The Effect of Mindfulness-based Programs on Cognitive Function in Adults: A Systematic Review and Meta-analysis.

Mindfulness-based programs (MBPs) are increasingly utilized to improve mental health. Interest in the putative effects of MBPs on cognitive function is also growing. This is the first meta-analysis of objective cognitive outcomes across multiple domains from randomized MBP studies of adults. Seven databases were systematically searched to January 2020. Fifty-six unique studies (n = 2,931) were included, of which 45 (n = 2,238) were synthesized using robust variance estimation meta-analysis. Meta-regression and subgroup analyses evaluated moderators. Pooling data across cognitive domains, the summary effect size for all studies favored MBPs over comparators and was small in magnitude (g = 0.15; [0.05, 0.24]). Across subgroup analyses of individual cognitive domains/subdomains, MBPs outperformed comparators for executive function (g = 0.15; [0.02, 0.27]) and working memory outcomes (g = 0.23; [0.11, 0.36]) only. Subgroup analyses identified significant effects for studies of non-clinical samples, as well as for adults aged over 60. Across all studies, MBPs outperformed inactive, but not active comparators. Limitations include the primarily unclear within-study risk of bias (only a minority of studies were considered low risk), and that statistical constraints rendered some p-values unreliable. Together, results partially corroborate the hypothesized link between mindfulness practices and cognitive performance. This review was registered with PROSPERO [CRD42018100904].

Incision site fat thickness and 90-day complications for direct anterior and posterior approach total hip arthroplasty.

BACKGROUND: Defining the distribution of subcutaneous fat around the hip in relation to different approaches for total hip arthroplasty (THA) may lead to a better understanding of the relationship between obesity and complications. The purpose of this study was to: (1) describe the intraoperative thickness of subcutaneous fat at the incision site for direct anterior (DAA) and posterior approaches (PA) for THA; and (2) examine the relationship between fat thickness and 90-day postoperative complications. METHODS: Intraoperative fat measurements were obtained at the anterior incision site (AT-IS) of the DAA (n = 60) and the lateral incision site (LT-IS) of the PA (n = 64). Lateral hip fat thickness was measured from preoperative anteroposterior pelvis radiographs (LT-XR). Body mass index (BMI), sex, age, and 90-day complications were collected retrospectively. RESULTS: Patients within the same demographic groupings had significantly more fat laterally than anteriorly, between 9.6 mm and 17.96 mm. Return to the OR was significantly associated with BMI, AT-IS, and LT-IS. Wound complications were significantly associated with AT-IS. Periprosthetic joint infection (PJI) was significantly associated with BMI and LT-IS. No outcome variables were associated with LT-XR, approach, sex, or age. LT-XR was strongly correlated with AT-IS and LT-IS. CONCLUSIONS: Regardless of BMI, sex, or age more soft tissue was encountered with a PA compared to a DAA. General adiposity was associated with return to the OR. Excess incisional fat was associated with wound complications following a DAA and PJI after a PA. LT-XR and clinical examination near the proposed incision, may provide helpful data in making preoperative risk assessments.

From Self-Esteem to Selflessness: An Evidence (Gap) Map of Self-Related Processes as Mechanisms of Mindfulness-Based Interventions.

Self-related processes (SRPs) have been theorized as key mechanisms of mindfulness-based interventions (MBIs), but the evidence supporting these theories is currently unclear. This evidence map introduces a comprehensive framework for different types of SRPs, and how they are theorized to function as mechanisms of MBIs (target identification). The evidence map then assesses SRP target engagement by mindfulness training and the relationship between target engagement and outcomes (target validation). Discussion of the measurement of SRPs is also included. The most common SRPs measured and engaged by standard MBIs represented valenced evaluations of self-concept, including rumination, self-compassion, self-efficacy, and self-esteem. Rumination showed the strongest evidence as a mechanism for depression, with other physical and mental health outcomes also supported. Self-compassion showed consistent target engagement but was inconsistently related to improved outcomes. Decentering and interoception are emerging potential mechanisms, but their construct validity and different subcomponents are still in development. While some embodied self-specifying processes are being measured in cross-sectional and meditation induction studies, very few have been assessed in MBIs. The SRPs with the strongest mechanistic support represent positive and negative evaluations of self-concept. In sum, few SRPs have been measured in MBIs, and additional research using well-validated measures is needed to clarify their role as mechanisms.

