Longer Completion Times Research Articles

Improving the Safety, Effectiveness, and Efficiency of Clinical Alarm Systems: Simulation-Based Usability Testing of Physiologic Monitors.

BackgroundClinical alarm system safety is a national patient safety goal in the United States. Physiologic monitors are associated with the highest number of device alarms and alarm-related deaths. However, research involving nurses’ use of physiologic monitors is rare. Hence, the identification of critical usability issues for monitors, especially those related to patient safety, is a nursing imperative.ObjectiveThis study examined nurses’ usability of physiologic monitors in intensive care units with respect to the effectiveness and efficiency of monitor use.MethodsIn total, 30 nurses from 4 adult intensive care units completed 40 tasks in a simulation environment. The tasks were common monitoring tasks that were crucial for appropriate monitoring and safe alarm management across four categories of competencies: admitting, transferring, and discharging patients using the monitors (7 tasks); managing measurements and monitor settings (23 tasks); performing electrocardiogram (ECG) analysis (7 tasks); and troubleshooting alarm conditions (3 tasks). The nurse-monitor interaction was video-recorded. The principal investigator and two expert intensive care units nurse educators identified, classified, and validated task success (effectiveness) and the time of task completion (efficiency).ResultsAmong the 40 tasks, only 2 (5%) were successfully completed by all the nurses. At least 1-27 (3%-90%) nurses abandoned or did not correctly perform 38 tasks. The task with the shortest completion time was “take monitor out of standby” (mean 0:02, SD 0:01 min:s), whereas the task “record a 25 mm/s ECG strip of any of the ECG leads” had the longest completion time (mean 1:14, SD 0:32 min:s). The total time to complete 37 navigation-related tasks ranged from a minimum of 3 min 57 s to a maximum of 32 min 42 s. Regression analysis showed that it took 6 s per click or step to successfully complete a task. To understand the nurses’ thought processes during monitor navigation, the authors analyzed the paths of the 2 tasks with the lowest successful completion rates, where only 13% (4/30) of the nurses correctly completed these 2 tasks. Although 30% (9/30) of the nurses accessed the correct screen first for task 1 and task 2, they could not find their way easily from there to successfully complete the 2 tasks.ConclusionsUsability testing of physiologic monitors revealed major ineffectiveness and inefficiencies in the current nurse-monitor interactions. The results indicate the potential for safety and productivity issues in completing routine tasks. Training on monitor use should include critical monitoring functions that are necessary for safe, effective, efficient, and appropriate monitoring to include knowledge of the shortest navigation path. It is imperative that vendors’ future monitor designs mimic clinicians’ thought processes for successful, safe, and efficient monitor navigation.

Questionnaire experience and the hybrid System Usability Scale: Using a novel concept to evaluate a new instrument

This article presents the concept of questionnaire experience (QX), intending to add a new element to the psychometric evaluation of questionnaires, which may eventually help increase the validity and reliability of instruments. The application of QX is demonstrated in the development of the Hybrid System Usability Scale (H-SUS), making use of items comprising pictorial and verbal elements to measure perceived usability. The H-SUS was modelled on the verbal version of the System Usability Scale (SUS). Since previous research showed advantages of pictorial scales over verbal scales (e.g., higher respondent motivation) but also disadvantages (e.g., longer completion times), we assumed that hybrid scales would combine the advantages of both scale types. The goal of this study was to compare the two instruments by assessing traditional psychometric criteria (convergent, divergent and criterion-related validity, reliability and sensitivity) and respondent-related aspects of QX (respondent workload, respondent motivation, questionnaire preference, and questionnaire completion time). An online experiment was carried out (N = 152), in which participants interacted with a smartphone prototype and subsequently completed the verbal SUS together with the H-SUS. Results indicate good psychometric properties of the H-SUS. Compared to the SUS, the H-SUS showed similar workload levels for questionnaire completion, higher levels of respondent motivation, but longer questionnaire completion time. Overall, the H-SUS is considered a promising alternative for the evaluation of perceived usability. Finally, QX can be considered a useful concept for identifying potential problems of psychometric instruments in a respondent-centred way, which may help improve the quality of future scales.

