Positive Negative Predictive Values Research Articles

792. Predictive Value of Methicillin-Resistant Staphylococcus aureus (MRSA) PCR Nasal Swab for Invasive MRSA Infection in Critically Ill Pediatric Patients: A Promising Tool for Antimicrobial Stewardship

Abstract Background Patients admitted to the pediatric intensive care unit (PICU) are frequently evaluated for bacterial infections and initiated on antibiotic regimens that include a MRSA-active agent even though invasive MRSA infections are rare in this population. The MRSA PCR nasal swab (MRSA-PCR) is a non-invasive test for MRSA colonization that has been shown within adult ICUs to have a high negative predictive value (NPV), making it a potentially valuable tool for antimicrobial stewardship. This study evaluated the performance of the MRSA-PCR in predicting invasive MRSA infection in critically ill pediatric patients. Methods A retrospective cohort study was performed in a 44-bed PICU from January 2013 to December 2018 when it was protocol for all admissions to be screened with a MRSA-PCR. Patients who had both a MRSA-PCR and cultures obtained to evaluate for invasive infection within seven days were included in the study. Invasive MRSA infection was defined by the isolation of MRSA from clinical cultures along with infectious signs and symptoms. A random sample comprising 55% of the patient population was evaluated. We calculated sensitivity, specificity, positive predictive value (PPV) and NPV of the MRSA-PCR for confirmed invasive MRSA infection. Results Of the 4,410 patients reviewed, 1,961 patients met inclusion criteria (45% female, mean age 7.4 yrs. [birth-19.9 yrs.]). MRSA-PCR was positive in 13.5% of patients. Invasive MRSA infection was identified in 25 patients (2 blood, 19 respiratory, 2 soft tissue, 1 pleural fluid, and 1 urine culture) equaling 1.2% of encounters and an incidence rate of 1.1 case per 1,000 patient days. The MRSA-PCR demonstrated a PPV of 8.7% and a NPV of 99.8% (see table). Conclusion The MRSA-PCR has a poor PPV but a very high NPV for invasive MRSA infection in critically ill pediatric patients, a result that is congruent with what has been reported in the adult literature. The high NPV of the MRSA-PCR in this vulnerable patient population makes it a potentially powerful tool for antimicrobial stewardship. Creation of protocols to guide antimicrobial selection based on MRSA-PCR results may lead to a significant reduction in unnecessary antibiotic exposure, drug level monitoring, and patient risk of renal injury or adverse reactions. Disclosures All Authors: No reported disclosures.

Predictive values of the modified Mallampati test, upper lip bite test, thyromental distance and ratio of height to thyromental distance to predict difficult laryngoscopy in pediatric elective surgical patients 5–12 years old at selected Addis Ababa governmental hospitals, Ethiopia: a multicenter cross-sectional study

BackgroundMaintaining patent airways is vital in pediatric anesthetic management. Failure to manage and anticipate difficult laryngoscopy (DL) preoperatively is the leading cause of morbidity and mortality. Data on the predictive values of screening parameters in predicting DL are limited in children. Therefore, this study aimed to assess the predictive value of the modified Mallampati test (MMT), upper lip bite test (ULBT), thyromental distance (TMD), and ratio of height to thyromental distance (RHTMD) in predicting DL in children aged 5–12 years at selected Addis Ababa governmental hospitals in Ethiopia.MethodsA multicenter cross-sectional study was conducted on 141 elective pediatric surgical patients aged 5 to 12 years selected using a systematic random sampling technique at three governmental hospitals from December 1, 2021, to April 30, 2022. The collected data were entered and analysed by SPSS version 26. Chi-square and Fisher’s exact tests were used to compare categorical variables. The receiver operating characteristic curve analysis was used to compare the accuracy of MMT, ULBT, TMD, and RHTMD against DL. A P value < 0.05 was considered statistically significant.ResultsThe magnitude of DL was 15.6%. MMT has the highest sensitivity (86.4%), specificity (91.6%), and negative predictive value (NPV) (97.3%) compared to other tests. The ULBT also has a high sensitivity (72.7%) and specificity (84%) with comparable diagnostic accuracy (90.8%) with the MMT (P < 0.05). The sensitivity, specificity, positive predictive value (PPV), NPV, and accuracy of TMD were 63.6%, 95.8%, 73.7%, 93.4%, and 82.2%, respectively. The RHTMD has the lowest specificity (63.6%), PPV (22.5%), NPV (91.4%), and accuracy (56.7%) in predicting DL.ConclusionThe MMT and ULBT are good screening tests, followed by the TMD in predicting DL, while the RHTMD was the least accurate predictor. Because no single test has 100% predictive value, a combination of screening tests is advised in pediatrics for predicting DL.