Emotion-related constructs engaged by mindfulness-based interventions: A systematic review and meta-analysis.

OBJECTIVES: Mindfulness-based interventions (MBIs) have been widely implemented to improve self-regulation behaviors, often by targeting emotion-related constructs to facilitate change. Yet the degree to which MBIs engage specific measures of emotion-related constructs has not been systematically examined. METHODS: Using advanced meta-analytic techniques, this review examines construct and measurement engagement in trials of adults that used standardized applications of the two most established MBIs: Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT), or modified variations of these interventions that met defined criteria. RESULTS: Seventy-two studies (N=7,378) were included (MBSR k=47, MBCT k = 21, Modified k=4). MBIs led to significant improvement in emotion-related processing overall, compared to inactive controls (d=0.58; k =36), and in all constructs assessed: depression (d=0.66; k=26), anxiety (d =0.63; k=19), combined mental health (d =0.75; k=7 ) and stress (d =0.44; k=11). Reactions to pain, mood states, emotion regulation, and biological measures lacked sufficient data for analysis. MBIs did not outperform active controls in any analyses. Measurement tool and population-type did not moderate results, but MBI-type did, in that MBCT showed stronger effects than MBSR, although these effects were driven by a small number of studies. CONCLUSIONS: This review is the first to examine the full scope of emotion-related measures relevant to self-regulation, to determine which measures are most influenced by MBCT/MBSR. Compared to extant reviews, which typically focused on MBI outcomes, this work examined mechanistic processes based on measurement domains and tools. While effect sizes were similar among measurement tools, this review also includes a descriptive evaluation of measures and points of caution, providing guidance to MBI researchers and clinicians for selection of emotion-related measurement tools.

Learning Collaboratives in Medical Education: Exploring the Impact of Collaboratives' Structure and Resources and Teams' Experience.

The Alliance of Independent Academic Medical Centers (AIAMC) organized and coordinated a multicenter learning collaborative, National Initiative V (NI V), focused on community health and health inequity. A pre-post descriptive study was designed to examine the outcomes of the AIAMC NI V. Data were collected from pre- and post-assessment surveys as well as a project milestone self-assessment survey. Twenty-nine institutions participated. By the conclusion of the NI, the majority of institutions had completed at least 1 of the milestones in each of the pre-work/background (65.52%), measurement (62.07%), methods (62.07%), and implement/sustain (20.69%) domains. Institutions reported a significant association between their readiness assessments prior to the start of the NI compared with their status of activities on completion. Milestone achievement is significantly associated with 3 of the assessment items. Learning collaboratives with thoughtfully integrated structure and support can be impactful on topic readiness for the participating organizations.

Association of admission clinical predictors and functional outcome in patients with Cerebral Venous and Dural Sinus Thrombosis.

OBJECTIVES: Cerebral venous sinus thrombosis (CVST) is a rare subtype of stroke that most commonly affects younger women. While most patients treated with anticoagulation therapy have good outcomes, a significant number go on to experience disability. The primary aim of this study was to identify objective, easily reproducible, clinical admission predictors of poor outcome at discharge in patients with CVST. PATIENTS AND METHODS: This was a retrospective cohort study of adult CVST patients admitted at our comprehensive stroke center between April 2004 and December 2017. The medical records of patients with a CVST discharge diagnosis code were reviewed for diagnosis confirmation and extraction of clinical and demographic admission data. Multivariable logistic regression was used to build predictive models of objective, standardized examination signs and adjusted for confounders. The primary endpoint was modified Rankin Scale score at discharge defined as good outcome (0-2) and poor outcome (3-6). Mortality was the secondary endpoint. RESULTS: A total of 176 CVST patients were identified. Most patients were white (91 %) and female (65 %). The median age was 40 years old. Headache was the most commonly reported symptom (74 %). Intracranial hemorrhage (ICH) was present in 27 % of patients, venous infarct occurred in 22 % of the patients, and 12 % had both. Age (OR = 1.03, 95 % CI 1.01-1.05), abnormal level of consciousness (OR = 4.38, 95 % CI 1.86-8.88), and focal motor deficits (OR = 3.49, 95 % CI 1.49-8.15) were found to be predictive of poor functional outcome. Pre-hospitalization infections (OR = 5.22, 95 % CI 1.51-18.07) and abnormal level of consciousness (OR = 9.22, 95 % CI 2.34-36.40) were significant predictors of mortality. The predictive effect remained significant after adjusting by median PTT level, presence of intracranial hemorrhage, and venous infarct. CONCLUSIONS: Age, abnormal level of consciousness, and focal motor deficits identified at admission are independently associated with poor outcome in CVST patients. These frequently prevalent, easily reproducible examination signs represent the first step to develop a clinical prediction tool toward stratifying CVST patients with poor prognosis at admission.

