Out Of Range Values Research Articles

Design of a novel multifunction decision support/alerting system for in-patient acute care, ICU and floor (AlertWatch AC)

BackgroundMultifunction surveillance alerting systems have been found to be beneficial for the operating room and labor and delivery. This paper describes a similar system developed for in-hospital acute care environments, AlertWatch Acute Care (AWAC).ResultsA decision support surveillance system has been developed which extracts comprehensive electronic health record (EHR) data including live data from physiologic monitors and ventilators and incorporates them into an integrated organ icon-based patient display. Live data retrieved from the hospitals network are processed by presenting scrolling median values to reduce artifacts. A total of 48 possible alerts are generated covering a broad range of critical patient care concerns. Notification is achieved by paging or texting the appropriated member of the critical care team. Alerts range from simple out of range values to more complex programing of impending Ventilator Associated Events, SOFA, qSOFA, SIRS scores and process of care reminders for the management of glucose and sepsis. As with similar systems developed for the operating room and labor and delivery, there are green, yellow, and red configurable ranges for all parameters. A census view allows surveillance of an entire unit with flashing or text to voice alerting and enables detailed information by windowing into an individual patient view including live physiologic waveforms. The system runs via web interface on desktop as well as mobile devices, with iOS native app available, for ease of communication from any location. The goal is to improve safety and adherence to standard management protocols.ConclusionsAWAC is designed to provide a high level surveillance view for multi-bed hospital units with varying acuity from standard floor patients to complex ICU care. Alerts are generated by algorithms running in the background and automatically notify the selected member of the patients care team. Its value has been demonstrated for low acuity patients, further study is required to determine its effectiveness in high acuity patients.

Anticoagulation and Transfusion Management During Neonatal and Pediatric Extracorporeal Membrane Oxygenation: A Survey of Medical Directors in the United States.

To compare current practices within the United States of anticoagulation management and blood transfusion in neonatal and pediatric extracorporeal membrane oxygenation patients with a 2013 international report. Cross-sectional survey distributed between August and December 2019. Extracorporeal Life Support Organization-registered neonatal and pediatric extracorporeal membrane oxygenation centers in the United States. Extracorporeal membrane oxygenation medical directors. None. Eighty-three medical directors at 108 centers responded. After removing four duplicate responses, 79 surveys were analyzed. Seventy-nine percent (n = 62) report a written extracorporeal membrane oxygenation protocol for both anticoagulation and blood product management. Ninety-four percent (n = 74) report unfractionated heparin as their primary anticoagulant; the remaining use the direct thrombin inhibitor, bivalirudin. Ninety percent (n = 71) report measuring antifactor Xa levels. Most centers report using a combination of assays to monitor heparin therapy, either antifactor Xa and activated partial thromboplastin time (54%) or more commonly antifactor Xa and activated clotting time (68%). Forty-one percent use viscoelastic tests to aid management. Goal monitoring levels and interventions generated by out of range values are variable. Fifty-one percent will replace antithrombin. Platelet transfusion thresholds vary by age and center with ranges from 50,000 to 100,000 cells/µL. Eighty-two percent of respondents are willing to participate in a randomized controlled trial comparing anticoagulation strategies for patients receiving extracorporeal membrane oxygenation. Compared with the 2013 pediatric population, extracorporeal membrane oxygenation center anticoagulation and blood transfusion approaches continue to vary widely. Most report continued use of heparin as their primary anticoagulant and follow a combination of monitoring assays with the majority using the antifactor Xa assay in their practices, a significant shift from prior results. Antithrombin activity levels and viscoelastic tests are followed by a growing number of centers. Platelet transfusion thresholds continue to vary widely. Future research is needed to establish optimal anticoagulation and blood transfusion management.

Determination of reference intervals from a laboratory database of an academic clinical research unit in a tertiary care teaching hospital and an audit of out of range values.

Background:Abnormal laboratory values are a common reason for the exclusion of participants in clinical studies, increasing the recruitment time and cost during conduct. The use of sample-specific reference intervals (RIs) may help to address this issue. Hence, the present study derived site-specific RIs using the department laboratory database and compare the proportion of “out of range” (OOR) values between the new and the old RIs used by the trial site.Methods:Institutional ethics committee approval was obtained. Data for hematology and biochemistry parameters were analyzed. Normality was assessed and RIs computed using nonparametric method. Data were partitioned for gender and descriptive statistics applied for demographics. The OOR values based on new RIs were compared with old RIs using Chi-squared tests. Between gender OOR proportions compared using Chi-squared test (significance at P< 0.05). Post hoc analysis was performed with Beasley's technique.Results:Data of 601 participants were analyzed. The median (Inter Quartile Range) age was 22 (47) years and 64.72% were male. New RIs for key parameters were: Haemoglobin (9.3–16.5 g/dl), alanine aminotransferase (11.4–47.74 U/I), aspartate aminotransferase (8.8–58 U/I), total bilirubin (0.27–1.4 mg/dl), and creatinine (0.59–1.36 mg/dl). Post partitioning, the RI for hemoglobin (g/dl) was lower (8.72–15.72) in females. The proportion of OOR values were lower with new RIs relative to old laboratory RIs (P < 0.0001).Conclusion:A reduction in the proportion of OORs and a change in the upper and lower bound laboratory intervals with new RIs emphasize the need for sample-specific ranges to prevent unnecessary exclusions of volunteers from trials.

