Low-risk Conditions Research Articles

Estimating teat canal cross-sectional area to determine the effects of teat-end and mouthpiece chamber vacuum on teat congestion

The primary objective of this experiment was to assess the effect of mouthpiece chamber vacuum on teat-end congestion. The secondary objective was to assess the interactive effects of mouthpiece chamber vacuum with teat-end vacuum and pulsation setting on teat-end congestion. The influence of system vacuum, pulsation settings, mouthpiece chamber vacuum, and teat-end vacuum on teat-end congestion were tested in a 2×2 factorial design. The low-risk conditions for teat-end congestion (TEL) were 40 kPa system vacuum (Vs) and 400-ms pulsation b-phase. The high-risk conditions for teat-end congestion (TEH) were 49 kPa Vs and 700-ms b-phase. The low-risk condition for teat-barrel congestion (TBL) was created by venting the liner mouthpiece chamber to atmosphere. In the high-risk condition for teat-barrel congestion (TBH) the mouthpiece chamber was connected to short milk tube vacuum. Eight cows (32 quarters) were used in the experiment conducted during 0400 h milkings. All cows received all treatments over the entire experimental period. Teatcups were removed after 150 s for all treatments to standardize the exposure period. Calculated teat canal cross-sectional area (CA) was used to assess congestion of teat tissue. The main effect of the teat-end treatment was a reduction in CA of 9.9% between TEL and TEH conditions, for both levels of teat-barrel congestion risk. The main effect of the teat-barrel treatment was remarkably similar, with a decrease of 9.7% in CA between TBL and TBH conditions for both levels of teat-end congestion risk. No interaction between treatments was detected, hence the main effects are additive. The most aggressive of the 4 treatment combinations (TEH plus TBH) had a CA estimate 20% smaller than for the most gentle treatment combination (TEL plus TBL). The conditions designed to impair circulation in the teat barrel also had a deleterious effect on circulation at the teat end. This experiment highlights the importance of elevated mouthpiece chamber vacuum on teat-end congestion and resultant decreases in CA.

Risk-induced neophobia: does sensory modality matter?

Recent studies have documented that exposure to high levels of background risk can induce neophobic predator avoidance in prey animals, whereby they respond to any novel cue with an anti-predator response. Such phenotypically plastic predator avoidance may allow prey to maximize anti-predator benefits in variable risk environments. It remains poorly understood whether risk assessment information from different sensory modalities can be integrated to induce generalized, cross-sensory system neophobic responses. Here, we directly test this hypothesis by exposing juvenile convict cichlids (Amatitlania nigrofasciata) to high- versus low-risk environments using either conspecific alarm cue (chemosensory risk) or a model avian predator (visual/mechanical risk) and testing their response to a novel chemosensory cue (Experiment 1) or visual cue (Experiment 2). Our results suggest that regardless of the sensory modality used to increased perceived risk, cichlids pre-exposed to high-risk conditions exhibited increased predator avoidance in response to any novel visual or chemical cue. As expected, cichlids pre-exposed to low-risk conditions did not display any neophobic responses. Our results suggest that induced neophobia is not cue specific; rather, it may function as a generalized response to perceived predation risk.

The association between graduated driver licensing laws and travel behaviors among adolescents: an analysis of US National Household Travel Surveys.

BackgroundYoung novice drivers have crash rates higher than any other age group. To address this problem, graduated driver licensing (GDL) laws have been implemented in the United States to require an extended learner permit phase, and create night time driving or passenger restrictions for adolescent drivers. GDL allows adolescents to gain experience driving under low-risk conditions with the aim of reducing crashes. The restricted driving might increase riding with parents or on buses, which might be safer, or walking or biking, which might be more dangerous. We examined whether GDL increases non-driver travels, and whether it reduces total travels combining drivers and non-drivers.MethodsWe used data from the US National Household Travel Survey for the years 1995–1996, 2001–2002, and 2008–2009 to estimate the adjusted ratio for the number of trips and trip kilometers made by persons exposed to a GDL law, compared with those not exposed.ResultsAdolescents aged 16 years had fewer trips and kilometers as drivers when exposed to a GDL law: ratio 0.84 (95 % confidence interval (CI) 0.71, 1.00) for trips; 0.79 (0.63, 0.98) for kilometers. For adolescents aged 17 years, the trip ratio was 0.94 (0.83, 1.07) and the kilometers ratio 0.80 (0.63, 1.03). There was little association between GDL laws and trips or kilometers traveled by other methods: ratio 1.03 for trips and 1.00 for kilometers for age 16 years, 0.94 for trips and 1.07 for kilometers for age 17.ConclusionsIf these associations are causal, GDL laws reduced driving kilometers by about 20 % for 16 and 17 year olds, and reduced the number of driving trips by 16 % among 16 year olds. GDL laws showed little relationship with trips by other methods.

