Using the Operating Room Black Box to Assess Surgical Team Member Adaptation Under Uncertainty: An Observational Study.

OBJECTIVE: Identify how surgical team members uniquely contribute to teamwork and adapt their teamwork skills during instances of uncertainty. BACKGROUND: The importance of surgical teamwork in preventing patient harm is well documented. Yet, little is known about how key roles (nurse, anesthesiologist, surgeon, and medical trainee) uniquely contribute to teamwork during instances of uncertainty, particularly when adapting to and rectifying an intraoperative adverse event (IAE). METHODS: Audiovisual data of 23 laparoscopic cases from a large community teaching hospital were prospectively captured using OR Black Box. Human factors researchers retrospectively coded videos for teamwork skills (backup behavior, coordination, psychological safety, situation assessment, team decision-making, and leadership) by team role under 2 conditions of uncertainty: associated with an IAE versus no IAE. Surgeons identified IAEs. RESULTS: In all, 1015 instances of teamwork skills were observed. Nurses adapted to IAEs by expressing more backup behavior skills (5.3× increase; 13.9 instances/hour during an IAE vs 2.2 instances/hour when no IAE) while surgeons and medical trainees expressed more psychological safety skills (surgeons: 3.6× increase; 30.0 instances/hour vs 6.6 instances/hour and trainees: 6.6× increase; 31.2 instances/hour vs 4.1 instances/hour). All roles expressed fewer situation assessment skills during an IAE versus no IAE. CONCLUSIONS: OR Black Box enabled the assessment of critically important details about how team members uniquely contribute during instances of uncertainty. Some teamwork skills were amplified, while others dampened when dealing with IAEs. The knowledge of how each role contributes to teamwork and adapts to IAEs should be used to inform the design of tailored interventions to strengthen interprofessional teamwork.

Cognitive biases in surgery: systematic review.

BACKGROUND: Although numerous studies have established cognitive biases as contributors to surgical adverse events, their prevalence and impact in surgery are unknown. This review aimed to describe types of cognitive bias in surgery, their impact on surgical performance and patient outcomes, their source, and the mitigation strategies used to reduce their effect. METHODS: A literature search was conducted on 9 April and 6 December 2021 using MEDLINE, Embase, PsycINFO, Scopus, Web of Science, Cochrane Central Register of Controlled Trials, and the Cochrane Database of Systematic Reviews. Included studies investigated how cognitive biases affect surgery and the mitigation strategies used to combat their impact. The National Institutes of Health tools were used to assess study quality. Inductive thematic analysis was used to identify themes of cognitive bias impact on surgical performance. RESULTS: Thirty-nine studies were included, comprising 6514 surgeons and over 200 000 patients. Thirty-one types of cognitive bias were identified, with overconfidence, anchoring, and confirmation bias the most common. Cognitive biases differentially influenced six themes of surgical performance. For example, overconfidence bias associated with inaccurate perceptions of ability, whereas anchoring bias associated with inaccurate risk-benefit estimations and not considering alternative options. Anchoring and confirmation biases associated with actual patient harm, such as never events. No studies investigated cognitive bias source or mitigation strategies. CONCLUSION: Cognitive biases have a negative impact on surgical performance and patient outcomes across all points of surgical care. This review highlights the scarcity of research investigating the sources that give rise to cognitive biases in surgery and the mitigation strategies that target these factors.

Effects of Unit Census and Patient Acuity Levels on Discussions During Patient Rounds.

OBJECTIVES: PICU teams adapt the duration of patient rounding discussions to accommodate varying contextual factors, such as unit census and patient acuity. Although studies establish that shorter discussions can lead to the omission of critical patient information, little is known about how teams adapt their rounding discussions about essential patient topics (i.e., introduction/history, acute clinical status, care plans) in response to changing contexts. To fill this gap, we examined how census and patient acuity impact time spent discussing essential topics during individual patient encounters. DESIGN: Observational study. SETTING: PICU at a university-affiliated children's hospital, Toronto, ON, Canada. SUBJECTS: Interprofessional morning rounding teams. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: We observed 165 individual patient encounters during morning rounds over 10 weeks. Regardless of census or patient acuity, the duration of patient introductions/history did not change. When census was high versus low, acute clinical status discussions significantly decreased for both low acuity patients (00 min:50 s high census; 01 min:39 s low census; -49.5% change) and high acuity patients (01 min:10 s high census; 02 min:02 s low census; -42.6% change). Durations of care plan discussions significantly reduced as a function of census (01 min:19 s high census; 02 min:52 s low census; -54.7% change) for low but not high acuity patients. CONCLUSIONS: Under high census and patient acuity levels, rounding teams disproportionately shorten time spent discussing essential patient topics. Of note, while teams preserved time to plan the care for acute patients, they cut care plan discussions of low acuity patients. This study provides needed detail regarding how rounding teams adapt their discussions of essential topics and establishes a foundation for consideration of varying contextual factors in the design of rounding guidelines. As ICUs are challenged with increasing census and patient acuity levels, it is critical that we turn our attention to these contextual aspects and understand how these adaptations impact clinical outcomes to address them.

