Chapter 7: grading a body of evidence on diagnostic tests

Cincinnati Prehospital Stroke Scale (CPSS) as a Screening Tool for Early Identification of Cerebral Large Vessel Occlusions; a Systematic Review and Meta-analysis

Introduction

Large vessel occlusion (LVO) strokes are associated with worse functional outcomes and higher mortality rates. In the present systematic review and meta-analysis, we evaluated the diagnostic yield of the Cincinnati Prehospital Stroke Scale (CPSS) in detecting LVO.

Methods

We performed an extensive systematic search among online databases including Medline, Embase, Web of Science, and Scopus, until July 31st, 2023. We also conducted a manual search on Google and Google scholar, along with citation tracking to supplement the systematic search in retrieving all studies that evaluated the diagnostic accuracy of the CPSS in detecting LVO among patients suspected to stroke.

Results

Fourteen studies were included in the present meta-analysis. CPSS showed the sensitivity of 97% (95% CI: 87%-99%) and the specificity of 17% (95% CI: 4%-54%) at the cut-off point of ≥1. The optimal threshold was determined to be ≥2, with a sensitivity of 82% (95% CI: 74%-88%) and specificity of 62% (95% CI: 48%-74%) in detecting LVO. At the highest cut-off point of ≥3, the CPSS had the lowest sensitivity of 60% (95% CI: 51%-69%) and the highest specificity of 81% (95% CI: 71%-88%). Sensitivity analyses showed the robustness of the results regardless of study population, inclusion of hemorrhagic stroke patients, pre-hospital or in-hospital settings, and the definition of LVO.

Conclusion

A very low level of evidence demonstrated that CPSS, with a threshold set at ≥2, is a useful tool for identifying LVO stroke and directing patients to CSCs, both in prehospital and in-hospital settings.

Prediction and diagnosis of chronic kidney disease development and progression using machine-learning: Protocol for a systematic review and meta-analysis of reporting standards and model performance

Chronic Kidney disease (CKD) is an important yet under-recognized contributor to morbidity and mortality globally. Machine-learning (ML) based decision support tools have been developed across many aspects of CKD care. Notably, algorithms developed in the prediction and diagnosis of CKD development and progression may help to facilitate early disease prevention, assist with early planning of renal replacement therapy, and offer potential clinical and economic benefits to patients and health systems. Clinical implementation can be affected by the uncertainty surrounding the methodological rigor and performance of ML-based models. This systematic review aims to evaluate the application of prognostic and diagnostic ML tools in CKD development and progression. The protocol has been prepared using the Preferred Items for Systematic Review and Meta-analysis Protocols (PRISMA-P) guidelines. The systematic review protocol for CKD prediction and diagnosis have been registered with the International Prospective Register of Systematic Reviews (PROSPERO) (CRD42022356704, CRD42022372378). A systematic search will be undertaken of PubMed, Embase, the Cochrane Central Register of Controlled Trials (CENTRAL), the Web of Science, and the IEEE Xplore digital library. Studies in which ML has been applied to predict and diagnose CKD development and progression will be included. The primary outcome will be the comparison of the performance of ML-based models with non-ML-based models. Secondary analysis will consist of model use cases, model construct, and model reporting quality. This systematic review will offer valuable insight into the performance and reporting quality of ML-based models in CKD diagnosis and prediction. This will inform clinicians and technical specialists of the current development of ML in CKD care, as well as direct future model development and standardization.

Informant-based screening tools for dementia: an overview of systematic reviews

BACKGROUND

Informant-based questionnaires may have utility for cognitive impairment or dementia screening. Reviews describing the accuracy of respective questionnaires are available, but their focus on individual questionnaires precludes comparisons across tools. We conducted an overview of systematic reviews to assess the comparative accuracy of informant questionnaires and identify areas where evidence is lacking.

METHODS

We searched six databases to identify systematic reviews describing diagnostic test accuracy of informant questionnaires for cognitive impairment or dementia. We pooled sensitivity and specificity data for each questionnaire and used network approaches to compare accuracy estimates across the differing tests. We used grading of recommendations, assessment, development and evaluation (GRADE) to evaluate the overall certainty of evidence. Finally, we created an evidence 'heat-map', describing the availability of accurate data for individual tests in different populations and settings.

RESULTS

We identified 25 reviews, consisting of 93 studies and 13 informant questionnaires. Pooled analysis (37 studies; 11 052 participants) ranked the eight-item interview to ascertain dementia (AD8) highest for sensitivity [90%; 95% credible intervals (CrI) = 82-95; 'best-test' probability = 36]; while the Informant Questionnaire on Cognitive Decline in the Elderly (IQCODE) was most specific (81%; 95% CrI = 66-90; 'best-test' probability = 29%). GRADE-based evaluation of evidence suggested certainty was 'low' overall. Our heat-map indicated that only AD8 and IQCODE have been extensively evaluated and most studies have been in the secondary care settings.

CONCLUSIONS

AD8 and IQCODE appear to be valid questionnaires for cognitive impairment or dementia assessment. Other available informant-based cognitive screening questionnaires lack evidence to justify their use at present. Evidence on the accuracy of available tools in primary care settings and with specific populations is required.

The accuracy of nucleic acid amplification tests (NAATs) in detecting human intestinal nematode infections: A protocol for a systematic review and meta-analysis

