A Bayesian decision support sequential model for severity of illness predictors and intensive care admissions in pneumonia

Abstract Background Community-acquired pneumonia (CAP) is one of the leading causes of morbidity and mortality in the USA. Our objective was to assess the predictive value on critical illness and disposition of a sequential Bayesian Model that integrates Lactate and procalcitonin (PCT) for pneumonia. Methods Sensitivity and specificity of lactate and PCT attained from pooled meta-analysis data. Likelihood ratios calculated and inserted in Bayesian/ Fagan nomogram to calculate posttest probabilities. Bayesian Diagnostic Gains (BDG) were analyzed comparing pre and post-test probability. To assess the value of integrating both PCT and Lactate in Severity of Illness Prediction we built a model that combined CURB65 with PCT as the Pre-Test markers and later integrated the Lactate Likelihood Ratio Values to generate a combined CURB 65 + Procalcitonin + Lactate Sequential value. Results The BDG model integrated a CUBR65 Scores combined with Procalcitonin (LR+ and LR-) for Pre-Test Probability Intermediate and High with Lactate Positive Likelihood Ratios. This generated for the PCT LR+ Post-test Probability (POSITIVE TEST) Posterior probability: 93% (95% CI [91,96%]) and Post Test Probability (NEGATIVE TEST) of: 17% (95% CI [15–20%]) for the Intermediate subgroup and 97% for the high risk sub-group POSITIVE TEST: Post-Test probability:97% (95% CI [95,98%]) NEGATIVE TEST: Post-test probability: 33% (95% CI [31,36%]) . ANOVA analysis for CURB 65 (alone) vs CURB 65 and PCT (LR+) vs CURB 65 and PCT (LR+) and Lactate showed a statistically significant difference (P value = 0.013). Conclusions The sequential combination of CURB 65 plus PCT with Lactate yielded statistically significant results, demonstrating a greater predictive value for severity of illness thus ICU level care.

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Accuracy of closed pleural biopsy in the diagnosis of malignant pleural effusion

Jornal Brasileiro de Pneumologia ◽

10.1590/s1806-37562016000000323 ◽

2017 ◽

Vol 43 (6) ◽

pp. 424-430 ◽

Cited By ~ 1

Author(s):

Renata Báez-Saldaña ◽

Uriel Rumbo-Nava ◽

Araceli Escobar-Rojas ◽

Patricia Castillo-González ◽

Santiago León-Dueñas ◽

...

Keyword(s):

Pleural Effusion ◽

Diagnostic Test ◽

Likelihood Ratio ◽

Predictive Value ◽

Definitive Diagnosis ◽

Accuracy Analysis ◽

Pleural Biopsy ◽

Post Test ◽

Post Test Probability ◽

Test Probability

ABSTRACT Objective: Previous studies have demonstrated that closed pleural biopsy (CPB) has a sensitivity of less than 60% for diagnosing malignancy. Therefore, controversy has recently emerged regarding the value of CPB as a diagnostic test. Our objective was to assess the accuracy of CPB in diagnosing malignancy in patients with pleural effusion. Methods: This was a prospective 8-year study of individuals who underwent CPB to establish the etiology of pleural effusion. Information on each patient was obtained from anatomopathological reports and medical records. When CPB findings showed malignancy or tuberculosis, the biopsy was considered diagnostic, and that was the definitive diagnosis. In cases in which biopsy histopathological findings were nonspecific, a definitive diagnosis was established on the basis of other diagnostic procedures, such as thoracoscopy, thoracotomy, fiberoptic bronchoscopy, biochemical and cellular measurements in pleural fluid, and/or microbiological tests. The accuracy of CPB was determined with 2 × 2 contingency tables. Results: A total of 1034 biopsies from patients with pleural effusion were studied. Of those, 171 (16.54%) were excluded from the accuracy analysis either because of inadequate samples or insufficient information. The results of the accuracy analysis were as follows: sensitivity, 77%; specificity, 98%; positive predictive value, 99%; negative predictive value, 66%; positive likelihood ratio, 38.5; negative likelihood ratio, 0.23; pre-test probability, 2.13; and post-test probability, 82. Conclusions: CPB is useful in clinical practice as a diagnostic test, because there is an important change from pre-test to post-test probability.