Assessing the Impact of Retailer Disclosure on the Effectiveness of U.S. Meat and Poultry Recalls

In August 2008, the Food Safety and Inspection Service of the U.S. Department of Agriculture (USDA) launched a new policy that required publication of a list of retail consignees for the meat and poultry products part of class I recalls, those with the greatest potential impact on public health. In this study, two recall effectiveness measures (recovery rate and completion time) and a difference-in-difference method were used to examine the effects of retailer disclosures. When controlling for factors previously determined to impact recall effectiveness, including product type, reasons for recall, the amount of food recalled, plant size, and the way the problem was discovered, no significant impact on recall effectiveness was discerned under the current disclosure policy. Recalls for bacterial contamination had higher recovery rates. Larger recalls had lower recovery rates and longer completion times. Recalls issued by very small plants had lower recovery rates. Compared with other stakeholders, government agency discovery of the problem was associated with lower recovery rates. As the U.S. Food and Drug Administration considers a similar retailer disclosure policy for foods regulated under the Food Safety Modernization Act, such lessons from the USDA experience should inform the policy debate.

A functional molecular marker for detecting blister blight disease resistance in tea (Camellia sinensis L.).

Identification of an EST-SSR molecular marker associated with Blister blight, a common fungal disease of tea, facilitating marker-assisted selection, marking a milestone in tea molecular breeding. lister blight (BB) leaf disease of tea, caused by the fungus Exobasidium vexans, results in 25-30% crop loss annually. BB is presently controlled by Cu based fungicides, but genetic resistance is the most viable option in disease management. Tea is a naturally out-crossing, woody perennial necessitating a long time for completion of a breeding programme. Marker-assisted selection (MAS) is vital to expedite breeding programmes and also for better accuracy in gene identification. The aim of the current research was to derive marker-trait associations using an F1 population segregating for BB. The population was genotyped at 11 expressed sequence tag simple sequence repeat loci followed by detecting the alleles by fragment analysis. The genotypic and phenotypic data were subjected to single-marker analysis resulting in the identification of EST-SSR073 as a diagnostic marker amplifying three alleles of the sizes, 168, 170 and 190bp in F1. Of them, alleles 190 and 168bp were confirmed to concur BB resistance and susceptibility, respectively. The alleles were validated in a panel of 64 tea cultivars, resulting in the amplification of 12 alleles at EST-SSR073. The EST-SSR073 allele sequences matched with Camellia sinensis photosystem-I reaction center subunit-II. The marker EST-SSR073 can be effectively used in breeding tea against BB, recording a milestone in MAS in tea.

Flow Scheduling of Service Chain Processing in a NFV-Based Network

Network Function Virtualization (NFV) is changing the way we implement the network functions from expensive hardware to software middleboxes, called Virtual Network Functions (VNFs). Flows always request to be processed by several middleboxes in a specific order, which is known as a service chain. Most researches study the middlebox placement problemand few of them pay attention to the flow scheduling of a deployed service chain, resulting in poor control of flow completion times. However, the flow completion time is an extreme metric to evaluate the performance of a network. Therefore, we focus on the service chain scheduling problem. We aim to minimize the flow completion time in two aspects:the longest completion time (makespan) and the average completion time. First, a transmission and processing delay model is proposed to formulate the communication latency behaviour of flows being processed by middleboxes. When there are only two middleboxes in theservice chain, we propose one optimal solution for each aspect, respectively. For a service chain with an arbitrary length, we prove the NP-hardness of our problem in both aspects and two corresponding heuristic algorithms are designed, which are extended from ourproposed optimal solutions for a service chain with a length of two. Real testbed experiments and extensive simulations are conducted to evaluate the performance of our proposed algorithms in various scenarios.

Rapid naming ability in adults with stuttering

The investigation of phonological encoding abilities in persons with stuttering has gained importance recently. There is limited information available on the rapid automatized naming ability in adults with stuttering. In the present study, rapid naming ability was assessed in 32 persons with stuttering and 32 persons without stuttering in the age range of 18–30 years on Rapid Automatized Naming and Rapid Alternating Stimulus test. The study findings indicated that the persons with stuttering took a longer time to complete the tasks as compared to persons without stuttering, suggestive of a possible breakdown in phonological encoding ability. Among the subtasks, the longer completion time was observed for the rapid alternating stimulus 3-set task and the color subtasks. The findings of the study clearly propose the need to encompass rapid naming skills, as a part of the assessment and management protocol for individuals with stuttering.