Human intestinal nematode infections are a global public health issue as they can result in considerable morbidity in infected individuals, mainly in developing countries. These infections continue to go undiagnosed, as they tend to be mainly endemic in resource-poor communities where there is a shortage of experienced laboratory staff and relevant diagnostic technologies. This is further exacerbated by the nature of intermittent shedding of eggs and larvae by these parasites. Diagnostic methods range from simple morphological identification to more specialised high-throughput sequencing technologies. Microscopy-based methods, although simple, are labour-intensive and considerably less sensitive than molecular methods which are rapid and have high levels of accuracy. Molecular methods use nucleic acid amplification (NAA) to amplify the deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) fragments of the parasite to detect and determine its presence using different technologies (NAAT). They have increased the sensitivity of detection and quantitation of intestinal nematode infections, especially in low infection intensity settings. The absence of a gold standard test limits current diagnosis and, in turn, restricts intervention measures and effective control efforts. The objective of this review is to determine the accuracy of NAATs in detecting human intestinal nematode infections using Kato-Katz as the reference test for the most common soil-transmitted helminth (STH) infections and the scotch tape test for enterobiasis and Baermann method for strongyloidiasis. Relevant studies will be identified by searches in electronic databases. Two reviewers will independently screen the literature against eligibility criteria. The methodological quality of studies will then be appraised by two reviewers using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Discrepancies will be addressed by a third reviewer. The true positives, false positives, true negatives and false negatives of all the studies will be extracted into contingency tables. In paired forest plots, study-specific sensitivity and specificity with a 95 per cent confidence interval will be displayed. The systematic review of this protocol will report the diagnostic accuracy of currently available NAATs for the detection of human intestinal nematode infections. This will help healthcare providers and administrators determine the diagnostic method to be used in different clinical and preventive settings. Trial registration: PROSPERO registration number for this protocol is CRD42022315730.

Diagnostic performance of DSC perfusion MRI to distinguish tumor progression and treatment-related changes: a systematic review and meta-analysis

Background

In patients with high-grade glioma (HGG), true disease progression and treatment-related changes often appear similar on magnetic resonance imaging (MRI), making it challenging to evaluate therapeutic response. Dynamic susceptibility contrast (DSC) MRI has been extensively studied to differentiate between disease progression and treatment-related changes. This systematic review evaluated and synthesized the evidence for using DSC MRI to distinguish true progression from treatment-related changes.

Methods

We searched Ovid MEDLINE and the Ovid MEDLINE in-process file (January 2005-October 2019) and the reference lists. Studies on test performance of DSC MRI using relative cerebral blood volume in HGG patients were included. One investigator abstracted data, and a second investigator confirmed them; two investigators independently assessed study quality. Meta-analyses were conducted to quantitatively synthesize area under the receiver operating curve (AUROC), sensitivity, and specificity.

Results

We screened 1177 citations and included 28 studies with 638 patients with true tumor progression, and 430 patients with treatment-related changes. Nineteen studies reported AUROC and the combined AUROC is 0.85 (95% CI, 0.81-0.90). All studies contributed data for sensitivity and specificity, and the pooled sensitivity and specificity are 0.84 (95% CI, 0.80-0.88), and 0.78 (95% CI, 0.72-0.83). Extensive subgroup analyses based on study, treatment, and imaging characteristics generally showed similar results.

Conclusions

There is moderate strength of evidence that relative cerebral blood volume obtained from DSC imaging demonstrated "excellent" ability to discriminate true tumor progression from treatment-related changes, with robust sensitivity and specificity.

Accuracy of imaging modalities at detecting extracapsular spread of cervical lymph node metastases in HPV-associated oropharyngeal cancer: a systematic review protocol of diagnostic test accuracy

OBJECTIVE

The objective of this review is to evaluate the accuracy of different imaging modalities in detecting extracapsular spread (ECS) of cervical lymph node metastases in human papillomavirus positive (HPV+) oropharyngeal squamous cell carcinoma (OPSCC).

INTRODUCTION

Extracapsular spread of lymph node metastases is associated with poor prognosis, and its detection in head and neck cancer is crucial for treatment planning. Commonly used imaging modalities to detect ECS in OPSCC include computed tomography, magnetic resonance imaging, positron emission tomography, and ultrasonography. Currently there is no gold standard imaging modality to detect ECS in OPSCC.

INCLUSION CRITERIA

This review will consider published studies examining the diagnostic accuracy (including sensitivity and specificity) of an imaging modality used to detect ECS in HPV+ OPSCC. Participants will have a diagnosis of HPV+ OPSCC and suspected diagnosis of ECS of cervical lymph node metastases. The index test will be different imaging modalities used to detect ECS, and the reference test will be histopathology.

METHODS

A three-step search strategy will be undertaken to identify relevant studies in MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus. A standardized critical appraisal tool (QUADAS-2) will be used to assess the methodological quality of the studies. The main outcomes will be sensitivity and specificity measures reported with 95% confidence intervals. Meta-analysis will be conducted using a bivariate model approach after pooling the studies according to imaging modality. Meta-regression will be used to explore heterogeneity. Meta-regression and subgroup analyses will be used to compare studies and imaging modalities. The results will be presented using either paired forest plots, summary receiver operator characteristic curves, or a narrative synthesis. A GRADE Summary of Findings will be provided.

SYSTEMATIC REVIEW REGISTRATION NUMBER

PROSPERO CRD42021250626.

Laboratory-based testing for hepatitis C infection using dried blood spot samples: A systematic review and meta-analysis of diagnostic accuracy

The use of dried blood spot (DBS) samples can facilitate the implementation of reflex testing by circumventing the need for centrifugation and freezing of venous blood samples. This systematic review assessed the accuracy of using DBS samples to diagnose chronic hepatitis C virus (HCV) infection. A comprehensive search was undertaken to identify articles published up to July 2020 evaluating the diagnostic accuracy of anti-HCV, HCV-RNA and HCV core antigen tests using DBS. Screening, data extraction, quality appraisal and Grading of Recommendations, Assessment, Development and Evaluations certainty of the evidence assessment were performed independently by two reviewers. Meta-analysis, meta-regression and sensitivity analyses were conducted. The evidence demonstrates that laboratory-based anti-HCV and HCV-RNA tests using DBS samples have high diagnostic accuracy. All comparisons were between DBS and venous samples. For the detection of anti-HCV, sensitivity was 95% (95% CI: 92%-97%) and specificity was 99% ([95% CI: 98%-99%]; n = 25; I²  = 81%; moderate certainty). For the detection of HCV-RNA, the sensitivity was 95% (95% CI: 93%-97%) and specificity was 97% ([95% CI: 94%-98%]; n = 20; I²  = 52%; moderate certainty). The sensitivity of HCV core antigen tests was 86% (95% CI: 79%-91%) and specificity was 98% ([95% CI: 94%-99%]; n = 5; I²  = 37%; low certainty) compared with HCV-RNA (the gold standard for detecting chronic HCV). DBS samples could facilitate diagnosis of chronic HCV infection as the necessary sequential tests (anti-HCV and then HCV-RNA or HCV core antigen) can be undertaken using the same blood sample. This could reduce loss of patient follow-up and support international efforts towards HCV elimination in both high and low prevalence settings.