Human Factors Analysis of Latent Safety Threats in a Pediatric Critical Care Unit.

OBJECTIVES: To identify unique latent safety threats spanning routine pediatric critical care activities and categorize them according to their underlying work system factors (i.e., "environment, organization, person, task, tools/technology") and associated clinician behavior (i.e., "legal": expected compliance with or "illegal-normal": deviation from and "illegal-illegal": disregard for standard policies and protocols). DESIGN: A prospective observational study with contextual inquiry of clinical activities over a 5-month period. SETTING: Two PICUs (i.e., medical-surgical ICU and cardiac ICU) in an urban free-standing quaternary children's hospital. SUBJECTS: Attending physicians and trainees, nurse practitioners, registered nurses, respiratory therapists, dieticians, pharmacists, and patient services assistants were observed. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Conducted 188 hours of observations to prospectively identify unique latent safety threats. Qualitative observational notes were analyzed by human factors experts using a modified framework analysis methodology to summarize latent safety threats and categorize them based on associated clinical activity, predominant work system factor, and clinician behavior. Two hundred twenty-six unique latent safety threats were observed. The latent safety threats were categorized into 13 clinical activities and attributed to work system factors as follows: "organization" (n = 83; 37%), "task" (n = 52; 23%), "tools/technology" (n = 40; 18%), "person" (n = 32; 14%), and "environment" (n = 19; 8%). Twenty-three percent of latent safety threats were identified when staff complied with policies and protocols (i.e., "legal" behavior) and 77% when staff deviated from policies and protocols (i.e., "illegal-normal" behavior). There was no "illegal-illegal" behavior observed. CONCLUSIONS: Latent safety threats span various pediatric critical care activities and are attributable to many underlying work system factors. Latent safety threats are present both when staff comply with and deviate from policies and protocols, suggesting that simply reinforcing compliance with existing policies and protocols, the common default intervention imposed by healthcare organizations, will be insufficient to mitigate safety threats. Rather, interventions must be designed to address the underlying work system threats. This human factors informed framework analysis of observational data is a useful approach to identifying and understanding latent safety threats and can be used in other clinical work systems.

Assessing the electronic Bedside Paediatric Early Warning System: A simulation study on decision-making and usability.

BACKGROUND: The Bedside Paediatric Early Warning System (BedsidePEWS) is a clinical decision support tool designed to augment clinician expertise, objectively identify children at risk for clinical deterioration, and standardize and prioritize care to improve outcomes in community settings. Although the paper-based BedsidePEWS documentation record has been shown to improve clinicians' perception of their ability to detect deterioration and follow care recommendations, research is needed to asses this impact empirically. Furthermore, as hospitals progressively move toward electronic clinical systems, knowledge regarding the impact of BedsidePEWS' novel electronic interface on clinicians' performance and user experience is required. OBJECTIVES: The primary objectives of this study were (1) to compare adherence to evidence-based care recommendations using a) electronic health record software, b) paper BedsidePEWS, and c) a novel electronic BedsidePEWS interface, and (2) to describe end-users' experiences of usability and opportunities for improvement of both paper and electronic BedsidePEWS. METHODS: Paediatric nurses participated in a repeated measures simulation study. Participants assessed simulated patients, documented patient data, and responded to a series of questions regarding follow-up care for each patient. Three patient types (i.e., stable, mild deterioration, severe deterioration) were assessed in each of three intervention conditions (i.e., electronic health record, paper BedsidePEWS, electronic BedsidePEWS). Following simulation scenarios, participants provided comments regarding the usability of the paper and electronic tools. RESULTS: Participants made 12.7% and 18.0% more appropriate care decisions with paper and electronic BedsidePEWS, respectively, than with the electronic health record intervention (p < 0.001). Accurate BedsidePEWS severity of illness score calculation was related to better adherence to evidence-based care recommendations (65%), compared to inaccurate calculation (55%), and electronic BedsidePEWS was associated with 15.7% fewer calculation errors than paper (p < 0.005). Electronic BedsidePEWS demonstrated usability benefits over its paper predecessor, including automatic score calculation and data plotting, and the potential to eliminate double charting, and participants expressed a preference for electronic BedsidePEWS in all aspects of the debrief questionnaire (p < 0.001). CONCLUSIONS: BedsidePEWS in both paper and electronic formats significantly improved participants' ability to detect deterioration and follow care recommendations compared to electronic health record software. Furthermore, results suggest that electronic BedsidePEWS would afford improved patient care in excess of the paper-based original and further contribute to the standardization, prioritization, and improvement of care in community settings.