Recurrence of stillbirth and second trimester pregnancy loss.

The 3,003 women referred to the Wisconsin Stillbirth Service Program following a stillbirth or second trimester fetal death reported a total of 4,563 previous pregnancies including 180 previous second or third trimester losses for a total precurrence rate of 3.95%. The 142 women with a history of at least one previous stillbirth and/or late miscarriage differed significantly from the entire cohort with respect to timing and cause of their losses. Women experiencing multiple losses frequently had both second trimester miscarriages and stillbirths >20 weeks but did not have an increased risk of first trimester miscarriage. Recurrences were more likely to be in the second trimester (52% vs. 37%) and to have a maternal (20% vs. 11%) or placental (27% vs. 19%) cause. While fetal causes overall were less common in the group with recurrence (18% vs. 27%), the difference was due mainly to fewer common aneuploidies and other low recurrence risk conditions. Not only known recessive conditions but also "idiopathic hydrops" and multiple congenital anomalies not fitting a known syndrome were more frequent than expected, suggesting that these groups should be investigated for underlying genetic causes that might have been overlooked. Women with second trimester losses and/or a maternal or placental cause of death face significantly higher empiric risks (7-8% vs. 4% for the entire cohort) and should be counseled accordingly. Study of recurrent fetal loss can help identify high risk women who may benefit from treatment and preventive strategies in the future.

Different Approaches to Fraud Risk Assessment and Their Implications on Audit Planning

As a result of financial scandals, fraud has become an important concern over the past decades, which has also raised the issue of independent auditors’ responsibilities for detecting fraud. This study examines how auditors perform fraud risk assessment by applying either the traditional or the decomposition methods to different perceived risk level settings. We also investigate how the outcomes of risk assessment influence the audit planning phase. The results prove that the decomposition approach more significantly enhances auditors’ sensitivity to fraud cues between a high and low fraud risk condition than using the traditional audit risk model. In addition, the perception of a more enhanced fraud risk leads to higher propensity to consult with forensic experts. Finally, the research also indicates that the assessed fraud risk level has fundamental impact on total hours budgeted for the audit engagement along with internal structure of total hours allocated to the audit.

The impact of PCAOB regulatory actions and engagement risk on auditors’ internal audit reliance decisions

This paper examines how two Public Company Accounting Oversight Board (PCAOB) regulatory actions (the risk-based audit approach required by auditing standards and a change in the focus of the PCAOB inspection process) interact with engagement risk to affect external auditors’ decisions to rely on the internal audit function (IAF). We predicted that when the focus of the PCAOB inspection process is based on effectiveness, there would be no difference in the external auditors’ planned reliance on the IAF (sensitivity to the risks of the tests) across the two levels of engagement risk and when the focus of the PCAOB inspection process is balanced (meaning both an effective and a efficiency focus), the external auditors’ planned reliance will be higher in the low engagement risk condition compared to the high engagement risk condition. Contrary to our prediction, we find that when the focus of the PCAOB inspection process is balanced, auditors’ reliance on the IAF is not impacted by engagement risk. However, when the PCAOB inspection process is focused on effectiveness, the auditors rely more on the IAF when engagement risk is low than when it is high. Thus, if the goal of Auditing Standard No. 5 (AS5) is to have external auditors be more sensitive to the risk of the tests to be performed, then the PCAOB’s efficiency focus for inspections did not have the intended effect.

Infectious Cognition

When speakers selectively retrieve previously learned information, listeners often concurrently, and covertly, retrieve their memories of that information. This concurrent retrieval typically enhances memory for mentioned information (the rehearsal effect) and impairs memory for unmentioned but related information (socially shared retrieval-induced forgetting, SSRIF), relative to memory for unmentioned and unrelated information. Building on research showing that anxiety leads to increased attention to threat-relevant information, we explored whether concurrent retrieval is facilitated in high-anxiety real-world contexts. Participants first learned category-exemplar facts about meningococcal disease. Following a manipulation of perceived risk of infection (low vs. high risk), they listened to a mock radio show in which some of the facts were selectively practiced. Final recall tests showed that the rehearsal effect was equivalent between the two risk conditions, but SSRIF was significantly larger in the high-risk than in the low-risk condition. Thus, the tendency to exaggerate consequences of news events was found to have deleterious consequences.

