The effects of Electronic Stability Control (ESC) on fatal crash rates in the United States

PROBLEM

Electronic Stability Control (ESC) is believed to be among the most efficient vehicle safety interventions with reported effects around 50% for fatal single and rollover crashes. However, such estimates have used sample data, which have not controlled for the possibilities of self-selection, behavioral adaptation, increased access to the technology by less safe drivers, and the calculation of effects on very specific categories of crashes. Effects of ESC in the population can therefore be expected to be smaller than is currently believed.

METHOD

National U.S. data for fatal crashes, driving exposure and other control factors, and market penetration of ESC over 1991-2021 were used to calculate whether the trends in fatalities over time in crash rates for singles, rollovers, and fatal crashes in general matched projections from estimates of effectiveness.

RESULTS

It was found that downward trends in the relevant crash types were generally present before ESC was introduced, and that the trends thereafter were weaker. Although some trends were consistent with effects of ESC, they were markedly smaller than the projected ones, and could be explained by other factors such as the number of vehicles per capita. At best, the effect for rollovers could be up to two-thirds of previous estimates, no effect was detected for singles, while for all fatal crashes results depended upon the type of analysis performed. These results conflict with conclusions in all published ESC crash sample studies, which have compared vehicles with and without ESC. This discrepancy can be explained by methodological errors in the previous studies using induced exposure methods and self-selected samples.

PRACTICAL APPLICATIONS

Traffic safety may not be as much improved by technological interventions as believed. Alternative approaches to traffic safety are needed, which do not rely on technology that interferes with driver behavior.

Clinical Course of acute-on-chronic liver failure syndrome and effects on prognosis

Acute-on-chronic liver failure (ACLF) is characterized by acute decompensation (AD) of cirrhosis, organ failure(s), and high 28-day mortality. We investigated whether assessments of patients at specific time points predicted their need for liver transplantation (LT) or the potential futility of their care. We assessed clinical courses of 388 patients who had ACLF at enrollment, from February through September 2011, or during early (28-day) follow-up of the prospective multicenter European Chronic Liver Failure (CLIF) ACLF in Cirrhosis study. We assessed ACLF grades at different time points to define disease resolution, improvement, worsening, or steady or fluctuating course. ACLF resolved or improved in 49.2%, had a steady or fluctuating course in 30.4%, and worsened in 20.4%. The 28-day transplant-free mortality was low-to-moderate (6%-18%) in patients with nonsevere early course (final no ACLF or ACLF-1) and high-to-very high (42%-92%) in those with severe early course (final ACLF-2 or -3) independently of initial grades. Independent predictors of course severity were CLIF Consortium ACLF score (CLIF-C ACLFs) and presence of liver failure (total bilirubin ≥12 mg/dL) at ACLF diagnosis. Eighty-one percent had their final ACLF grade at 1 week, resulting in accurate prediction of short- (28-day) and mid-term (90-day) mortality by ACLF grade at 3-7 days. Among patients that underwent early LT, 75% survived for at least 1 year. Among patients with ≥4 organ failures, or CLIF-C ACLFs >64 at days 3-7 days, and did not undergo LT, mortality was 100% by 28 days.

CONCLUSIONS

Assessment of ACLF patients at 3-7 days of the syndrome provides a tool to define the emergency of LT and a rational basis for intensive care discontinuation owing to futility.

Culpable versus non-culpable traffic accidents; what is wrong with this picture?

INTRODUCTION

It is often implicitly or explicitly assumed in traffic accident research that drivers with accidents designated as non-culpable are a random sample from the population. However, this assumption is dependent upon differences in the criterion used for culpability. If drivers are erroneously categorized by assuming randomness, results could be grossly misleading.

METHOD

The assumption of randomness leads to two predictions: first, no correlation should exist between culpable and non-culpable crashes; and second, the accident groups should differ on the variables known to be associated with accidents, such as amount of driving experience. These predictions were tested in two samples of bus drivers.

RESULTS

It was found that in a sample with a harsh criterion (70% culpable accidents) for crash responsibility, the drivers with non-culpable accidents had the features expected, namely, they were more experienced for example, while in a sample with a lenient criterion (50 % culpable), this was not so.

DISCUSSION

It was concluded that similar studies to the present one would need to be undertaken to establish exactly what percentage of drivers in a given population should be assigned culpable accidents, and construct a criterion that yields this ratio. Otherwise, the theoretical assumptions of randomness and non-responsibility will probably be violated to some degree.

IMPACT ON INDUSTRY

Many estimates of risk of crash involvement may have been wrong. Given the potential for erroneous criteria, a number of studies may make invalid assumptions from their data.