Untangling Infusion Confusion: A Comparative Evaluation of Interventions in a Simulated Intensive Care Setting.

OBJECTIVES: Assess interventions' impact on preventing IV infusion identification and disconnection mix-ups. DESIGN: Experimental study with repeated measures design. SETTING: High fidelity simulated adult ICU. SUBJECTS: Forty critical care nurses. INTERVENTIONS: Participants had to correctly identify infusions and disconnect an infusion in four different conditions: baseline (current practice); line labels/organizers; smart pump; and light-linking system. MEASUREMENTS AND MAIN RESULTS: Participants identified infusions with significantly fewer errors when using line labels/organizers (0; 0%) than in the baseline (12; 7.7%) and smart pump conditions (10; 6.4%) (p < 0.01). The light-linking system did not significantly affect identification errors (5; 3.2%) compared with the other conditions. Participants were significantly faster identifying infusions when using line labels/organizers (0:31) than in the baseline (1:20), smart pump (1:29), and light-linking (1:22) conditions (p < 0.001). When disconnecting an infusion, there was no significant difference in errors between conditions, but participants were significantly slower when using the smart pump than all other conditions (p < 0.001). CONCLUSIONS: The results suggest that line labels/organizers may increase infusion identification accuracy and efficiency.

Intravenous Chemotherapy Compounding Errors in a Follow-Up Pan-Canadian Observational Study.

PURPOSE: Intravenous (IV) compounding safety has garnered recent attention as a result of high-profile incidents, awareness efforts from the safety community, and increasingly stringent practice standards. New research with more-sensitive error detection techniques continues to reinforce that error rates with manual IV compounding are unacceptably high. In 2014, our team published an observational study that described three types of previously unrecognized and potentially catastrophic latent chemotherapy preparation errors in Canadian oncology pharmacies that would otherwise be undetectable. We expand on this research and explore whether additional potential human failures are yet to be addressed by practice standards. METHODS: Field observations were conducted in four cancer center pharmacies in four Canadian provinces from January 2013 to February 2015. Human factors specialists observed and interviewed pharmacy managers, oncology pharmacists, pharmacy technicians, and pharmacy assistants as they carried out their work. Emphasis was on latent errors (potential human failures) that could lead to outcomes such as wrong drug, dose, or diluent. RESULTS: Given the relatively short observational period, no active failures or actual errors were observed. However, 11 latent errors in chemotherapy compounding were identified. In terms of severity, all 11 errors create the potential for a patient to receive the wrong drug or dose, which in the context of cancer care, could lead to death or permanent loss of function. Three of the 11 practices were observed in our previous study, but eight were new. Applicable Canadian and international standards and guidelines do not explicitly address many of the potentially error-prone practices observed. CONCLUSION: We observed a significant degree of risk for error in manual mixing practice. These latent errors may exist in other regions where manual compounding of IV chemotherapy takes place. Continued efforts to advance standards, guidelines, technological innovation, and chemical quality testing are needed.

MEDICAL DEVICE RECALLS IN CANADA FROM 2005 TO 2015.

OBJECTIVES: Medical devices are ubiquitous in modern medical care. However, little is known about the epidemiology of medical devices in the healthcare marketplace, including the rate at which medical devices are subject to recalls or other advisories. We sought to study the epidemiology of medical devices in Canada, focusing on device recalls. In Canada, a recall may signify a variety of events, ranging from relatively minor field safety notifications, to removal of a product from the marketplace. METHODS: We used data from Health Canada to study medical device recalls in Canada from 2005 to 2015. We analyzed the risks of medical device recalls according to the risk class of the device (I lowest; IV highest) and the hazard priority of the recall (Type I highest potential harm; Type III lowest potential harm). RESULTS: During a 10-year period, there were 7,226 medical device recalls. Most recalls were for intermediate risk class (Class II, 40.1 percent; Class III, 38.7 percent) medical devices. Among recalled devices, 5.0 percent were judged to have a reasonable probability of serious adverse health consequences or death (Type I recall Hazard Priority classification). While the number of medical devices marketed in Canada is not known, over a similar 10-year period, 24,849 new Class II, II, and IV medical device licenses were issued by Health Canada. CONCLUSIONS: Several hundred medical device recalls occur in Canada each year. Further research is needed to characterize the nature of medical device recalls, and to explore how consumers use information about recalls.

