Using Time Series Analysis to Predict Cardiac Arrest in a PICU.

OBJECTIVES: To build and test cardiac arrest prediction models in a PICU, using time series analysis as input, and to measure changes in prediction accuracy attributable to different classes of time series data. DESIGN: Retrospective cohort study. SETTING: Thirty-one bed academic PICU that provides care for medical and general surgical (not congenital heart surgery) patients. SUBJECTS: Patients experiencing a cardiac arrest in the PICU and requiring external cardiac massage for at least 2 minutes. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: One hundred three cases of cardiac arrest and 109 control cases were used to prepare a baseline dataset that consisted of 1,025 variables in four data classes: multivariate, raw time series, clinical calculations, and time series trend analysis. We trained 20 arrest prediction models using a matrix of five feature sets (combinations of data classes) with four modeling algorithms: linear regression, decision tree, neural network, and support vector machine. The reference model (multivariate data with regression algorithm) had an accuracy of 78% and 87% area under the receiver operating characteristic curve. The best model (multivariate + trend analysis data with support vector machine algorithm) had an accuracy of 94% and 98% area under the receiver operating characteristic curve. CONCLUSIONS: Cardiac arrest predictions based on a traditional model built with multivariate data and a regression algorithm misclassified cases 3.7 times more frequently than predictions that included time series trend analysis and built with a support vector machine algorithm. Although the final model lacks the specificity necessary for clinical application, we have demonstrated how information from time series data can be used to increase the accuracy of clinical prediction models.

Errors in after-hours phone consultations: a simulation study.

BACKGROUND: After-hours out-of-hospital phone consultations require physicians to make decisions based on information provided by a nurse over the phone. METHODS: We conducted a simulation study to evaluate physicians' actions following communication of key information. 22 nurses were asked to call physicians with six cases based on the six most common reasons for after-hours phone calls. We evaluated physicians' actions following the communication of key clinical information: A situation cue described a patient's problem (eg, confusion). A background cue described a specific clinical finding regarding the cause of the problem (eg, patient's sodium is low). For each cue we defined a list of indicators, based on the medical literature, to ascertain whether physicians acted upon the provided information (which was defined as addressing at least one of the indicators). RESULTS: A total of 108 phone consultations (containing 88 situation and 93 background cues) were analysed. Situation cues were communicated in 90% (79/88) of the calls and background cues in 33% (31/93). Physician acted upon the provided information in 57% (45/79) and 48% (15/31) of the communicated situation and background cues, respectively. When the background cues were not communicated, physicians asked questions expected to elicit the cue in 12% of the cases. Responding to the situation cue was associated with longer conversations and active inquiry by the physician. CONCLUSIONS: After-hours phone calls are error prone. Both nurse communication and physician decision-making are problematic. Efforts to improve patient safety in this setting must address both communication and decision-making.

Evaluation of a problem-specific SBAR tool to improve after-hours nurse-physician phone communication: a randomized trial.

BACKGROUND: After-hours telephone communications are common in patient management. Patterns of communication of key information during after-hours phone calls were evaluated, and the utility of problem-specific Situation, Background, Assessment, Recommendation (SBAR) forms in improving this communication was assessed. METHODS: In a randomized trial using a simulated on-call setting, 20 nurses called physicians regarding six cases adapted from inpatient records and based on the six most common reasons for after-hours nurse-physician communication. Three of the cases were handled without the SBAR forms (control cases), and three cases were handled with the forms (SBAR cases). Two cue types of communication were evaluated: situation cues, which conveyed the patient's situation (for example, a patient is confused), and background cues, which conveyed problem-specific data indicated on the SBAR forms (for example, the patient has a low sodium level). RESULTS: Ninety-two phone calls were analyzed (43 SBAR/49 controls). Most of the nurses reported the situation cues (SBAR 88%, control 84%, p = .60) but not the background cues. There was a trend toward fewer background cues communicated in the SBAR cases (14% versus 31%, p = .08). In 14% of the cases, on average, nurses omitted information or reported wrong information regarding the background cue. Physicians asked questions that resulted in the communication of the cues in a minority of the cases when the background cues were not originally provided by the nurses (SBAR 6%, control 16%, p = .39). CONCLUSIONS: In after-hours phone communication between physicians and nurses, significant information was often not communicated and physicians did not elicit the necessary information. Simply providing an SBAR-based form did not ensure complete communication of key information.

