Estimating predictive value of tests without having a Gold Standard: the concept of Etiologic Predictive Value (EPV)

Background: Patients with infectious diseases often require the use of microbiologic diagnostic tests. Predictive value of tests are used to describe the usefulness of a diagnostic test in a specific setting. Sometimes an acceptable Gold standard is lacking making it difficult to evaluate the usefulness of a new diagnostic test. Aims Of Study/project: Describe how predictive value of tests can be calculated despite the absence of an acceptable Gold Standard. Also to describe how to account for asymptomatic carriers. Methods: Mathematical derivation shows that information from a healthy control population can, for most scenarios, be used to calculate predictive value of tests despite the absence of a Gold Standard. Results: Rules for how the usefulness of diagnostic tests can be estimated in the absence of a Gold Standard. The new statistical method considers the influence asymptomatic carriers will have on the diagnostic process. These rules are especially suited for evaluating microbiologic diagnostic tests but can be used also in other scenarios. Conclusions/ Recommendations: The existing Gold Standard should always be challenged when evaluating a new diagnostic test. Etiologic Predictive Value offers an alternative to comparing the new test with a conventional Gold Standard

Examining the uses of shared data

Background
 Many initiatives and repositories exist to encourage the sharing of research data, and thousands of microarray gene expression datasets are publicly available. Many studies reuse this data, but it is not well understood which datasets are reused and for what purpose.

 Materials and Methods
 We trained a machine-learning algorithm to automatically classify full-text gene expression microarray studies into two classes: those that generated original microarray data (n=900) and those which only reused data (n=250). We then compared the Medical Subject Heading (MeSH) terms of two classes to identify MeSH topics which were over- or under-represented by publications with reused data.

 Results
 Studies on humans, mice, chordata, and invertebrates were equally likely to be conducted using original or shared microarray data, whereas shared data was used in a relatively high proportion of studies involving fungi (odds ratio (OR)=2.4), and a relatively low proportion involving rats, bacteria, viruses, plants, or genetically-altered or inbred animals (OR<0.05). Unsurprisingly, when we looked at Major MeSH terms to represent the primary purpose of the studies, statistical and computational methods clearly dominated. The only biomedical topics with a relatively high proportion of data reuse Major MeSH terms were Promoter Regions, Evolution, and Protein Interaction Mapping.

 Discussion
 Identifying areas of particularly successful microarray data reuse—such as Saccharomyces cerevisiae datasets and studies of promoter regions and evolution—can highlight best practices to be used when developing research agendas, tools, standards, repositories, and communities in areas which have yet to receive major benefits from shared data.
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Is Dementia Screening of Apparently Healthy Individuals Justified?

Despite efforts to raise awareness and develop guidelines for care of individuals with dementia, reports of poor detection and inadequate management persist. This has led to a call for more identification of people with dementia, that is, screening individuals who may or may not complain of symptoms of dementia in both acute settings and primary care. The following should be considered before recommending screening for dementia among individuals in the general population. Dementia Tests. Low prevalence reduces positive predictive value of tests and screening tests will miss people who have dementia and identify people who do not have dementia in substantial numbers. Clinical Issues. The clinical course of dementia has not yet been shown to be amenable to intervention. Misdiagnosis and overdiagnosis can have significant long-term effects including stigmatization, loss of employment, and autonomy. Economic Issues. Health systems do not have the capacity to respond to increased demand resulting from screening. In conclusion, at present attention to life-course risk reduction and support in the community for frail and cognitively impaired older adults is a better use of limited healthcare resources than introduction of unevaluated dementia screening programs.Peer Reviewe

The predictive value of early behavioural assessments in pet dogs: a longitudinal study from neonates to adults

Studies on behavioural development in domestic dogs are of relevance for matching puppies with the right families, identifying predispositions for behavioural problems at an early stage, and predicting suitability for service dog work, police or military service. The literature is, however, inconsistent regarding the predictive value of tests performed during the socialisation period. Additionally, some practitioners use tests with neonates to complement later assessments for selecting puppies as working dogs, but these have not been validated. We here present longitudinal data on a cohort of Border collies, followed up from neonate age until adulthood. A neonate test was conducted with 99 Border collie puppies aged 2–10 days to assess activity, vocalisations when isolated and sucking force. At the age of 40–50 days, 134 puppies (including 93 tested as neonates) were tested in a puppy test at their breeders' homes. All dogs were adopted as pet dogs and 50 of them participated in a behavioural test at the age of 1.5 to 2 years with their owners. Linear mixed models found little correspondence between individuals' behaviour in the neonate, puppy and adult test. Exploratory activity was the only behaviour that was significantly correlated between the puppy and the adult test. We conclude that the predictive validity of early tests for predicting specific behavioural traits in adult pet dogs is limited

Searching biomedical databases on complementary medicine: the use of controlled vocabulary among authors, indexers and investigators