Increased Prognostic Yield by Combined Assessment of Non-Contrast Computed Tomography Markers of Antithrombotic-Related Spontaneous Intracerebral Hemorrhage Expansion.

Background and aims: The utility of proposed non-contrast computed tomography (NCCT) markers for the prediction of hematoma expansion in patients with antithrombotic-related spontaneous intracerebral hemorrhage (ICH) is limited. Additionally, there is significant overlap between different suggested ICH shape and density markers. Methods: We assessed the prognostic yield for hematoma expansion of a combined score incorporating features of ICH shape irregularity (satellite sign and/or Barras score ≥ 3), heterogeneous ICH density (swirl sign and/or Barras score ≥ 3) on baseline NCCT and timing from ICH onset to NCCT. Results: We evaluated data from 79 patients with antithrombotic-related spontaneous ICH (32% with hematoma expansion). Swirl (84% vs. 39%) and satellite signs (20% vs. 7%) on baseline NCCT were significantly more prevalent (p < 0.001) in patients with hematoma expansion. Patients with hematoma expansion had more irregular and heterogeneous bleeds on baseline NCCT scans, as quantified by higher (p < 0.001) Barras shape (4 (4–5) vs. 3 (2–4)) and density scores (4 (3–5) vs. 2 (1–3)), respectively. The overall diagnostic yield of the combined score (area under the curve: 0.86, 95%CI: 0.78–0.94) significantly outperformed (p < 0.001) the diagnostic yield of each individual marker. Scores of 4 or 5 in the combined score were associated with a sensitivity of 60.0%, specificity of 90.7%, overall diagnostic accuracy of 81.0%, positive likelihood ratio (LR) of 6.48, negative LR of 0.44, positive predictive value (PV) of 0.76 and negative PV of 0.83. Conclusion: Combined NCCT marker assessment seems to increase the prognostic accuracy for hematoma expansion in antithrombotic-related spontaneous ICH patients.

Can Bone Erosion in Axial Spondyloarthropathy be Detected by Ultrashort Echo Time Imaging? A Comparison With Computed Tomography in the Sacroiliac Joint.

Structural lesion evaluation in axial spondyloarthropathy (SpA) can improve accuracy of diagnosis. However, structural lesions (bone erosions) are difficult to be assessed using conventional MRI compared to computed tomography (CT). To evaluate the diagnostic performance of ultrashort echo time (UTE) for detecting bone erosion in axial SpA compared to T1WI and three-dimensional double-echo steady-state (3D DESS) imaging using CT as the reference standard. Retrospective. Fourteen patients (eight females, 57.1%) and 14 healthy controls (seven females, 50.0%) who underwent sacroiliac (SI) joint MRI and CT. 3 T; TSE T1WI, 3D DESS, 2D UTE. The bilateral SI joints were assessed for bone erosion. Three observers scored bone erosion for all three sequences of MRI. CT was used as the gold standard. Diagnostic confidence in axial SpA was measured based on a four-point confidence score. Correlation of erosion scores between CT and MRI were evaluated using Spearman's correlation test. Sensitivity, specificity, and positive-negative predictive values were calculated. Confidence scores were compared using the Wilcoxon sum rank test. Statistical significance was set at P < 0.05. Compared with erosion scores of CT, the correlation coefficients for each MRI sequence showed significant low-to-high positive correlations (0.39-0.72). UTE imaging showed the highest correlation coefficients for all observers (0.70, 0.72, and 0.67, respectively). The specificity of UTE imaging was equal or higher than those of T1WI and 3D DESS for all observers (0.86 vs. 0.71 vs. 0.57; 0.93 vs. 0.71 vs. 0.57; 0.79 vs. 0.79 vs. 0.43). All observers had the highest confidence in interpreting UTE imaging for detecting bone erosion among the three sequences (3.5, 3.4, and 3.3 for UTE; 3.1, 3.0, and 2.6 for T1WI; and 3.2, 2.7, and 2.4 for DESS). UTE imaging can detect bone erosions in patients with axial SpA and show higher specificity than conventional T1WI and 3D DESS. 4 TECHNICAL EFFICACY: Stage 2.

Discriminant Ability of the Eating Assessment Tool-10 to Detect Swallowing Safety and Efficiency Impairments.