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A “Clinician’s Probability Calculator” to convert pre-test to post-test probability of COVID-19 , based on method validation from each laboratory

10.20944/preprints202012.0094.v1 ◽

2020 ◽

Author(s):

Zoe Brooks ◽

Saswati Das ◽

Tom Pliura

Keyword(s):

Health Staff ◽

Test Results ◽

Likelihood Ratios ◽

Percent Agreement ◽

Public Health Staff ◽

Post Test ◽

Online Calculator ◽

Test Result ◽

Post Test Probability ◽

Test Probability

During coronavirus pandemic testing and identifying the virus has been a unique and constant challenge for the scientific community. In this paper, we discuss a practical solution to help guide clinicians and public health staff with the interpretation of the probability that a positive, or negative, COVID-19 test result indicates an infected person, based on their clinical estimate of pre-test probability of infection. The LinkedIn survey confirmed that the pre-test probability of COVID-19 increases with patient age, known contact, and severity of symptoms, as well as prevalence of disease in the local population. PPA (Positive Percent Agreement, PPA) and NPA (Negative Percent Agreement, specificity), differ between individual methods. Results vary between laboratories and the manufacturer for the same method. The confidence intervals of results vary with the number of samples tested, often adding a large range of possibilities to the reported test result. The online calculator met the objective.The authors postulated that the clinical pre-test probability of COVID-19 increases relative to local prevalence of disease plus patient age, known contact, and severity of symptoms. We conducted a small survey on LinkedIn to confirm that hypothesis. We examined results of PPA (Positive Percent Agreement, sensitivity) and NPA (Negative Percent Agreement, specificity) from 73 individual laboratory experiments for molecular tests for SARS-CoV-2as reported to the FIND database,(1) and for selected methods in FDA EUA submissions (2,3). We calculated likelihood ratios to convert pre-test to post-test probability of disease, then further calculated the number of true and false results expected in every ten positive or negative test results, plus an estimate that one in ‘x’ test results is true. We designed an online calculator to create graphics and text to fulfill the objective. A positive or negative test result from one laboratory conveys a higher probability for the presence or absence of COVID-19 than the same result from another laboratory, depending on clinical pre-test probability of disease plus proven method PPA and NPA in each laboratory. Likelihood ratios and confidence intervals provide valuable information but are seldom used in clinical settings. We recommend that testing laboratories verify PPA and NPA, and utilize a tool such as the “Clinician’s Probability Calculator” to verify acceptable test performance and create reports to help guide clinicians and public health staff with estimation of post-test probability of COVID-19 .

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The diagnostic accuracy of wrist cineradiography in diagnosing scapholunate dissociation

Journal of Hand Surgery (European Volume) ◽

10.1177/1753193413489056 ◽

2013 ◽

Vol 39 (3) ◽

pp. 263-271 ◽

Cited By ~ 20

Author(s):

G. S. I. Sulkers ◽

N. W. L. Schep ◽

M. Maas ◽

C. M. A. M. van der Horst ◽

J. C. Goslings ◽

...

Keyword(s):

Diagnostic Accuracy ◽

Predictive Value ◽

Diagnostic Value ◽

Inclusion Criteria ◽

Scapholunate Ligament ◽

Scapholunate Dissociation ◽

Post Test ◽

Sensitivity Specificity ◽

Post Test Probability ◽

Test Probability

Ruptures of the scapholunate ligament (SLL) may cause carpal instability, also known as scapholunate dissociation (SLD). SLD may lead to osteoarthritis of the radiocarpal and midcarpal joints. The aim of this retrospective study was to determine the diagnostic value of wrist cineradiography in detecting SLD. All cineradiographic studies made during a 24 year period were retrieved. All patients who underwent the confirmation method (arthroscopy and/or arthrotomy) and cineradiography were included. In total, 84 patients met the inclusion criteria. Sensitivity, specificity, likelihood ratio, positive predictive value, negative predictive value, and diagnostic accuracy for detecting SLD were calculated for radiography and cineradiography. Cineradiography had a sensitivity of 90%, a specificity of 97%, and a diagnostic accuracy of 0.93 in detecting SLD. Radiography had a sensitivity of 81%, a specificity of 80%, and a diagnostic accuracy of 0.81. Cineradiography has a high diagnostic value for diagnosing SLDs. A positive cineradiography markedly increases the post-test probability of SLD.