BACKGROUND: The optimal retrieval of a literature search in biomedicine depends on the appropriate use of Medical Subject Headings (MeSH), descriptors and keywords among authors and indexers. We hypothesized that authors, investigators and indexers in four biomedical databases are not consistent in their use of terminology in Complementary and Alternative Medicine (CAM). METHODS: Based on a research question addressing the validity of spinal palpation for the diagnosis of neuromuscular dysfunction, we developed four search concepts with their respective controlled vocabulary and key terms. We calculated the frequency of MeSH, descriptors, and keywords used by authors in titles and abstracts in comparison to standard practices in semantic and analytic indexing in MEDLINE, MANTIS, CINAHL, and Web of Science. RESULTS: Multiple searches resulted in the final selection of 38 relevant studies that were indexed at least in one of the four selected databases. Of the four search concepts, validity showed the greatest inconsistency in terminology among authors, indexers and investigators. The use of spinal terms showed the greatest consistency. Of the 22 neuromuscular dysfunction terms provided by the investigators, 11 were not contained in the controlled vocabulary and six were never used by authors or indexers. Most authors did not seem familiar with the controlled vocabulary for validity in the area of neuromuscular dysfunction. Recently, standard glossaries have been developed to assist in the research development of manual medicine. CONCLUSIONS: Searching biomedical databases for CAM is challenging due to inconsistent use of controlled vocabulary and indexing procedures in different databases. A standard terminology should be used by investigators in conducting their search strategies and authors when writing titles, abstracts and submitting keywords for publications

A Correlation Study of the Sixth Grade Verbal School and College Ability Test with Eighth Grade Reading Achievement

It was the purpose of this study to compare the test scores of one group of children who took the verbal ability section of the sixth grade School and College Ability Test (SCAT) with the test scores of the same group of children on the eighth grade reading Sequential Test of Educational Progress (STEP) and to determine the degree of relationship between the tests

Recommendations for a core outcome set for measuring standing balance in adult populations: a consensus-based approach

Standing balance is imperative for mobility and avoiding falls. Use of an excessive number of standing balance measures has limited the synthesis of balance intervention data and hampered consistent clinical practice.To develop recommendations for a core outcome set (COS) of standing balance measures for research and practice among adults.A combination of scoping reviews, literature appraisal, anonymous voting and face-to-face meetings with fourteen invited experts from a range of disciplines with international recognition in balance measurement and falls prevention. Consensus was sought over three rounds using pre-established criteria.The scoping review identified 56 existing standing balance measures validated in adult populations with evidence of use in the past five years, and these were considered for inclusion in the COS.Fifteen measures were excluded after the first round of scoring and a further 36 after round two. Five measures were considered in round three. Two measures reached consensus for recommendation, and the expert panel recommended that at a minimum, either the Berg Balance Scale or Mini Balance Evaluation Systems Test be used when measuring standing balance in adult populations.Inclusion of two measures in the COS may increase the feasibility of potential uptake, but poses challenges for data synthesis. Adoption of the standing balance COS does not constitute a comprehensive balance assessment for any population, and users should include additional validated measures as appropriate.The absence of a gold standard for measuring standing balance has contributed to the proliferation of outcome measures. These recommendations represent an important first step towards greater standardization in the assessment and measurement of this critical skill and will inform clinical research and practice internationally

Executive Functioning and Risk for Alzheimer\u27s Disease in The Cognitively Intact: Family History Predicts Wisconsin Card Sorting Test Performance

Alzheimer’s disease (AD) research typically focuses on memory. However, executive functioning (EF) deficits are also common among AD patients; these deficits are associated with decreased functioning in activities of daily living, an important criterion in diagnosing AD. A classic test of EF ability, the Wisconsin Card Sort Test (WCST), has demonstrated sensitivity to differentiating individuals with AD from healthy controls, discriminating AD groups based on disease severity, and distinguishing AD from other types of dementia. Such sensitivity to AD raises the possibility that the WCST is also sensitive to very early, preclinical differences between those who have heightened risk for AD and those with lower risks. Method: The current study, therefore, examined WCST performance in healthy, cognitively intact older adults with a first-degree (i.e., sibling or parent) family history (FH) of AD (n _ 18) and those with no such FH of AD (n _ 24). Results: Results revealed significant group differences for Categories Achieved, Percent Conceptual Level Responses, Total Errors, Perseverative Errors, and Non-Perseverative Errors, with the FH_ group consistently exhibiting poorer performance. Moreover, hierarchical regression analyses indicated that after accounting for age, sex, and education, FH significantly predicted all 5 of these variables. Conclusions: These results speak to the potential role of EF in bolstering the current understanding of early cognitive markers of future decline. Furthering what is known about the relationship between AD and nonmemory specific domains of cognition such as executive functioning may allow for better prediction of cognitive decline and potential progression to AD