Quick, sensitive dysphagia screening tools are necessary to identify high-risk patients for further evaluation in busy multidisciplinary amyotrophic lateral sclerosis (ALS) clinics. We examined the relationship between self-perceived dysphagia using the validated Eating Assessment Tool-10 (EAT-10) and videofluoroscopic analysis of swallowing safety and efficiency. Prospective, observational, longitudinal study. Individuals with ALS completed the EAT-10 and a videofluoroscopic swallowing study. Duplicate, independent, blinded analyses of the validated Dynamic Imaging Grade of Swallowing Toxicity (DIGEST) scale were performed to index swallowing safety and efficiency (mild dysphagia: DIGEST ≥ 1, moderate dysphagia: DIGEST ≥ 2). A between-groups analysis of variance with Games-Howell test for post-hoc pairwise comparisons was performed to examine EAT-10 scores across dysphagia severity levels. Receiver operator characteristic curve analysis, area under the curve (AUC), sensitivity, specificity, positive-negative predictive values (PPV, NPV), and odds ratios (OR) were derived. Four hundred and thirty five paired EAT-10 and DIGEST scores were analyzed. Mean EAT-10 score was 8.48 (95% confidence interval [CI]: 7.63-9.33). Individuals with dysphagia demonstrated higher EAT-10 scores (mild: 4.1 vs. 11.3, moderate: 6.0 vs. 17.5, P < .001). Mean EAT-10 scores increased across DIGEST levels (D0: 4.1, D1: 7.9, D2: 15.1, D3: 20.4, D4: 39.0). For mild dysphagia, an EAT-10 cut score of 3 was optimal: AUC 0.74 (95% CI: 0.69-0.78; sensitivity: 77%; specificity: 53%; PPV: 71%; NPV: 60%; OR: 3.5). An EAT-10 cut score of 7 optimized detection of moderate dysphagia: AUC 0.83 (95% CI: 0.78-0.87; sensitivity: 81%; specificity: 66%; PPV: 39%; NPV: 93%; OR: 8.1). The EAT-10 is an easy-to-administer dysphagia screening tool with good discriminant ability for use in ALS clinics. 2 Laryngoscope, 132:2319-2326, 2022.

Turkish Adaptation Study of the Ask Suicide-Screening Questions in Adolescents.

This study aimed to demonstrate the validity of the Ask Suicide-Screening Questions (ASQ) in a clinical sample consisting of adolescents admitted to child and adolescent psychiatry (CAP), and then to confirm its validation in those presenting to the pediatric emergency department (PED), which was the main target group for the study. This cross-sectional study evaluated the compatibility of the ASQ with the suicide probability scale, which is a standardized measure, to identify cases with suicide risk in 248 adolescents aged 10-18 years. To demonstrate the clinical validity of the scale, sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (PLR), negative likelihood ratio (NLR), Kappa, and area under the curve (AUC) performance metrics and 95% confidence interval (CI) values were calculated. Positive screening rate, sensitivity, specificity, PPV and NPV for the CAP patients were calculated as 31.8%, 100% (95% CI: 100.0-100.0), 70.9% (95% CI: 63.4-78.4), 12.8% (95% CI: 3.2-22.3) and 100% (95% CI: 100.0-100.0), respectively. The PLR and AUC were calculated as 3.4% (95% CI: 2.7-4.5) and 0.855 (95% CI: 0.817-0.892), respectively. Positive screening rate, sensitivity, specificity, PPV and NPV for the PED patients were calculated as 28%, 100% (95% CI: 100.0-100.0), 75.3% (95% CI: 66.3-84.2), 21.4% (95% CI: 6.2-36.6) and 100% (95% CI: 100.0-100.0), respectively. The PLR, Kappa and AUC were 4.05% (95% CI: 2.82-5.81), 0.278 and 0.876 (95% CI: 0.832-0.921), respectively. This study showed the first evidence that Turkish adaptation of the ASQ is a valid screening tool for identifying those at risk of suicide among adolescents who applied to the CAP and PED.

Vitals are Vital: Simpler Clinical Data Model Predicts Decompensation in COVID-19 Patients

Abstract Objective Several risk scores have been developed and tested on coronavirus disease 2019 (COVID-19) patients to predict clinical decompensation. We aimed to compare an institutional, automated, custom-built early warning score (EWS) to the National Early Warning Score (NEWS) in COVID-19 patients. Methods A retrospective cohort analysis was performed on patients with COVID-19 infection who were admitted to an intermediate ward from March to December 2020. A machine learning–based customized EWS algorithm, which incorporates demographics, laboratory values, vital signs, and comorbidities, and the NEWS, which uses vital signs only, were calculated at 12-hour intervals. These patients were retrospectively assessed for decompensation in the subsequent 12 or 24 hours, defined as death or transfer to an intensive care unit. Results Of 709 patients, 112 (15.8%) had a decompensation event. Using the custom EWS, decompensation within 12 and 24 hours was predicted with areas under the receiver operating curve (AUC) of 0.81 and 0.79, respectively. The NEWS score applied to the same population yielded AUCs of 0.83 and 0.81, respectively. The 24-hour negative predictive values (NPV) of the NEWS and EWS in patients identified as low risk were 99.6 and 99.2%, respectively. Conclusion The NEWS score performs as well as a customized EWS in COVID-19 patients, demonstrating the significance of vital signs in predicting outcomes. The relatively high positive predictive value and NPV of both scores are indispensable for optimally allocating clinical resources. In this relatively young, healthy population, a more complex score incorporating electronic health record data beyond vital signs does not add clinical benefit.

