strategies and existing MMLTs. The primary search terms included "multimedia learning," "cognitive load," and "surgical education." The resulting articles were evaluated and reviewed for educational and interface design techniques, and a list of common features was generated. The authors cross-referenced these features with extensive theories of cognitive load to create a list of methods that demonstrated improved learning. Techniques common to existing MMLTs often neglect to account for theories of cognitive load and may be detrimental to the learning process. The authors outlined important educational considerations and guidelines for the design of effective MMLTs. With large resources being spent to produce MMLTs, more research is necessary to establish successful design techniques. The authors summarized existing research, outlined educational issues in multimedia design, and proposed future directions for study.     

When do medical students become human subjects of research? The case of program evaluation.

Intense national dialogue exists around federal requirements protecting the rights of human subjects in clinical research. There is much less discussion surrounding protections for human subjects in such areas as evaluation research when the subjects are also students. Differential interpretation of 45 CFR 46 (the standing regulation on research involving human subjects) by institutional review boards (IRBs) leaves many confused about whether research using student data requires IRB review. At the heart of the uncertainty are "dual purpose activities," for example, when student data from program evaluation or routine assessments subsequently become the basis for faculty scholarship that is disseminated as "generalizable knowledge" to the community of medical educators. The authors identify two factors that should be considered as institutions develop applications and interpretations of 45 CFR 46. First, medical educators should enter into dialogues with their IRBs to become more familiar with these regulations and their application in evaluation or assessment studies. Second, for reasons of professionalism, faculty should seek opportunities to model in their role as researchers those ethical behaviors that are central to an honest relationship between physician and patient. In the educational context this means faculty disclosure of how student data may be used by faculty in their own scholarship and determination of when student consent is needed. The authors also describe how one medical school addressed this thorny challenge with assistance from the university IRB and offer suggestions to improve institutional procedures.     

"Is Cybermedicine Killing You?"--The story of a Cochrane disaster

This editorial briefly reviews the series of unfortunate events that led to the publication, dissemination, and eventual retraction of a flawed Cochrane systematic review on interactive health communication applications (IHCAs), which was widely reported in the media with headlines such as "Internet Makes Us Sick," "Knowledge May Be Hazardous to Web Consumers' Health," "Too Much Advice Can Be Bad for Your Health," "Click to Get Sick?," and even "Is Cybermedicine Killing You?". While the media attention helped to speed up the identification of errors, leading to a retraction of the review after only 13 days, a paper published in this issue of JMIR by Rada shows that the retraction, in contrast to the original review, remained largely unnoticed by the public. We discuss the three flaws of the review, which include (1) data extraction and coding errors, (2) the pooling of heterogeneous studies, and (3) a problematic and ambiguous scope and, possibly, some overlooked studies. We then discuss "retraction ethics" for researchers, editors/publishers, and journalists. Researchers and editors should, in the case of retractions, match the aggressiveness of the original dissemination campaign if errors are detected. It is argued that researchers and their organizations may have an ethical obligation to track down journalists who reported stories on the basis of a flawed study and to specifically ask them to publish an article indicating the error. Journalists should respond to errors or retractions with reports that have the same prominence as the original story. Finally, we look at some of the lessons for the Cochrane Collaboration, which include (1) improving the peer-review system by routinely sending out pre-prints to authors of the original studies, (2) avoiding downplay of the magnitude of errors if they occur, (3) addressing the usability issues of RevMan, and (4) making critical articles such as retraction notices open access.     

Methods of measuring asthma severity and influence on patient assignment.

BACKGROUND: There is a need for nonclinical measures in studies where objective clinical data used to determine asthma severity, such as spirometry and peak expiratory flow rate meter readings, are not available. OBJECTIVE: To determine whether different methods of defining asthma severity provide different distributions of patients across the categories of mild, moderate, and severe asthma. METHODS: Data were obtained from a mail survey and the database of a managed care organization located in Michigan. Seven methods of asthma severity that used either patient self-report or claims data were evaluated and divided into 3 categories: patient-perceived severity (1 method), symptom-derived severity (4 methods), and medication-derived severity (2 methods). To further evaluate the extent of the degree of agreement among the 7 severity methods, percent agreement and Cohen K scores were calculated. RESULTS: Surveys were sent to 1,139 persons, and 603 responses were usable. Substantial differences exist in the number of patients in each severity level for different methods of determining asthma severity. The proportion of persons identified as having mild, moderate, and severe asthma ranged from 48% to 82%, 16% to 38%, and 2% to 33%, respectively. The percent agreement and Cohen kappa scores were generally low among the 7 methods. CONCLUSIONS: Due to variations caused by the method of measuring asthma severity, comparability among studies using different methods of classifying asthma severity is limited. Although a uniform evaluation of asthma severity is needed, the results of this study do not identify one preferable method. Rather, investigators should know the limitations of the methods used.     