Train early and with deliberate practice: simple coronary surgery simulation platform results in fast increase in technical surgical skills in residents and students.

The amount of intense and focused training with the specific goal to improve performance (i.e. deliberate practice) is a predictor of expert-level performance in multiple domains of psychomotor skill learning. Simulation training improves surgical skills in cardiac surgery. We established a training programme that enables early surgical exposure and assessment. We investigated the training effects in coronary surgery simulations in trainees with different levels of surgical experience. The early surgical exposure and assessment programme comprises a low- and high-fidelity simulation, self-organized training, instructed workshops and a stepwise challenge increase. Performance was assessed with a multidimensional skill matrix using video recordings. Two groups of trainees [students (N = 7), 1-/2-year residents (N = 6)] completed introductory training (pretraining, level 1) and two 3-week training periods (levels 2 and 3). Fellows (N = 6) served as controls. Residents and students underwent deliberate practice training with specific training targets. Fellows performed regularly scheduled coronary surgery cases. Entry and exit assessments were conducted for levels 2 and 3. Fellows did not improve overall performance. Residents and students showed significant improvements in both technical accuracy and completion times. Residents reached an overall performance level comparable to fellows. Students reached similar accuracy of surgical skills with longer completion times [level 3 exit score/time: fellows 27 (24-29)/min; residents 27 (21-30)/min, P = 0.94; students 17 (17-25)/min, P = 0.068]. Deliberate practice training resulted in a fast and substantial increase in surgical skills in residents and students. Unexperienced residents reach performance levels of fellows. Deliberate practice simulation programmes should be a mandatory component of surgical training.

User perspective and higher cognitive task-loads influence movement and performance in immersive training environments

BackgroundIn virtual reality (VR) applications such as games, virtual training, and interactive neurorehabilitation, one can employ either the first-person user perspective or the third-person perspective to perceive the virtual environment; however, applications rarely offer both perspectives for the same task. We used a targeted-reaching task in a large-scale virtual reality environment (N=30 healthy volunteers) to evaluate the effects of user perspective on the head and upper extremity movements, and on user performance. We further evaluated how different cognitive challenges would modulate these effects. Finally, we obtained the user-reported engagement level under the different perspectives.ResultsWe found that first-person perspective resulted in larger head movements (3.52±1.3m) than the third-person perspective (2.41±0.7m). First-person perspective also resulted in more upper-extremity movement (30.08±7.28m compared to 26.66±4.86m) and longer completion times (61.3±16.4s compared to 53±10.4s) for more challenging tasks such as the “flipped mode”, in which moving one arm causes the opposite virtual arm to move. We observed no significant effect of user perspective alone on the success rate. Subjects reported experiencing roughly the same level of engagement in both first-person and third-person perspectives (F(1.58)=0.9,P=.445).ConclusionUser perspective and its interaction with higher-cognitive load tasks influences the extent of movement and user performance in a virtual theater environment, and may influence the choice of the interface type (first or third person) in immersive training depending on the user conditions and exercise requirements.

Does Device or Connection Type Affect Health Preferences in Online Surveys?

Recent evidence has shown that online surveys can reliably collect preference data, which markedly decrease the cost of health preference studies and expand their representativeness. As the use of mobile technology continues to grow, we wanted to examine its potential impact on health preferences. Two recently completed discrete choice experiments using members of the US general population (n = 15,292) included information on respondent device (cell phone, tablet, Mac, PC) and internet connection (business, cellular, college, government, residential). In this analysis, we tested for differences in respondent characteristics, participation, response quality, and utility values for the 5-level EQ-5D (EQ-5D-5L) by device and connection. Compared to Mac and PC users, respondents using a cell phone or tablet had longer completion times and were significantly more likely to drop out during the surveys (p < 0.001). Tablet users also demonstrated more logical inconsistencies (p = 0.05). Likewise, respondents using a cellular internet connection exhibit significantly less consistency in their health preferences. However, matched samples for tablets and cell phones produced similar EQ-5D-5L utility values (mean differences < 0.06 on a quality-adjusted life-year [QALY] scale for all potential health states). Allowing respondents to complete online surveys using a cell phone or tablet or over a cellular connection substantially increases the diversity of respondents and the likelihood of obtaining a representative sample, as many individuals have cell phones but not a computer. While the results showed systematic variability in participation and response quality by device and connection type, this study did not show any meaningful changes in utility values.