A radiological predictor for pneumomediastinum/pneumothorax in COVID-19 ARDS patients.

PurposeTo determine whether Macklin effect (a linear collection of air contiguous to the bronchovascular sheath) on baseline CT imaging is an accurate predictor for subsequent pneumomediastinum (PMD)/pneumothorax (PNX) development in invasively ventilated patients with COVID-19-related acute respiratory distress syndrome (ARDS).Materials and methodsThis is an observational, case-control study. From a prospectively acquired database, all consecutive invasively ventilated COVID-19 ARDS patients who underwent at least one baseline chest CT scan during the study time period (February 25th, 2020–December 31st, 2020) were identified; those who had tracheal lesion or already had PMD/PNX at the time of the first available chest imaging were excluded.Results37/173 (21.4%) patients enrolled had PMD/PNX; specifically, 20 (11.5%) had PMD, 10 (5.8%) PNX, 7 (4%) both. 33/37 patients with subsequent PMD/PNX had Macklin effect on baseline CT (89.2%, true positives) 8.5 days [range, 1–18] before the first actual radiological evidence of PMD/PNX. Conversely, 6/136 patients without PMD/PNX (4.4%, false positives) demonstrated Macklin effect (p < 0.001). Macklin effect yielded a sensitivity of 89.2% (95% confidence interval [CI]: 74.6–96.9), a specificity of 95.6% (95% CI: 90.6–98.4), a positive predictive value (PV) of 84.5% (95% CI: 71.3–92.3), a negative PV of 97.1% (95% CI: 74.6–96.9) and an accuracy of 94.2% (95% CI: 89.6–97.2) in predicting PMD/PNX (AUC:0.924).ConclusionsMacklin effect accurately predicts, 8.5 days in advance, PMD/PNX development in COVID-19 ARDS patients.

Use of electronic self-administered bleeding assessment tool in diagnosis of paediatric bleeding disorders.

In the era of electronic medical records, pen-and-paper-based physician-administered bleeding assessment tools (BAT) remain under-utilized in the clinical setting, as they are noted to be time-consuming. The current study reviews the use of an electronic self-administered bleeding assessment tool (eBAT) prospectively in a paediatric haematology clinic and in comparison with a physician administered BAT (pBAT). This was reviewed and approved in the current form because the aims statement includes the method regarding comparison of 2 groups. So no additional section required. A total of 94 BAT response pairs were available for analysis. The median time required for patients or parents to complete the eBAT was 8 min, with less than a third of the patients requiring over 10 min. The median bleeding scores noted in this study were 4 for both the BATs, with strong positive correlation between the eBAT and the physician administered bleeding questionnaire. The eBAT had a sensitivity of 93.8% (95% CI 82.8%-98.7%), a specificity of 34.8% (95% CI 21.4%-50.3%), a positive predictive value (PV) of 60.0% (95% CI 54.5%-65.2%) and a negative PV of 84.2% (95% CI 62.5%-94.5%) for identifying a bleeding disorder. Findings indicate that eBAT is a valid and time-efficient screening tool for evaluating patients' bleeding symptoms, which can improve clinical applicability of BATs by reducing time for bleeding history review.

Secondhand tobacco smoke exposure among children under 5 years old: questionnaires versus cotinine biomarkers: a cohort study

ObjectivesCotinine is the gold standard to estimate prevalence of secondhand tobacco smoke (SHS) exposure, and assay limit of detection (LOD) cut-points are typically used regardless of age. Our aim was...

Performance of simple serum-based tests to exclude cirrhosis prior to hepatitis C treatment in non-hospital settings in Australia.