Effects of Nested Interruptions on Task Resumption: A Laboratory Study With Intensive Care Nurses.

OBJECTIVE: Interruptions to secondary tasks resulting in multiple tasks to resume may tax working memory. The objective of this research is to study such interruptions experienced by intensive care unit (ICU) nurses. BACKGROUND: ICU nurses are frequently interrupted, resulting in a switch from primary to secondary tasks. In two recent studies, we observed that some of these secondary tasks also get interrupted, resulting in multiple tasks that have to be resumed, a phenomenon we refer to as nested interruptions. Although completing multiple secondary tasks in a serial fashion during an interruption period can create context-switching costs, we hypothesize that nested interruptions tax the working memory even more than just performing multiple secondary tasks sequentially because the nurse would have to encode in working memory the resumption goals for both the primary and the interrupted secondary tasks. METHOD: We conducted a laboratory study with 30 ICU nurses, who performed an electronic order-entry task under three interruption conditions: (a) baseline-no secondary task during the interruption period; (2) serial-performance of two tasks one after the other during the interruption period; and (3) nested-performance of two tasks during the interruption period, one of which was also interrupted. RESULTS: Nested interruptions resulted in significantly longer primary-task resumption lag and less accurate task resumption compared with both the serial interruption and baseline conditions. CONCLUSION: The nested nature of interruptions adds to the resumption lag and diminishes resumption accuracy by likely populating the working memory with goals associated with interrupted secondary tasks.

ReCAP: Comparison of Independent Error Checks for Oral Versus Intravenous Chemotherapy.

PURPOSE: Intravenous (IV) chemotherapy is routinely delivered to patients in hospital settings, where safeguards such as independent checks and guidelines govern their administration. In contrast, oral chemotherapy, which is typically ordered in a cancer center but dispensed and administered in the community and home, respectively, is subject to fewer controls. Research in the United States has found that few safeguards in routine use for IV chemotherapy have been adopted for oral chemotherapy; however, less is known about the Canadian context. The objective of this study was to determine whether similar safeguards, in the form of independent checks, existed to identify potential errors related to both formulations. METHODS: Human factors specialists conducted observations and interviews in cancer center clinics, a cancer center pharmacy, and four community pharmacies across Nova Scotia. Processes were analyzed to determine if an independent check was performed, which qualified provider completed the check, and at what point of the process the check occurred. RESULTS: A total of 57 systematic checks were identified for IV chemotherapy, whereas only six systematic checks were identified for oral chemotherapy. Community pharmacists were the only qualified professionals involved in independent systematic checking of oral chemotherapy, which occurred during ordering and dispensing. CONCLUSION: There is an enormous opportunity for pharmacists and other qualified professionals to take on an expanded role in improving patient safety for oral chemotherapy. Greater involvement of pharmacists, in both the clinic environment and the community, would facilitate increased systematic checking, which could improve patient safety related to oral chemotherapy.

The relationship between interruption content and interrupted task severity in intensive care nursing: an observational study.