Observation for isolated traumatic skull fractures in the pediatric population: unnecessary and costly

BackgroundBlunt head trauma accounts for a majority of pediatric trauma admissions. There is a growing subset of these patients with isolated skull fractures, but little evidence guiding their management. We hypothesized that inpatient neurological observation for pediatric patients with isolated skull fractures and normal neurological examinations is unnecessary and costly. MethodsWe performed a single center 10year retrospective review of all head traumas with isolated traumatic skull fractures and normal neurological examination. Exclusion criteria included: penetrating head trauma, depressed fractures, intracranial hemorrhage, skull base fracture, pneumocephalus, and poly-trauma. In each patient, we analyzed: age, fracture location, loss of consciousness, injury mechanism, Emergency Department (ED) disposition, need for repeat imaging, hospital costs, intracranial hemorrhage, and surgical intervention. ResultsSeventy-one patients presented to our ED with acute isolated skull fractures, 56% were male and 44% were female. Their ages ranged from 1week to 12.4years old. The minority (22.5%) of patients were discharged from the ED following evaluation, whereas 77.5% were admitted for neurological observation. None of the patients required neurosurgical intervention. Age was not associated with repeat imaging or inpatient observation (p=0.7474, p=0.9670). No patients underwent repeat head imaging during their index admission. Repeat imaging was obtained in three previously admitted patients who returned to the ED. Cost analysis revealed a significant difference in total hospital costs between the groups, with an average increase in charges of $4,291.50 for admitted patients (p<0.0001). ConclusionPediatric isolated skull fractures are low risk conditions with a low likelihood of complications. Further studies are necessary to change clinical practice, but our research indicates that these patients can be discharged safely from the ED without inpatient observation. This change in practice, additionally, would allow for huge health care dollar savings.

Permission to park: A statewide study of high school parking permits to determine compliance with graduated driver licensing law.

Motor vehicle crashes are the leading cause of fatality among teens in the United States. Beginning in the 1990s, many states enacted graduated driver licensing (GDL) systems to delay full licensure while allowing beginners to obtain experience under lower-risk conditions. Many high schools require parent and guardians of newly licensed teen drivers to complete a student parking pass application (PPA) for their son/daughter to drive, park, and transport themselves to and from school activities. The objective of this study was to describe the content of these PPAs for compliance with Connecticut's GDL law. PPAs were requested via e-mail, fax, or telephone from all Connecticut's high schools (n = 233). PPA variables included school demographics, parking rules, prohibitions and sanctions for violations, as well as reference to GDL law. Seventy-four schools were excluded because students were not allowed to park and schools did not require PPAs or declined to send us a copy of their PPAs. Of the remaining 159 schools, 122 (76.7%) sent us their PPAs. Responding schools were more likely to be suburban or rural. Most PPAs included a section on prohibitions and sanctions for driving misbehavior. Forty-three percent prohibited students from going to car during school hours, and 34% prohibited driving off campus/parking lot. Seventy percent warned of consequences for dangerous driving in parking lot, and 88% included the possibility of revocation for infractions. Only 14% had any reference to Connecticut's GDL law on their PPAs. A small percentage of Connecticut high schools include information about GDL laws on their PPAs. All states should examine their PPA content and adopt a uniform high school PPA that includes key provisions of their state's GDL laws in an effort to promote teen driving safety. Therapeutic study, level V.

PTH-021 A single centre audit of compliance with guidelines for management of anticoagulation and antiplatelet therapy in patients undergoing endoscopic procedures