Current guidelines suggest using transient elastography (TE) or aspartate aminotransferase to platelet ratio index (APRI) score <1 to exclude cirrhosis prior to commencing treatment for hepatitis C virus (HCV). Recently, fibrosis-4 (FIB-4) <0.93 has been shown to have a high negative predictive value (NPV) for the presence of cirrhosis. To assess FIB-4 and APRI in a cohort of HCV patients and to validate FIB-4 <0.93 in populations of HCV-infected individuals with differing cirrhosis prevalence, including secondary care, primary care and prisons. From our treatment database, we identified patients with complete data (n = 793). We calculated FIB-4 and APRI and correlated this with the presence of cirrhosis, determined by TE. We analysed the performance of FIB-4 and APRI using area under the receiver operating curve analysis. We calculated sensitivity, specificity, positive predictive value, NPV and number of patients misclassified using published cut-offs in populations with varying cirrhosis prevalence. FIB-4 was superior to APRI for the diagnosis of cirrhosis (area under the receiver operating curve 0.868 vs 0.802). In secondary care (cirrhosis prevalence 32%), APRI <1 had a NPV of 80% and misclassified 14% of patients. FIB-4 <0.93 had a NPV of 97% and misclassified 1%. In primary care and prison (cirrhosis prevalence 13% and 8%), the NPV for APRI <1 was 93% and 96%, respectively, but 5% of patients with cirrhosis were misclassified. FIB-4 <0.93 had excellent NPV in both primary care (97%) and prisoners (100%). FIB-4 <0.93 is highly efficient at ruling out cirrhosis in HCV patients and allows TE to be appropriately avoided, thereby streamlining treatment algorithms.

Usefulness of quantitative hepatitis B surface antigen testing in hepatitis B community-based screening

Low viral load (LVL) of hepatitis B virus (HBV) is a predictor of chronic HBV infection. However, the usefulness of quantitative hepatitis B surface antigen (qHBsAg) in predicting LVL in community-based screening has not been well studied. We aimed to measure the prevalence of LVL in HBV carriers and validate the efficacy of qHBsAg in predicting LVL. This community-based screening study was conducted in Taiwan. HBV DNA was assayed in HBsAg carriers. Participants were randomized to training and validation sets to determine the ability of qHBsAg to predict LVL. Receiver operating characteristic curves were used to identify the best cutoff values in the training set. Among the 2919 participants, 359 (12.2%) were HBsAg carriers. There were 132 and 137 carriers in the training and validation sets, respectively. Significant correlations were found between qHBsAg and HBV DNA in both training and validation sets. Thirty and 29 participants with qHBsAg <8IU/mL in the training and validation sets, respectively, had LVL. Using 8IU/mL as the cutoff, negative predictive value (NPV) of qHBsAg for HBV DNA levels >2000IU/mL was 100%. The best cutoff level of qHBsAg to predict HBV LVL was 200IU/mL, with a sensitivity, specificity, and accuracy of 75.0%, 76.1%, and 75.8%, respectively, in the training set. The positive predictive value and NPV were 70.0% and 77.9%, respectively, in the validation set. Approximately 60% of HBsAg carriers had HBV LVL, and qHBsAg <8IU/mL accurately predicts LVL. This quantitative test provides additional information for community-based screening.

Comparison of Immunohistochemistry and Conventional Stains for Helicobacter Pylori Detection in Gastric Biopsies of Patients Receiving Proton Pump Inhibitors

Objective: To evaluate the diagnostic performance of different staining methods for Helicobacter pylori (H. pylori) in patients treated with proton pump inhibitors (PPI) Material and Methods: This is a retrospective study involving 75 gastric biopsies from patients with and without PPI therapy between October 2018 and September 2019. Slides were stained with hematoxylin and eosin (H&amp;E); Giemsa and immunohistochemical staining (IHC) was done using polyclonal anti-H. pylori antibodies. Statistical analysis was performed to determine any association between the results of different staining methods and PPI consumption. Sensitivity, specificity and positive-negative predictive values of H&amp;E and Giemsa stains were calculated. Results: Overall, H. pylori infection was detected in 33.3% of patients using IHC, 26.7% using H&amp;E, and 28.0% via Giemsa staining. A strong correlation was found between PPI consumption and low H. pylori density detected via IHC (p-value=0.015) but not using H&amp;E and Giemsa staining. The sensitivity of H&amp;E and Giemsa was markedly reduced as a result of PPI consumption (57.1% to 18.2% vs. 85.7% to 27.3%, respectively). Conclusion: Identification of H. pylori using IHC in patients treated with PPI was superior to H&amp;E and Giemsa stains. Both H&amp;E and Giemsa stains showed a marked decrease in sensitivity in patients receiving PPI. The results indicate that IHC should be performed in patients with PPI therapy instead of H&amp;E or Giemsa stains, and PPI should be discontinued for at least 14 days before the performance of endoscopy.