One Size Does Not Fit All: EHR Clinical Summary Design Requirements for Nurses.

Research has established the pivotal role of cognitive artifacts to human information visualization, the reduction of memory load, and critical thinking. A long-standing nursing practice is the development of a personal cognitive artifact that summarizes the clinical condition and plan of care for the patient(s) in the care of the nurse. Distributed cognition establishes the importance of the role of cognitive artifacts to the cognition of each individual. A feature/function of electronic health record applications is to supply a real-time clinical overview of a patient's clinical condition and care needs, which is often referenced as a patient clinical summary. Research regarding the requirements of electronic clinical summaries to support clinician cognition has not been reported to date. This paper reports the results of initial research to establish foundational principles for the development of EHR patient clinical summaries that support the cognition and critical thinking of the registered nurse.

Time series analysis as input for clinical predictive modeling: modeling cardiac arrest in a pediatric ICU.

BACKGROUND: Thousands of children experience cardiac arrest events every year in pediatric intensive care units. Most of these children die. Cardiac arrest prediction tools are used as part of medical emergency team evaluations to identify patients in standard hospital beds that are at high risk for cardiac arrest. There are no models to predict cardiac arrest in pediatric intensive care units though, where the risk of an arrest is 10 times higher than for standard hospital beds. Current tools are based on a multivariable approach that does not characterize deterioration, which often precedes cardiac arrests. Characterizing deterioration requires a time series approach. The purpose of this study is to propose a method that will allow for time series data to be used in clinical prediction models. Successful implementation of these methods has the potential to bring arrest prediction to the pediatric intensive care environment, possibly allowing for interventions that can save lives and prevent disabilities. METHODS: We reviewed prediction models from nonclinical domains that employ time series data, and identified the steps that are necessary for building predictive models using time series clinical data. We illustrate the method by applying it to the specific case of building a predictive model for cardiac arrest in a pediatric intensive care unit. RESULTS: Time course analysis studies from genomic analysis provided a modeling template that was compatible with the steps required to develop a model from clinical time series data. The steps include: 1) selecting candidate variables; 2) specifying measurement parameters; 3) defining data format; 4) defining time window duration and resolution; 5) calculating latent variables for candidate variables not directly measured; 6) calculating time series features as latent variables; 7) creating data subsets to measure model performance effects attributable to various classes of candidate variables; 8) reducing the number of candidate features; 9) training models for various data subsets; and 10) measuring model performance characteristics in unseen data to estimate their external validity. CONCLUSIONS: We have proposed a ten step process that results in data sets that contain time series features and are suitable for predictive modeling by a number of methods. We illustrated the process through an example of cardiac arrest prediction in a pediatric intensive care setting.

Informaticians: how they may benefit your healthcare organization.

The heightened focus on health information technology deployment, specifically the electronic health record, has magnified the need for the knowledge and skills of informaticians. The clinical informatician is frequently confused with system analyst and project management roles. In this article, the authors explore the knowledge and skills of informaticians and how to determine the skill combinations most suited to an organization and compare the roles of informaticians, project managers, and information technology professionals.

Concept analysis of cognitive artifacts.

Cognitive artifacts--information displays that inform thought processes and increase knowledge--fulfill a fundamental role in distributed cognition. Cognitive work--the mental processes of selecting and evaluating data, reasoning, and making decisions--is guided and informed by cognitive artifacts, especially in clinical areas. The importance of cognitive artifacts to cognitive work suggests the need to study and comprehensively understand cognitive artifacts prepared and used by the clinical nurses and how these documents influence and guide nursing practice. This article identifies and describes the attributes of effectively constructed cognitive artifacts using the concept analysis process described by Walker and Avant.

Self-assessed emergency readiness and training needs of nurses in rural Texas.