Barriers to Establishing and Maintaining Therapeutic Anticoagulation in Pediatric Ventricular Assist Device Support: Advanced Cardiac Therapies Improving Outcomes Network Initiative

Establishing and maintaining target anticoagulation (AC) levels is perceived as a way to mitigate the risk of bleeding and thrombotic complications in pediatric ventricular assist device (VAD) support. To better understand potential reasons of having monitoring labs outside institutionally-set goal ranges, we surveyed centers to understand perceived barriers. As part of the Advanced Cardiac Therapies Improving Outcomes Network (ACTION), a 37-center collaborative, we surveyed participating VAD centers across North America. The survey was comprised of multiple choice questions addressing reasons for out of range coagulation labs. Specifically, asking centers to rate the frequency of occurrences; low, happens rarely, medium, happens often, high, happens almost daily and not applicable, meaning this barrier does not exists. We then weighted the average responses. Of the 49 responses received from the pediatric VAD-ACTION centers that responded to a 4-question multiple choice survey, the most commonly reported barrier was contamination of lab samples by sampling from a line infusing an anticoagulant through it in over 65% of respondents. This was followed by multiple providers involved in managing AC and micro-managing lab results as the second and third chosen as barriers reported in just under 50%. Interestingly, lack of documentation and obscure guidelines were not perceived as frequent causes of out of range values. While achieving and maintaining stable anticoagulation is the goal of therapy, understanding perceived obstacles is vital to targeted intervention. Targeted interventions to decrease the most common barriers, such as contaminated labs, will guide future ACTION quality improvement initiatives.

Establishment of reference intervals during normal pregnancy through six months postpartum in western Kenya.

BackgroundPregnancy is associated with changes in hematological and biochemistry values, yet there are no African reference intervals for clinical management of pregnant women. We sought to 1) develop laboratory reference intervals during pregnancy and up to 24 weeks postpartum and 2) determine the proportion of women in a previous clinical trial who would be misclassified as having out-of-range values using reference intervals from a United States (U.S.) population.Methods and findingsThis was a longitudinal sub-study of 120 clinically healthy, HIV-uninfected, self-selected pregnant women seeking antenatal care services at either of two public hospitals in western Kenya. Blood specimens were obtained from consented women at gestational ages 28 and 36 weeks and at 2, 6, 14 and 24 weeks postpartum. Median and 95% reference intervals were calculated for immune-hematological and biochemistry parameters and compared to reference intervals from a Kenyan and United States (U.S.) population, using Wilcoxon tests. Differences with p≤0.05 were considered significant. Some hematological parameters, including hemoglobin and neutrophils showed significant variations compared to reference intervals for non-pregnant women. Hemoglobin values were significantly lower during pregnancy but were comparable to the values in non-pregnant women by 6 weeks postpartum. CD4, CD8 and platelets were significantly elevated in early postpartum but declined gradually, reaching normal levels by 24 weeks postpartum. Using the new hemoglobin reference levels from this study to estimate prevalence of ‘out of range’ values in a prior Kisumu research cohort of pregnant/postpartum women, resulted in 0% out of range values, in contrast to 96.3% using US non-pregnant reference valuesConclusionThere were substantial differences in U.S. and Kenyan values for immune-hematological parameters among pregnant/postpartum women, specifically in red blood cell parameters in late pregnancy and 2 weeks postpartum. Use of U.S. reference intervals markedly increases likelihood of out of range values, highlighting the need for suitable locally developed reference intervals.