Introduction Patients on anticoagulation and antiplatelet therapy undergoing endoscopic procedures need to be assessed for their risk of bleeding depending on the procedure. BSG guidelines for management of antiplatelet and anticoagulation therapy have standardised the care of patients attending for endoscopy procedures taking Clopidogrel and Warfarin. Newer anticoagulants have been popular among patients and there has been recommendation regarding management of these patients undergoing endoscopic procedures but standard guidelines for this group of patients are still awaited. Method This audit was designed to assess compliance with current guidelines and recommendations for management of patients on antiplatelet and anticoagulation therapy undergoing endoscopic procedures. 50 patients on Clopidogrel, Warfarin and newer anticoagulants undergoing endoscopic procedures has been audited prospectively. Collected data was analysed and compared with guidelines. Results Out of the 50 patients, 23 were taking Warfarin, 17 were on Clopidogrel while 10 were on newer anticoagulants (Dabigatran, Rivaroxaban). 10 patients with warfarin were taking it for Atrial Fibrillation (AF) while 13 had high risk condition (prosthetic heart valves, Venous thromboembolism). 12 of the 17 patients on Clopidogrel had low risk condition while 5 had underlying coronary artery stents. All of the 10 patients with newer anticoagulants had same indication (AF). 19 of the total 50 patients had undergone high risk procedures (10 of them were on warfarin, 6 on Clopidogrel while 3 on newer anticoagulants). Compliance with BSG guidelines has been noted in all patients on Warfarin and Clopidogrel except one patient. We found variability in management of patients on newer anticoagulants probably due to lack of standard guidelines and awareness and in 8 cases out of 10, eGFR (Glomerular Filtration Rate) was not calculated and these medications were not stopped as per recommendation. Conclusion It has been concluded that there has been excellent compliance with guidelines for management of patients on Warfarin and Clopidogrel undergoing endoscopic procedures. We have noted lack of standard guidelines for management of patients on newer anticoagulants and inadequate awareness to current recommendation has effected compliance to the current evidence in this group of patients. We would also like to highlight the importance of calculation of eGFR in decisions of duration of newer anticoagulants to be stopped. Disclosure of interest None Declared.

Geochemical Fraction, Mobility And Bioavailability Of Lead In Unsaturated Soil Of Yogyakarta City, Indonesia

Lead (Pb) is one of common heavy metals found inthe soil of urban environment. In Yogyakarta City,Indonesia, lead content in the soil was already reported by some researchers, however all of the report were only reveals the distribution of lead concentration in the soil. Therefore, this research paper aims to understand the geochemical fraction leadin the soil of Yogyakarta City and assess the mobility and bioavailability of lead release to the environment. The soil sampling location is selected on Kotagede District, representing the oldest urban area of Yogyakarta city. A shallow bore hole was drill until about 7 m below the surface and soil/sediments weresampled for each 1 m depth started from the surface. Six steps of sequential extraction procedures were carried out to assess the geochemical fraction of Pb for each of soil samples. The sequential extraction shows that the highest amount of Pb in thesoil of Yogyakarta City is found in amorphous ironoxide, crystalline iron oxide and non residual fraction form of Pb. Based on the results of geochemical fraction, the mobility factor of lead can be calculated and reveals low mobility factor range from 0.4 to 3.3%. The mobility of lead is decreased from the surface to the deeper soil, on the other hand the bioavailability of Pb calculated from exchangeable and carbonate fraction is also show low risk of bioavailability. Therefore, it can be concluded that although Pb concentration is high in non-residual fraction, Pb isin low risk condition due to its poor mobility and bioavailability. But, concern on lead contamination should be considered because if the concentration of Pb is enriched over the adsorption capacity of ironoxide, it can easily release to the environment and can impact to human in the future.Keywords: Yogyakarta city, Lead, Sequential extraction, Geochemical fraction

Differential Effects of Irrelevant Emotional Context on Regret and Rejoice: A Behavioural Economic Investigation of Decision Making under Risk

This study investigates the role of incidental emotion and probability on two aspects of decision making: decision time and post-choice satisfaction (regret and rejoice). We used a modified regret paradigm in which people made choices in the context of pleasant, neutral and unpleasant emotional International Affective Picture System (IAPS) pictures present throughout the decision making and post-decision stages. Both pleasant and unpleasant emotional contexts led to a slower decision time compared to neutral context. With respect to post-choice feeling, participants experienced more regret after losing and less rejoice after winning in unpleasant compared to pleasant and neutral contexts. Further, we observed decreased regret rating from low to high risk conditions in the pleasant context. The regret rating was also observed to be more in the unpleasant compared to the neutral and pleasant contexts during low and high risk conditions, respectively. The results suggest that incidental emotions present during decision making do influence both decision time and post-choice ratings. These results imply that decision making theories need to consider incidental emotional context to explain decision making. We also discuss similarities and differences when incidental emotions are present during decision making with incidental emotions that are present prior to decision making.