BACKGROUND: In a previous study, we observed that the majority of interruptions experienced by nurses in a cardiovascular intensive care unit (CVICU) carried information directly related to their patient or other aspects of work affecting other patients or indirectly affecting their patient. Further, the proportion of interruptions with personal content was significantly higher during low-severity (in case of an error as defined by nurses) tasks compared to medium- and high-severity tasks suggesting that other personnel may have evaluated the criticality of the nurses' tasks before interrupting. However, this earlier study only collected data when an interruption happened and thus could not investigate interruption rate as a function of primary task type and severity while controlling for primary task duration as an exposure variable. OBJECTIVES: We addressed this methodological limitation in a second observational study that was conducted to further study interruptions and also to evaluate an interruption mitigation tool. The data from the baseline condition (i.e., no tool) is analyzed in this paper to validate the results of our previous study and to report interruption rates observed during tasks of varying severities (low, medium, high), with a particular focus on comparing different interruption contents. DESIGN AND SETTING: The study was conducted in a 24-bed closed CVICU at a Canadian hospital, during day shifts. PARTICIPANTS: The baseline condition involved thirteen nurses. METHODS: Over a 3-week period, three researchers observed these nurses 46-120 min each, with an average of 89 min. Data were collected in real time, using a tablet computer and software designed for this purpose. The rate of interruptions with different content was compared across varying task severity levels as defined by CVICU nurses. RESULTS: Nurses spent about 50% of their time conducting medium-severity tasks (e.g., documentation), 35% conducting high-severity tasks (e.g., procedure), and 14% conducting low-severity tasks (e.g., general care). The rate of interruptions with personal content observed during low-severity tasks was 1.97 (95% confidence interval, CI: 1.04, 3.74) and 3.23 (95% CI: 1.51, 6.89) times the rate of interruptions with personal content observed during high- and medium-severity tasks, respectively. CONCLUSIONS: Interrupters might have evaluated task severity before interrupting. Increasing the transparency of the nature and severity of the task being performed may help others further modulate when and how they interrupt a nurse. Overall, rather than try to eliminate all interruptions, mitigation strategies should consider the relevance of interruptions to a task or patient as well as their urgency.

Mitigating nonurgent interruptions during high-severity intensive care unit tasks using a task-severity awareness tool: A quasi-controlled observational study.

PURPOSE: In a previous study of interruptions to intensive care unit (ICU) nurses, we found that other personnel tend to regulate their interruptions based on nurses' tasks. However, nurses' tasks are not always immediately visible to an interrupter. This article evaluates a task-severity awareness tool (TAT) designed for nurses to inform others when they are performing high-severity tasks. When a nurse engages the tool within an ICU room, a "do not disturb please!" message is displayed outside the room. METHODS: Task-severity awareness tool was installed in a cardiovascular ICU room at a Canadian hospital. Fifteen nurses assigned to the TAT room and 13 nurses assigned to 11 other rooms were observed, approximately 2 hours each, over a 3-week period. Data were collected in real time, using a tablet computer. RESULTS: Interruption rate during high-severity tasks in the TAT room was significantly lower than in other rooms; interruptions with personal content were entirely mitigated during high-severity tasks. Furthermore, interruptions from nurses and medical doctors were also entirely mitigated during high-severity tasks but happened more frequently during non-high-severity tasks compared with rooms with no TAT. CONCLUSIONS: Task-severity awareness tool proved to be effective in mitigating unnecessary interruptions to critical tasks. Future research should assess its long-term effectiveness.

The effects of interruptions on oncologists' patient assessment and medication ordering practices.

Interruptions are causal factors in medication errors. Although researchers have assessed the nature and frequency of interruptions during medication administration, there has been little focus on understanding their effects during medication ordering. The goal of this research was to examine the nature, frequency, and impact of interruptions on oncologists' ordering practices. Direct observations were conducted at a Canadian cancer treatment facility to (1) document the nature, frequency, and timing of interruptions during medication ordering, and (2) quantify the use of coping mechanisms by oncologists. On average, oncologists were interrupted 17 % of their time, and were frequently interrupted during safety-critical stages of medication ordering. When confronted with interruptions, oncologists engaged/multitasked more often than resorting to deferring/blocking. While some interruptions are necessary forms of communication, efforts must be made to reduce unnecessary interruptions during safety-critical tasks, and to develop interventions that increase oncologists' resiliency to inevitable interruptions.

Implementation and optimization of smart infusion systems: are we reaping the safety benefits?

To address the high incidence of infusion errors, manufacturers have replaced the development of standard infusion pumps with smart pump systems. The implementation and ongoing optimization processes for smart pumps are more complex, as they require larger coordinated efforts with stakeholders throughout the medication process. If improper implementation/optimization processes are followed, hospitals invest in this technology while extracting minimal benefit. We assessed the processes hospitals employed when migrating from standard to smart infusion systems, and the extent to which they leveraged their investments from both a systems and resource perspective. Twenty-nine hospitals in Ontario, Canada, were surveyed that had either implemented smart pump systems or were in the process of implementing, representing a response rate of 69%. Results demonstrated that hospitals purchased smart pumps for reasons other than safety, did not involve a multidisciplinary team during implementation, made little effort to standardize drug concentrations or develop drug libraries and dosing limits, seldom monitored how nurses use the pumps, and failed to ensure wireless connectivity to upgrade protocols and download use data. Consequently, they are failing to realize the safety benefits these systems can provide.

