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PLoS Neglected Tropical Diseases Mar 2018Diagnosing scrub typhus clinically is difficult, hence laboratory tests play a very important role in diagnosis. As performing sophisticated laboratory tests in... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Diagnosing scrub typhus clinically is difficult, hence laboratory tests play a very important role in diagnosis. As performing sophisticated laboratory tests in resource-limited settings is not feasible, accurate point-of-care testing (POCT) for scrub typhus diagnosis would be invaluable for patient diagnosis and management. Here we summarise the existing evidence on the accuracy of scrub typhus POCTs to inform clinical practitioners in resource-limited settings of their diagnostic value.
METHODOLOGY/PRINCIPAL FINDINGS
Studies on POCTs which can be feasibly deployed in primary health care or outpatient settings were included. Thirty-one studies were identified through PubMed and manual searches of reference lists. The quality of the studies was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 (QUADAS-2). About half (n = 14/31) of the included studies were of moderate quality. Meta-analysis showed the pooled sensitivity and specificity of commercially available immunochromatographic tests (ICTs) were 66.0% (95% CI 0.37-0.86) and 92.0% (95% CI 0.83-0.97), respectively. There was a significant and high degree of heterogeneity between the studies (I2 value = 97.48%, 95% CI 96.71-98.24 for sensitivity and I2 value = 98.17%, 95% CI 97.67-98.67 for specificity). Significant heterogeneity was observed for total number of samples between studies (p = 0.01), study design (whether using case-control design or not, p = 0.01), blinding during index test interpretation (p = 0.02), and QUADAS-2 score (p = 0.01).
CONCLUSIONS/SIGNIFICANCE
There was significant heterogeneity between the scrub typhus POCT diagnostic accuracy studies examined. Overall, the commercially available scrub typhus ICTs demonstrated better performance when 'ruling in' the diagnosis. There is a need for standardised methods and reporting of diagnostic accuracy to decrease between-study heterogeneity and increase comparability among study results, as well as development of an affordable and accurate antigen-based POCT to tackle the inherent weaknesses associated with serological testing.
Topics: Chromatography, Affinity; Humans; Orientia tsutsugamushi; Point-of-Care Testing; Scrub Typhus; Sensitivity and Specificity; Serologic Tests
PubMed: 29579046
DOI: 10.1371/journal.pntd.0006330 -
Malaria Journal Mar 2016The World Health Organization recommends malaria to be confirmed by either microscopy or a rapid diagnostic test (RDT) before treatment. The correct use of RDTs in... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The World Health Organization recommends malaria to be confirmed by either microscopy or a rapid diagnostic test (RDT) before treatment. The correct use of RDTs in resource-limited settings facilitates basing treatment onto a confirmed diagnosis; contributes to speeding up considering a correct alternative diagnosis, and prevents overprescription of anti-malarial drugs, reduces costs and avoids unnecessary exposure to adverse drug effects. This review aims to evaluate health workers' compliance to RDT results and factors contributing to compliance.
METHODS
A PROSPERO-registered systematic review was conducted to evaluate health workers' compliance to RDTs in sub-Saharan Africa, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies published up to November 2015 were searched without language restrictions in Medline/Ovid, Embase, Cochrane Central Register of Controlled Trials, Web of Science, LILACS, Biosis Previews and the African Index Medicus. The primary outcome was health workers treating patients according to the RDT results obtained.
RESULTS
The literature search identified 474 reports; 14 studies were eligible and included in the quantitative analysis. From the meta-analysis, health workers' overall compliance in terms of initiating treatment or not in accordance with the respective RDT results was 83% (95% CI 80-86%). Compliance to positive and negative results was 97% (95% CI 94-99%) and 78% (95% CI 66-89%), respectively. Community health workers had higher compliance rates to negative test results than clinicians. Patient expectations, work experience, scepticism of results, health workers' cadres and perceived effectiveness of the test, influenced compliance.