Serum or plasma ferritin concentration as an index of iron deficiency and overload

BACKGROUND

Reference standard indices of iron deficiency and iron overload are generally invasive, expensive, and can be unpleasant or occasionally risky. Ferritin is an iron storage protein and its concentration in the plasma or serum reflects iron stores; low ferritin indicates iron deficiency, while elevated ferritin reflects risk of iron overload. However, ferritin is also an acute-phase protein and its levels are elevated in inflammation and infection. The use of ferritin as a diagnostic test of iron deficiency and overload is a common clinical practice.

OBJECTIVES

To determine the diagnostic accuracy of ferritin concentrations (serum or plasma) for detecting iron deficiency and risk of iron overload in primary and secondary iron-loading syndromes.

SEARCH METHODS

We searched the following databases (10 June 2020): DARE (Cochrane Library) Issue 2 of 4 2015, HTA (Cochrane Library) Issue 4 of 4 2016, CENTRAL (Cochrane Library) Issue 6 of 12 2020, MEDLINE (OVID) 1946 to 9 June 2020, Embase (OVID) 1947 to week 23 2020, CINAHL (Ebsco) 1982 to June 2020, Web of Science (ISI) SCI, SSCI, CPCI-exp & CPCI-SSH to June 2020, POPLINE 16/8/18, Open Grey (10/6/20), TRoPHI (10/6/20), Bibliomap (10/6/20), IBECS (10/6/20), SCIELO (10/6/20), Global Index Medicus (10/6/20) AIM, IMSEAR, WPRIM, IMEMR, LILACS (10/6/20), PAHO (10/6/20), WHOLIS 10/6/20, IndMED (16/8/18) and Native Health Research Database (10/6/20). We also searched two trials registers and contacted relevant organisations for unpublished studies.

SELECTION CRITERIA

We included all study designs seeking to evaluate serum or plasma ferritin concentrations measured by any current or previously available quantitative assay as an index of iron status in individuals of any age, sex, clinical and physiological status from any country.

DATA COLLECTION AND ANALYSIS

We followed standard Cochrane methods. We designed the data extraction form to record results for ferritin concentration as the index test, and bone marrow iron content for iron deficiency and liver iron content for iron overload as the reference standards. Two other authors further extracted and validated the number of true positive, true negative, false positive, false negative cases, and extracted or derived the sensitivity, specificity, positive and negative predictive values for each threshold presented for iron deficiency and iron overload in included studies. We assessed risk of bias and applicability using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS)-2 tool. We used GRADE assessment to enable the quality of evidence and hence strength of evidence for our conclusions.

MAIN RESULTS

Our search was conducted initially in 2014 and updated in 2017, 2018 and 2020 (10 June). We identified 21,217 records and screened 14,244 records after duplicates were removed. We assessed 316 records in full text. We excluded 190 studies (193 records) with reasons and included 108 studies (111 records) in the qualitative and quantitative analysis. There were 11 studies (12 records) that we screened from the last search update and appeared eligible for a future analysis. We decided to enter these as awaiting classification. We stratified the analysis first by participant clinical status: apparently healthy and non-healthy populations. We then stratified by age and pregnancy status as: infants and children, adolescents, pregnant women, and adults. Iron deficiency We included 72 studies (75 records) involving 6059 participants. Apparently healthy populations Five studies screened for iron deficiency in people without apparent illness. In the general adult population, three studies reported sensitivities of 63% to 100% at the optimum cutoff for ferritin, with corresponding specificities of 92% to 98%, but the ferritin cutoffs varied between studies. One study in healthy children reported a sensitivity of 74% and a specificity of 77%. One study in pregnant women reported a sensitivity of 88% and a specificity of 100%. Overall confidence in these estimates was very low because of potential bias, indirectness, and sparse and heterogenous evidence. No studies screened for iron overload in apparently healthy people. People presenting for medical care There were 63 studies among adults presenting for medical care (5042 participants). For a sample of 1000 subjects with a 35% prevalence of iron deficiency (of the included studies in this category) and supposing a 85% specificity, there would be 315 iron-deficient subjects correctly classified as having iron deficiency and 35 iron-deficient subjects incorrectly classified as not having iron deficiency, leading to a 90% sensitivity. Thresholds proposed by the authors of the included studies ranged between 12 to 200 µg/L. The estimated diagnostic odds ratio was 50. Among non-healthy adults using a fixed threshold of 30 μg/L (nine studies, 512 participants, low-certainty evidence), the pooled estimate for sensitivity was 79% with a 95% confidence interval of (58%, 91%) and specificity of 98%, with a 95% confidence interval of (91%, 100%). The estimated diagnostic odds ratio was 140, a relatively highly informative test. Iron overload We included 36 studies (36 records) involving 1927 participants. All studies concerned non-healthy populations. There were no studies targeting either infants, children, or pregnant women. Among all populations (one threshold for males and females; 36 studies, 1927 participants, very low-certainty evidence): for a sample of 1000 subjects with a 42% prevalence of iron overload (of the included studies in this category) and supposing a 65% specificity, there would be 332 iron-overloaded subjects correctly classified as having iron overload and 85 iron-overloaded subjects incorrectly classified as not having iron overload, leading to a 80% sensitivity. The estimated diagnostic odds ratio was 8.

AUTHORS' CONCLUSIONS

At a threshold of 30 micrograms/L, there is low-certainty evidence that blood ferritin concentration is reasonably sensitive and a very specific test for iron deficiency in people presenting for medical care. There is very low certainty that high concentrations of ferritin provide a sensitive test for iron overload in people where this condition is suspected. There is insufficient evidence to know whether ferritin concentration performs similarly when screening asymptomatic people for iron deficiency or overload.

