Pre-test probability for SARS-Cov-2-related infection score: The PARIS score

Introduction In numerous countries, large population testing is impossible due to the limited availability of RT-PCR kits and CT-scans. This study aimed to determine a pre-test probability score for SARS-CoV-2 infection. Methods This multicenter retrospective study (4 University Hospitals) included patients with clinical suspicion of SARS-CoV-2 infection. Demographic characteristics, clinical symptoms, and results of blood tests (complete white blood cell count, serum electrolytes and CRP) were collected. A pre-test probability score was derived from univariate analyses of clinical and biological variables between patients and controls, followed by multivariate binary logistic analysis to determine the independent variables associated with SARS-CoV-2 infection. Results 605 patients were included between March 10th and April 30th, 2020 (200 patients for the training cohort, 405 consecutive patients for the validation cohort). In the multivariate analysis, lymphocyte (<1.3 G/L), eosinophil (<0.06 G/L), basophil (<0.04 G/L) and neutrophil counts (<5 G/L) were associated with high probability of SARS-CoV-2 infection but no clinical variable was statistically significant. The score had a good performance in the validation cohort (AUC = 0.918 (CI: [0.891–0.946]; STD = 0.014) with a Positive Predictive Value of high-probability score of 93% (95%CI: [0.89–0.96]). Furthermore, a low-probability score excluded SARS-CoV-2 infection with a Negative Predictive Value of 98% (95%CI: [0.93–0.99]). The performance of the score was stable even during the last period of the study (15-30th April) with more controls than infected patients. Conclusions The PARIS score has a good performance to categorize the pre-test probability of SARS-CoV-2 infection based on complete white blood cell count. It could help clinicians adapt testing and for rapid triage of patients before test results.

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Pre-test probability for SARS-Cov-2-related Infection Score: the PARIS score

10.1101/2020.04.28.20081687 ◽

2020 ◽

Cited By ~ 1

Keyword(s):

Cell Count ◽

White Blood Cell Count ◽

White Blood Cell ◽

High Probability ◽

Validation Cohort ◽

Rt Pcr ◽

Blood Cell Count ◽

Probability Score ◽

Low Probability ◽

Test Probability

AbstractBackgroundDiagnostic tests for SARS-CoV-2 infection (mostly RT-PCR and Computed Tomography) are not widely available in numerous countries, expensive and with imperfect performanceMethodsThis multicenter retrospective study aimed to determine a pre-test probability score for SARS-CoV-2 infection based on clinical and biological variables. Patients were recruited from emergency and infectious disease departments and were divided into a training and a validation cohort. Demographic characteristics, clinical symptoms, and results of blood tests (complete white blood cell count, serum electrolytes and CRP) were collected. The pre-test probability score was derived from univariate analyses between patients and controls, followed by multivariate binary logistic analysis to determine the independent variables associated with SARS-CoV-2 infection. Points were assigned to each variable to create the PARIS score. ROC curve analysis determined the area under the curve (AUC).FindingsOne hundred subjects with clinical suspicion of SARS-CoV-2 infection were included in the training cohort, and 300 other consecutive individuals were included in the validation cohort. Low lymphocyte (<1·3 G/L), eosinophil (<0·06G/L), basophil (<0·04G/L) and neutrophil counts (<5G/L) were associated with a high probability of SARS-CoV-2 infection. No clinical variable was statistically significant. The score had a good performance in the validation cohort (AUC=0.889 (CI: [0.846–0.932]; STD=0.022) with a sensitivity and Positive Predictive Value of high-probability score of 80·3% and 92·3% respectively. Furthermore, a low-probability score excluded SARS-CoV-2 infection with a Negative Predictive Value of 99.5%.InterpretationThe PARIS score based on complete white blood cell count has a good performance to categorize the pre-test probability of SARS-CoV-2 infection. It could help clinicians avoid diagnostic tests in patients with a low-probability score and conversely keep on testing individuals with high-probability score but negative RT-PCR or CT. It could prove helpful in countries with a low-availability of PCR and/or CT during the current period of pandemic.FundingNonePutting research into contextEvidence before this studyIn numerous countries, large population testing is impossible due to the limited availability and costs of RT-PCR kits and CT-scan. Furthermore, false-negativity of PCR or CT as well as COVID-19 pneumonia mimickers on CT may lead to inaccurate diagnoses. Pre-test probability combining clinical and biological features has proven to be a particularly useful tool, already used in clinical practice for management of patients with a suspicion of pulmonary embolism.Added value of this studyThis retrospective study including 400 patients with clinical suspicion of SARS-CoV-2 infection was composed of a training and a validation cohort. The pre-test probability score (PARIS score) determines 3 levels of probability of SARS-CoV2 infection based on white blood cell count (lymphocyte, eosinophil, basophil and neutrophil cell count).Implications of the available evidenceThis pre-test probability may help to adapt SARS-CoV-2 infection diagnostic tests. The high negative predictive value (99·5%) of the low probability category may help avoid further tests, especially during a pandemic with overwhelmed resources. A high probability score combined with typical CT features can be considered sufficient for diagnosis confirmation.

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Diagnostic value of post-operative platelet-to-white blood cell ratio after splenectomy in patients with advanced ovarian cancer

International Journal of Gynecological Cancer ◽

10.1136/ijgc-2019-000712 ◽

2019 ◽

Vol 29 (8) ◽

pp. 1292-1297 ◽

Cited By ~ 4

Author(s):

Konstantinos Lathouras ◽

Georgios Panagakis ◽

Sarah Joanne Bowden ◽

Konstantinos Saliaris ◽

Srdjan Saso ◽

...