OBJECTIVE: Nurses, particularly public health nurses, play a key role in emergency preparedness and response in rural areas. To prepare rural jurisdictions for unforeseen disastrous events it is imperative to assess the public health emergency readiness and training needs of nurses. The objective of this study was to assess the self-reported terrorism preparedness and training needs of a nurse workforce. DESIGN AND SAMPLE: Cross-sectional prevalence of practicing nurses in regions of North Texas. 3,508 rural nurses practicing in North Texas participated in the study. MEASUREMENTS: Data were collected through a mailed survey; analyses included multinominal logistic regression and descriptive statistics. RESULTS: A total of 941 (27%) nurses completed the survey. The majority of respondents reported limited bioterrorism-related training. Fewer than 10% were confident in their ability to diagnose or treat bioterrorism-related conditions. Although only 30% expressed a willingness to collaborate with state and local authorities during a bioterrorism event, more than 69% indicated interest in future training opportunities. Preferred training modalities included small group workshops with instructor-led training, and Internet-based training. CONCLUSIONS: Licensing agencies, professional organizations, and community constituencies may need to play a stronger role in improving the bioterrorism-related emergency preparedness of rural nurses.

Modeling complex workflow in molecular diagnostics: design specifications of laboratory software for support of personalized medicine.

One of the hurdles to achieving personalized medicine has been implementing the laboratory processes for performing and reporting complex molecular tests. The rapidly changing test rosters and complex analysis platforms in molecular diagnostics have meant that many clinical laboratories still use labor-intensive manual processing and testing without the level of automation seen in high-volume chemistry and hematology testing. We provide here a discussion of design requirements and the results of implementation of a suite of lab management tools that incorporate the many elements required for use of molecular diagnostics in personalized medicine, particularly in cancer. These applications provide the functionality required for sample accessioning and tracking, material generation, and testing that are particular to the evolving needs of individualized molecular diagnostics. On implementation, the applications described here resulted in improvements in the turn-around time for reporting of more complex molecular test sets, and significant changes in the workflow. Therefore, careful mapping of workflow can permit design of software applications that simplify even the complex demands of specialized molecular testing. By incorporating design features for order review, software tools can permit a more personalized approach to sample handling and test selection without compromising efficiency.

The roles of MDs and RNs as initiators and recipients of interruptions in workflow.

BACKGROUND: Previous research studies have focused on the recipients of interruptions because of the negative impact interruptions have on task performance. It is equally important to understand the initiators of interruptions to help design strategies to lessen the number of interruptions and the possible negatives consequences. The purpose of this study was to examine MDs and RNs as initiators and recipients of interruptions. METHODS: This was an instrumental case study using the shadowing method. A convenience sample of five attending trauma MDs and eight RNs were observed during the 07:00-15:00 and 15:00-21:00 shifts in the trauma section of a level one trauma center. RESULT: Seventy hours of observations were recorded. Initiator and recipient of an interruption emerged as major roles during categorization of the notes. Medical doctors and RNs were found to be the recipient of an interruption more frequently than the initiator. Findings from this study indicate that MDs and RNs initiate interruptions most often through face-to-face interactions and use of the telephone. CONCLUSIONS: A role-based taxonomy of interruptions was derived from the recorded notes. Strategies to successfully manage interruptions must consider both the role of initiator as well as the recipient when an interruption occurs. It is suggested that the role-based taxonomy presented in this paper be used to classify interruptions in future studies.

Developing a taxonomy and an ontology of nurses' patient clinical summaries.

Nurses prepare a summary of patient information that they consult and update throughout the shift. This document is believed to be integral to cognition, working memory, and decision-making. While serving as a key support to nursing practice, this summary also represents risks to patient safety. Characterized as a PCCAT, or Personally Created Cognitive Artifact, studies of this document in the context of nursing practice have not been reported. The absence of reported research, the importance of the document to nurse cognition and practice, and related safety risks prompted the research that this paper discusses. A taxonomy was developed through the analysis and coding of 151 PCCATs. Further analysis and mapping provided an ontology of the PCCAT. Content differences were noted between nursing units and among nurses. This may reflect differences in unit-based culture and/or differences in the patient complexity. The interaction between culture and perceived complexity of practice is one of the great difficulties in generating automated information systems for clinical practice settings. This paper is part of a larger research protocol that explores meta-level knowledge structures and revision to the understanding of the granularity of nursing knowledge. Development of a taxonomy and ontology of the nurse PCCAT, an important component of the larger research protocol, is described in this paper.

