scholarly journals Correlating data from different sensors to increase the positive predictive value of alarms: an empiric assessment

F1000Research ◽  
2012 ◽  
Vol 1 ◽  
pp. 45 ◽  
Author(s):  
Yuval Bitan ◽  
Michael F O’Connor
Keyword(s):  
Positive Predictive Value ◽  
False Alarm ◽  
False Alarm Rate ◽  
Predictive Value ◽  
Left Ventricular ◽  
False Alarms ◽  
Expert Clinician ◽  
Correlated Information ◽  
Sensitivity Specificity ◽  
High False Alarm Rate

Objectives: Alarm fatigue from high false alarm rate is a well described phenomenon in the intensive care unit (ICU). Progress to further reduce false alarms must employ a new strategy. Highly sensitive alarms invariably have a very high false alarm rate. Clinically useful alarms have a high Positive-Predictive Value. Our goal is to demonstrate one approach to suppressing false alarms using an algorithm that correlates information across sensors and replicates the ways that human evaluators discriminate artifact from real signal.Methods: After obtaining IRB approval and waiver of informed consent, a set of definitions, (hypovolemia, left ventricular shock, tamponade, hemodynamically significant ventricular tachycardia, and hemodynamically significant supraventricular tachycardia), were installed in the monitors in a 10 bed cardiothoracic ICU and evaluated over an 85 day study period. The logic of the algorithms was intended to replicate the logic of practitioners, and correlated information across sensors in a way similar to that used by practitioners. The performance of the alarms was evaluated via a daily interview with the ICU attending and review of the tracings recorded over the previous 24 hours in the monitor. True alarms and false alarms were identified by an expert clinician, and the performance of the algorithms evaluated using the standard definitions of sensitivity, specificity, positive predictive value, and negative predictive value.Results: Between 1 and 221 instances of defined events occurred over the duration of the study, and the positive predictive value of the definitions varied between 4.1% and 84%.Conclusions: Correlation of information across alarms can suppress artifact, increase the positive predictive value of alarms, and can employ more sophisticated definitions of alarm events than present single-sensor based systems.

scholarly journals False alarms and the positive predictive value of smartphone-based hyperacuity home monitoring for the progression of macular disease: a prospective cohort study

Eye ◽  
2021 ◽  
Author(s):  
Livia Faes ◽  
Meriam Islam ◽  
Lucas M. Bachmann ◽  
Kenny R. Lienhard ◽  
Martin K. Schmid ◽  
...  
Keyword(s):  
Cohort Study ◽  
Positive Predictive Value ◽  
False Alarm ◽  
False Alarm Rate ◽  
Prospective Cohort Study ◽  
Predictive Value ◽  
Prospective Cohort ◽  
Home Monitoring ◽  
False Alarms ◽  
Macular Disease

Abstract Background Home monitoring of hyperacuity allows early detection of progression in exudative neovascular age-related macular degeneration (nvAMD) and diabetic macular oedema (DMO). However, false alarms may pose a significant burden to both patients and healthcare professionals alike. Purpose To assess the false alarm rate and positive predictive value of smartphone-based home monitoring of nvAMD and DMO. Methods Patients treated with anti-angiogenic therapy in a pro re nata scheme for nvAMD or DMO at the Medical Retina service (Lucerne, Switzerland) between March and June 2016 were included in this prospective cohort study. The home monitoring test Alleye (Oculocare Ltd, Switzerland) provided a session score from 0–100 in addition to a traffic-light system feedback via the smartphone application. Three consecutive “red” scores were considered as a positive test or alarm signal. Specificity, 1-specificity (false alarm rate) and the predictive value for optical coherence tomography-based disease progression were analysed. Results 73 eyes of 56 patients performed 2258 tests in 222 “follow-up periods”. Progression was observed in 141 periods (63.5%). The specificity of the test was 93.8% (95% CI: 86.2–98.0%), the false alarm rate 6.1% (95% CI: 2.0–13.8%), and the positive predictive value 80.0% (95% CI: 59.3–93.2%) for the detection of progression. Conclusion False alarm rates for the detection of progression in macular disease via home monitoring is low. These findings suggest that home monitoring may be a useful adjunct for remote management of nvAMD and DMO.