PRM152 - Data Cleaning Paper Patient Reported Outcome (PRO) Data Versus Electronic Patient Reported Outcome (EPRO) Data

This conceptual paper will illustrate the impacts of low quality data, describe the requirements of the data cleaning process, compare the data cleaning process for paper versus ePRO, and provide recommendations of how ePRO can be implemented to decrease the level of effort of data cleaning. Before data can be analyzed, data cleaning must occur to ensure high data quality. Low quality data can have major impacts on data analysis/results along with cost impact. As estimated by the Data Warehousing Institute, the costs of low quality data exceeds $600 billion annually. Data cleaning process includes querying for errors, typos, outliers, out-of-range responses, missing data, deviations, etc. Paper: query data for erroneous/out-of range values; these values need to be cross-checked with original paper form to identify if error is associated with patient entry or data entry staff. If associated with patient entry, it may need to be set as missing. When original paper is lost, values may need to be set to missing as accuracy cannot be confirmed. Time/dates may be out-of-range or missing, which require cross-checking with original paper. If time/date cannot be confirmed, the entire entry may need to be set as missing. Missing values in data need to be identified and cross-checked with original paper to confirm if value was skipped by patient or by data entry staff. ePRO: can be implemented to prevent entry of out-of range values; includes time/date stamps; patient direct data entry eliminates error by data entry staff; can be programmed to not allow skipped responses to prevent missing data responses. End-of-study time is precious to the pharma industry where results need to be analyzed for submissions. Data cleaning with paper can be labor intensive and ePRO can save time with preventing errors from occurring, reducing time needed for data cleaning.

Safety of Spironolactone in Dogs with Chronic Heart Failure because of Degenerative Valvular Disease: A Population‐Based, Longitudinal Study

Spironolactone treatment in humans is associated with an increased risk of hyperkalemia and renal dysfunction. Dogs with cardiac disease treated with spironolactone, in addition to conventional therapy, are not at higher risk for adverse events (AEs) than those receiving solely conventional therapy. One hundred and ninety-six client-owned dogs with naturally occurring myxomatous mitral valve disease. Prospective, double-blinded field study with dogs randomized to receive either spironolactone (2 mg/kg once a day) or placebo in addition to conventional therapy (angiotensin-converting enzyme inhibitor, plus furosemide and digoxin if needed). Safety was compared between treatment groups, using the frequency of AEs, death caused by cardiac disease, renal disease, or both, and variations in serum sodium, potassium, urea, and creatinine concentrations. For the latter, population-specific reference intervals were established and out of range values (ORV) analyzed. The number of AEs was similar in the spironolactone and reference groups (188 and 208, respectively), when followed for median duration of 217 days (range [2-1,333]). At each study time point, the percentage of dogs showing ORV was similar between groups. There were a higher number of deaths because of cardiac disease, renal disease or both in the reference group (30.7% versus 13.7%) (P = .0043). Dogs with heart failure receiving spironolactone in addition to conventional treatment are not at a higher risk for AEs, death caused by cardiac disease, renal disease, or both, hyperkalemia, or azotemia.

Systematic Evaluation of Land Use Regression Models for NO2

Land use regression (LUR) models have become popular to explain the spatial variation of air pollution concentrations. Independent evaluation is important. We developed LUR models for nitrogen dioxide (NO(2)) using measurements conducted at 144 sampling sites in The Netherlands. Sites were randomly divided into training data sets with a size of 24, 36, 48, 72, 96, 108, and 120 sites. LUR models were evaluated using (1) internal "leave-one-out-cross-validation (LOOCV)" within the training data sets and (2) external "hold-out" validation (HV) against independent test data sets. In addition, we calculated Mean Square Error based validation R(2)s. The mean adjusted model and LOOCV R(2) slightly decreased from 0.87 to 0.82 and 0.83 to 0.79, respectively, with an increasing number of training sites. In contrast, the mean HV R(2) was lowest (0.60) with the smallest training sets and increased to 0.74 with the largest training sets. Predicted concentrations were more accurate in sites with out of range values for prediction variables after changing these values to the minimum or maximum of the range observed in the corresponding training data set. LUR models for NO(2) perform less well, when evaluated against independent measurements, when they are based on relatively small training sets. In our specific application, models based on as few as 24 training sites, however, achieved acceptable hold out validation R(2)s of, on average, 0.60.

A Case Control Study of the Implementation of Change Model Versus Passive Dissemination of Practice Guidelines for Compliance in Monitoring for Metabolic Syndrome

We developed an intervention to improve compliance with guidelines for monitoring metabolic syndrome and compared compliance prior to intervention and three times post-intervention at three community mental health clinics in Texas. One test clinic received intervention and two other clinics served as controls. Fifty random charts were reviewed from each clinic for three specific, 1-2weeks periods over the course of 18months. There were significant improvements in the ordering of labs, the presence of lab results in the chart, and documentation of blood pressure, body mass index and waist circumference in the intervention clinic over time in comparison to the control clinics. Documented evidence of physician action with respect to out of range values remained low. Metabolic monitoring is a multi-step process. Removing barriers, creating specific procedures, and dedicating staff resources can improve compliance with monitoring.

