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The Lancet. Infectious Diseases Mar 2014The aim of diagnostic point-of-care testing is to minimise the time to obtain a test result, thereby allowing clinicians and patients to make a quick clinical decision.... (Review)
Review
The aim of diagnostic point-of-care testing is to minimise the time to obtain a test result, thereby allowing clinicians and patients to make a quick clinical decision. Because point-of-care tests are used in resource-limited settings, the benefits need to outweigh the costs. To optimise point-of-care testing in resource-limited settings, diagnostic tests need rigorous assessments focused on relevant clinical outcomes and operational costs, which differ from assessments of conventional diagnostic tests. We reviewed published studies on point-of-care testing in resource-limited settings, and found no clearly defined metric for the clinical usefulness of point-of-care testing. Therefore, we propose a framework for the assessment of point-of-care tests, and suggest and define the term test efficacy to describe the ability of a diagnostic test to support a clinical decision within its operational context. We also propose revised criteria for an ideal diagnostic point-of-care test in resource-limited settings. Through systematic assessments, comparisons between centralised testing and novel point-of-care technologies can be more formalised, and health officials can better establish which point-of-care technologies represent valuable additions to their clinical programmes.
Topics: Diagnostic Tests, Routine; Health Resources; Humans; Point-of-Care Systems
PubMed: 24332389
DOI: 10.1016/S1473-3099(13)70250-0 -
The British Journal of General Practice... Feb 2017
Topics: Decision Making; Diagnostic Tests, Routine; General Practice; General Practitioners; Humans
PubMed: 28126866
DOI: 10.3399/bjgp17X689161 -
Health Technology Assessment... Jun 2006To determine the most effective diagnostic strategy for the investigation of microscopic and macroscopic haematuria in adults. (Review)
Review
OBJECTIVES
To determine the most effective diagnostic strategy for the investigation of microscopic and macroscopic haematuria in adults.
DATA SOURCES
Electronic databases from inception to October 2003, updated in August 2004.
REVIEW METHODS
A systematic review was undertaken according to published guidelines. Decision analytic modelling was undertaken, based on the findings of the review, expert opinion and additional information from the literature, to assess the relative cost-effectiveness of plausible alternative tests that are part of diagnostic algorithms for haematuria.
RESULTS
A total of 118 studies met the inclusion criteria. No studies that evaluated the effectiveness of diagnostic algorithms for haematuria or the effectiveness of screening for haematuria or investigating its underlying cause were identified. Eighteen out of 19 identified studies evaluated dipstick tests and data from these suggested that these are moderately useful in establishing the presence of, but cannot be used to rule out, haematuria. Six studies using haematuria as a test for the presence of a disease indicated that the detection of microhaematuria cannot alone be considered a useful test either to rule in or rule out the presence of a significant underlying pathology (urinary calculi or bladder cancer). Forty-eight of 80 studies addressed methods to localise the source of bleeding (renal or lower urinary tract). The methods and thresholds described in these studies varied greatly, precluding any estimate of a 'best performance' threshold that could be applied across patient groups. However, studies of red blood cell morphology that used a cut-off value of 80% dysmorphic cells for glomerular disease reported consistently high specificities (potentially useful in ruling in a renal cause for haematuria). The reported sensitivities were generally low. Twenty-eight studies included data on the accuracy of laboratory tests (tumour markers, cytology) for the diagnosis of bladder cancer. The majority of tumour marker studies evaluated nuclear matrix protein 22 or bladder tumour antigen. The sensitivity and specificity ranges suggested that neither of these would be useful either for diagnosing bladder cancer or for ruling out patients for further investigation (cystoscopy). However, the evidence remains sparse and the diagnostic accuracy estimates varied widely between studies. Fifteen studies evaluating urine cytology as a test for urinary tract malignancies were heterogeneous and poorly reported. The calculated specificity values were generally high, suggesting some possible utility in confirming malignancy. However, the evidence suggests that urine cytology has no application in ruling out malignancy or excluding patients from further investigation. Fifteen studies evaluated imaging techniques [computed tomography (CT), intravenous urography (IVU) or ultrasound scanning (US)] to detect the underlying cause of haematuria. The target condition and the reference standard varied greatly between these studies. The diagnostic