Defining cardiotoxicity of doxorubicin and trastuzumab.

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. e23097-e23097
Author(s):  
Abir Khan ◽  
Omid Amidi ◽  
Kenneth R. Hess ◽  
Michael S. Ewer ◽  
Wamique Yusuf ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Heart Failure ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Ventricular Ejection Fraction ◽  
Clinical Heart Failure ◽  
Definition Of ◽  
Sensitivity Specificity

e23097 Background: Doxorubicin and trastuzumab have been described to cause clinical heart failure and asymptomatic declines in left ventricular ejection fraction (LVEF). Initial studies of doxorubicin in the 1970’s defined cardiotoxicity by the clinical syndrome of heart failure without imaging for LVEF determination. Trials with adjuvant trastuzumab used various LVEF cut-offs that were arbitrarily determined. This study aims to compare the predictive value of commonly used definitions of cardiotoxicity associated with chemotherapy for the development of clinical heart failure. Methods: A retrospective chart review was performed on an IRB approved cohort of 638 patients with breast cancer who received doxorubicin, trastuzumab, or both and who had baseline and follow up echocardiograms, collecting LVEF values for each echocardiogram. Clinical heart failure was determined by formal cardiology evaluations denoting clinical heart failure in patients. Four different definitions of cardiotoxicity were compared; American Society of Echocardiography (ASE), Cardiac Review and Evaluation Committee (CREC), Alexander et al, and Schwartz et al (Table). Results: Only 8 patients (1.25%) developed clinical heart failure. The sensitivity, specificity, positive predictive value, and negative predictive value of each definition of cardiotoxicity are listed in the table. Conclusions: Overall there is a low threshold for detection of clinical heart failure in breast cancer therapy. While the ASE definition has the highest combination of sensitivity, specificity, and positive predictive value, it has a sensitivity of only 62.5%. Thus, cardiologists and oncologists should collaborate to develop a definition of cardiotoxicity better correlated to clinical outcomes. [Table: see text]

scholarly journals Realizing Target Detection in SAR Images Based on Multiscale Superpixel Fusion

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1643
Author(s):  
Ming Liu ◽  
Shichao Chen ◽  
Fugang Lu ◽  
Mengdao Xing ◽  
Jingbiao Wei
Keyword(s):  
Synthetic Aperture Radar ◽  
False Alarm ◽  
False Alarm Rate ◽  
Target Detection ◽  
Synthetic Aperture ◽  
False Alarms ◽  
Sar Image ◽  
Constant False Alarm Rate ◽  
Sar Images ◽  
Complex Scenes

For target detection in complex scenes of synthetic aperture radar (SAR) images, the false alarms in the land areas are hard to eliminate, especially for the ones near the coastline. Focusing on the problem, an algorithm based on the fusion of multiscale superpixel segmentations is proposed in this paper. Firstly, the SAR images are partitioned by using different scales of superpixel segmentation. For the superpixels in each scale, the land-sea segmentation is achieved by judging their statistical properties. Then, the land-sea segmentation results obtained in each scale are combined with the result of the constant false alarm rate (CFAR) detector to eliminate the false alarms located on the land areas of the SAR image. In the end, to enhance the robustness of the proposed algorithm, the detection results obtained in different scales are fused together to realize the final target detection. Experimental results on real SAR images have verified the effectiveness of the proposed algorithm.

scholarly journals Foundational Statistical Principles in Medical Research: Sensitivity, Specificity, Positive Predictive Value, and Negative Predictive Value

Medicina ◽  
2021 ◽  
Vol 57 (5) ◽  
pp. 503
Author(s):  
Thomas F. Monaghan ◽  
Syed N. Rahman ◽  
Christina W. Agudelo ◽  
Alan J. Wein ◽  
Jason M. Lazar ◽  
...  
Keyword(s):  
Positive Predictive Value ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Medical Literature ◽  
Disease Prevalence ◽  
Positive Test Result ◽  
Predictive Values ◽  
Sensitivity Specificity ◽  
Test Result ◽  
Test Probability