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Hip aspiration culture: analysing data from a single operator series investigating periprosthetic joint infection

Journal of Bone and Joint Infection ◽

10.5194/jbji-6-165-2021 ◽

2021 ◽

Vol 6 (6) ◽

pp. 165-170

Author(s):

Connor J. Barker ◽

Alan Marriot ◽

Munir Khan ◽

Tamsin Oswald ◽

Samuel J. Tingle ◽

...

Keyword(s):

Periprosthetic Joint Infection ◽

Joint Infection ◽

Surgical Care ◽

Comparison Results ◽

Significant Difference ◽

Post Test ◽

Single Operator ◽

Sensitivity Specificity ◽

Post Test Probability ◽

Test Probability

Abstract. Introduction: We undertook this study to know the sensitivity, specificity and post-test probabilities of hip aspiration when diagnosing periprosthetic hip infections. We also examined “dry tap” (injection with saline and aspiration) results and aspiration volumes. Methods: This is a retrospective cohort study of patients aspirated for suspected periprosthetic joint infection between July 2012 and October 2016. All aspirations were carried out by one trained surgical care practitioner (SCP). All aspirations followed an aseptic technique and fluoroscopic guidance. Aspiration was compared to tissue biopsy taken at revision. Aspiration volumes were analysed for comparison. Results: Between January 2012 and September 2016, 461 hip aspirations were performed by our SCP. Of these 125 progressed to revision. We calculated sensitivity 59 % (confidence interval (CI) 35 %–82 %) and specificity 94 % (CI 89 %–98 %). Pre-test probability for our cohort was 0.14. Positive post-test probability was 0.59 and negative post-test probability 0.06. Aspiration volume for infected (n=17) and non-infected (n=108) joints was compared and showed no significant difference. Dry taps were experienced five times; in each instance the dry tap agreed with the biopsy result. Conclusions: Our data show that hip aspiration culture is a highly specific investigation for diagnosing infection but that it is not sensitive. Aspiration volume showed no significant difference between infected and non-infected groups. Each time a joint was infiltrated with saline to achieve a result, the result matched tissue sampling.

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“Clinician’s Probability Calculator” to Convert Pre-Test to Post-Test Probability of COVID-19, Based on Method Validation from Each Laboratory

10.20944/preprints202012.0094.v3 ◽

2021 ◽

Author(s):

Zoe Brooks ◽

Saswati Das ◽

Tom Pliura

Keyword(s):

Test Performance ◽

False Negative ◽

Likelihood Ratios ◽

Unique Challenge ◽

Molecular Tests ◽

Percent Agreement ◽

Post Test ◽

Test Result ◽

Post Test Probability ◽

Test Probability

Identifying the SARS-CoV-2 virus has been a unique challenge for the scientific community. In this paper, we discuss a practical solution to help guide clinicians with interpretation of the probability that a positive, or negative, COVID-19 test result indicates an infected person, based on their clinical estimate of pre-test probability of infection.The authors conducted a small survey on LinkedIn to confirm that hypothesis that that the clinical pre-test probability of COVID-19 increases relative to local prevalence of disease plus patient age, known contact, and severity of symptoms. We examined results of PPA (Positive Percent Agreement, sensitivity) and NPA (Negative Percent Agreement, specificity) from 73 individual laboratory experiments for molecular tests for SARS-CoV-2 as reported to the FIND database 1, and for selected methods in FDA EUA submissions2,3. Authors calculated likelihood ratios to convert pre-test to post-test probability of disease and designed an online calculator to create graphics and text to report results. Despite best efforts, false positive and false negative Covid-19 test results are unavoidable4,5. A positive or negative test result from one laboratory has a different probability for the presence of disease than the same result from another laboratory. Likelihood ratios and confidence intervals can convert the physician or other healthcare professional’s clinical estimate of pre-test probability to post-test probability of disease. Ranges of probabilities differ depending on proven method PPA and NPA in each laboratory. We recommend that laboratories verify PPA and NPA and utilize a the “Clinician’s Probability Calculator” to verify acceptable test performance and create reports to help guide clinicians with estimation of post-test probability of COVID-19.