Out-of-hospital Circulatory Measures to Identify Patients With Serious Injury: A Systematic Review

OBJECTIVE

The objective was to systematically identify and summarize out-of-hospital measures of circulatory compromise as diagnostic predictors of serious injury, focusing on measures usable by emergency medical services to inform field triage decisions.

METHODS

We searched Ovid MEDLINE, CINAHL, and the Cochrane databases from 1996 through August 2017 for published literature on individual circulatory measures in trauma. We reviewed reference lists of included articles for additional relevant citations. Measures of diagnostic accuracy included sensitivity, specificity, and area under the receiver operating characteristic curve (AUROC). Indicators of serious injury included resource need, serious anatomic injury, and mortality. We pooled estimates when data permitted.

RESULTS

We identified 114 articles, reporting results of 111 studies. Measures included systolic blood pressure (sBP), heart rate (HR), shock index (SI), lactate, base deficit, and HR variability. Pooled out-of-hospital sensitivity estimates were sBP < 90 mm Hg = 19% (95% confidence interval [CI] = 12% to 29%), HR ≥ 110 beats/min = 28% (95% CI = 20% to 37%), SI > 0.9 = 37% (95% CI = 22% to 56%), and lactate > 2.0 mmol/L = 74% (95% CI = 48% to 90%). Pooled specificity estimates were sBP < 90 mm Hg = 95% (95% CI = 91% to 97%), HR ≥ 110 beats/min = 85% (95% CI = 74% to 91%), SI > 0.9 = 85% (95% CI = 72% to 92%), and lactate > 2.0 mmol/L = 62% (95% CI = 51% to 72%). Pooled AUROCs included sBP = 0.67 (95% CI = 0.58 to 0.75), HR = 0.67 (95% CI = 0.56 to 0.79), SI = 0.72 (95% CI = 0.66 to 0.77), and lactate = 0.77 (95% CI = 0.67 to 0.82). Strength of evidence was low to moderate.

CONCLUSIONS

Out-of-hospital circulatory measures are associated with poor to fair discrimination for identifying trauma patients with serious injuries. Many seriously injured patients have normal circulatory measures (low sensitivity), but when present, the measures are highly specific for identifying patients with serious injuries.

Out-of-hospital Respiratory Measures to Identify Patients With Serious Injury: A Systematic Review

OBJECTIVES

The objective was to systematically review the published literature on the diagnostic accuracy of out-of-hospital respiratory measures for identifying patients with serious injury, focusing on measures feasible for field triage by emergency medical services personnel.

METHODS

We searched Ovid MEDLINE, CINAHL, and the Cochrane databases from January 1, 1996, through August 31, 2017. We included studies on the diagnostic accuracy (sensitivity, specificity, and area under the receiver operating characteristic curve [AUROC]) for all respiratory measures used to identify patients with serious injury (resource use, serious anatomic injury, and mortality). We assessed studies for risk of bias and strength of evidence (SOE). We performed meta-analysis for measures with sufficient data.

RESULTS

We identified 46 articles reporting results of 44 studies. Out-of-hospital respiratory measures included respiratory rate, pulse oximetry, and airway support. Meta-analysis was only possible for respiratory rate, which demonstrated a pooled sensitivity for serious injury of 13% (95% confidence interval [CI] = 5 to 29, I²  = 97.8%), specificity of 96% (95% CI = 83 to 99, I²  = 99.6%), and AUROC of 0.70 (95% CI = 0.66 to 0.79, I²  = 16.6%). For oxygen saturation, sensitivity ranged from 13% to 63%; specificity, 85% to 99%; and AUROC, 0.53 to 0.76. Need for airway support had a sensitivity of 8% to 53% and specificity of 61% to 100%; studies did not report AUROC. Across respiratory measures, the SOE was low. Other respiratory measures (pH, end-tidal carbon dioxide [CO₂ ], and sublingual partial pressure of CO₂ ) were reported only in emergency department studies.

CONCLUSIONS

Data on the accuracy of out-of-hospital respiratory measures for field triage are limited and of low quality. Based on available research, respiratory rate, oxygen saturation, and need for airway intervention all have low sensitivity, high specificity, and poor to fair discrimination for identifying seriously injured patients.

Informant-based screening tools for diagnosis of dementia, an overview of systematic reviews of test accuracy studies protocol

BACKGROUND

Robust diagnosis of dementia requires an understanding of the accuracy of the available diagnostic tests. Informant questionnaires are frequently used to assess for dementia in clinical practice. Recent systematic reviews have sought to establish the diagnostic test accuracy of various dementia informant screening tools. However, most reviews to date have focused on a single diagnostic tool and this does not address which tool is 'best'. A key aim of the overview of systematic reviews is to present a disparate evidence base in a single, easy to access platform.

METHODS

We will conduct an overview of systematic reviews in which we 'review the systematic reviews' of diagnostic test accuracy studies evaluating informant questionnaires for dementia. As an overview of systematic reviews of test accuracy is a relatively novel approach, we will use this review to explore methods for visual representation of complex data, for highlighting evidence gaps and for indirect comparative analyses. We will create a list of informant tools by consulting with dementia experts. We will search 6 databases (EMBASE (OVID); Health and Psychosocial Instruments (OVID); Medline (OVID); CINAHL (EBSCO); PSYCHinfo (EBSCO) and the PROSPERO registry of review protocols) to identify systematic reviews that describe the diagnostic test accuracy of informant questionnaires for dementia. We will assess review quality using the AMSTAR-2 (Assessment of Multiple Systematic Reviews) and assess reporting quality using PRISMA-DTA (Preferred Reporting Items for Systematic Review and Meta-analysis of Diagnostic Test Accuracy Studies) checklists. We will collate the identified reviews to create an 'evidence map' that highlights where evidence does and does not exist in relation to informant questionnaires. We will pool sensitivity and specificity data via meta-analysis to generate a diagnostic test accuracy summary statistic for each informant questionnaire. If data allow, we will perform a statistical comparison of the diagnostic test accuracy of each informant questionnaire using a network approach.

DISCUSSION

Our overview of systematic reviews will provide a concise summary of the diagnostic test accuracy of informant tools and highlight areas where evidence is currently lacking in this regard. It will also apply network meta-analysis techniques to a new area.