Sensitivity, which denotes the proportion of subjects correctly given a positive assignment out of all subjects who are actually positive for the outcome, indicates how well a test can classify subjects who truly have the outcome of interest. Specificity, which denotes the proportion of subjects correctly given a negative assignment out of all subjects who are actually negative for the outcome, indicates how well a test can classify subjects who truly do not have the outcome of interest. Positive predictive value reflects the proportion of subjects with a positive test result who truly have the outcome of interest. Negative predictive value reflects the proportion of subjects with a negative test result who truly do not have the outcome of interest. Sensitivity and specificity are inversely related, wherein one increases as the other decreases, but are generally considered stable for a given test, whereas positive and negative predictive values do inherently vary with pre-test probability (e.g., changes in population disease prevalence). This article will further detail the concepts of sensitivity, specificity, and predictive values using a recent real-world example from the medical literature.

scholarly journals 3124 Early Electrographic Seizure Detection by Neuro ICU Nurses via Bedside Real-Time Quantitative EEG

2019 ◽  
Vol 3 (s1) ◽  
pp. 38-38
Author(s):  
Safa Kaleem ◽  
Christa B. Swisher
Keyword(s):  
Positive Predictive Value ◽  
Real Time ◽  
Predictive Value ◽  
Quantitative Eeg ◽  
University Hospital ◽  
Duke University ◽  
Study Population ◽  
Time To Detection ◽  
Sensitivity Specificity ◽  
Improve Patient

OBJECTIVES/SPECIFIC AIMS: 1. Determine positive predictive value, negative predictive value, sensitivity, and specificity of Neuro ICU nurse interpretation of real-time bedside qEEG. 2. Determine difference in time to detection of first seizure between Neuro ICU nurse qEEG interpretation and EEG fellow reads of cEEG. 3. Determine what qualities of seizures make detection by neuro ICU nurses more or less likely – e.g. duration of seizures, type of seizures, spatial extent of seizures. METHODS/STUDY POPULATION: Recruit neuro ICU nurses taking care of 150 patients admitted to the Neuro ICU at Duke University Hospital who are initiated on cEEG monitoring. Nurses will be consented for their participation in the study. Neuro ICU nurses will evaluate the qEE RESULTS/ANTICIPATED RESULTS: From literature estimates of a 20% seizure prevalence in critical care settings, we hope to have 30 patients with seizures and 120 without. Based on prior study in the Duke Neuro ICU, we hypothesize that Neuro ICU nurses will have sensitivity and DISCUSSION/SIGNIFICANCE OF IMPACT: This is the first prospective study of neuro ICU nurse interpretation of real-time bedside qEEG in patients with unknown NCSE/NCS presence. If nurse sensitivity, specificity, and positive predictive value are clinically useful, which we deem would be so at a sensitivity of 70% or greater, with acceptable false alarm rate, nurse readings of qEEG could significantly decrease the time to treatment of seizures in the Neuro ICU patient population, and perhaps could improve patient outcomes.

Drawing the line in the Edinburgh Postnatal Depression Scale (EPDS): a vital decision

2011 ◽  
Vol 23 (1) ◽  
Author(s):  
Dagmar Lagerberg ◽  
Margaretha Magnusson ◽  
Claes Sundelin
Keyword(s):  
Positive Predictive Value ◽  
Predictive Value ◽  
Postnatal Depression ◽  
Edinburgh Postnatal Depression Scale ◽  
Depression Scale ◽  
Child Interaction ◽  
Mother Child Interaction ◽  
Problem Behaviours ◽  
Low Sensitivity ◽  
Sensitivity Specificity

Abstract Background: The Edinburgh Postnatal Depression Scale (EPDS) is widely used in early child health care. This study examined the appropriateness of the recommended EPDS cut-off score 11/12. Methods: Two main analyses were performed: 1. Associations between EPDS scores and maternal health behaviour, stress, life events, perceived mother-child interaction quality and child behaviour. 2. Screening parameters of the EPDS, i.e., sensitivity, specificity and positive predictive value. EPDS scores were available for 438 mothers and maternal questionnaires for 361 mothers. Results: Already in the EPDS score intervals 6–8 and 9–11, there were notable adversities, according to maternal questionnaires, in stress, perceived quality of mother-child interaction, perceived child difficultness and child problem behaviours. Using maternal questionnaire reports about sadness/distress postpartum as standard, the recommended EPDS cut-off score 11/12 resulted in a very low sensitivity (24%). The cut-off score 6/7 yielded a sensitivity of 61%, a specificity of 82% and a positive predictive value of 61%. Conclusions: In terms of both clinical relevance and screening qualities, an EPDS cut-off score lower than 11/12 seems recommendable.