Assessing adherence and cost-benefit of colorectal cancer screening for accountable providers.

The objective of this study was to assess adherence and costs-benefits of colorectal cancer (CRC) screenings from an accountable care organization/population health perspective. We performed a retrospective review of 94 patients (50-75 years of age) in an integrated safety net system for whom fecal CRC screening was abnormal for the period of June 1, 2014, to June 1, 2016. A cost-benefit model was constructed using Medicare payment rates and a sensitivity analysis. Most patients included in the study (64/94, 68%) received or were offered a colonoscopy. Of those receiving a colonoscopy, 24 of 45 (53%) had an abnormal finding. Total direct medical costs avoided by screening the patient panel was $32,926 but could have exceeded $63,237 had more patients received follow-up colonoscopies. A sensitivity analysis with 1000 patients demonstrated total monetary benefits between $2.2 million and $8.16 million when follow-up and colonoscopy rates were allowed to vary. Although the resulting rates of follow-up were within the range reported in the literature, there is room for improvement, especially considering the monetary benefit that could be used on other diseases. Health systems and payers should work cooperatively to structure payment models to better incentivize CRC screenings.

Quantity and characteristics of flap or graft repairs for skin cancer on the nose or ears: a comparison between Mohs micrographic surgery and plastic surgery.

One benefit of Mohs micrographic surgery (MMS) is maximal tissue sparing compared to standard excisional surgery techniques. It also has the highest statistical cure rate for appropriately selected nonmelanoma skin cancers (NMSCs) in cosmetically sensitive areas, making it a preferred choice for many self-referred patients or their referring physicians. Patients and nondermatologist physicians may be unaware of how frequently Mohs surgeons perform complex surgical repairs compared to other specialists. Our objective was to compare the quantity and characteristics of flap or graft repairs on the nose or ears following skin cancer extirpation performed by either a fellowship-trained Mohs surgeon or plastic surgeons at 1 academic institution. A retrospective chart review of all skin cancer surgeries was performed to collect data on all flap or graft repairs on the nose or ears at Baylor Scott and White Health (Temple, Texas) from October 1, 2016, to October 1, 2017. We collected secondary data on final defect size prior to the repair, skin tumor type, referring specialty for the procedure, and patient demographics. We found that Mohs surgeons performed a larger number of complex repairs on cosmetically sensitive areas compared to plastic surgeons following skin cancer removal, which may be unrecognized in several specialties that refer patients for management of skin cancers, creating a possible practice gap. More data may aid referring providers in optimally advising and managing patients with cutaneous malignancies.

Urine citrate excretion identifies changes in acid retention as eGFR declines in patients with chronic kidney disease.

Previous studies have shown that acid (H+) retention in patients with chronic kidney disease (CKD) but without metabolic acidosis increases as the estimated glomerular filtration rate (eGFR) decreases over time. The present study examined whether changes in urine excretion of the pH-sensitive metabolite citrate predicted changes in H+ retention over time in similar patients with CKD that were followed for 10 yr. We randomized 120 CKD2 nondiabetic, hypertension-associated nephropathy patients with plasma total CO2 of >24 mM to receive 0.5 meq·kg body wt-1·day-1 NaHCO3 ([Formula: see text]; n = 40), 0.5 meq·kg body wt-1·day-1 NaCl (NaCl; n = 40), or usual care (UC; n = 40). We assessed eGFR (CKD-EPI) and H+ retention by comparing the observed with expected plasma total CO2 increase 2 h after an oral NaHCO3 bolus (0.5 meq/kg body wt). Although 10 yr versus baseline eGFR was lower for each group, 10-yr eGFR was higher (P < 0.01) in [Formula: see text] (59.6 ± 4.8 ml·min-1·1.73 m-2) than NaCl and UC (52.1 ± 5.9 and 52.3 ± 4.1 ml·min-1·1.73 m-2, respectively) groups. Less eGFR preservation was associated with higher 10-yr versus baseline H+ retention in the NaCl group (26.5 ± 13.1 vs. 18.2 ± 15.3 mmol, P < 0.01) and UC group (24.8 ± 11.3 vs. 17.7 ± 10.9 mmol, P < 0.01) and with lower 10-yr versus baseline 8-h urine citrate excretion (UcitrateV) for the NaCl group (162 ± 47 vs. 196 ± 52 mg, respectively, P < 0.01) and UC group (153 ± 41 vs. 186 ± 42 mg, respectively, P < 0.01). Conversely, better eGFR preservation in the [Formula: see text] group was associated with no differences in 10-yr versus baseline H+ retention (14.2 ±13.5 vs. 16.1 ± 15.1 mmol, P = 1.00) or UcitrateV (212 ± 45 vs. 203 ± 49 mg, respectively, P = 0.74). An overall generalized linear model for repeated measures showed that UcitrateV predicted H+ retention (P < 0.01). Less eGFR preservation in patients with CKD2 without metabolic acidosis was associated with increased H+ retention that was predicted by decreased UcitrateV.