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Accuracy of a pediatric early warning score in the recognition of clinical deterioration

Revista Latino-Americana de Enfermagem ◽

10.1590/1518-8345.1733.2912 ◽

2017 ◽

Vol 25 (0) ◽

Cited By ~ 4

Author(s):

Juliana de Oliveira Freitas Miranda ◽

Climene Laura de Camargo ◽

Carlito Lopes Nascimento Sobrinho ◽

Daniel Sales Portela ◽

Alan Monaghan

Keyword(s):

Early Warning ◽

Predictive Value ◽

Warning Signs ◽

Clinical Deterioration ◽

Early Warning Score ◽

Reference Standard ◽

Predictive Values ◽

Post Test ◽

Post Test Probability ◽

Test Probability

ABSTRACT Objective: to evaluate the accuracy of the version of the Brighton Pediatric Early Warning Score translated and adapted for the Brazilian context, in the recognition of clinical deterioration. Method: a diagnostic test study to measure the accuracy of the Brighton Pediatric Early Warning Score for the Brazilian context, in relation to a reference standard. The sample consisted of 271 children, aged 0 to 10 years, blindly evaluated by a nurse and a physician, specialists in pediatrics, with interval of 5 to 10 minutes between the evaluations, for the application of the Brighton Pediatric Early Warning Score for the Brazilian context and of the reference standard. The data were processed and analyzed using the Statistical Package for the Social Sciences and VassarStats.net programs. The performance of the Brighton Pediatric Early Warning Score for the Brazilian context was evaluated through the indicators of sensitivity, specificity, predictive values, area under the ROC curve, likelihood ratios and post-test probability. Results: the Brighton Pediatric Early Warning Score for the Brazilian context showed sensitivity of 73.9%, specificity of 95.5%, positive predictive value of 73.3%, negative predictive value of 94.7%, area under Receiver Operating Characteristic Curve of 91.9% and the positive post-test probability was 80%. Conclusion: the Brighton Pediatric Early Warning Score for the Brazilian context, presented good performance, considered valid for the recognition of clinical deterioration warning signs of the children studied.

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Stratum-specific likelihood ratios of two versions of the General Health Questionnaire

Psychological Medicine ◽

10.1017/s0033291701003713 ◽

2001 ◽

Vol 31 (3) ◽

pp. 519-529 ◽

Cited By ~ 36

Author(s):

T. A. FURUKAWA ◽

D. P. GOLDBERG, ◽

S. RABE-HESKETH ◽

T. B. ÜSTÜN

Keyword(s):

General Health ◽

Meta Analysis ◽

General Health Questionnaire ◽

Likelihood Ratios ◽

Random Samples ◽

Post Test ◽

Meta Regression ◽

Post Test Probability ◽

Threshold Approach ◽

Test Probability

Background. In other branches of epidemiology, stratum specific likelihood ratios (SSLRs) have been found to be preferable to fixed best threshold approaches to screening instruments. This paper presents SSLRs of GHQ-12 and GHQ-28 and compares the SSLR method with the traditional optimal threshold approach.Methods. Random effects meta-analysis and meta-regression were used to obtain pooled estimates of SSLRs of the two questionnaires for the 15 centres participating in the WHO study of Psychological Problems in General Health Care. We illustrated the use of SSLRs by applying them to random samples of patients from centres with different backgrounds.Results. For developed and urban centres, the estimates of SSLRs were homogeneous for 10 out of 12 strata of the GHQ-12 and GHQ-28. For other centres, the overall results, which were heterogeneous for six out of 12 strata, were deemed the currently available best estimates. When we applied these results to centres with different prevalences of mental disorders and backgrounds, the estimates matched the actually observed closely. These examples showed how the SSLR approach is more informative than the traditional threshold approach.Conclusions. Those working in developed urban settings can use the corresponding SSLRs with reasonable confidence. Those working in non-urban or developing areas may wish to use the overall results, while acknowledging that they must remain less certain until further research can explicate heterogeneity. These SSLRs have been incorporated into nomograms and spreadsheet programmes so that future researchers can swiftly derive the post-test probability for a patient or a group of patients from a pre-test probability and GHQ score.