CONCLUSIONS
With regard to published data, compliance to RDT appears to be generally fair in sub-Saharan Africa; compliance to negative results will need to improve to prevent mismanagement of patients and overprescribing of anti-malarial drugs. Improving diagnostic capacity for other febrile illnesses and developing local evidence-based guidelines may help improve compliance and management of negative RDT results.
TRIAL REGISTRATION
CRD42015016151 (PROSPERO).
Topics: Africa South of the Sahara; Antimalarials; Attitude of Health Personnel; Chromatography, Affinity; Diagnostic Tests, Routine; Guideline Adherence; Humans; Malaria
PubMed: 26979286
DOI: 10.1186/s12936-016-1218-5 -
PloS One 2014Pharyngitis management guidelines include estimates of the test characteristics of rapid antigen streptococcus tests (RAST) using a non-systematic approach. (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Pharyngitis management guidelines include estimates of the test characteristics of rapid antigen streptococcus tests (RAST) using a non-systematic approach.
OBJECTIVE
To examine the sensitivity and specificity, and sources of variability, of RAST for diagnosing group A streptococcal (GAS) pharyngitis.
DATA SOURCES
MEDLINE, Cochrane Reviews, Centre for Reviews and Dissemination, Scopus, SciELO, CINAHL, guidelines, 2000-2012.
STUDY SELECTION
Culture as reference standard, all languages.
DATA EXTRACTION AND SYNTHESIS
Study characteristics, quality.
MAIN OUTCOME(S) AND MEASURE(S)
Sensitivity, specificity.
RESULTS
We included 59 studies encompassing 55,766 patients. Forty three studies (18,464 patients) fulfilled the higher quality definition (at least 50 patients, prospective data collection, and no significant biases) and 16 (35,634 patients) did not. For the higher quality immunochromatographic methods in children (10,325 patients), heterogeneity was high for sensitivity (inconsistency [I(2)] 88%) and specificity (I(2) 86%). For enzyme immunoassay in children (342 patients), the pooled sensitivity was 86% (95% CI, 79-92%) and the pooled specificity was 92% (95% CI, 88-95%). For the higher quality immunochromatographic methods in the adult population (1,216 patients), the pooled sensitivity was 91% (95% CI, 87 to 94%) and the pooled specificity was 93% (95% CI, 92 to 95%); however, heterogeneity was modest for sensitivity (I(2) 61%) and specificity (I(2) 72%). For enzyme immunoassay in the adult population (333 patients), the pooled sensitivity was 86% (95% CI, 81-91%) and the pooled specificity was 97% (95% CI, 96 to 99%); however, heterogeneity was high for sensitivity and specificity (both, I(2) 88%).
CONCLUSIONS
RAST immunochromatographic methods appear to be very sensitive and highly specific to diagnose group A streptococcal pharyngitis among adults but not in children. We could not identify sources of variability among higher quality studies. The present systematic review provides the best evidence for the wide range of sensitivity included in current guidelines.
Topics: Chromatography, Affinity; Humans; Immunoenzyme Techniques; Pharyngitis; Sensitivity and Specificity; Streptococcal Infections; Streptococcus pyogenes
PubMed: 25369170
DOI: 10.1371/journal.pone.0111727 -
The Cochrane Database of Systematic... Jun 2014The diagnosis of visceral leishmaniasis (VL) in patients with fever and a large spleen relies on showing Leishmania parasites in tissue samples and on serological tests.... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The diagnosis of visceral leishmaniasis (VL) in patients with fever and a large spleen relies on showing Leishmania parasites in tissue samples and on serological tests. Parasitological techniques are invasive, require sophisticated laboratories, consume time, or lack accuracy. Recently, rapid diagnostic tests that are easy to perform have become available.
OBJECTIVES
To determine the diagnostic accuracy of rapid tests for diagnosing VL in patients with suspected disease presenting at health services in endemic areas.