Do Forced-Choice (FC) Questions Trigger Deeper Cognition than Check-All-That-Apply (CATA) Questions?

Abstract Existing research shows that response options are endorsed at a higher rate when presented in forced-choice format (FC, yes-no grids) than in check-all-that-apply format (CATA). Information Processing Theory explains this contrast with differential effects on the level of cognitive reflection. The study tests this hypothesis with eye movement data collected in a randomized laboratory experiment in which 131 respondents participated in a web survey with four treatment questions. In one condition (CATA) the questions were presented in check-all format, in the other (FC) in forced-choice structure. I find higher levels of affirmative responses and longer completion times in FC compared to CATA in three of the questions. With all four questions, respondents invested more cognitive effort—measured by fixation counts and times—in FC than in CATA when considering the question in total. I find no differences when considering only the list of response options, however. This indicates that the longer fixation times did not result from a more careful evaluation of the response options. Other possible causes and practical implications are discussed.

Haptic feedback in the da Vinci Research Kit (dVRK): A user study based on grasping, palpation, and incision tasks.

It was suggested that the lack of haptic feedback, formerly considered a limitation for the da Vinci robotic system, does not affect robotic surgeons because of training and compensation based on visual feedback. However, conclusive studies are still missing, and the interest in force reflection is rising again. We integrated a seven-DoF master into the da Vinci Research Kit. We designed tissue grasping, palpation, and incision tasks with robotic surgeons, to be performed by three groups of users (expert surgeons, medical residents, and nonsurgeons, five users/group), either with or without haptic feedback. Task-specific quantitative metrics and a questionnaire were used for assessment. Force reflection made a statistically significant difference for both palpation (improved inclusion detection rate) and incision (decreased tissue damage). Haptic feedback can improve key surgical outcomes for tasks requiring a pronounced cognitive burden for the surgeon, to be possibly negotiated with longer completion times.

A mixed-methods evaluation framework for electronic health records usability studies.

Poor EHR design adds further challenges, especially in the areas of order entry and information visualization, with a net effect of increased rates of incidents, accidents, and mortality in ICU settings. The purpose of this study was to propose a novel, mixed-methods framework to understand EHR-related information overload by identifying and characterizing areas of suboptimal usability and clinician frustration within a vendor-based, provider-facing EHR interface. A mixed-methods, live observational usability study was conducted at a single, large, tertiary academic medical center in the Southeastern US utilizing a commercial, vendor based EHR. Physicians were asked to complete usability patient cases, provide responses to three surveys, and participant in a semi-structured interview. Of the 25 enrolled ICU physician participants, there were 5(20%) attending physicians, 9 (36%) fellows, and 11 (44%) residents; 52% of participants were females. On average, residents were the quickest in completing the tasks while attending physician took the longest to complete the same task. Poor usability, complex interface screens, and difficulty to navigate the EHR significantly correlated with high frustration levels. Significant association were found between the occurrence of error messages and temporal demand such that more error messages resulted in longer completion time (p = .03). Physicians remain frustrated with the EHR due to difficulty in finding patient information. EHR usability remains a critical challenge in healthcare, with implications for medical errors, patient safety, and clinician burnout. There is a need for scientific findings on current information needs and ways to improve EHR-related information overload.

Exploring relationships among recall effectiveness indicators in the US meat and poultry industry

Food recalls need to balance speed and completeness, consumer and firm interests and thus meet managerial and social goals. Effective recalls play a vital role in protecting public health and reducing economic consequences. This paper develops a simultaneous equation model to explore the relationships among three effectiveness indicators; discovery time, completion time and recovery rate. A three-stage least square estimator is applied to control for endogeneity among these indicators. The results suggest that higher recovery rates are associated with shorter discovery times. Longer discovery times led to longer completion times. Longer completion times elicited higher recovery rates. Recalls with high risk to human health had shorter discovery times but longer completion times and lower recovery rates. Recalls issued by large plants had shorter discovery times. Large recalls and national distribution channels negatively impacted discovery times. Compared to other stakeholders, government agencies took longer to discover the problem leading to a recall.