Summarizing benchmarks in the national database of nursing quality indicators using bootstrap confidence intervals

When summarizing the benchmarks for nursing quality indicators with confidence intervals around the means, bounds too high or too low are sometimes found due to small sample size or violation of the normality assumption. Transforming the data or truncating the confidence intervals at realistic values can solve the problem of out of range values. However, truncation does not improve upon the non-normality of the data, and transformations are not always successful in normalizing the data. The percentile bootstrap has the advantage of providing realistic bounds while not relying upon the assumption of normality and may provide a convenient way of obtaining appropriate confidence intervals around the mean for nursing quality indicators.

Mortality assessment in intensive care units via adverse events using artificial neural networks

This work presents a novel approach for the prediction of mortality in intensive care units (ICUs) based on the use of adverse events, which are defined from four bedside alarms, and artificial neural networks (ANNs). This approach is compared with two logistic regression (LR) models: the prognostic model used in most of the European ICUs, based on the simplified acute physiology score (SAPS II), and a LR that uses the same input variables of the ANN model. A large dataset was considered, encompassing forty two ICUs of nine European countries. The recorded features of each patient include the final outcome, the case mix (e.g. age) and the intermediate outcomes, defined as the daily averages of the out of range values of four biometrics (e.g. heart rate). The SAPS II score requires 17 static variables (e.g. serum sodium), which are collected within the first day of the patient's admission. A nonlinear least squares method was used to calibrate the LR models while the ANNs are made up of multilayer perceptrons trained by the RPROP algorithm. A total of 13,164 adult patients were randomly divided into training (66%) and test (33%) sets. The two methods were evaluated in terms of receiver operator characteristic (ROC) curves. The event based models predicted the outcome more accurately than the currently used SAPS II model (P<0.05), with ROC areas within the ranges 83.9-87.1% (ANN) and 82.6-85.2% (LR) versus 80% (LR SAPS II). When using the same inputs, the ANNs outperform the LR (improvement of 1.3-2%). Better prognostic models can be achieved by adopting low cost and real-time intermediate outcomes rather than static data.

The Impact of Patient Self-Testing of Prothrombin Time for Managing Anticoagulation: Rationale and Design of VA Cooperative Study #481—The Home INR Study (THINRS)

Anticoagulation (AC) with warfarin reduces the risk of thromboembolism (TE) in a variety of applications, yet despite compelling evidence of the value and importance of high quality AC, warfarin remains underused, and dosing is often suboptimal. Approaches to improve AC quality include (1) an AC service (ACS), which allows the physician to delegate day-to-day details of AC management to another provider dedicated to AC care, and (2) incorporating into the treatment plan patient self-testing (PST) under which, after completing a training program, patients perform their own blood testing (typically, using a finger-stick blood analyzer), have dosage adjustments guided by a standard protocol, and forward test results, dosing and other information to the provider. Studies have suggested that PST can improve the quality of AC and perhaps lower TE and bleed rates. The purpose of Department of Veterans Affairs (VA) Cooperative Studies Program (CSP) #481, "The Home INR Study" (THINRS) is to compare AC management with frequent PST using a home monitoring device to high quality AC management (HQACM) implemented by an ACS with conventional monitoring of prothrombin time by international normalized ratio (INR) on major health outcomes. PST in THINRS involves use of an INR monitoring device that is FDA approved for home use. Sites are VA Medical Centers where the ACS has an active roster of more than 400 patients. THINRS includes patients with atrial fibrillation (AF) and/or mechanical heart valve (MHV) expected to be anticoagulated indefinitely. THINRS has two parts. In Part 1, candidates for PST are evaluated for 2 to 4 weeks for their ability to use home monitoring devices. In Part 2, individuals capable of performing PST are randomized to (1) HQACM with testing every 4 weeks and as indicated for out of range values, medication/clinical changes, or (2) PST with testing every week and as indicated for out of range values, medication/clinical changes. The primary outcome measure is event rates, defined as the percent of patients who have a stroke, major bleed, or die. Secondary outcomes include total time in range (TTR), other events (myocardial infarction (MI), non-stroke TE, minor bleeds), competence and compliance with PST, satisfaction with AC, AC associated quality of life (QOL), and cost-effectiveness. To assess the effect of PST frequency on TTR and other outcomes, at selected sites patients randomized to perform PST are assigned one of three test frequencies (weekly, twice weekly, or once every four weeks).

Inversion of picture operators

Inversion of operators on pictures is shown to be an important part of classical image restoration techniques. A method is presented for nonlinear inversion of operators that enables nonlinear restoration. The problem of out of range values is handled by introducing a new definition for operations on pictures such that the set of all pictures is a vector space. It is empirically shown that the Conjugate Gradients algorithm converges quickly in this vector space and enables inversion of operators on big pictures with relatively little computation. Examples are given for applications of this method to linear and nonlinear operators.