CLEAR-test: combining inference for differential expression and variability in microarray data analysis

A common goal of microarray experiments is to detect genes that are differentially expressed under distinct experimental conditions. Several statistical tests have been proposed to determine whether the observed changes in gene expression are significant. The t-test assigns a score to each gene on the basis of changes in its expression relative to its estimated variability, in such a way that genes with a higher score (in absolute values) are more likely to be significant. Most variants of the t-test use the complete set of genes to influence the variance estimate for each single gene. However, no inference is made in terms of the variability itself. Here, we highlight the problem of low observed variances in the t-test, when genes with relatively small changes are declared differentially expressed. Alternatively, the z-test could be used although, unlike the t-test, it can declare differentially expressed genes with high observed variances. To overcome this, we propose to combine the z-test, which focuses on large changes, with a chi(2) test to evaluate variability. We call this procedure CLEAR-test and we provide a combined p-value that offers a compromise between both aspects. Analysis of three publicly available microarray datasets reveals the greater performance of the CLEAR-test relative to the t-test and alternative methods. Finally, empirical and simulated data analyses demonstrate the greater reproducibility and statistical power of the CLEAR-test and z-test with respect to current alternative methods. In addition, the CLEAR-test improves the z-test by capturing reproducible genes with high variability.     

Carcinoma of the anal canal: a study of 79 cases

Seventy-nine cases of carcinoma of the anal canal treated initially by surgery and having a minimum follow-up of five years were reviewed. It was found that all of the tumors were basically squamous cell carcinomas. They were divided into five histologic categories: keratinizing squamous cell carcinoma (52 cases), nonkeratinizing squamous cell carcinoma (6 cases), basaloid squamous cell carcinoma (11 cases), squamous cell carcinoma with mucous microcysts (6 cases), and pseudoadenoid cystic squamous cell carcinoma (4 cases). There was considerable overlap among the categories. The neoplasms also were stratified according to depth of invasion: 4 into submucosa only, 30 into smooth muscle of the anal sphincter, and 45 into perianal tissue. There were no significant differences in survival among the histologic categories but marked differences relating to depth of invasion: none of the 4 patients with submucosal invasion died of tumor, whereas 8 of the 30 with smooth muscle invasion and 35 of the 45 with perianal tissue invasion did so. The histologic categories also did not differ significantly in regard to the rates of lymph node metastasis (either at the time of initial surgery or later) or local recurrence; however, the rate of distant metastasis was higher in pseudoadenoid cystic squamous cell carcinoma (three of four cases) than in the other categories (11 of 75 cases combined). Based on our pathologic and clinical findings, we believe that there is no entity "cloacogenic carcinoma," "transitional cell carcinoma," "basaloid carcinoma," or "mucoepidermoid carcinoma" in the anal canal separable from squamous cell carcinoma, and we therefore suggest that these terms be dropped (or restricted to appropriate tumors in other locations). Pseudoadenoid cystic squamous cell carcinoma was the most distinctive of our histologic categories and is deserving of further study.     

Benefits of off-campus education for students in the health sciences: a text-mining analysis

ABSTRACT: BACKGROUND: In Japan, few community-based approaches have been adopted in health-care professional education, and the appropriate content for such approaches has not been clarified. In establishing community-based education for health-care professionals, clarification of its learning effects is required. A community-based educational program was started in 2009 in the health sciences course at Gunma University, and one of the main elements in this program is conducting classes outside school. The purpose of this study was to investigate using text-analysis methods how the off-campus program affects students. METHODS: In all, 116 self-assessment worksheets submitted by students after participating in the off-campus classes were decomposed into words. The extracted words were carefully selected from the perspective of contained meaning or content. With the selected terms, the relations to each word were analyzed by means of cluster analysis. RESULTS: Cluster analysis was used to select and divide 32 extracted words into four clusters: cluster 1---"actually/direct," "learn/watch/hear," "how," "experience/participation," "local residents," "atmosphere in community-based clinical care settings," "favorable," "communication/conversation," and "study"; cluster 2---"work of staff member" and "role"; cluster 3---"interaction/communication," "understanding," "feel," "significant/important/necessity," and "think"; and cluster 4---"community," "confusing," "enjoyable," "proactive," "knowledge," "academic knowledge," and "class." CONCLUSIONS: The students who participated in the program achieved different types of learning through the off-campus classes. They also had a positive impression of the community-based experience and interaction with the local residents, which is considered a favorable outcome. Off-campus programs could be a useful educational approach for students in health sciences.     