Long-Term Exposure to Anticholinergic and Sedative Medications and Cognitive and Physical Function in Later Life.

Anticholinergic and sedative medications are frequently prescribed to older individuals. These medications are associated with short-term cognitive and physical impairment, but less is known about long-term associations. We therefore examined whether over 20 years cumulative exposure to these medications was related to poorer cognitive and physical functioning. Older adult participants of the Longitudinal Aging Study Amsterdam (LASA) were followed from 1992 to 2012. On seven measurement occasions, cumulative exposure to anticholinergic and sedative medications was quantified with the drug burden index (DBI), a linear additive pharmacological dose-response model. Cognitive functioning was assessed with the Mini-Mental State Examination (MMSE), Alphabet Coding Task (ACT, three trials), Auditory Verbal Learning Test (AVLT, learning and retention condition), and Raven Colored Progressive Matrices (RCPM, two trials). Physical functioning was assessed with the Walking Test (WT), Cardigan Test (CT), Chair Stands Test (CST), Balance Test (BT), and self-reported Functional Independence (FI). Data were analyzed with linear mixed models adjusted for age, education, sex, living with a partner, BMI, depressive symptoms, comorbidities (cardiovascular disease, diabetes, cancer, COPD, osteoarthritis, CNS diseases), and prescribed medications. Longitudinal associations were found of the DBI with poorer cognitive functioning (less items correct on the three ACT trials, AVLT learning condition, and the two RCPM trials) and with poorer physical functioning (longer completion time on the CT, CST, and lower self-reported FI). This longitudinal analysis of data collected over 20 years, showed that higher long-term cumulative exposure to anticholinergic and sedative medications was associated with poorer cognitive and physical functioning.

How serious is the ‘carelessness’ problem on Mechanical Turk?

ABSTRACTThis study compared the quality of survey data collected from Mechanical Turk (MTurk) workers and college students. Three groups of participants completed the same survey. MTurk respondents completed the survey as paid workers using the Mechanical Turk crowdsourcing platform. Student Online respondents also completed the survey online after having been recruited in class. Finally, Student Paper-and-Pencil respondents completed the survey on paper in a classroom setting. Validity checks embedded in the survey were designed to gauge participants’ haste and carelessness in survey completion. MTurk respondents were significantly more likely to fail validity checks by contradicting their own answers or simply completing the survey too quickly. Student groups showed fewer careless mistakes and longer completion times. The MTurk sample tended to be older, more educated, and more ethnically diverse than student samples. Results suggest that researchers should pay special attention to the use of validity checks when recruiting MTurk samples.

Contextual factors affecting hint utility

BackgroundInteractive learning environments often provide help strategies to facilitate learning. Hints, for example, help students recall relevant concepts, identify mistakes, and make inferences. However, several studies have shown cases of ineffective help use. Findings from an initial study on the availability of hints in a mathematics problem-solving activity showed that early access to on-demand hints were linked to lack of performance improvements and longer completion times in students answering problems for summer work. The same experimental methodology was used in the present work with a different student sample population collected during the academic year to check for generalizability.ResultsResults from the academic year study showed that early access to on-demand-hints in an online mathematics assignment significantly improved student performance compared to students with later access to hints, which was not observed in the summer study. There were no differences in assignment completion time between conditions, which had been observed in the summer study and has been attributed to engagement in off-task activities. Although the summer and academic year studies were internally valid, there were significantly more students in the academic year study who did not complete their assignment. The sample populations differed significantly by student characteristics and external factors, possibly contributing to differences in the findings. Notable contextual factors that differed included prior knowledge, grade level, and assignment deadlines.ConclusionsContextual differences influence hint effectiveness. This work found varying results when the same experimental methodology was conducted on two separate sample populations engaged in different learning settings. Further work is needed, however, to better understand how on-demand hints generalize to other learning contexts. Despite its limitations, the study shows how randomized controlled trials can be used to better understand the effectiveness of instructional designs applied in online learning systems that cater to thousands of learners across diverse student populations. We hope to encourage additional research that will validate the effectiveness of instructional designs in different learning contexts, paving the way for the development of robust and generalizable designs.