Absolute Lymphocyte Count as a Surrogate for Lymphocyte Phenotype Analysis of CD3 Count in Monitoring Thymoglobulin Response Post Heart Transplantation

Dosing of Anti-thymocyte globulin therapy (ATG), used in the prevention and treatment of rejection, is optimally guided by CD3 levels. The purpose of this study was to establish the reliability of using Absolute Lymphocyte Count (ALC) as a substitute for CD3 given its ready availability and low cost. A retrospective review was conducted of heart transplant recipients from 9/2014 to 2/2019 who received ATG and had a CD3 count with corresponding ALC. The Pearson correlation coefficient was used to examine the correlation between ALC and CD3. Validity tests and the Youden Index were performed to identify an appropriate range for an ALC cutoff that would provide the greatest degree of validity of ALC as an appropriate surrogate for a CD3 cutoff of 100 cells/mm3. 332 paired samples were collected. Analysis demonstrated correlation between ALC and CD3 count. The Pearson correlation coefficient was 0.45 (R-Square 0.23), p less than 0.0001. Validity testing of ALC of 200 cells/mm3 against CD3 counts 100 cells/mm3 showed sensitivity 0.635 (160/252), specificity 0.875 (70/80), positive predictive value (PV) 0.941 (160/170), and negative PV 0.432 (70/162). Based on the Youden index, the zone for the optimal cutoff points ranged from 100 to 200 cells (Figure 1). AUC for the ROC analysis was 0.81 (Figure 2). This study suggests that ALC may have validity as a selective substitute for CD3 monitoring in patients receiving ATG. Further studies of this novel approach are warranted.

Predictive value of p16INK4a, Ki-67 and ProExC immuno-qualitative features in LSIL progression into HSIL.

The current nested case-control study was conducted to explore the prognostic value of cyclin-dependent kinase inhibitor 2A (p16INK4a), marker of proliferation Ki-67 (Ki-67) and immunohistochemical cocktail containing antibodies directed against topoisomerase IIα (TOP2A) and minichromosome maintenance 2 (MCM2) proteins (ProExC) immuno-qualitative features to predict low-grade squamous intraepithelial lesion (LSIL) progression. A total of 92 LSIL patients were followed-up for 2 years, where those with high-grade squamous intraepithelial lesion (HSIL) or persistent LSIL were designated as the case group and those who spontaneously regressed were designated as the control group. The infection status of human papillomavirus (HPV) was evaluated using flow-through hybridization and gene chip, whilst the expression of p16INK4a, Ki-67 and ProExC were tested in LSIL patient biopsies by immunohistochemistry. All data were collected at the beginning of the follow-up and patient outcomes were diagnosed by histopathological examination. To analyze the risk factors for LSIL progression, sensitivity, specificity, positive-negative predictive value (PPV-NPV), positive-negative likelihood ratio (PLR-NLR), Youden's index (YI) and multinomial logistic regression analysis was performed. The expression rates of p16INK4a, Ki-67, and ProExC were found to be higher in the progression group compared with those in the persistence and regression groups. Only p16INK4a expression significantly associated with high-risk HPV infection. With respect to predicting HSIL, p16INK4a staining was the most sensitive but Ki-67 staining was found to be the most specific. YI was the highest (42.1%) for p16INK4a expression in the present study, followed by ProExC (39.5%) and Ki-67 (28.3%). However, the expression of ProExC was found to be an independent risk factor for LSIL progression into HSIL. In conclusion, whilst immunohistochemical staining for p16INK4a, Ki-67, and ProExC can be used to predict HSIL progression, only ProExC expression can be applied an independent risk factor for LSIL progression.

Comparison of the clinical significance of serum HE4, CA125 and ROMA in the differential diagnosis of ovarian tumor

Objective To compare the clinical significance of human epididymis protein 4(HE4), CA125, ROMA in the differential diagnosis of ovarian cancer. Methods From May 2016 to October 2017, 240 patients with ovarian tumor in Xuzhou Cancer Hospital were selected.According to the result of postoperative pathology, the patients were divided into benign ovarian disease group(n=120) and ovarian cancer group(n=120). And 100 healthy women from medical examination center were selected as control group.The electrochemiluminescence (ECLIA) technique was used to assess the serum levels of CA125, HE4, and ROMA was calculated.The clinical significance of HE4, CA125, ROMA in the differential diagnosis of ovarian cancer was analyzed by statistic methods. Results The CA125, HE4 concentrations and ROMA in the ovarian cancer group[(370.9±213.2)U/mL, (364.4±227.0)pmpl/L, (80.2±26.1)%]were higher than those in the benign ovarian disease group and the health control group(all P<0.01), there were no statistically significant differences between the benign ovarian disease group and the healthy control group(P=0.356, P=0.321, P=0.292). The sensitivity, specificity, positive and negative predictive values, accuracy of ROMA were higher than those of HE4 and CA125.By using the ROC analysis, the AUC for CA125, HE4, ROMA were 0.832, 0.888, 0.960, respectively, AUC(CA125)<AUC(HE4)<AUC(ROMA). Conclusion CA125 and HE4 have important value in the diagnosis of ovarian cancer, but the ROMA shows the best diagnostic performance and actual value. Key words: Ovarian neoplasms; CA-125 antigen; Human epididymis protein 4; ROC curve; Diagnosis, differential; ROMA