Testing the ability of the nonalcoholic fatty liver disease fibrosis score to predict 1-year all-cause hospital admission.

The nonalcoholic fatty liver disease fibrosis score (NFS) has been shown to be a cost-effective screening strategy in the primary care setting to determine when gastroenterology referral is needed, but NFS as a predictor of hospitalization within 1 year is uncertain. This retrospective observational cohort study involved 1803 patients with a diagnosis of nonalcoholic fatty liver disease or nonalcoholic steatohepatitis. The NFS was categorized into the following: low (less than -1.455), moderate (between -1.455 and 0.676), and high (>0.676). The average NFS score by hospital admission was -0.760, the average number of admissions was 1.81, and the median number of days to hospital admission was 135.8 days (45.5-363, 25th to 75th percentile). A univariate logistic regression model showed that NFS significantly predicted hospital admission (P = 0.007); however, a multivariate logistic regression model, after adjusting for hypertension and tobacco use, indicated that NFS was not significantly associated with hospital admission. Using the logistic regression model, hypertension predicted admission at low (P < 0.0001) and moderate (P = 0.0005) NFS. Using this same model, tobacco use also predicted admission at low (P < 0.0001) and moderate (P = 0.0002) NFS. The NFS should not be used to determine which patients are at increased risk of hospitalization.

Urine citrate excretion as a marker of acid retention in patients with chronic kidney disease without overt metabolic acidosis.

Acid (H+) retention appears to contribute to progressive decline in glomerular filtration rate (GFR) in patients with chronic kidney disease (CKD), including some patients without metabolic acidosis. Identification of patients with H+ retention but without metabolic acidosis could facilitate targeted alkali therapy; however, current methods to assess H+ retention are invasive and have little clinical utility. We tested the hypothesis that urine excretion of the pH-sensitive metabolite citrate can identify H+ retention in patients with reduced GFR but without overt metabolic acidosis. H+ retention was assessed based on the difference between observed and expected plasma total CO2 after an oral sodium bicarbonate load. The association between H+ retention and urine citrate excretion was evaluated in albuminuric CKD patients with eGFR 60-89 ml/min/1.73m2 (CKD 2, n=40) or >90 ml/min/1.73m2 (CKD 1, n = 26) before and after 30 days of base-producing fruits and vegetables. Baseline H+ retention was higher in CKD 2, while baseline urine citrate excretion was lower in CKD 2 compared to CKD 1. Base-producing fruits and vegetables decreased H+ retention in CKD 2 and increased urine citrate excretion in both groups. Thus, H+ retention is associated with lower urine citrate excretion, and reduction of H+ retention with a base-producing diet is associated with increased urine citrate excretion. These results support further exploration of the utility of urine citrate excretion to identify H+ retention in CKD patients with reduced eGFR but without metabolic acidosis, to determine their candidacy for kidney protection with dietary H+ reduction or alkali therapy.

Cetirizine versus diphenhydramine in the prevention of chemotherapy-related hypersensitivity reactions.