Checking it twice: an evaluation of checklists for detecting medication errors at the bedside using a chemotherapy model.

OBJECTIVE: To determine what components of a checklist contribute to effective detection of medication errors at the bedside. DESIGN: High-fidelity simulation study of outpatient chemotherapy administration. SETTING: Usability laboratory. PARTICIPANTS: Nurses from an outpatient chemotherapy unit, who used two different checklists to identify four categories of medication administration errors. MAIN OUTCOME MEASURES: Rates of specified types of errors related to medication administration. RESULTS: As few as 0% and as many as 90% of each type of error were detected. Error detection varied as a function of error type and checklist used. Specific step-by-step instructions were more effective than abstract general reminders in helping nurses to detect errors. Adding a specific instruction to check the patient's identification improved error detection in this category by 65 percentage points. Matching the sequence of items on the checklist with nurses' workflow had a positive impact on the ease of use and efficiency of the checklist. CONCLUSIONS: Checklists designed with explicit step-by-step instructions are useful for detecting specific errors when a care provider is required to perform a long series of mechanistic tasks under a high cognitive load. Further research is needed to determine how best to assist clinicians in switching between mechanistic tasks and abstract clinical problem solving.

Human factors perspectives on a systemic approach to ensuring a safer medication delivery process.

The current, prevailing approach to addressing medication delivery safety issues has been to apply solutions at the point of failure with direct, local remediation. These include computerized physician order entry to address transcription and prescribing problems, tall man lettering for label clarity and smart pump systems to address programming use errors. We discuss the lack of a systemic, holistic approach to addressing medication delivery issues that has led to fragmented solutions that do not address the problem as intended and introduce new, unintended patient safety issues. We use recent case studies in addition to our own experimental data from human factors investigations to show how a comprehensive human factors approach can be applied to address systemic error in medication delivery. Only by identifying how (1) subsystems interconnect, (2) information flows, (3) care providers communicate and (4) users are impacted will healthcare organizations and system vendors be able to fully address error in medication delivery. Much of what is required from organizations is to transcend the organizational boundaries of medicine, pharmacy and nursing to produce a delivery system that ensures an integrated approach that addresses all stakeholders' needs.

An on-road assessment of cognitive distraction: impacts on drivers' visual behavior and braking performance.

In this on-road experiment, drivers performed demanding cognitive tasks while driving in city traffic. All task interactions were carried out in hands-free mode so that the 21 drivers were not required to take their visual attention away from the road or to manually interact with a device inside the vehicle. Visual behavior and vehicle control were assessed while they drove an 8 km city route under three conditions: no additional task, easy cognitive task and difficult cognitive task. Changes in visual behavior were most apparent when performance between the No Task and Difficult Task conditions were compared. When looking outside of the vehicle, drivers spent more time looking centrally ahead and spent less time looking to the areas in the periphery. Drivers also reduced their visual monitoring of the instruments and mirrors, with some drivers abandoning these tasks entirely. When approaching and driving through intersections, drivers made fewer inspection glances to traffic lights compared to the No Task condition and their scanning of intersection areas to the right was also reduced. Vehicle control was also affected; during the most difficult cognitive tasks there were more occurrences of hard braking. Although hands-free designs for telematics devices are intended to reduce or eliminate the distraction arising from manual operation of these units, the potential for cognitive distraction associated with their use must also be considered and appropriately assessed. These changes are captured in measures of drivers' visual behavior.

Phonological and visual working memory in mental addition.

The goal of the present research was to examine the role of working memory in mental arithmetic. Adults (n = 96) solved multidigit arithmetic problems (e.g., 52 + 3; 3 + 52) alone and in combination with either a phonological memory load (i.e., nonwords, such as gup) or a visual memory load (i.e., random pattern of asterisks). The participants solved problems presented in a vertical format significantly faster than problems presented in a horizontal format. They also solved double digit first problems (e.g., 52 + 3) more quickly than the reverse (e.g., 3 + 52), but only when the problems were presented horizontally. Performance was worse in the phonological load condition than in the visual load condition for the participants who solved problems presented horizontally, whereas performance was worse in the visual load condition than in the phonological load condition when problems were presented vertically. The present research provides evidence that both phonological and visual aspects of working memory are involved in mental arithmetic but that the role of each working memory component will depend on such factors as presentation format.