Diagnostic accuracy of monofilament test to detect diabetic neuropathy

2021 ◽  
Vol 10 (1) ◽  
pp. 20-25
Author(s):  
Sujan Shrestha ◽  
Mamen Prasad Gorhaly ◽  
Manil Ratna Bajracharya
Keyword(s):  
Peripheral Neuropathy ◽  
Positive Predictive Value ◽  
Diagnostic Accuracy ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Diabetic Peripheral Neuropathy ◽  
Perception Threshold ◽  
Sensitivity Specificity ◽  
Vibration Perception ◽  
Monofilament Test

Background Diabetic peripheral neuropathy (DPN) is a significant independent risk factor for diabetic foot, and an effective screening instrument is required to diagnose DPN early to prevent future ulceration and amputation. This study aims to determine the diagnostic accuracy of monofilament test to detect diabetic peripheral neuropathy. Methods This cross-sectional study was conducted in National Academy of Medical Sciences, Bir hospital, Mahabouddha, Kathmandu from February 2016 to January 2017. A total of 96 diabetic patients attending inpatient and outpatient Department were selected. Diabetic peripheral neuropathy was assessed by measurement of loss of protective sensation (LOPS) by monofilament test and compared with vibration perception threshold by standard biothesiometer. The sensitivity, specificity, positive predictive value and negative predictive value of monofilament test were calculated. Results The prevalence of diabetic peripheral neuropathy was 26%. The sensitivity, specificity, positive predictive value and negative predictive value of monofilament test were found to be 92.0%, 95.8%, 88.5% and 97.1% respectively. There was strong association between LOPS by monofilament and vibration perception threshold by biothesiometer. Conclusion This study showed a strong diagnostic accuracy of monofilament test to detect DPN when compared with biothesiometer. As monofilament test is a cheap, easily available, and portable, it can be used in the periphery where biothesiometer is not available.  

DIAGNOSTIC ACCURACY OF GRAY SCALE ULTRASONOGRAPHY VERSUS COLOR DOPPLER IN SUSPECTED CASES OF ACUTE APPENDICITIS

2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Tahir Iqbal ◽  
Muhammad Usman Shahid ◽  
Ishfaq Ahmad Shad ◽  
Shahzad Karim Bhatti ◽  
Syed Amir Gilani ◽  
...  
Keyword(s):  
Acute Appendicitis ◽  
Positive Predictive Value ◽  
Diagnostic Accuracy ◽  
Negative Predictive Value ◽  
Predictive Value ◽  
Color Doppler ◽  
Diagnostic Tools ◽  
Gray Scale ◽  
Versus Color ◽  
Sensitivity Specificity

ABSTRACT: BACKGROUND: A common surgical emergency is acute appendicitis. Various diagnostic tools are available to diagnosis acute appendicitis. Radiological investigations play an important role in making accurate and early diagnosis and thus preventing morbidity associated with the disease. OBJECTIVE: To determine the diagnostic accuracy of gray scale ultrasonography versus color Doppler in suspected cases of acute appendicitis. MATERIALS AND METHODS: The study was carried in the department of Radiology of Mayo Hospital, Lahore. A total of 75 patients were enrolled of age 18-40 years, both genders who were suspected cases of acute appendicitis. All patients underwent baseline investigations along with gray scale ultrasonography and color Doppler. All patients were subjected to surgery to confirm the diagnosis and findings were subjected to statistical analysis. RESULTS: The mean age of the patients was 23.25 ±10.55 and mean transverse diameter of appendix was 8.37 ±3.39. There were 62.7% males and 37.3%females. Findings of gray scale ultrasonography and color Doppler were then correlated with surgical findings to calculate the diagnostic accuracy of these modalities. The results revealed that gray scale ultrasonography sensitivity, specificity, positive predictive value, negative predictive value and accuracy was 92.7%, 94.32%, 95%, 91.4% and 93.3% respectively, whereas color Doppler had sensitivity, specificity, positive predictive value, negative predictive value and accuracy of 97.7%, 93.9%, 95.3%, 97% and 96% respectively. Diagnostic accuracy of both modalities together was 98.6%. CONCLUSION: Color Doppler has better diagnostic accuracy than gray scale ultrasonography for diagnosis of acute appendicitis and the combination of both modalities yields diagnostic accuracy that is similar to gold standard.