OBJECTIVE: This study evaluated the role of cetirizine compared to diphenhydramine as premedications for patients receiving paclitaxel, cetuximab, and rituximab infusions. Historically, diphenhydramine has been linked with more sedation in comparison to cetirizine; however, it is unknown if cetirizine can replace diphenhydramine in the prevention of hypersensitivity reactions in patients receiving chemotherapy. METHODS: This is a retrospective study designed to assess infusion reactions occurring in patients receiving diphenhydramine or cetirizine premedication for rituximab, paclitaxel, or cetuximab therapies. Infusion reactions were defined as various symptoms such as flushing, itching, alterations in heart rate and blood pressure, and dyspnea plus the clinical setting of a concurrent or very recent infusion. RESULTS: A total of 207 patients were evaluated in this study with 83 patients receiving cetirizine and 124 diphenhydramine patients. Overall, the percentage of patients with at least one chemotherapy-related infusion event in the cetirizine group was 19.3% (95% CI 11.4-29.4) compared to diphenhydramine group 24.2% (95% CI 17.0-32.7), P = 0.40. Of the patients who received cetirizine and then experienced an event in the first cycle, 41.7% (95% CI 13.7-74.3) of the events were due to paclitaxel, 50.0% (95% CI 19.4-80.6) were due to rituximab, and 8.3% (95% CI 0.1-43.6) were due to cetuximab. Of the patients who received diphenhydramine and then experienced an event in the first cycle, 26.1% (95% CI 5.7-51.4) were due to paclitaxel, 73.9% (95% CI 48.6-94.3) were due to rituximab and none due to cetuximab. CONCLUSION: Cetirizine appears to be a viable substitute for diphenhydramine for the prevention of infusions reactions with cetuximab, paclitaxel, and rituximab infusions in adults. Prospective studies are needed to determine the efficacy and safety of cetirizine compared with diphenhydramine in the prevention of chemotherapy-related infusion reactions.

Implementation of a Clinical Bundle to Reduce Out-of-Hospital Peri-intubation Hypoxia.

STUDY OBJECTIVE: Peri-intubation hypoxia is an important adverse event of out-of-hospital rapid sequence intubation. The aim of this project is to determine whether a clinical bundle encompassing positioning, apneic oxygenation, delayed sequence intubation, and goal-directed preoxygenation is associated with decreased peri-intubation hypoxia compared with standard out-of-hospital rapid sequence intubation. METHODS: We conducted a retrospective, before-after study using data from a suburban emergency medical services (EMS) system in central Texas. The study population included all adults undergoing out-of-hospital intubation efforts, excluding those in cardiac arrest. The before-period intervention was standard rapid sequence intubation using apneic oxygenation at flush flow, ketamine, and a paralytic. The after-period intervention was a care bundle including patient positioning (elevated head, sniffing position), apneic oxygenation, delayed sequence intubation (administration of ketamine to facilitate patient relaxation and preoxygenation with a delayed administration of paralytics), and goal-directed preoxygenation. The primary outcome was the rate of peri-intubation hypoxia, defined as the percentage of patients with a saturation less than 90% during the intubation attempt. RESULTS: The before group (October 2, 2013, to December 13, 2015) included 104 patients and the after group (August 8, 2015, to July 14, 2017) included 87 patients. The 2 groups were similar in regard to sex, age, weight, ethnicity, rate of trauma, initial oxygen saturation, rates of initial hypoxia, peri-intubation peak SpO2, preintubation pulse rate and systolic blood pressure, peri-intubation cardiac arrest, and first-pass and overall success rates. Compared with the before group, the after group experienced less peri-intubation hypoxia (44.2% versus 3.5%; difference -40.7% [95% confidence interval -49.5% to -32.1%]) and higher peri-intubation nadir SpO2 values (100% versus 93%; difference 5% [95% confidence interval 2% to 10%]). CONCLUSION: In this single EMS system, a care bundle encompassing patient positioning, apneic oxygenation, delayed sequence intubation, and goal-directed preoxygenation was associated with lower rates of peri-intubation hypoxia than standard out-of-hospital rapid sequence intubation.

Acid retention in chronic kidney disease is inversely related to GFR.