2157. Evaluation of the Utility of the MRSA Nasal PCR Assay in a Community Healthcare System

BackgroundThe MRSA nasal PCR assay is a rapid, noninvasive test that has demonstrated a strong negative predictive value (NPV), as high as 99%, for ruling out MRSA pneumonia. These findings are based primarily on literature from large academic centers, which have evaluated both the positive predictive value (PPV) and NPV of MRSA nasal PCR assays. Investigators sought to assess the NPV of the MRSA nasal PCR assay to rule out MRSA pneumonia within a community healthcare system. To the best of our knowledge, this is the largest study from a community hospital and the only study from a community healthcare system for the utilization of a nasal PCR assay to rule out MRSA pneumonia.MethodsThis is a multicenter, retrospective study of adult patients with both an MRSA nasal PCR assay and positive respiratory culture (sputum, bronchoalveolar lavage, or endotracheal aspirate). Data were collected from September 2014 through August 2015 at three community hospitals (bed size ranging from 328 to 706) across two states within a healthcare system. The study was approved by the Baptist Memorial Hospital Institutional Review Board. PPV and NPV 95% confidence intervals (95% CI) were calculated as previously described in the literature.ResultsA total of 808 patients were included in the analysis across the three hospitals. The total incidence of MRSA in positive sputum samples was 14.9% across the three facilities. Our study demonstrated an overall NPV of 95.1% (93.2, 96.6%) and a PPV of 65.9% (95% CI 57.2, 73.9%). The high NPV was retained despite unit type, resulting in 94.9% (95% CI 92.7, 96.6%), 96.3% (95% CI 90.8, 99.0%), and 94.7% (95% CI 74.0, 99.9%) for the intensive care units (ICU), medical-surgical units, and the emergency department, respectively (Table 1).ConclusionWe concluded that the high NPV of a negative MRSA nasal PCR assay to rule out MRSA pneumonia persisted within a community hospital system. With the results of our study, we plan to utilize institution-specific data along with previously published literature to encourage earlier discontinuation of anti-MRSA antibiotics in patients being treated for pneumonia with negative MRSA nasal PCR assays. Our study demonstrates the validity of the assay in the large community hospital setting with similar findings to studies at large academic institutions. Disclosures All authors: No reported disclosures.

Agreement between results of meta-analyses from case reports and clinical studies, regarding efficacy and safety of idursulfase therapy in patients with mucopolysaccharidosis type II (MPS-II). A new tool for evidence-based medicine in rare diseases

BackgroundA preliminary exploratory study shows solid agreement between the results of case reports and clinical study meta-analyses in mucopolysaccharidosis Type I (MPS-I) adult patients. The aim of the present study is to confirm previous results in another patient population, suffering from mucopolysaccharidosis Type II (MPS-II).MethodsA systematic review and meta-analysis of case reports published by April 2018 was conducted for MPS-II patients treated with enzyme replacement therapy (ERT). The study is reported in accordance with PRISMA and MOOSE guidelines (PROSPERO database code CRD42018093408). The assessed population and outcomes were the same as previously analyzed in a meta-analysis of MPS-II clinical studies. The primary endpoint was the percent of clinical cases showing improvement in efficacy outcome, or no harm in safety outcome after ERT initiation. A restrictive procedure to aggregate case reports, by selecting standardized and well-defined outcomes, was proposed. Different sensitivity analyses were able to evaluate the robustness of results.ResultsEvery outcome classified as “acceptable evidence group” in our case report meta-analysis had been graded as “moderate strength of evidence” in the aforementioned meta-analysis of clinical studies. Sensitivity, specificity, and positive-negative predictive values for results of both meta-analyses reached 100%, and were deemed equivalent.ConclusionsAggregating case reports quantitatively, rather than analyzing them qualitatively, may improve conclusions in rare diseases and personalized medicine. Additionally, we propose some methods to evaluate publication bias and heterogeneity of the included studies in a meta-analysis of case reports.