accuracy data for several individual studies appeared promising but meaningful comparison of the available imaging technologies was impossible. Eight studies met the inclusion criteria but addressed different parts of the diagnostic chain (e.g. screening programmes, laboratory investigations, full urological work-up). No single study addressed the complete diagnostic process. The review also highlighted a number of methodological limitations of these studies, including their lack of generalisability to the UK context. Separate decision analytic models were therefore developed to progress estimation of the optimal strategy for the diagnostic management of haematuria. The economic model for the detection of microhaematuria found that immediate microscopy following a positive dipstick test would improve diagnostic efficiency as it eliminates the high number of false positives produced by dipstick testing. Strategies that use routine microscopy may be associated with high numbers of false results, but evidence was lacking regarding the accuracy of routine microscopy and estimates were adopted for the model. The model for imaging the upper urinary tract showed that US detects more tumours than IVU at one-third of the cost, and is also associated with fewer false results. For any cause of haematuria, CT was shown to have a mean incremental cost-effectiveness ratio of pounds sterling 9939 in comparison with the next best option, US. When US is followed up with CT for negative results with persistent haematuria, it dominates the initial use of CT alone, with a saving of pounds sterling 235,000 for the evaluation of 1000 patients. The model for investigation of the lower urinary tract showed that for low-risk patients the use of immediate cystoscopy could be avoided if cystoscopy were used for follow-up patients with a negative initial test using tumour markers and/or cytology, resulting in a saving of pounds sterling 483,000 for the evaluation of 1000 patients. The clinical and economic impact on delayed detection of both upper and lower urinary tract tumours through the use of follow-up testing should be evaluated in future studies.
CONCLUSIONS
There are insufficient data currently available to derive an evidence-based algorithm of the diagnostic pathway for haematuria. A hypothetical algorithm based on the opinion and practice of clinical experts in the review team, other published algorithms and the results of economic modelling is presented in this report. This algorithm is presented, for comparative purposes, alongside current US and UK guidelines. The ideas contained in these algorithms and the specific questions outlined should form the basis of future research. Quality assessment of the diagnostic accuracy studies included in this review highlighted several areas of deficiency.
Topics: Algorithms; Cost-Benefit Analysis; Diagnostic Tests, Routine; Hematuria; Humans; State Medicine; United Kingdom
PubMed: 16729917
DOI: 10.3310/hta10180 -
Tidsskrift For Den Norske Laegeforening... Oct 2018
Topics: Area Under Curve; Diagnostic Tests, Routine; Humans; ROC Curve; Reference Standards
PubMed: 30277050
DOI: 10.4045/tidsskr.18.0542 -
Journal of Clinical Microbiology Dec 2017Dengue detection strategies involve viral RNA, antigen, and/or antibody detection. Each strategy has its advantages and disadvantages. Optimal, user-friendly, rapid... (Review)
Review
Dengue detection strategies involve viral RNA, antigen, and/or antibody detection. Each strategy has its advantages and disadvantages. Optimal, user-friendly, rapid diagnostic tests based on immunochromatographic assays are pragmatic point-of-care tests (POCTs) in regions where dengue is endemic where there are limited laboratory capabilities and optimal storage conditions. Increasingly, there is a greater public health significance for a multiplexing assay that differentiates dengue from Zika or pathogens with similar clinical presentations. Although there have been many assay/platform developments toward POCTs, independent validation and implementation remain very limited. This review highlights the current key progress and challenges toward the development of a dengue POCT.
Topics: Dengue; Diagnostic Tests, Routine; Humans; Point-of-Care Systems
PubMed: 28904181
DOI: 10.1128/JCM.00707-17 -
Journal of Clinical Epidemiology Jan 2021New diagnostic tests to identify a well-established disease state must undergo a series of scientific studies from test construction to finally demonstrating a societal...
BACKGROUND AND OBJECTIVE
New diagnostic tests to identify a well-established disease state must undergo a series of scientific studies from test construction to finally demonstrating a societal impact. Traditionally, these studies are performed with substantial time gaps in between, resulting in a long time period from the initial idea to roll out in clinical practice including reimbursement. Seamless designs allowing us to combine a sequence of studies in one protocol may hence accelerate this process. Currently, a systematic investigation of the potential of seamless designs in diagnostic research is lacking.