Laboratory-based dried blood spot testing for hepatitis C: A protocol for systematic review and meta-analysis of diagnostic accuracy

Background: Diagnosis of chronic hepatitis C virus (HCV) infection typically involves collection of venous blood samples prior to serological investigation of an antibody response followed by a confirmatory viral load or antigen test to verify active HCV infection. This conventional pathway poses logistical challenges for the implementation of reflex testing, whereby the confirmatory test is performed on the same sample used for serological investigation. Dried blood spot (DBS) testing, in which capillary blood is deposited on filter paper, is a less invasive alternative that can enable reflex testing without the need for venepuncture, centrifugation and freezing of samples. Methods: This systematic review aims to assess the diagnostic accuracy of DBS compared with venous blood samples for diagnosis of chronic HCV infection. Observational studies which compare diagnostic tests using DBS with those using serum, plasma or whole blood in patients with chronic or resolved HCV infection will be included. Electronic searches will be conducted in PubMed, Embase, Scopus, Web of Science, Lilacs and the Cochrane library. Citation screening, data extraction and quality appraisal of included studies will be performed in duplicate using the Quality Assessment of Diagnostic Accuracy Studies-2 (QUADAS-2) tool. A meta-analysis will be conducted to derive pooled estimates of sensitivity, specificity, positive likelihood ratios, negative likelihood ratios, and diagnostic odds ratios. Sensitivity analyses and meta-regression will also be performed. Quality of the evidence will be evaluated using the GRADE criteria. Discussion: Identifying and linking people with currently undiagnosed chronic HCV infection to care is pivotal to attaining global viral hepatitis elimination targets. The use of DBS could simplify diagnostic testing strategies by integrating reflex testing into the care pathway and reducing drop-off along the cascade of care. Registration: PROSPERO, CRD42020205204. Registered 19 th September 2020.

Diagnostic test accuracy of jolt accentuation for headache in acute meningitis in the emergency setting

BACKGROUND

Meningitis is inflammation of the meninges, the layers that protect the brain and spinal cord. Acute meningitis is an emergent disease that develops over the course of hours to several days. Delay in treatment can lead to serious outcomes. Inflammation of the meninges is assessed by analysing cerebrospinal fluid. Identifying the pathogen in cerebrospinal fluid is another way to diagnose meningitis. Cerebrospinal fluid is collected by doing a lumbar puncture, which is an invasive test, and can be avoided if a physical examination excludes the diagnosis of meningitis. However, most physical examinations, such as nuchal rigidity, Kernig's test, and Brudzinski's test, are not sufficiently sensitive to exclude meningitis completely. Jolt accentuation of headache is a new and less well-recognised physical examination, which assesses meningeal irritation. It is judged as positive if the headache is exacerbated by rotating the head horizontally two or three times per second. A 1991 observational study initially reported high sensitivity of this examination to predict pleocytosis. Pleocytosis, an abnormally high cerebrospinal fluid sample white cell count, is an accepted indicator of nervous system infection or inflammation. Jolt accentuation of headache may therefore accurately rule out meningitis without the use of lumbar puncture. However, more recent cross-sectional studies have reported variable diagnostic accuracy.

OBJECTIVES

To estimate the diagnostic accuracy of jolt accentuation of headache for detecting acute meningitis in emergency settings. Secondary objectives: to investigate the sources of heterogeneity, including study population, patient condition, and types of meningitis.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid), and Embase (Elsevier) to 27 April 2020. We searched ClinicalTrials.gov, the World Health Organization International Clinical Trials Registry Platform, and Ichushi-Web Version 5.0 to 28 April 2020.

SELECTION CRITERIA

We included cross-sectional studies that assessed the diagnostic accuracy of jolt accentuation of headache for people with suspected meningitis in emergency settings. We included participants of any age and any severity of illness. Meningitis should be diagnosed with any reference standard, such as cerebrospinal fluid pleocytosis, proof of causative agents, or autopsy.

DATA COLLECTION AND ANALYSIS

Two review authors independently collated study data. We assessed methodological quality of studies using QUADAS-2 criteria. We used a bivariate random-effects model to determine summary estimates of sensitivity and specificity where meta-analysis was possible. We performed sensitivity analyses to validate the robustness of outcomes. We assessed the certainty of the evidence using the GRADE approach.

MAIN RESULTS

We included nine studies (1161 participants). Five studies included only adults. Four studies included both adults and children; however, the proportion was not reported in three of these studies. The youngest child reported in the studies was aged 13 years. There was no study including only children. The reference standard was pleocytosis in eight studies, and the combination of pleocytosis and increased protein in the cerebrospinal fluid in one study. Two studies also used smear or positive culture of cerebrospinal fluid. Risk of bias and concern about applicability was high in the participant selection domain for all included studies and the consciousness subgroup. Overall, pooled sensitivity was 65.3% (95% confidence interval (CI) 37.3 to 85.6), and pooled specificity was 70.4% (95% CI 47.7 to 86.1) (very low-certainty evidence). We established the possibility of heterogeneity from visual inspection of forest plots. However, we were unable to conduct further analysis for study population, types of meningitis, and participants' condition, other than disturbance of consciousness (a secondary outcome). Amongst participants whose consciousness was undisturbed (8 studies, 921 participants), pooled sensitivity and specificity were 75.2% (95% CI 54.3 to 88.6) and 60.8% (95% CI 43.4 to 75.9), respectively (very low-certainty evidence).

AUTHORS' CONCLUSIONS

Jolt accentuation for headache may exclude diagnoses of meningitis in emergency settings, but high-quality evidence to support use of this test is lacking. Even where jolt accentuation of headache is negative, there is still the possibility of acute meningitis. This review identified the possibility of heterogeneity. However, factors that contribute to heterogeneity are incompletely understood, and should be considered in future research.