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Utility of Bone Marrow Biopsy, Bone Marrow Aspirate, Flow Cytometry, and Molecular Testing in the Clinical Staging of Lymphoma: An Institutional Experience.

Blood ◽

10.1182/blood.v108.11.4596.4596 ◽

2006 ◽

Vol 108 (11) ◽

pp. 4596-4596

Author(s):

Randall J. Dumont ◽

Louis A.V. Fernandez ◽

Ridas Juskevicius

Keyword(s):

Bone Marrow ◽

Predictive Value ◽

Bone Marrow Aspirate ◽

Bone Marrow Involvement ◽

Performance Characteristics ◽

Positive Test Result ◽

Post Test ◽

Test Result ◽

Post Test Probability ◽

Test Probability

Abstract Lymphomas are a diverse group of solid tumors of lymphoid cells that are broadly subdivided into Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) categories. In the Western world, lymphoma is the most common hematologic malignancy. Complete and accurate staging of the patient with lymphoma is essential in determining the extent of initial disease. Bone marrow biopsy (BMB) remains the gold standard for assessing bone marrow involvement by lymphoma. It allows morphological diagnosis as well as the use of immunohistochemistry in difficult cases. At the time of BMB, other specimens are often gathered for use in ancillary investigations that can aid in diagnosis and/or staging. These investigations include bone marrow aspirate (BMA), flow cytometry (FC), and molecular studies (M) such as PCR. The objectives of this study were to evaluate the performance characteristics of BMA, FC, and M relative to BMB in lymphoma staging, to determine how frequently ancillary testing is positive for bone marrow involvement with lymphoma while BMB is negative, as well as to determine the clinical significance of this situation. Retrospective analysis was performed on 294 lymphoma cases from 1997 to 2002 at a single adult tertiary care center. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), pre-test probability (PreTP), post-test probability given a positive test result (PTP+), and post-test probability given a negative test result (PTP−) were determined. Chart review was performed to determine clinical significance of the situation when BMB is negative and one or more ancillary investigations are positive. The number of cases positive for lymphoma by BMB, BMA, M, and FC was 157,113, 109, and 111, respectively. The performance characteristics are indicated in Table I. Twelve cases in which one or more ancillary investigations were positive when BMB was negative were identified. Clinical management was not altered in these cases. In staging of lymphoma, BMB remains the gold standard for the determination of bone marrow involvement. When compared to BMB, ancillary investigations have a high specificity and PPV, but only moderate sensitivity and NPV. Ancillary bone marrow investigations appear to add little information to lymphoma staging, and may not be fiscally justified. Table I. Performance Characteristics Of Ancillary Bone Marrow Investigations In The Staging Of Lymphoma Parameter Bone Marrow Aspirate Molecular FlowCytometry Abbreviations: PPV = positive predictive value; NPV = negative predictive; PreTP = pre-test probability; PTP+ = post-test probability given a positive test result; PTP− = post-test probability given a negative test result Sensitivity 71% 64% 68% Specificity 98% 93% 96% PPV 97% 92% 95% PreTP 53% 53% 53% PTP+ 97% 92% 95% PTP− 26% 31% 28%

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Diagnostic accuracy of a fully automated multiplex celiac disease antibody panel for serum and plasma

Clinical Chemistry and Laboratory Medicine (CCLM) ◽

10.1515/cclm-2019-0088 ◽

2019 ◽

Vol 57 (8) ◽

pp. 1207-1217

Author(s):

Jeff Terryberry ◽

Jani Tuomi ◽

Subo Perampalam ◽

Russ Peloquin ◽

Eric Brouwer ◽

...