Health informatics: moving from a discipline to a science.

This paper examines the historical definitions of Health (Biomedical) Informatics. It is clear that a majority of the definitions refer to Health Informatics as a discipline. Rather it can be argued that the maturation of Health Informatics is beginning to culminate in a distinct science. This progress need to be reflected in academic programs as well as our conferences and publications.

Second Life and health information.

Second Life (SL) is emerging as a repository of health information. The purpose of this study was to determine the number of places and groups that offer specific health information in SL. A retrospective analysis of SL places and groups was conducted for cancer. Findings indicate that more cancer information is available from groups than specific places in SL. All current and future cancer information will need to be evaluated for reliability and efficacy.

Legibility of a volumetric infusion pump in a shock trauma ICU.

BACKGROUND: Reports submitted to the Federal Food and Drug Administration (FDA) indicate that legibility of infusion pump interfaces contributes to medication errors (for example, patients have been seriously injured when nurses overinfused them after reading the number 7 as a 1). Health care has experienced an influx of medical devices with small-screen interfaces, generically described as small-screen devices. Legibility is widely acknowledged as a necessary aspect of safe operation of medical devices. Contextual analysis was used to observe conditions affecting the legibility of the screen interface of a dual-channel infusion volumetric infusion pump in a shock trauma intensive care unit (STICU). METHODS: Observations were made of registered nurses and physicians using the infusion pumps during a four-hour period. RESULTS: Results from the observations indicated that there was reduced legibility of the infusion pump screen interface because of an inherently subdued light situation, reduced screen contrast, and the small font size of the lettering. DISCUSSION: It was clear from the beginning of the observations that the screen of the infusion pump had limited legibility. In some instances, nurses attached handmade tape labels to the infusion pump to enhance and supplement the small screen. The pump was often positioned facing away from the nurses, who then had to reposition it to view the screen, contributing to interruptions in work flow and creating a potential safety hazard. A variety of strategies are recommended to ensure legibility of infusion pump interfaces and of medical-device labels. CONCLUSIONS: A more complete environmental approach is needed to determine the legibility and usefulness of microdisplay and small-screen devices in health care.

Taxonomy development and knowledge representation of nurses' personal cognitive artifacts.

Nurses prepare knowledge representations, or summaries of patient clinical data, each shift. These knowledge representations serve multiple purposes, including support of working memory, workload organization and prioritization, critical thinking, and reflection. This summary is integral to internal knowledge representations, working memory, and decision-making. Study of this nurse knowledge representation resulted in development of a taxonomy of knowledge representations necessary to nursing practice.This paper describes the methods used to elicit the knowledge representations and structures necessary for the work of clinical nurses, described the development of a taxonomy of this knowledge representation, and discusses translation of this methodology to the cognitive artifacts of other disciplines. Understanding the development and purpose of practitioner's knowledge representations provides important direction to informaticists seeking to create information technology alternatives. The outcome of this paper is to suggest a process template for transition of cognitive artifacts to an information system.

When your words count: a discriminative model to predict approval of referrals.

OBJECTIVE: To develop and test a statistical model which correctly predicts the approval of outpatient referrals when reviewed by a specialty service based on nine discriminating variables. DESIGN: Retrospective cross-sectional study. SETTING: Large public county hospital system in a southern US city. PARTICIPANTS: Written documents and associated data from 500 random adult referrals made by primary care providers to various specialty services during the course of one month. MAIN OUTCOME MEASURES: The resulting correct prediction rates obtained by the model. RESULTS: The model correctly predicted 78.6% of approved referrals using all nine discriminating variables, 75.3% of approved referrals using all variables in a stepwise manner and 74.7% of approved referrals using only the referral total word count as a single discriminating variable. CONCLUSIONS: Three iterations of the model correctly predicted at least 75% of the approved referrals in the validation set. A correct prediction of whether or not a referral will be approved can be made in three out of four cases.

Interruptions in a level one trauma center: a case study.