Keyword(s):

Ovarian Cancer ◽

Platelet Count ◽

Blood Cell ◽

Cell Count ◽

White Blood Cell Count ◽

White Blood Cell ◽

Predictive Value ◽

Blood Cell Count ◽

Cell Ratio ◽

Grade Iii

IntroductionSplenectomy-induced thrombocytosis and leukocytosis may obscure the early diagnosis of post-operative infection or sepsis. In trauma patients after splenectomy, a platelet-to-white blood cell ratio of <20 has been shown to reliably differentiate post-operative sepsis from transient physiological responses.ObjectiveTo determine whether the platelet-to-white blood cell ratio can be applied to differentiate between reactive post-operative changes and latent infection.MethodsAll consecutive patients with ovarian cancer who underwent splenectomy between January 2013 and October 2018 in two large European gynecological cancer centers were retrospectively evaluated. Main outcome measures were white blood cell count, platelet count, and platelet-to-white blood cell ratio on post-operative days 1, 5, and 7. These were correlated with surgical outcome and morbidity according to the Clavien-Dindo classification. A binomial logistic regression was applied to assess the predictive value of day 5 platelet-to-white blood cell ratio, white blood cell count, and platelet count for predicting grade III post-operative sepsis.ResultsNinety-five patients with ovarian cancer (mean age 54 years, range 18–75) were identified. Seventeen patients (17.9%) developed a grade III post-operative sepsis. In all post-operative patients, mean white blood cell count on day 5 decreased (from 15.4×103/μL to 11.4×103/μL), while the mean platelet count rose (from 260.7×103/μL to 385.3×103/μL). A high platelet count (>313×103/μL) failed to show any predictive value (OR=0.94; 95% CI 0.30 to 3.0; p=0.921). A low platelet-to-white blood cell ratio (<26) (OR=3.49; 95% CI 1.18 to 10.32; p=0.0241) and high white blood cell count (>14.5×103/μL) on day 5 (OR=11.0; 95% CI 3.3 to 36.2; p<0.001) were significant for predicting sepsis. Despite a significant OR, the sensitivity and specificity were low; day 5 platelet-to-white blood cell ratio at a cut-off point of 26 achieved a sensitivity of 72% and specificity of 53% (area under the curve 0.637, 95% CI 0.480 to 0.796) in predicting grade III post-operative sepsis.ConclusionsPlatelet-to-white blood cell ratio after cytoreductive surgery for ovarian cancer with splenectomy does not appear to have a strong predictive value in differentiating between sepsis and reactive splenectomy-induced changes. Leukocytosis, in combination with clinical assessment, may remain the most useful tool for prediction of sepsis after cytoreductive surgery with splenectomy.

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Predictive value of white blood cell count and C-reactive protein in children with appendicitis

Journal of Pediatric Surgery ◽

10.1016/j.jpedsurg.2007.02.010 ◽

2007 ◽

Vol 42 (7) ◽

pp. 1208-1214 ◽

Cited By ~ 72

Author(s):

Marcelo A. Beltrán ◽

Jorge Almonacid ◽

Alfonso Vicencio ◽

Jorge Gutiérrez ◽

Karina S. Cruces ◽

...

Keyword(s):

Blood Cell ◽

Cell Count ◽

White Blood Cell Count ◽

White Blood Cell ◽

Predictive Value ◽

C Reactive Protein ◽

Blood Cell Count ◽

Reactive Protein

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Predictive value of white blood cell count on admission for in-hospital mortality in acute stroke patients

Clinical Neurology and Neurosurgery ◽

10.1016/j.clineuro.2004.03.003 ◽

2004 ◽

Vol 107 (1) ◽

pp. 38-43 ◽

Cited By ~ 34

Author(s):

Radoslaw Kazmierski ◽

Przemyslaw Guzik ◽

Wojciech Ambrosius ◽

Anna Ciesielska ◽

Jakub Moskal ◽

...

Keyword(s):

Blood Cell ◽

Hospital Mortality ◽

Acute Stroke ◽

Cell Count ◽

White Blood Cell Count ◽

White Blood Cell ◽

Predictive Value ◽

Blood Cell Count ◽

Stroke Patients

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Phospholipase A2, C-reactive protein, and white blood cell count in the diagnosis of acute appendicitis

Clinical Chemistry ◽

10.1093/clinchem/40.9.1757 ◽

1994 ◽

Vol 40 (9) ◽

pp. 1757-1760 ◽

Cited By ~ 43

Author(s):

J M Grönroos ◽

J J Forsström ◽

K Irjala ◽

T J Nevalainen

Keyword(s):

Acute Appendicitis ◽

Blood Cell ◽

Phospholipase A2 ◽

Cell Count ◽

White Blood Cell Count ◽

White Blood Cell ◽

Predictive Value ◽

C Reactive Protein ◽

Blood Cell Count ◽

Reactive Protein

Abstract We compared the predictive value of determining group II phospholipase A2 (PLA2) in serum for diagnosing acute appendicitis with the predictive values of white blood cell count (WBC) and measurement of C-reactive protein (CRP). In this prospective study, we included 186 patients who were undergoing appendectomy after clinical diagnoses of acute appendicitis. The performance of each test was measured by receiver-operating characteristic curves. WBC was the test of choice in diagnosing uncomplicated acute appendicitis. However, in contrast to CRP and PLA2, which increased in patients with protracted inflammation, there was not a concomitant increase in WBC. Therefore, especially CRP, but also PLA2, were better indicators of appendiceal perforation or abscess formation than was WBC. Increased WBC, CRP, and PLA2 values did not unequivocally corroborate the clinical suspicion of appendicitis, but if all three values were within normal limits, acute appendicitis could be excluded with a 100% predictive value. PLA2 values showed a highly significant correlation with CRP but not with WBC values, which supports the view that PLA2 represents an acute-phase reactant.

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