Keyword(s):

Celiac Disease ◽

Diagnostic Accuracy ◽

Response To Treatment ◽

Likelihood Ratios ◽

Post Test ◽

Biopsy Confirmation ◽

Automated Platform ◽

Disease Antibody ◽

Post Test Probability ◽

Test Probability

Abstract Background An automated multiplex platform using capillary blood can promote greater throughput and more comprehensive studies in celiac disease (CD). Diagnostic accuracy should be improved using likelihood ratios for the post-test probability of ruling-in disease. Methods The Ig_plex™ Celiac Disease Panel on the sqidlite™ automated platform measured IgA and IgG antibodies to tTG and DGP in n = 224 CD serum or plasma samples. Diagnostic accuracy metrics were applied to the combined multiplex test results for several CD populations and compared to conventional single antibody ELISA tests. Results With multiple positive antibody results, the post-test probability for ruling-in untreated and treated CD increased to over 90%. The number of samples positive for more than one antibody also increased in untreated CD to ≥90%. Measurement of all four CD antibodies generate cut-off dependent accuracy profiles that can monitor response to treatment with the gluten-free diet (GFD). Higher positive tTG and DGP antibodies are seen more frequently in confirmed CD without (81%–94%) than with GFD treatment (44%–64%). In CD lacking biopsy confirmation, overall agreement of plasma to serum was ≥98% for all antibodies, and 100% for venous to capillary plasma. Conclusions The Ig_plex Celiac Disease Panel increases the likelihood of confirming CD based on the post-test probability of disease results for multi-reactive markers. Specific positivity profiles and cut-off intervals can be used to monitor GFD treatment and likely disease progression. Using serum, venous and capillary plasma yield comparable and accurate results.

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Validation of Methicillin-Resistant Staphylococcus aureus (MRSA) Risk Factors in Predicting MRSA Community-Acquired Pneumonia at an Academic Medical Center

Hospital Pharmacy ◽

10.1177/00185787211010149 ◽

2021 ◽

pp. 001857872110101

Author(s):

Joelle Arieno ◽

Robert Seabury ◽

Wesley Kufel ◽

William Darko ◽

Christopher D. Miller ◽

...

Keyword(s):

Risk Factors ◽

Staphylococcus Aureus ◽

Predictive Value ◽

Community Acquired Pneumonia ◽

Respiratory Specimen ◽

The Past ◽

Post Test ◽

History Of ◽

Post Test Probability ◽

Test Probability

Background: The 2019 Infectious Diseases Society of America community-acquired pneumonia (CAP) guidelines recommend antimethicillin- resistant Staphylococcus aureus (MRSA) therapy in patients with CAP based on previously identified risk factors for MRSA with an emphasis on local epidemiology and institutional validation of risk. Thus, we sought to assess the ability of guideline-recognized risk factors to predict MRSA CAP at our institution. Methods: This was a single-center, retrospective cohort study from January 2016 to March 2020. Patients were included if they were >18 years old, diagnosed with CAP, and had a MRSA nasal screen and respiratory culture obtained on admission. Patients were excluded if CAP diagnosis was not met, respiratory cultures were not obtained within 48 hours of antibiotic initiation, or they had cystic fibrosis. Sensitivity, specificity, negative predictive value, positive predictive value, and likelihood ratios (LR) were calculated using Vasser Stats 2019. Pre/post-test odds and pre/post-test probabilities were calculated using Excel 2019. Results: Of 705 screened patients, 221 were included. MRSA prevalence in CAP patients at our institution was 3.6%. History of MRSA isolated from a respiratory specimen had high specificity (98%), high positive LR of 20 (95% CI 5.3–74.8), and high post-test probability of 42.8%. Receipt of IV antibiotics during hospitalization within the past 90 days had a positive LR of 1.9 (95% CI 0.74–4.84). A positive MRSA nasal screen on admission had a positive LR of 6.9 (95% CI 4.0–12.1), negative LR 0.28 (95% CI 0.08–0.93), positive post-test probability of 20.7%, and negative post-test probability of 1.04%. Conclusion: Our study utilized institutional data to validate guideline recognized risk factors for MRSA CAP specifically at our institution. Risk factors including history of MRSA isolated from a respiratory specimen, and positive post-admission MRSA nasal screen were validated as significant risk factors; receipt of IV antibiotics during hospitalization within the past 90 days was not shown to be a risk factor for MRSA CAP based on our institutional data. Validated risk factors may help providers discern which patients with CAP at our institution would benefit most from empiric MRSA treatment.

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