Background risk and recent experience influences retention of neophobic responses to predators

Recent studies have shown that prey living under conditions of elevated predation risk respond very differently to novel predators than prey living under low-risk conditions, by displaying generalized avoidance patterns to novel stimuli. This phenotypic plasticity in neophobic responses provides prey with the means to respond flexibly to uncertain risks, but we know almost nothing about how long neophobic responses are maintained. Using extinction testing, we demonstrate that neophobic responses of guppies (Poecilia reticulata) to a novel odour waned relatively quickly over five consecutive exposures, but the waning of responses to one stimulus does not affect neophobic responses to other novel odours. In a subsequent experiment, we demonstrate that learned responses to predator cues in fish from high- and low-risk populations both waned over time, but fish from the high-risk population retained the response longer than those from the low-risk population. Background levels of predation risk appear to be crucial factors in driving differences in retention of risk-related information.

Background level of risk and the survival of predator-naive prey: can neophobia compensate for predator naivety in juvenile coral reef fishes?

Neophobia--the generalized fear response to novel stimuli--provides the first potential strategy that predator-naive prey may use to survive initial predator encounters. This phenotype appears to be highly plastic and present in individuals experiencing high-risk environments, but rarer in those experiencing low-risk environments. Despite the appeal of this strategy as a 'solution' for prey naivety, we lack evidence that this strategy provides any fitness benefit to prey. Here, we compare the relative effect of environmental risk (high versus low) and predator-recognition training (predator-naive versus predator-experienced individuals) on the survival of juvenile fish in the wild. We found that juveniles raised in high-risk conditions survived better than those raised in low-risk conditions, providing the first empirical evidence that environmental risk, in the absence of any predator-specific information, affects the way naive prey survive in a novel environment. Both risk level and experience affected survival; however, the two factors did not interact, indicating that the information provided by both factors did not interfere or enhance each other. From a mechanistic viewpoint, this indicates that the combination of the two factors may increase the intensity, and hence efficacy, of prey evasion strategies, or that both factors provide qualitatively separate benefits that would result in an additive survival success.

Hospital-Level Variation in ICU Admission and Critical Care Procedures for Patients Hospitalized for Pulmonary Embolism

BACKGROUND:Variation in the use of ICUs for low-risk conditions contributes to health system inefficiency. We sought to examine the relationship between ICU use for patients with pulmonary embolism (PE) and cost, mortality, readmission, and procedure use.METHODS:We performed a retrospective cohort study including 61,249 adults with PE discharged from 263 hospitals in three states between 2007 and 2010. We generated hospital-specific ICU admission rate quartiles and used a series of multilevel models to evaluate relationships between admission rates and risk-adjusted in-hospital mortality, readmission, and costs and between ICU admission rates and several critical care procedures.RESULTS:Hospital quartiles varied in unadjusted ICU admission rates for PE (range, ≤ 15% to > 31%). Among all patients, there was a small trend toward increased use of arterial catheterization (0.6%-1.1%,P< .01) in hospital quartiles with higher levels of ICU admission. However, use of invasive mechanical ventilation (14.4%-7.9%,P< .01), noninvasive ventilation (6.6%-3.0%,P< .01), central venous catheterization (14.6%-11.3%,P< .02), and thrombolytics (11.0%-4.7%,P< .01) in patients in the ICU declined across hospital quartiles. There was no relationship between ICU admission rate and risk-adjusted hospital mortality, costs, or readmission.CONCLUSIONS:Hospitals vary widely in ICU admission rates for acute PE without a detectable impact on mortality, cost, or readmission. Patients admitted to ICUs in higher-using hospitals received many critical care procedures less often, suggesting that these patients may have had weaker indications for ICU admission. Hospitals with greater ICU admission may be appropriate targets for improving efficiency in ICU admissions.

Risk-taking under low risk condition

Risk-taking under low risk condition

Assessment of Achieved Clinic and Ambulatory Blood Pressure Recordings and Outcomes During Treatment in Hypertensive Patients With CKD: A Multicenter Prospective Cohort Study