Evaluating the efficacy of bronchoscopy for the diagnosis of early stage lung cancer

Novel diagnostic techniques for lung cancer are rapidly evolving. Specifically, several novel changes to bronchoscopy are reaching clinical evaluation. It is critical to think about historical standards for evaluating new diagnostic testing, and put those concepts into the framework of lung cancer. Often a thorough evaluation of new technology is not performed as a part of regulatory marketing clearance. Therefore, we must consider how to best study novel testing beyond these regulatory minimums. There are several methodological principles that can achieve this goal such as using a control arm, more thorough reporting of enrolled patients, consecutive patient enrollment, and adequate sample size. We hope clinicians, particularly those performing bronchoscopy for lung nodules, will feel empowered to critically appraise the evaluation of new diagnostic testing for lung cancer moving forward.

Accuracy of near-infrared light transillumination (NILT) compared to bitewing radiograph for detection of interproximal caries in the permanent dentition: A systematic review and meta-analysis

OBJECTIVE

To evaluate the accuracy of the near-infrared light transillumination (NILT) for the detection of interproximal dental caries in permanent dentition when compared to bitewing X-ray (BW).

DATA

In vivo studies that detected interproximal primary caries in permanent teeth by using NILT and BW were selected. QUADAS-2 was used to assess the risk of bias. Pooled sensitivity and specificity forest plots were calculated, summary receiver operator characteristics (SROC) curves were constructed. The certainty of the evidence was rated using the GRADE system.

SOURCES

Pubmed, Cochrane Library, Web of Science, Scopus, Lilacs/BBO and grey literature databases were surveyed.

STUDY SELECTION

From 1594 retrieved articles, 13 studies were included. Six studies had a low risk of bias and a low level of concern regarding applicability. Four studies had an unclear risk of bias, while three presented a high risk of bias. The meta-analysis of six studies demonstrated that NILT presented good overall accuracy. Of 6110 teeth, 92.3 % (5639) were accurately classified (776 as true positive and 4863 as true negative). The pooled sensitivity was 0.97 (0.96 to 0.98; p = 0.0000; I² = 93.2 %) with moderate certainty of evidence, and the pooled specificity was 0.91 (0.91 to 0.92; p = 0.0000; I² = 98.3 %) with high certainty of evidence. Symmetric (0.9837) and asymmetric (0.9836) SROC showed a high discrimination and determination effect of NILT.

CONCLUSION

The current literature, with moderate certainty and a middling quality of evidence, demonstrates that NILT presents a reasonably comparable accuracy to that of BW for detecting interproximal carious lesions in the permanent dentition.

CLINICAL SIGNIFICANCE

Since NILT presented good overall accuracy for the detection of interproximal primary caries, it could be routinely used in dental check-ups, especially in high-risk caries populations and in patients where the use of radiation should be reduced, like pregnant women or children.

Impact on prognosis of rebiopsy in advanced non-small cell lung cancer patients after epidermal growth factor receptor-tyrosine kinase inhibitor treatment: a systematic review

Background

Osimertinib, the third-generation epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has become the standard treatment in cases where rebiopsy reveals T790M mutation after the first-line EGFR-TKI treatment. However, the prognosis of patients after rebiopsy, the most important outcome for cancer patients, has not been described sufficiently. This systematic review aimed to clarify whether rebiopsy contributes to improved prognosis in the first- or second-generation EGFR-TKI refractory patients.

Methods

Using free word and control terms related to “non-small cell lung cancer” and “rebiopsy,” we searched studies from Medical Literature Analysis and Retrieval System Online via PubMed, Embase, Cochrane Central Register of Controlled Trials, and World Health Organization International Clinical Trials Registry Platform. We included cohort studies and case reports written in English and judged whether each study answers our research questions.

Results

Of the 144 studies included, only one reported the prognosis of patients with/without rebiopsy showing that in EGFR-TKI refractory non-small cell lung cancer patients, the post-progression survival (PPS) was significantly longer in patients who received rebiopsy and treatment based on a resistant mechanism (median PPS 24.2 months) than those who received rebiopsy and salvage regimen (median PPS 15.2 months, p = 0.002) and who did not receive rebiopsy (median PPS 9.7 months, p < 0.001). Most of the other studies reported the detection rate of T790M mutation or rebiopsy procedure.

Conclusions

Only a few previous studies have investigated the effectiveness of rebiopsy. Hence, further study is needed to determine the prognosis or adverse events of rebiopsy.

C-reactive protein for diagnosing late-onset infection in newborn infants

BACKGROUND

Late-onset infection is the most common serious complication associated with hospital care for newborn infants. Because confirming the diagnosis by microbiological culture typically takes 24 to 48 hours, the serum level of the inflammatory marker C-reactive protein (CRP) measured as part of the initial investigation is used as an adjunctive rapid test to guide management in infants with suspected late-onset infection.

OBJECTIVES

To determine the diagnostic accuracy of serum CRP measurement in detecting late-onset infection in newborn infants.

SEARCH METHODS

We searched electronic databases (MEDLINE, Embase, and Science Citation Index to September 2017), conference proceedings, previous reviews, and the reference lists of retrieved articles.

SELECTION CRITERIA

We included cohort and cross-sectional studies evaluating the diagnostic accuracy of serum CRP levels for the detection of late-onset infection (occurring more than 72 hours after birth) in newborn infants.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed eligibility for inclusion, evaluated the methodological quality of included studies, and extracted data to estimate diagnostic accuracy using hierarchical summary receiver operating characteristic (SROC) models. We assessed heterogeneity by examining variability of study estimates and overlap of the 95% confidence interval (CI) in forest plots of sensitivity and specificity.

MAIN RESULTS

The search identified 20 studies (1615 infants). Most were small, single-centre, prospective cohort studies conducted in neonatal units in high- or middle-income countries since the late 1990s. Risk of bias in the included studies was generally low with independent assessment of index and reference tests. Most studies used a prespecified serum CRP threshold level as the definition of a 'positive' index test (typical cut-off level between 5 mg/L and 10 mg/L) and the culture of a pathogenic micro-organism from blood as the reference standard.At median specificity (0.74), sensitivity was 0.62 (95% CI 0.50 to 0.73). Heterogeneity was evident in the forest plots but it was not possible to conduct subgroup or meta-regression analyses by gestational ages, types of infection, or types of infecting micro-organism. Covariates for whether studies used a predefined threshold or not, and whether studies used a standard threshold of between 5 mg/L and 10 mg/L, were not statistically significant.