P308Utility of a prominent R wave in lead V1 of a resting electrocardiogram for detecting significant cardiac pathology in an unselected population of young males

Abstract Background Pre-participation electrocardiogram (ECG) screening is proposed as a means to detect cardiac pathology in asymptomatic individuals, and to select individuals for further cardiac investigation. Isolated ECG finding of Right Ventricular Hypertrophy (RVH) does not require further investigation based on the recent 2017 International Criteria. However, a prominent R wave in V1 has been described in cardiac abnormalities such as Wolff-Parkinson-White syndrome, hypertrophic cardiomyopathy, cardiomyopathy in Duchenne muscular dystrophy, arrhythmogenic right ventricular cardiomyopathy (ARVC), atrial septal defect and pulmonary hypertension. Purpose We sought to examine the utility of a prominent R wave in V1 as a screening criterion in an asymptomatic young male population of predominantly non-athletes, to detect significant structural cardiac pathology. Methods As part of the Singapore Armed Forces Electrocardiographic and Echocardiographic (SAFE) Protocol Study, pre-military enlistment screening ECG data was collected from 144,346 males between the ages of 16 to 22 from November 2009 to December 2014. Patients with ECGs with a prominent R wave, defined as an R wave ≥0.5mV in lead V1 with an R/S ratio of ≥1, were sent to a tertiary medical facility for a detailed transthoracic echocardiogram and subsequent cardiologist review. Any cardiac pathology identified was deemed significant if it led to the patient being excluded from participation in vigorous physical activity. Results 1,144 patients with an isolated prominent R wave in V1 were studied. The mean age was 18.2±1.09 years and 81% were of Chinese ethnicity. None of the patients had echocardiographic evidence of RVH, 5 patients had a dilated right ventricle and 3 individuals had an elevated pulmonary artery systolic pressure. 11 patients (0.96%) had significant structural heart disease known to be associated with a prominent R wave in V1 that excluded them from participation in physical activity. These included large atrial septal defects (n=8), pulmonary stenosis (n=1), total anomalous pulmonary venous return (n=1) and hypertrophic cardiomyopathy (n=1). The test has a sensitivity of 21.6%, specificity of 93.4%, positive predictive value of 0.96% and negative predictive value of 99.8%, Performance As Screening Criteria Number of Patients With Cardiac Pathology In Those Tested Positive Number of Patients With Cardiac Pathology In Those Tested Negative Positive Predictive Value (%) Negative Predictive Value (%) Sensitivity (%) Specificity (%) 11 40 0.96 99.8 21.6 93.4 Significant Cardiac Pathology Identified Conclusion A prominent R in V1 is not associated with echocardiographic RVH, or ARVC even in a large predominantly non-athletic male population. However, 0.96% of such patients would have other significant cardiac pathologies such as a large atrial septal defect.

External Validation of ASPECT (Algorithm for Suspected Pulmonary Embolism Confirmation and Treatment).

Administrative health care databases are increasingly being used to study pulmonary embolism (PE), but the validity of single PE codes is variable. Using data from Quebec, Canada, we developed ASPECT (Algorithm for Suspected Pulmonary Embolism Confirmation and Treatment), combining 3 components to ascertain confirmed PE: emergency department (ED) diagnoses, imaging codes, and dispensed prescriptions or hospital diagnoses. Herein, we used unrelated administrative health care databases to externally validate ASPECT. We used ED electronic health records (ED-EHRs) to identify all residents of Calgary (Alberta, Canada) with PE codes between January and June, 2016. We applied ASPECT by identifying imaging studies in the ED-EHR, admission diagnoses in linked discharge abstract database and filled prescriptions in linked pharmacy information. Confirmed PE in ASPECT was validated against chart review in the ED-EHR. The cohort included 498 patients. Overall, 258 (51.9%) were managed as outpatients and 327 were adjudicated to have confirmed PE; the positive predictive value (PV) of single PE codes was 65.6%. With ASPECT the positive PV was 96.5% [95% confidence interval (CI), 94.4-98.5%] and positive likelihood ratio was 10.9 (95% CI, 6.8-15.1). The negative PV and negative likelihood ratio were 85.1% (95% CI, 80.0-90.2%) and 0.1 (95% CI, 0.0-0.1), respectively. Overall agreement of ASPECT with confirmed PE was 92.2%. Further, ASPECT was similarly robust in inpatients and outpatients and was more precise than any 2-component combination of ASPECT. Our findings reiterate the limitations of using single administrative codes for PE and suggest ASPECT as an acceptable tool to study PE.