SEARCH METHODS
We searched MEDLINE, EMBASE, LILACS, CIDG SR, CENTRAL, SCI-expanded, Medion, Arif, CCT, and the WHO trials register on 3 December 2013, without applying language or date limits.
SELECTION CRITERIA
This review includes original, phase III, diagnostic accuracy studies of rapid tests in patients clinically suspected to have VL. As reference standards, we accepted: (1) direct smear or culture of spleen aspirate; (2) composite reference standard based on one or more of the following: parasitology, serology, or response to treatment; and (3) latent class analysis.
DATA COLLECTION AND ANALYSIS
Two review authors independently extracted data and assessed quality of included studies using the QUADAS-2 tool. Discrepancies were resolved by a third author. We carried out a meta-analysis to estimate sensitivity and specificity of rapid tests, using a bivariate normal model with a complementary log-log link function. We analysed each index test separately. As possible sources of heterogeneity, we explored: geographical area, commercial brand of index test, type of reference standard, disease prevalence, study size, and risk of bias (QUADAS-2). We also undertook a sensitivity analysis to assess the influence of imperfect reference standards.
MAIN RESULTS
Twenty-four studies containing information about five index tests (rK39 immunochromatographic test (ICT), KAtex latex agglutination test in urine, FAST agglutination test, rK26 ICT, and rKE16 ICT) recruiting 4271 participants (2605 with VL) were included. We carried out a meta-analysis for the rK39 ICT (including 18 studies; 3622 participants) and the latex agglutination test (six studies; 1374 participants). The results showed considerable heterogeneity. For the rK39 ICT, the overall sensitivity was 91.9% (95% confidence interval (95% CI) 84.8 to 96.5) and the specificity 92.4% (95% CI 85.6 to 96.8). The sensitivity was lower in East Africa (85.3%; 95% CI 74.5 to 93.2) than in the Indian subcontinent (97.0%; 95% CI 90.0 to 99.5). For the latex agglutination test, overall sensitivity was 63.6% (95% CI 40.9 to 85.6) and specificity 92.9% (95% CI 76.7 to 99.2).
AUTHORS' CONCLUSIONS
The rK39 ICT shows high sensitivity and specificity for the diagnosis of visceral leishmaniasis in patients with febrile splenomegaly and no previous history of the disease, but the sensitivity is notably lower in east Africa than in the Indian subcontinent. Other rapid tests lack accuracy, validation, or both.
Topics: Africa, Eastern; Agglutination Tests; Antigens, Protozoan; Asymptomatic Infections; Biomarkers; Chromatography, Affinity; Clinical Trials, Phase III as Topic; Humans; India; Latex Fixation Tests; Leishmaniasis, Visceral; Nepal; Protozoan Proteins; Sensitivity and Specificity
PubMed: 24947503
DOI: 10.1002/14651858.CD009135.pub2 -
Journal of Clinical Microbiology Jul 2013Standard culture methods for diagnosis of Streptococcus pneumoniae pneumonia take at least 24 h. The BinaxNOW urine-based test for S. pneumoniae (BinaxNOW-SP) takes only... (Meta-Analysis)
Meta-Analysis Review
Standard culture methods for diagnosis of Streptococcus pneumoniae pneumonia take at least 24 h. The BinaxNOW urine-based test for S. pneumoniae (BinaxNOW-SP) takes only 15 min to conduct, potentially enabling earlier diagnosis and targeted treatment. This study was conducted to assess whether the use of BinaxNOW-SP at the time of hospital admission would provide adequate sensitivity and specificity for diagnosis of community-acquired pneumonia (CAP) in adult patients. We searched PubMed, EMBASE/OVID, Cochrane Collaboration, Centre for Reviews and Dissemination, INAHTA, and CADTH for diagnostic or etiologic studies of hospitalized predominately adult patients with clinically defined CAP that reported the diagnostic performance of BinaxNOW-SP versus cultures. Two authors independently extracted study details and diagnostic two-by-two tables. We found that 27 studies met our inclusion criteria, and three different reference standards were used between them. A bivariate meta-analysis of 12 studies using a composite of culture tests as the reference standard estimated the sensitivity of BinaxNOW-SP as 68.5% (95% credibility interval [CrI], 62.6% to 74.2%) and specificity as 84.2% (95% CrI, 77.5% to 89.3%). A meta-analysis of all 27 studies, adjusting for the imperfect and variable nature of the reference standard, gave a higher sensitivity of 74.0% (CrI, 66.6% to 82·3%) and specificity of 97.2% (CrI, 92.7% to 99.8%). The analysis showed substantial heterogeneity across studies, which did not decrease with adjustment for covariates. We concluded that the higher pooled sensitivity (compared to culture) and high specificity of BinaxNOW-SP suggest it would be a useful addition to the diagnostic workup for community-acquired pneumonia. More research is needed regarding the impact of BinaxNOW-SP on clinical practice.