AUTHORS' CONCLUSIONS

The serum CRP level at initial evaluation of an infant with suspected late-onset infection is unlikely to be considered sufficiently accurate to aid early diagnosis or select infants to undergo further investigation or treatment with antimicrobial therapy or other interventions.

Accuracy and utility of using administrative healthcare databases to identify people with epilepsy: a protocol for a systematic review and meta-analysis

INTRODUCTION

In an increasingly digital age for healthcare around the world, administrative data have become rich and accessible tools for potentially identifying and monitoring population trends in diseases including epilepsy. However, it remains unclear (1) how accurate administrative data are at identifying epilepsy within a population and (2) the optimal algorithms needed for administrative data to correctly identify people with epilepsy within a population. To address this knowledge gap, we will conduct a novel systematic review of all identified studies validating administrative healthcare data in epilepsy identification. We provide here a protocol that will outline the methods and analyses planned for the systematic review.

METHODS AND ANALYSIS

The systematic review described in this protocol will be conducted to follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. MEDLINE and Embase will be searched for studies validating administrative data in epilepsy published from 1975 to current (01 June 2018). Included studies will validate the International Classification of Disease (ICD), Ninth Revision (ICD-9) onwards (ie, ICD-9 code 345 and ICD-10 codes G40-G41) as well as other non-ICD disease classification systems used, such as Read Codes in the UK. The primary outcome will be providing pooled estimates of accuracy for identifying epilepsy within the administrative databases validated using sensitivity, specificity, positive and negative predictive values, and area under the receiver operating characteristic curves. Heterogeneity will be assessed using the I² statistic and descriptive analyses used where this is present. The secondary outcome will be the optimal administrative data algorithms for correctly identifying epilepsy. These will be identified using multivariable logistic regression models. 95% confidence intervals will be quoted throughout. We will make an assessment of risk of bias, quality of evidence, and completeness of reporting for included studies.

ETHICS AND DISSEMINATION

Ethical approval is not required as primary data will not be collected. Results will be disseminated in peer-reviewed journals, conference presentations and in press releases.

PROSPERO REGISTRATION

CRD42017081212.

Common evidence gaps in point-of-care diagnostic test evaluation: a review of horizon scan reports

OBJECTIVE

Since 2008, the Oxford Diagnostic Horizon Scan Programme has been identifying and summarising evidence on new and emerging diagnostic technologies relevant to primary care. We used these reports to determine the sequence and timing of evidence for new point-of-care diagnostic tests and to identify common evidence gaps in this process.

DESIGN

Systematic overview of diagnostic horizon scan reports.

PRIMARY OUTCOME MEASURES

We obtained the primary studies referenced in each horizon scan report (n=40) and extracted details of the study size, clinical setting and design characteristics. In particular, we assessed whether each study evaluated test accuracy, test impact or cost-effectiveness. The evidence for each point-of-care test was mapped against the Horvath framework for diagnostic test evaluation.

RESULTS

We extracted data from 500 primary studies. Most diagnostic technologies underwent clinical performance (ie, ability to detect a clinical condition) assessment (71.2%), with very few progressing to comparative clinical effectiveness (10.0%) and a cost-effectiveness evaluation (8.6%), even in the more established and frequently reported clinical domains, such as cardiovascular disease. The median time to complete an evaluation cycle was 9 years (IQR 5.5-12.5 years). The sequence of evidence generation was typically haphazard and some diagnostic tests appear to be implemented in routine care without completing essential evaluation stages such as clinical effectiveness.

CONCLUSIONS

Evidence generation for new point-of-care diagnostic tests is slow and tends to focus on accuracy, and overlooks other test attributes such as impact, implementation and cost-effectiveness. Evaluation of this dynamic cycle and feeding back data from clinical effectiveness to refine analytical and clinical performance are key to improve the efficiency of point-of-care diagnostic test development and impact on clinically relevant outcomes. While the 'road map' for the steps needed to generate evidence are reasonably well delineated, we provide evidence on the complexity, length and variability of the actual process that many diagnostic technologies undergo.

Clinical utility of the (-2)proPSA and evaluation of the evidence: a systematic review

Diagnostic studies usually provide important information about the analytical and diagnostic performances. We investigated the clinical utility of (-2)proPSA in identifying patients with prostate cancer (PCa).

We performed electronic searches in five databases as well as a list of reference literature. Studies were included if they evaluated the diagnostic accuracy of (-2)proPSA in men with PSA value ranged from 2.0 to 10 μg/L. We also analyzed data about total PSA (tPSA), %(-2)proPSa, freePSA (fPSA), its percentage (%fPSA) and the prostate health index (phi). The selection of the studies, the screening of the full texts and the data extraction, as well as the assessment of risk of bias using the QUADAS-2 tool were conducted independently by two authors. Grading the quality of the evidence was carried out according to the GRADE method. The random effects model was used for the meta-analyses.

We included 17 studies, including 6912 patients. The pooled sensitivity of (-2)proPSA was 90% and the summary specificity was 13%. The tPSA sensitivity and specificity were 89% and 25%, respectively. Considering (-2)proPSA, 225 men out of 1000 have been identified having PCa true positives (TP). However, 652 persons have been incorrectly identified and undergo biopsy. The majority of studies were judged to carry a moderate risk of bias. Therefore, the overall quality of evidences was deemed to be low.

The (-2)proPSA could be useful to identify men at risk of PCa, but its accuracy still remains uncertain and the level of evidence does not support an improved clinical utility.

A protocol for a systematic review of the diagnostic accuracy of blood markers, synovial fluid, and tissue testing in periprosthetic joint infections (PJI)

BACKGROUND

Total joint replacement (TJR) procedures have been one of the most rewarding interventions for treating patients suffering from joint disease. However, developing a periprosthetic joint infection (PJI) is a serious complication that is associated with the highest burden of cost and reduction in patients' quality of life compared to other complications following TJRs. One of the main challenges facing clinicians who are treating PJIs is accurately diagnosing infection in a timely fashion. Multiple orthopedic associations have published clinical guidelines for diagnosing PJI which are based solely on consensus approaches, expert opinions, and narrative reviews. We believe that a higher quality of scientific rigor is necessary to establish a diagnostic guideline that represents current evidence more accurately and that identifies important knowledge gaps in PJI diagnosis. Therefore, we will conduct a systematic review on diagnostic performance of blood markers, synovial fluids, and tissue tests for diagnosing PJI.