METHODS
We identify major study types in diagnostic research and their basic characteristics with respect to the application of seamless designs. This information is used to identify major hurdles and opportunities for seamless designs.
RESULTS
The following major study types were identified: Variable construction studies, cut point finding studies, variable value studies, single-arm accuracy studies, comparative accuracy studies, change-in-management studies, observational discordant pair studies, randomized discordant pair studies, and randomized diagnostic studies. The following characteristics were identified: Type of recruitment (case-control vs. population-based), application of a reference standard, inclusion of a comparator, paired or unpaired application of a comparator, assessment of patient-relevant outcomes, and possibility for blinding of test results. Two basic hurdles could be identified: 1) Accuracy studies are hard to combine with postaccuracy studies in a seamless design for the following reasons. First, because the former are required to justify the latter and application of a reference test in outcome studies may be a threat to the integrity of the study. 2) Randomized diagnostic studies are probably best placed as singular studies at the end of the process, as all other questions should be clarified before performing such a study. However, otherwise there is a substantial potential for seamless designs. All steps from the construction to the comparison with the comparator can be combined in one protocol. This may include a switch from case-control to population-based recruitment as well as a switch from a single-arm study to a comparative accuracy study. In addition, change-in-management studies can be combined with an outcome study in discordant pairs.
CONCLUSION
There is a potential for seamless designs in diagnostic research. It is wise to have the whole sequence of necessary studies in mind and to plan a full programme than rather individual studies one by one.
Topics: Comparative Effectiveness Research; Data Accuracy; Diagnostic Tests, Routine; Humans; Patient Selection; Randomized Controlled Trials as Topic; Reference Standards; Research Design; Treatment Outcome
PubMed: 32991994
DOI: 10.1016/j.jclinepi.2020.09.019 -
Clinical Microbiology and Infection :... Feb 2014Systematic reviews of diagnostic test accuracy summarize the accuracy, e.g. the sensitivity and specificity, of diagnostic tests in a systematic and transparent way. The... (Meta-Analysis)
Meta-Analysis Review
Systematic reviews of diagnostic test accuracy summarize the accuracy, e.g. the sensitivity and specificity, of diagnostic tests in a systematic and transparent way. The aim of such a review is to investigate whether a test is sufficiently specific or sensitive to fit its role in practice, to compare the accuracy of two or more diagnostic tests, or to investigate where existing variation in results comes from. The search strategy should be broad and preferably fully reported, to enable readers to assess the completeness of it. Included studies usually have a cross-sectional design in which the tests of interest, ideally both the index test and its comparator, are evaluated against the reference standard. They should be a reflection of the situation that the review question refers to. The quality of included studies is assessed with the Quality Assessment of Diagnostic Accuracy Studies-2 checklist, containing items such as a consecutive and all-inclusive patient selection process, blinding of index test and reference standard assessment, a valid reference standard, and complete verification of all included participants. Studies recruiting cases separately from (healthy) controls are regarded as bearing a high risk of bias. For meta-analysis, the bivariate model or the hierarchical summary receiver operating characteristic model is used. These models take into account potential threshold effects and the correlation between sensitivity and specificity. They also allow addition of covariates for investigatation of potential sources of heterogeneity. Finally, the results from the meta-analyses should be explained and interpreted for the reader, to be well understood.
Topics: Communicable Diseases; Diagnostic Tests, Routine; Humans; Meta-Analysis as Topic; Reference Standards; Review Literature as Topic; Sensitivity and Specificity
PubMed: 24274632
DOI: 10.1111/1469-0691.12474 -
Theranostics 2016DNA methyltransferases (MTases), a family of enzymes that catalyse the methylation of DNA, have a profound effect on gene regulation. A large body of evidence has... (Review)
Review
DNA methyltransferases (MTases), a family of enzymes that catalyse the methylation of DNA, have a profound effect on gene regulation. A large body of evidence has indicated that DNA MTase is potentially a predictive biomarker closely associated with genetic disorders and genetic diseases like cancer. Given the attention bestowed onto DNA MTases in molecular biology and medicine, highly sensitive detection of DNA MTase activity is essential in determining gene regulation, epigenetic modification, clinical diagnosis and therapeutics. Conventional techniques such as isotope labelling are effective, but they often require laborious sample preparation, isotope labelling, sophisticated equipment and large amounts of DNA, rendering them unsuitable for uses at point-of-care. Simple, portable, highly sensitive and low-cost assays are urgently needed for DNA MTase activity screening. In most recent technological advances, many alternative DNA MTase activity assays such as fluorescent, electrochemical, colorimetric and chemiluminescent assays have been proposed. In addition, many of them are coupled with nanomaterials and/or enzymes to significantly enhance their sensitivity. Herein we review the progress in the development of DNA MTase activity assays with an emphasis on assay mechanism and performance with some discussion on challenges and perspectives. It is hoped that this article will provide a broad coverage of DNA MTase activity assays and their latest developments and open new perspectives toward the development of DNA MTase activity assays with much improved performance for uses in molecular biology and clinical practice.