We investigated the effect of having clinic and/or ambulatory blood pressures (BPs) not at goal on cardiorenal risk in patients with non-dialysis-dependent chronic kidney disease (CKD). Multicenter prospective study. 489 consecutive hypertensive patients with CKD (stages 1-5) with concomitant assessment of ambulatory and clinic BPs followed up in tertiary nephrology clinics. Achievement of goal for ambulatory (day- and night-time BPs<135/85 and<120/70mmHg, respectively) and clinic (<140/90mmHg) BPs was used to create 4 BP groups: clinic and ambulatory BPs at goal (group 1), clinic BP above goal and ambulatory BP at goal (group 2), clinic BP at goal and ambulatory BP above goal (group 3), and clinic and ambulatory BPs above goal (group 4). Composite cardiovascular event outcome (fatal and nonfatal myocardial infarction, congestive heart failure, stroke, revascularization, peripheral vascular disease, and nontraumatic amputation) and a composite renal outcome (maintenance dialysis therapy or death). Clinic and 24-hour ambulatory BPs. Mean age was 64.4±14.2 (SD) years; 41% were women, and diabetes and previous cardiovascular disease were present in 36% and 30%, respectively. Groups 1-4 contained 16.8%, 22.1%, 14.5%, and 46.6%, respectively, of the overall number of participants. Median follow-up was 5.2 years. Compared to group 1, the adjusted risk of the composite cardiovascular outcome was higher in groups 3 (HR, 3.17; 95%CI, 1.50-6.69) and 4 (HR, 2.83; 95%CI, 1.50-5.34), but not in group 2 (HR, 1.55; 95%CI, 0.75-3.19). Similarly, the risk of the composite renal outcome was higher in groups 3 (HR, 3.59; 95%CI, 2.05-6.27) and 4 (HR, 2.96; 95%CI, 1.83-4.78), but not group 2 (HR, 1.24; 95%CI, 0.67-2.27). Sensitivity analyses confirmed that these results were independent from the thresholds used for defining groups. Only white patients were enrolled. Observational design does not allow for causality to be established. In patients with treated CKD, clinic BP above goal and ambulatory BP at goal identify a low-risk condition, whereas clinic BP at goal and ambulatory BP above goal are associated with higher cardiorenal risk, similar to that observed in patients with both clinic and ambulatory BPs above goal.

Did compulsory wear regulations increase personal flotation device (PFD) use by boaters in small power recreational vessels? A before-after observational study conducted in Victoria, Australia

ObjectiveTo estimate the effect of the 2005 Victorian mandatory personal flotation device (PFD) wearing regulations on PFD use by occupants of small (hull length ≤4.8 m) power recreational vessels.DesignBefore-after observational...

Pathological Gambling: Update on Decision Making and Neuro-functional Studies in Clinical Samples

Given the importance and the burden of pathological gambling (PG) and its effect on gamblers and their relatives, better comprehension of the phenomena involved in its development and persistence is needed. The present paper describes the previous 5 years of studies on decision making and magnetic resonance imaging in people with PG. Twenty-six studies (456 participants with PG) were included. Perseveration in monetary tasks was associated with PG despite intact executive planning abilities. PG was linked with impairment in decision making under uncertainty. Hyperactivation of the reward pathway was repeatedly found. PG was also linked with neural hyperactivation of the reward pathway during high-risk conditions and hypoactivation in low-risk conditions. Furthermore, in PG, near misses activated the brain regions related to wins. Numerous similarities were found between PG and substance use disorders, highlighting the scientific basis of the recent reclassification of PG in the spectrum of addictive disorders.

ABSTRACT 914

Background and aims: Motor vehicle crashes(MVCs) are the most common cause of death in the United States for adolescents. Since 1998, Massachusetts has implemented a Graduated Driver Licensing (GDL) system requiring teenagers to gain experience under conditions of low crash risk before gaining full privileges. Aims: To evaluate the impact of changes to strengthen Massachusetts’ GDL law on MVCs in 16-18 year olds, and to assess whether these effects persist into young adulthood. Methods: Massachusetts MVC rates were analyzed for drivers aged 16-24 years during two time periods: 2002-2006, before the GDL law was strengthened, and 2007(fourth quarter)-2010, after implementation. Piecewise regression was performed to test whether the rate of change in crash rates by quarter was different for the two time periods, after controlling for age and sex of the driver. Results: MVC rates for drivers aged 16-24 declined by 0.5% per quarter prior to implementation of changes to GDL in 2007, with an accelerated drop of 3.7% per quarter after 2007, a difference of 3.5% (p< 0.001). Results: showed a significant difference in hour of crash and age group of driver. For those 16-18, the percentage of crashes occurring between 12-5am dropped from 7.2% before 2007 to 6.3% after 2007 (p<0.001). For 19-24-year olds there was a similar decrease during those hours from 12.1% before 2007 to 11.2% after 2007. Conclusions: Changes to the Massachusetts GDL law in 2007 to enhance driver education, as well as to enact stricter penalties for violations have contributed to a significant decline in crash rates for Massachusetts youth. These effects persist into young adulthood.