METHODS/DESIGN

Electronic search strategies will be developed and tested by an experienced medical information specialist in consultation with the review team, and gray literature will be searched using the checklist from CADTH's Grey Matters Light. Two reviewers will independently screen the literature for inclusion using the prespecified eligibility criteria. Non-English language and animal-only studies will be excluded. Quality assessment and data extractions by reviewers will be verified, and disagreements will be resolved through consensus or third party adjudication. We will assess the quality of individual studies using the QUADAS-2 tool and use GRADE to summarize the strength of body of evidence. Analyses of evidence will be conducted in accordance with the Cochrane Handbook for Diagnostic Test Accuracy Reviews.

DISCUSSION

We will conduct a systemic review of tests (blood markers, synovial fluids, and tissue testing) for diagnosing PJI in patients' knee, hip, and shoulder joint replacements. This will be the first scientifically rigorous and comprehensive systematic review in the field and may feed into an evidence-based clinical practice guideline. We will compare the findings of this review with the consensus-based guides and discuss the differences, similarities, and knowledge gaps.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015023768.

Grading Evidence for Laboratory Test Studies Beyond Diagnostic Accuracy: Application to Prognostic Testing

BACKGROUND

Evidence-based guideline development requires transparent methodology for gathering, synthesizing and grading the quality and strength of evidence behind recommendations. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) project has addressed diagnostic test use in many of their publications. Most of the work has been directed at diagnostic tests and no consensus has been reached for prognostic biomarkers.

AIM OF THIS PAPER

The GRADE system for rating the quality of evidence and the strength of a recommendation is described. The application of GRADE to diagnostic testing is discussed and a description of application to prognostic testing is detailed. Some strengths and limitations of the GRADE process in relation to clinical laboratory testing are presented.

CONCLUSIONS

The GRADE system is applicable to clinical laboratory testing and if correctly applied should improve the reporting of recommendations for clinical laboratory tests by standardising the style of recommendation and by encouraging transparent reporting of the actual guideline process.

Imaging Techniques for the Diagnosis of Hepatocellular Carcinoma: A Systematic Review and Meta-analysis

BACKGROUND

Several imaging modalities are available for diagnosis of hepatocellular carcinoma (HCC).

PURPOSE

To evaluate the test performance of imaging modalities for HCC.

DATA SOURCES

MEDLINE (1998 to December 2014), the Cochrane Library Database, Scopus, and reference lists.

STUDY SELECTION

Studies on test performance of ultrasonography, computed tomography (CT), or magnetic resonance imaging (MRI).

DATA EXTRACTION

One investigator abstracted data, and a second investigator confirmed them; 2 investigators independently assessed study quality and strength of evidence.

DATA SYNTHESIS

Few studies have evaluated imaging for HCC in surveillance settings. In nonsurveillance settings, sensitivity for detection of HCC lesions was lower for ultrasonography without contrast than for CT or MRI (pooled difference based on direct comparisons, 0.11 to 0.22), and MRI was associated with higher sensitivity than CT (pooled difference, 0.09 [95% CI, 0.07 to 12]). For evaluation of focal liver lesions, there were no clear differences in sensitivity among ultrasonography with contrast, CT, and MRI. Specificity was generally 0.85 or higher across imaging modalities, but this item was not reported in many studies. Factors associated with lower sensitivity included use of an explanted liver reference standard, and smaller or more well-differentiated HCC lesions. For MRI, sensitivity was slightly higher for hepatic-specific than nonspecific contrast agents.

LIMITATIONS

Only English-language articles were included, there was statistical heterogeneity in pooled analyses, and costs were not assessed. Most studies were conducted in Asia and had methodological limitations.

CONCLUSION

CT and MRI are associated with higher sensitivity than ultrasonography without contrast for detection of HCC; sensitivity was higher for MRI than CT. For evaluation of focal liver lesions, the sensitivities of ultrasonography with contrast, CT, and MRI for HCC are similar.

PRIMARY FUNDING SOURCE

Agency for Healthcare Research and Quality. (

PROSPERO

CRD42014007016).

Grading the strength of a body of evidence when assessing health care interventions: an EPC update

OBJECTIVES

To revise 2010 guidance on grading the strength of evidence (SOE) of the effectiveness of drugs, devices, and other preventive and therapeutic interventions in systematic reviews produced by the Evidence-based Practice Center (EPC) program, established by the US Agency for Healthcare Research and Quality (AHRQ).

STUDY DESIGN AND SETTING

A cross-EPC working group reviewed authoritative systems for grading SOE [primarily the approach from the Grading of Recommendations Assessment, Development and Evaluation (GRADE) working group] and conducted extensive discussions with GRADE and other experts.

RESULTS

Updated guidance continues to be conceptually similar to GRADE. Reviewers are to evaluate SOE separately for each major treatment comparison for each major outcome. We added reporting bias as a required domain and retained study limitations (risk of bias), consistency, directness, and precision (and three optional domains). Additional guidance covers scoring consistency, precision, and reporting bias, grading bodies of evidence with randomized controlled trials and observational studies, evaluating single study bodies of evidence, using studies with high risk of bias, and presenting findings with greater clarity and transparency. SOE is graded high, moderate, low, or insufficient, reflecting reviewers' confidence in the findings for a specific treatment comparison and outcome.

CONCLUSION

No single approach for grading SOE suits all reviews, but a more consistent and transparent approach to reporting summary information will make reviews more useful to the broad range of audiences that AHRQ's work aims to reach. EPC working groups will consider ongoing challenges and modify guidance as needed, on issues such as combining trials and observational studies in bodies of evidence, weighting domains, and combining qualitative and quantitative syntheses.