Topics: Adult; Aged; Antigens, Bacterial; Chromatography, Affinity; Clinical Laboratory Techniques; Community-Acquired Infections; Diagnostic Tests, Routine; Female; Humans; Male; Middle Aged; Pneumonia, Pneumococcal; Sensitivity and Specificity; Streptococcus pneumoniae
PubMed: 23678060
DOI: 10.1128/JCM.00137-13 -
BMC Clinical Pathology 2014Levels of haemoglobin A1c (HbA1c) and blood lipids are important determinants of risk in patients with diabetes. Standard analysis methods based upon venous blood...
BACKGROUND
Levels of haemoglobin A1c (HbA1c) and blood lipids are important determinants of risk in patients with diabetes. Standard analysis methods based upon venous blood samples can be logistically challenging in resource-poor settings where much of the diabetes epidemic is occurring. Dried blood spots (DBS) provide a simple alternative method for sample collection but the comparability of data from analyses based on DBS is not well established.
METHODS
We conducted a systematic review and meta-analysis to define the association of findings for HbA1c and blood lipids for analyses based upon standard methods compared to DBS. The Cochrane, Embase and Medline databases were searched for relevant reports and summary regression lines were estimated.
RESULTS
705 abstracts were found by the initial electronic search with 6 further reports identified by manual review of the full papers. 16 studies provided data for one or more outcomes of interest. There was a close agreement between the results for HbA1c assays based on venous and DBS samples (DBS = 0.9858venous + 0.3809), except for assays based upon affinity chromatography. Significant adjustment was required for assays of total cholesterol (DBS = 0.6807venous + 1.151) but results for triglycerides (DBS = 0.9557venous + 0.1427) were directly comparable.
CONCLUSIONS
For HbA1c and selected blood lipids, assays based on DBS samples are clearly associated with assays based on standard venous samples. There are, however, significant uncertainties about the nature of these associations and there is a need for standardisation of the sample collection, transportation, storage and analysis methods before the technique can be considered mainstream. This should be a research priority because better elucidation of metabolic risks in resource poor settings, where venous sampling is infeasible, will be key to addressing the global epidemic of cardiovascular diseases.