Online scheduling of moldable parallel tasks

In this paper, we study an online scheduling problem with moldable parallel tasks on m processors. Each moldable task can be processed simultaneously on any number of processors of a parallel computer, and the processing time of a moldable task depends on the number of processors allotted to it. Tasks arrive one by one. Upon arrival of each task, the scheduler has to determine both the number of processors and the starting time for the task. Moreover, these decisions cannot be changed in the future. The objective is to attain a schedule such that the longest completion time over all tasks, i.e., the makespan, is minimized. First, we provide a general framework to show that any $$\rho $$ -bounded algorithm for scheduling of rigid parallel tasks (the number of processors for a task is fixed a prior) can be extended to yield an algorithm for scheduling of moldable tasks with a competitive ratio of $$4\rho $$ if the ratio $$\rho $$ is known beforehand. As a consequence, we achieve the first constant competitive ratio, 26.65, for the moldable parallel tasks scheduling problem. Next, we provide an improved algorithm with a competitive ratio of at most 16.74.

Validation of a Novel Inverted Peg Transfer Task: Advancing Beyond the Regular Peg Transfer Task for Surgical Simulation-Based Assessment

To evaluate the validity of a novel inverted peg transfer (iPT) task for assessing laparoscopic skills of novices and experts and compare iPT to the regular PT (rPT) task to ensure surgical trainee acquisition of an adequate advanced laparoscopic skills level for safe laparoscopic practice in the operating room. Prospective crossover study. Multidisciplinary simulation center and motion analysis laboratory, Mayo Clinic. Novices were medical students and surgical interns without laparoscopic experience. Experts were surgeons with at least 3 years of experience in laparoscopic surgery. This was the first exposure to iPT for both groups. Completion time and performance metrics were recorded. A scoring rubric was used to calculate a normalized performance score between 0 and 100. Wilcoxon rank sum and Mann-Whitney tests were performed with α = 0.05. Receiver-operating characteristic curves were graphed for the 2 task scores to assess the tasks' sensitivity and specificity in differentiating laparoscopic experience level. Performance measures of completion time, transferred triangles, dropped triangles (errors), and the overall performance score on both tasks between- and within-subjects (i.e., novices and experts). Thirty-six novices and eight experts participated. Both experts and novices had longer completion time and lower scores during iPT than rPT (p < 0.05). Within iPT, novice completion times were 144 seconds longer (p = 0.04), and performance score was 35 points lower than experts (p < 0.01). No differences between novices and experts were observed for completion time or performance scores (p > 0.05) for rPT. The iPT scores had a higher sensitivity and specificity than the rPT (area under the receiver-operating characteristic curve: iPT = 0.91; rPT = 0.69). iPT is a valid assessment of advanced laparoscopic skills for surgical trainees with higher specificity and sensitivity than rPT. As advanced minimally invasive surgery becomes more common, it is important that tasks such as iPT be included in surgical simulation curricula and training assessment.

Marriage of Opposites? Social Capital Differences in Mergers and Acquisitions

This paper studies the role of regional cultural differences in M\&A transactions in the U.S. We construct a county-level measure of cultural trust based on the World Values Survey data and find that a larger social trust distance between two companies reduces the likelihood of them combining via an M\&A transaction. Conditional on the deal being announced, a larger social trust distance between the acquirer and the target results in lower completion rates and longer completion times, indicating a higher complexity in deal execution. However, we also find that a larger social trust distance is associated with higher gains from mergers, as measured by both acquirer and combined announcement returns as well as medium-term buy-and-hold abnormal returns. The result suggests that for these announced deals, the synergy potential is high enough to offset the costs induced by the large cultural distance.

Modeling and evaluation of hand-eye coordination of surgical robotic system on task performance.

Robotic-assisted minimally invasive surgery changes the direct hand and eye coordination in traditional surgery to indirect instrument and camera coordination, which affects the ergonomics, operation performance, and safety. A camera, two instruments, and a target, as the descriptors, are used to construct the workspace correspondence and geometrical relationships in a surgical operation. A parametric model with a set of parameters is proposed to describe the hand-eye coordination of the surgical robot. From the results, optimal values and acceptable ranges of these parameters are identified from two tasks. A 90° viewing angle had the longest completion time; 60° instrument elevation angle and 0° deflection angle had better performance; there is no significant difference among manipulation angles and observing distances on task performance. This hand-eye coordination model provides evidence for robotic design, surgeon training, and robotic initialization to achieve dexterous and safe manipulation in surgery.