scholarly journals Reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications

2014 ◽  
Vol 47 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Vilson Lacerda Brasileiro Junior ◽  
Aníbal Henrique Barbosa Luna ◽  
Marcelo Augusto Oliveira de Sales ◽  
Tânia Lemos Coelho Rodrigues ◽  
Priscilla Lopes da Fonseca Abrantes Sarmento ◽  
...  
Keyword(s):  
High Risk ◽  
Carotid Artery ◽  
Positive Predictive Value ◽  
Predictive Value ◽  
Carotid Arteries ◽  
Panoramic Radiography ◽  
Digital Panoramic Radiography ◽  
Significant Difference ◽  
Mcnemar’S Test ◽  
Sensitivity Specificity

Objective The present study evaluated the reliability of digital panoramic radiography in the diagnosis of carotid artery calcifications. Materials and Methods Thirty-five patients under high-risk for development of carotid artery calcifications who had digital panoramic radiography were referred to undergo ultrasonography. Thus, 70 arteries were assessed by both methods. The main parameters utilized to evaluate the panoramic radiography reliability in the diagnosis of carotid artery calcifications were accuracy, sensitivity, specificity and positive predictive value of this method as compared with ultrasonography. Additionally, the McNemar's test was utilized to verify whether there was a statistically significant difference between digital panoramic radiography and ultrasonography. Results Ultrasonography demonstrated carotid artery calcifications in 17 (48.57%) patients. Such individuals presented with a total of 29 (41.43%) carotid arteries affected by calcification. Radiography was accurate in 71.43% (n = 50) of cases evaluated. The degree of sensitivity of this method was 37.93%, specificity of 95.12% and positive predictive value of 84.61%. A statistically significant difference (p < 0.001) was observed between the methods evaluated in their capacity to diagnose carotid artery calcifications. Conclusion Digital panoramic radiography should not be indicated as a method of choice in the investigation of carotid artery calcifications.

scholarly journals The slipping slipper sign: a simple test with high specificity and positive predictive value for peripheral neuropathy among diabetic patients

2012 ◽  
Vol 2 (2) ◽  
pp. 51 ◽  
Author(s):  
Krystal A.T. Gayle ◽  
Marshall K. Tulloch-Reid ◽  
Rainford J. Wilks ◽  
Trevor S. Ferguson
Keyword(s):  
Peripheral Neuropathy ◽  
Positive Predictive Value ◽  
Diabetic Neuropathy ◽  
Predictive Value ◽  
High Specificity ◽  
Diabetic Patients ◽  
Simple Test ◽  
Diabetes Clinic ◽  
Sensitivity Specificity ◽  
Single Question

This study evaluated the ability of the slipping slipper sign (defined as unknowingly losing a slipper while walking) to identify diabetic neuropathy in Jamaican patients. A single question was used to ascertain the presence of the slipping slipper sign (SSS) among 69 patients attending a diabetes clinic. Nurses assessed pain, vibration and pressure perception among the same patients in order to detect diabetic neuropathy. The sensitivity, specificity and positive predictive value for the SSS were calculated. Eight participants (men=5, women=3) reported positive SSS. The SSS had a sensitivity of 28.6%, specificity of 100% and positive predictive value (PPV) 100% for neuropathy on at least one of the three tests. These findings indicate that the SSS has high specificity and PPV for diabetic neuropathy but the sensitivity is low. The sign may be a useful adjuvant to conventional methods of screening for severe neuropathy

Sign in / Sign up

Export Citation Format

Share Document