Genetic classification of "Rickettsia heilongjiangii" and "Rickettsia hulinii," two Chinese spotted fever group rickettsiae

To determine the phylogenetic position of two new rickettsial strains isolated from ticks in China, 16S ribosomal DNA, gltA, and ompA (apart from the tandem repeat units) genes were amplified by PCR and sequenced. The phylogenetic relationships between these strains and other rickettsiae were inferred from the comparison of sequences of the three genes by the parsimony, neighbor-joining, and maximum-likelihood methods. The results demonstrated that the 054 strain, a rickettsia pathogenic in humans, and the HL-93 strain were related and clustered together with Rickettsia japonica. Significant statistical bootstrap values (100 and 92%) supported the nodes in this cluster. Based on previous genotypic and antigenic data and the phylogenetic analysis presented here, the 054 and HL-93 strains should be considered as new species, and we formally propose that they be named "Rickettsia heilongjiangii" and "Rickettsia hulinii," respectively.     

A pilot study assessing the influences of charge data and group process on diagnostic test ordering by residents.

PURPOSE: Providing charge data to resident physicians has been shown to reduce the amounts spent on diagnostic testing. This pilot study sought to determine the influences of charge data and group decision making on diagnostic test ordering by internal medicine residents. METHOD: In an interactive workshop, 23 internal medicine residents received a hypothetical case. They completed an 18-item questionnaire estimating charges for diagnostic tests and then "ordered" tests. The residents were then randomly divided into groups that either received charge data, received charge data after ordering tests, or received no charge data. The groups ordered tests by consensus. Tests were weighted for appropriateness (+1 to +6) and inappropriateness (-1 to -6). Analyses compared individual and group decisions and effect of availability of charge data. RESULTS: Residents with access to charge data spent less on tests, but also had lower appropriateness scores. The appropriateness of the diagnostic workup was better by groups than by individuals, but cost more. CONCLUSION: Cost-containment interventions targeted towards doctors in training need to address the effect on quality of care and the influence of the group process in clinical decision making. Group diagnostic decisions may be more costly, but more appropriate.     

Using "concept sorting" to study learning processes and outcomes.

PURPOSE: First, to evaluate "concept sorting" as a tool for assessing knowledge organization in the memories of first-year medical students, and second, to study the relationship between knowledge organization and examination performance. METHOD: During 2001, first-year medical students taking the Renal Course at the University of Calgary Faculty of Medicine were given a questionnaire on scheme use and were given a concept-sorting task in the domain of metabolic alkalosis. The sophistication of their concept sorting was graded using the number of physiology-based groups they formed. Review of the course's examination scores allowed correlation with concept-sorting scores. Statistical analyses used Fisher's exact test and the two-sample t-test. Pearson's correlation coefficient and the kappa statistic were used for correlation between raters. RESULTS: A total of 81 of 99 students completed the study. The concept-sorting score (mean +/- SEM) for students who used the scheme was higher than was the score for students who did not (2.5 +/- 0.14 versus 1.91 +/- 0.12, p =.016). Students who scored higher in the concept-sorting task, referred to as "deep learners," scored higher than did "surface learners" on exam questions on metabolic alkalosis (2.81 versus 2.29, p =.02). There was no difference in the overall examination performances between the two groups. CONCLUSIONS: Concept sorting may be a useful tool for studying the learning process. Scheme use by students produces a positive outcome on examination performance.     

The application of special technologies in diagnostic anatomic pathology: is it consistent with the principles of evidence-based medicine?

Proponents of evidence-based medicine (EBM) have emphasized the need to consider the quality of different sources of medical information and have proposed various methods to integrate available "best evidence" into rules, guidelines and other diagnostic, therapeutic and prognostic models. The various factors that can affect the internal validity of studies in anatomic pathology, such as interobserver variability, use of retrospective rather than prospective data and others, are reviewed. The need for testing for the external validity of the results of anatomic pathology studies is introduced, using "test sets" of cases that have not been used to generate the classification or prognostic models. This methodology has been seldom used in anatomic pathology to validate the generalizability of various "entities," usefulness of diagnostic tests under different conditions and other information. Basic concepts of meta-analysis for research synthesis are introduced; these methods have been seldom used in anatomic pathology to integrate information from different studies using quantitative techniques rather than summary tables that merely list the results of various publications. The potential use of decision analysis and value of information analysis for the adoption of new tests is briefly discussed.