BACKGROUND: The emergency department has been characterized as interrupt-driven. Government agencies and patient safety organizations recognize that interruptions contribute to medical errors. The purpose of this study was to observe, record, and contextualize activities and interruptions experienced by physicians and Registered Nurses (RNs) working in a Level One Trauma Center. DESIGN: A case study that relied on an ethnographic study design using the shadowing method. SUBJECTS: A convenience sample of physicians and RNs, each with at least 6 months of experience in the Emergency Department (ED), were asked to participate. In these kinds of detailed qualitative investigations, it is quite common to have a small sample size. Ethical approval: Approval was obtained from institutional ethic committees prior to initiating the study. Community consent was obtained from the ED staff through in-service education. SETTING: All observations were made in the trauma section of the ED of a tertiary teaching hospital. The hospital is situated in a major medical center in the Gulf Coast region of the United States of America (USA). FINDINGS: Five attending ED physicians were observed for a total of 29h, 31min. Eight RNs were shadowed for a total of 40 h, 9min. Interruptions and activities were categorized using the Hybrid Method to Categorize Interruptions and Activities (HyMCIA). Registered Nurses received slightly more interruptions per hour than physicians. People, pagers, and telephones were identified as mediums through which interruptions were delivered. The physical environment was found to contribute to interruptions in workflow because of physical design and when supplies were not available. Physicians and RNs usually returned to the original, interrupted activity more often than leaving the activity unfinished. CONCLUSION: This research provides an enhanced understanding of interruptions in workflow in the ED, the identification of work constraints, and the need to develop interventions to manage interruptions. It is crucial that interruptions be delivered in such a way that there is minimal negative impact on performance. The significance and importance of the interruption must always be weighed against the negative impact that it has on smooth, efficient workflow.

Attitudes toward medical device use errors and the prevention of adverse events.

BACKGROUND: The design of a device's user interface often contributes to the chance of a user making an error in using the device. However, there is evidence that most such errors that occur in practice are attributed solely to the user and that the primary method of error prevention is to retrain the user. Yet this attitude may decrease the quality of error reports and the use of more effective error prevention strategies. A qualitative study was conducted to assess health care employees' attitudes toward device use errors and the prevention of adverse events. METHODS: Twenty-six health care employees from three hospital systems, including 11 device users and 15 nonusers who had participated in infusion pump purchasing decisions were given a scenario describing a device use error involving an infusion pump. Several open-ended questions assessed what they felt led to the event and how they would prevent the event from reccurring. RESULTS: The top three reported types of factors leading to the adverse event, in decreasing order of frequency, were the user, pump design problems, and lack of training. The top three prevention strategies reported by the participants were retraining the user, redesigning the device, and telling the user to be careful. DISCUSSION: These results suggest that health care employees still put too much emphasis on the traditional view of blaming and retraining the user.

Clinical communication ontology for medical errors.

Clinical communication failures caused 60% of sentinel events reported by the Joint Commission on Accreditation of Healthcare Organizations. The difficulties of communication have been the primary cause of errors leading to patients' death. For analyzing medical error events, uncovering the patterns of clinical communication, this paper reports the design and development of clinical communication ontology. The ontology contains eight axes and was validated using ten medical error cases, where communication was the main factor. The coding process demonstrates that the ontology can be used as a guideline for future medical error reporting system, through which the root cause of medical error due to communication will be revealed in a clear pattern. This ontology contributes to the generation of proper interventions and effective strategies for reducing medical errors.

Initiators of interruption in workflow: the role of MDs and RNs.

The healthcare environment has been characterized as interrupt-driven with medical doctors (MDs) and registered nurses (RNs) receiving many interruptions during a shift. Previous research studies have focused on the recipient because of the negative impact on task performance. It is equally important to understand the initiator of an interruption to help design strategies to lessen the number of interruptions and the possible negatives consequences. The purpose of this instrumental study was to examine MDs and RNs as initiators of interruptions. Results of this study indicate that MDs and RNs initiate interruptions most often through face-to-face situations and use of the telephone. Strategies to successfully manage interruptions must consider both the role of initiator as well as the recipient in an interruption event.