Greater H+ retention in animal models of chronic kidney disease (CKD) mediates faster glomerular filtration rate (GFR) decline and dietary H+ reduction slows eGFR decline in CKD patients with reduced eGFR and H+ retention due to the high acid (H+) diets of developed societies. We examined if H+ retention in CKD is inversely associated with estimated GFR (eGFR) using cross-sectional and longitudinal analysis of individuals with CKD stage 1 (>90 ml·min- 1·1.73 m-2), CKD stage 2 (60-89 ml/min per 1.73 m2), and CKD stage 3 (30-59 ml·min- 1·1.73 m-2) eGFR. H+ retention was assessed using the difference between observed and expected plasma total CO2 2 h after 0.5 meq/kg body wt oral NaHCO3. H+ retention was higher in CKD 2 vs. CKD 1 ( P < 0.01) and in CKD 3 vs. CKD 2 ( P < 0.02) at baseline and 5 yr, and was higher in CKD 2 vs. CKD 1 ( P < 0.01) at 10 yr. All groups had lower eGFR at subsequent time points ( P < 0.01) but H+ retention was not different among the three time points for CKD 1. By contrast, eGFR decrease was associated with higher H+ retention in CKD 2 at 5 yr ( P = 0.04) and 10 yr ( P < 0.01) and with higher H+ retention in CKD 3 at 5 yr ( P < 0.01). Yearly eGFR decline rate was faster in CKD 2 vs. CKD 1 ( P < 0.01) and in CKD 3 vs. CKD 2 ( P < 0.01). The data show that H+ retention is inversely associated with eGFR, with faster eGFR decline, and support the need for greater dietary H+ reduction therapy for CKD individuals with lower eGFR.

From menarche to menopause: A population-based assessment of water, sanitation, and hygiene risk factors for reproductive tract infection symptoms over life stages in rural girls and women in India.

Women face greater challenges than men in accessing water, sanitation, and hygiene (WASH) resources to address their daily needs, and may respond to these challenges by adopting unsafe practices that increase the risk of reproductive tract infections (RTIs). WASH practices may change as women transition through socially-defined life stage experiences, like marriage and pregnancy. Thus, the relationship between WASH practices and RTIs might vary across female reproductive life stages. This cross-sectional study assessed the relationship between WASH exposures and self-reported RTI symptoms in 3,952 girls and women from two rural districts in India, and tested whether social exposures represented by reproductive life stage was an effect modifier of associations. In fully adjusted models, RTI symptoms were less common in women using a latrine without water for defecation versus open defecation (Odds Ratio (OR) = 0.69; Confidence Interval (CI) = 0.48, 0.98) and those walking shorter distances to a bathing location (OR = 0.79, CI = 0.63, 0.99), but there was no association between using a latrine with a water source and RTIs versus open defecation (OR = 1.09; CI = 0.69, 1.72). Unexpectedly, RTI symptoms were more common for women bathing daily with soap (OR = 6.55, CI = 3.60, 11.94) and for women washing their hands after defecation with soap (OR = 10.27; CI = 5.53, 19.08) or ash/soil/mud (OR = 6.02; CI = 3.07, 11.77) versus water only or no hand washing. WASH practices of girls and women varied across reproductive life stages, but the associations between WASH practices and RTI symptoms were not moderated by or confounded by life stage status. This study provides new evidence that WASH access and practices are associated with self-reported reproductive tract infection symptoms in rural Indian girls and women from different reproductive life stages. However, the counterintuitive directions of effect for soap use highlights that causality and mechanisms of effect cannot be inferred from this study design. Future research is needed to understand whether improvements in water and sanitation access could improve the practice of safe hygiene behaviors and reduce the global burden of RTIs in women.

Individual differences in cognitive functioning predict effectiveness of a heads-up lane departure warning for younger and older drivers.

The effectiveness of an idealized lane departure warning (LDW) was evaluated in an interactive fixed base driving simulator. Thirty-eight older (mean age=77years) and 40 younger drivers (mean age=35years) took four different drives/routes similar in road culture composition and hazards encountered with and without LDW. The four drives were administered over visits separated approximately by two weeks to examine changes in long-term effectiveness of LDW. Performance metrics were number of LDW activations and average correction time to each LDW. LDW reduced correction time to re-center the vehicle by 1.34s on average (95% CI=1.12-1.57s) but did not reduce the number of times the drivers drifted enough in their lanes to activate the system (LDW activations). The magnitude of reductions in average correction RT was similar for older and younger drivers and did not change with repeated exposures across visits. The contribution of individual differences in basic visual and motor function, as well as cognitive function to safety gains from LDW was also examined. Cognitive speed of processing predicted lane keeping performance for older and younger drivers. Differences in memory, visuospatial construction, and executive function tended to predict performance differences among older but not younger drivers. Cognitive functioning did not predict changes in the magnitude of safety benefits from LDW over time. Implications are discussed with respect to real-world safety systems.

Forward Collision Warning: Clues to Optimal Timing of Advisory Warnings.