PubMed: 25045323
DOI: 10.1186/1472-6890-14-21 -
PloS One 2020The aim of this study was to evaluate the diagnostic performance of immunochromatographic tests (ICTs) for the detection of Mycoplasma pneumoniae. Medline/Pubmed,... (Meta-Analysis)
Meta-Analysis
The aim of this study was to evaluate the diagnostic performance of immunochromatographic tests (ICTs) for the detection of Mycoplasma pneumoniae. Medline/Pubmed, Embase, the Cochrane Library, and ISI Web of Science were searched through June 12, 2019 for relevant studies that used ICTs for the detection of M. pneumoniae infection with polymerase chain reaction (PCR) or microbial culturing as reference standards. Pooled diagnostic accuracy with 95% confidence interval (CI) was calculated using a bivariate random effects model. We also constructed summary receiver operating characteristic curves and calculated the area under the curve (AUC). Statistical heterogeneity was evaluated by χ2 test or Cochrane's Q test. Thirteen studies including 2,235 samples were included in the meta-analysis. The pooled sensitivity and specificity for diagnosing M. pneumoniae infection were 0.70 (95% CI: 0.59-0.79) and 0.92 (95% CI: 0.87-0.95), respectively. The positive likelihood ratio (LR) was 8.94 (95% CI: 4.90-14.80), negative LR 0.33 (95% CI: 0.22-0.46), diagnostic odds ratio 29.20 (95% CI: 10.70-64.20), and AUC 0.904. In subgroup analysis, ICTs demonstrated similar pooled sensitivities and specificities in populations of children only and mixed populations (children + adults). Specimens obtained from oropharyngeal swabs exhibited a higher sensitivity and specificity than those of nasopharyngeal swab. Moreover, pooled estimates of sensitivity and accuracy for studies using PCR as a reference standard were higher than those using culture. The pooled sensitivity and specificity of Ribotest Mycoplasma®, the commercial kit most commonly used in the included studies, were 0.66 and 0.89, respectively. Overall, ICT is a rapid user-friendly method for diagnosing M. pneumoniae infection with moderate sensitivity, high specificity, and high accuracy. This suggests that ICT may be useful in the diagnostic workup of M. pneumoniae infection; however, additional studies are needed for evaluating the potential impact of ICT in clinical practice.
Topics: Adult; Child; Chromatography, Affinity; Diagnostic Tests, Routine; Humans; Microbiological Techniques; Mycoplasma pneumoniae; Oropharynx; Pneumonia, Mycoplasma; Polymerase Chain Reaction; ROC Curve; Reference Standards
PubMed: 32182283
DOI: 10.1371/journal.pone.0230338 -
PloS One 2021Immunological tests may represent valuable tools for the diagnosis of human tegumentary leishmaniasis (TL) due to their simple execution, less invasive nature and...
Immunological tests may represent valuable tools for the diagnosis of human tegumentary leishmaniasis (TL) due to their simple execution, less invasive nature and potential use as a point-of-care test. Indeed, several antigenic targets have been used with the aim of improving the restricted scenario for TL-diagnosis. We performed a worldwide systematic review to identify antigenic targets that have been evaluated for the main clinical forms of TL, such as cutaneous (CL) and mucosal (ML) leishmaniasis. Included were original studies evaluating the sensitivity and specificity of immunological tests for human-TL, CL and/or ML diagnosis using purified or recombinant proteins, synthetic peptides or polyclonal or monoclonal antibodies to detect Leishmania-specific antibodies or antigens. The review methodology followed PRISMA guidelines and all selected studies were evaluated in accordance with QUADAS-2. Thirty-eight original studies from four databases fulfilled the selection criteria. A total of 79 antigens were evaluated for the detection of antibodies as a diagnostic for TL, CL and/or ML by ELISA. Furthermore, three antibodies were evaluated for the detection of antigen by immunochromatographic test (ICT) and immunohistochemistry (IHC) for CL-diagnosis. Several antigenic targets showed 100% of sensitivity and specificity, suggesting potential use for TL-diagnosis in its different clinical manifestations. However, a high number of proof-of-concept studies reinforce the need for further analysis aimed at verifying true diagnostic accuracy in clinical practice.
Topics: Antibodies, Protozoan; Antigens, Protozoan; Chromatography, Affinity; Enzyme-Linked Immunosorbent Assay; Humans; Immunohistochemistry; Leishmania; Leishmaniasis, Diffuse Cutaneous; Leishmaniasis, Mucocutaneous; Point-of-Care Testing; Practice Guidelines as Topic; Sensitivity and Specificity
PubMed: 34043671
DOI: 10.1371/journal.pone.0251956