Topics: DNA; DNA Modification Methylases; Diagnostic Tests, Routine; Humans; Molecular Biology
PubMed: 26909112
DOI: 10.7150/thno.13438 -
Clinical Gastroenterology and... Nov 2018The widespread adoption of high-resolution manometry (HRM) has led to a restructuring in the classification of esophageal motility disorder classification summarized in... (Review)
Review
The widespread adoption of high-resolution manometry (HRM) has led to a restructuring in the classification of esophageal motility disorder classification summarized in the Chicago Classification, currently in version 3.0. It has become apparent that the cardinal feature of achalasia, impaired lower esophageal sphincter relaxation, can occur in several disease phenotypes: without peristalsis, with premature (spastic) distal esophageal contractions, with panesophageal pressurization, or even with preserved peristalsis. Furthermore, despite these advances in diagnostics, no single manometric pattern is perfectly sensitive or specific for idiopathic achalasia and complimentary assessments with provocative maneuvers during HRM or interrogating the esophagogastric junction with the functional luminal imaging probe during endoscopy can be useful in clarifying equivocal or inexplicable HRM findings. Using these tools, we have come to conceptualize esophageal motility disorders as characterized by obstructive physiology at the esophagogastric junction, smooth muscle esophagus, or both. Recognizing obstructive physiology as a primary target of therapy has become particularly relevant with the development of a minimally invasive technique for performing a calibrated myotomy of the esophageal circular muscle, the POEM procedure. Now and going forward, optimal management is to render treatment in a phenotype-specific manner: e.g. POEM calibrated to patient-specific physiology for spastic achalasia and spastic disorders of the smooth muscle esophagus, more conservative strategies (pneumatic dilation) for the disorders limited to the sphincter.
Topics: Diagnostic Tests, Routine; Disease Management; Esophageal Motility Disorders; Esophagoscopy; Gastroenterology; Humans; Manometry
PubMed: 29702296
DOI: 10.1016/j.cgh.2018.04.026 -
Patient Education and Counseling Jan 2012This review is a narrative synthesis of the RCTs which studied the efficacy of using diagnostic tests to reassure patients. (Review)
Review
OBJECTIVE
This review is a narrative synthesis of the RCTs which studied the efficacy of using diagnostic tests to reassure patients.
METHODS
We searched for RCTs that examined the level of reassurance after diagnostic testing in outpatients. We used PubMed, Psychinfo, Cochrane Central, Ongoing Trials Database and Scopus.
RESULTS
We found 5 randomized controlled trials that included 1544 patients. The trials used different diagnostic tests (ECG, radiography of lumbar spine, MR brain scan, laboratory tests, MR of lumbar spine) for different complaints (e.g. chest pain, low back pain and headache). Four out of 5 RCTs did not find a significant reassuring value of the diagnostic tests. One study reported a reassuring effect at 3 months which had disappeared after one year.
CONCLUSION
Despite the sparse and heterogeneous studies, the results point in the direction of diagnostic tests making hardly any contribution to the level of reassurance. We recommend further studies on the use of diagnostic tests and other strategies to reassure the patient.
PRACTICE IMPLICATIONS
A clear explanation and watchful waiting can make additional diagnostic testing unnecessary. If diagnostic tests are used, it is important to provide adequate pre-test information about normal test results.
Topics: Chest Pain; Communication; Diagnostic Tests, Routine; Fear; Headache; Humans; Low Back Pain; Patient Education as Topic; Patient Satisfaction; Physician-Patient Relations; Watchful Waiting
PubMed: 21382687
DOI: 10.1016/j.pec.2011.02.003