We examined the effectiveness of a heads-up Forward Collision Warning (FCW) system in 39 younger to middle aged drivers (25-50, mean = 35 years) and 37 older drivers (66-87, mean = 77 years). The warnings were implemented in a fixed based, immersive, 180 degree forward field of view simulator. The FCW included a visual advisory component consisting of a red horizontal bar which flashed in the center screen of the simulator that was triggered at time-to-collision (TTC) 4 seconds. The bar roughly overlapped the rear bumper of the lead vehicle, just below the driver's line-of-sight. A sustained auditory tone (~80 dB) was activated at TTC=2 to alert the driver to an imminent collision. Hence, the warning system differed from the industry standard in significant ways. 95% Confidence intervals for the safety gains ranged from -.03 to .19 seconds in terms of average correction time across several activations. Older and younger adults did not differ in terms of safety gains. Closer inspection of data revealed that younger to middle aged drivers were already braking (42%) on a larger proportion of FCW activations than older drivers (26%), p < .001. Conversely, older drivers were still accelerating (38%) on a larger proportion of FCW activations than younger to middle aged drivers (23%) at the time FCW was activated, p < .009. There were no differences in the proportion of activations when drivers were coasting at the time FCW was activated, p = .240. Furthermore, large individual differences in basic visual, motor, and cognitive function predicted the tendency to brake prior to FCW activation. Those who tended to be better functioning in each of these domains were more likely to be already braking prior to FCW activation at the fixed threshold of TTC=4. These findings suggest optimal timing for advisory alerts for forward events may need to be larger than TTC=4.

Correspondence between Simulator and On-Road Drive Performance: Implications for Assessment of Driving Safety.

Forty-two younger (Mean age = 35) and 37 older drivers (Mean age = 77) completed four similar simulated drives. In addition, 32 younger and 30 older drivers completed a standard on-road drive in an instrumented vehicle. Performance in the simulated drives was evaluated using both electronic drive data and video-review of errors. Safety errors during the on-road drive were evaluated by a certified driving instructor blind to simulator performance, using state Department of Transportation criteria. We examined the degree of convergence in performance across the two platforms on various driving tasks including lane change, lane keeping, speed control, stopping, turns, and overall performance. Differences based on age group indicated a pattern of strong relative validity for simulator measures. However, relative rank-order in specific metrics of performance suggested a pattern of moderate relative validity. The findings have implications for the use of simulators in assessments of driving safety as well as its use in training and/or rehabilitation settings.

PILOT RESULTS ON FORWARD COLLISION WARNING SYSTEM EFFECTIVENESS IN OLDER DRIVERS.

Advanced Driver Assistance Systems (ADAS) have largely been developed with a "one-size-fits-all" approach. This approach neglects the large inter-individual variability in perceptual and cognitive abilities that affect aging ADAS users. We investigated the effectiveness of a forward collision warning (FCW) with fixed response parameters in young and older drivers with differing levels of cognitive functioning. Drivers responded to a pedestrian stepping into the driver's path on a simulated urban road. Behavioral metrics included response times (RT) for pedal controls and two indices of risk penetration (e.g., maximum deceleration and minimum time-to-collision (TTC)). Older drivers showed significantly slower responses at several time points compared to younger drivers. The FCW facilitated response times (RTs) for older and younger drivers. However, older drivers still showed smaller safety gains compared to younger drivers at accelerator pedal release and initial brake application when the FCW was active. No significant differences in risk metrics were observed within the condition studied. The results demonstrate older drivers likely differ from younger drivers using a FCW with a fixed parameter set. Finally, we briefly discuss how future research should examine predictive relationships between domains of cognitive functioning and ADAS responses to develop parameter sets to fit the individual.

EFFECTIVENESS OF A HEADS-UP ADAPTIVE LANE DEVIATION WARNING SYSTEM FOR MIDDLE-AGED & OLDER ADULTS.

46 participants (24 younger and 22 older) completed at least one out of four simulated drives designed to test the effectiveness of an Adaptive Lane Deviation Warning (LDW) system, and they drove through both a warnings-on and warnings-off version of each drive. Findings showed that LDW was effective in reducing reaction time for lane deviation corrections for both older (by 1.2 seconds) and younger drivers (by 1.6 seconds). The older and younger drivers did not differ in correction RTs when the warnings were turned off. But older drivers showed slower correction RTs than younger drivers in the warning-on drives. The data indicate that these benefits were specific to LDW rather than general improvement in driving performance. Cognitive processing speed emerged as a particularly robust predictor of benefits from the LDW compared to other domains of cognitive function.