Effects of 5-aza-2'-deoxycytidine on fetal hemoglobin levels, red cell adhesion, and hematopoietic differentiation in patients with sickle cell disease

Fetal hemoglobin (HbF) decreases polymerization of sickle hemoglobin (HbS) and improves outcomes in sickle cell disease (SSD). Therefore, a therapeutic goal in SSD is pharmacologic reactivation of HbF. Silencing of the gamma-globin (HbF) gene is associated with DNA methylation. The cytosine analog 5-aza-2'-deoxycytidine (decitabine) hypomethylates DNA by inhibiting DNA methyltransferase. We examined if subcutaneous decitabine could increase HbF levels and improve SSD pathophysiology without cytotoxicity. Eight symptomatic SSD patients resistant or intolerant of standard treatment with hydroxyurea received decitabine 0.2 mg/kg subcutaneously 1 to 3 times per week in 2 cycles of 6-week duration. Treatment decreased neutrophils and increased mean HbF (6.5% to 20.4%, P <.0001) and mean total hemoglobin (76 to 96 g/L [7.6 to 9.6 g/dL], P <.001). Features of vaso-occlusive crisis pathophysiology such as red cell adhesion, endothelial damage, and coagulation pathway activity significantly improved. gamma-Globin gene promoter methylation decreased, and platelets and the proportion of megakaryocytes and erythroid cells in the marrow increased without a decrease in marrow cellularity, consistent with a DNA hypomethylating, noncytotoxic mechanism of action. Weekly subcutaneous decitabine produces cumulative increases in HbF and total hemoglobin through a noncytotoxic mechanism of action. Chronic dosing and sustained increases in hemoglobin F and total hemoglobin levels may be possible. Further studies in SSD and thalassemia are indicated.

Maintenance of elevated fetal hemoglobin levels by decitabine during dose interval treatment of sickle cell anemia

We have previously demonstrated that 5-aza-2'-deoxycytidine (decitabine) augments fetal hemoglobin (HbF) levels in patients with sickle cell anemia (SS) who did not respond to hydroxyurea (HU). The present study was designed to determine the effect of repeated decitabine dosing on HbF levels and hematologic toxicity over a 9-month treatment period. Seven patients (5 HU nonresponders) were entered. One patient had alpha-thalassemia sickle cell anemia. Decitabine was administered by intravenous infusion at a starting dose of 0.3 mg/kg per day, 5 days a week for 2 weeks, followed by a 4-week observation period. If the absolute neutrophil count dropped below 1000, the dose was reduced by 0.05 mg/kg per day in the next cycle. A drug dose was obtained for each patient, and it resulted in an elevated HbF without neutropenia (absolute neutrophil count nadir greater than 1500) or evidence of cumulative toxicity. Average HbF and average maximal HbF levels attained during the last 20 weeks of treatment for the 6 SS patients increased to 13.93% +/- 2.75% and 18.35% +/- 4.46%, respectively, from a pretreatment mean of 3.12% +/- 2.75%. Mean and mean maximal hemoglobin (Hb) levels increased from 7.23 +/- 2.35 g/dL to 8.81 +/- 0.42 g/dL and 9.73 +/- 0.53 g/dL, respectively. Individual maximal F-cell number observed during the trial was 69% +/- 10.12%. The absence of cumulative toxicity may allow shorter intervals between drug treatments, which may lead to higher hemoglobin and HbF levels after several treatment cycles and, therefore, to greater clinical improvement.

A natural history study of adolescents and young adults with sickle cell disease as they transfer to adult care: a need for case management services

Life expectancy for adolescents with SCD now extends well into adulthood. As a result, adolescents transfer to adult care. Little empirical evidence exists to show how transfer occurs and how well the current practices now work. The aim of this study was to obtain a database on the experience of adolescents/young adults with SCD that transfer to adult care. We assessed their treatment compliance, independence, and whether they receive uninterrupted care. Data were obtained through patient and provider interviews and patient record reviews. Results indicate patients leave pediatric care without adequate transfer preparation and readiness to transfer is not the major consideration in the decision to transfer, follow-up often ceases once the patients leave pediatric care, and patients who maintain follow-up appointments are more efficient in managing their illness (self-efficacy). The model for a structured transitioning process is provided with recommendations for nurse case managers to maintain follow-up.

Allogeneic stem cell transplantation for sickle cell disease. A study of patients' decisions

Allogeneic stem cell transplantation is increasingly considered as a curative though risky treatment option for adults with sickle cell disease. Little is known about attitudes of adult patients and their health care providers regarding the risks and benefits of transplantation. A survey of 100 patients and their health care providers was undertaken. Assessment of risk was by a reference gamble paradigm. Comparison was made of the characteristics of those accepting substantial risk vs those not accepting risk, as well as assessment of agreement on risks recommended by health care providers and accepted by patients. Sixty-three of 100 patients were willing to accept some short-term risk of mortality in exchange for the certainty of cure. Fifteen patients were willing to accept more than 35% mortality risk. No differences in patient or disease-related variables were identified between those accepting risk and those not accepting risk. There was no agreement between the recommendations of health care providers and the risk accepted by patients. A substantial proportion of adults with sickle cell disease are interested in curative treatment, at the expense of considerable risk. The decision to accept risk is influenced by individual patient values that cannot be easily quantified and that do not correlate with the assessment of the health care provider. Given the substantial interest in curative therapy, education about and consultation for allogeneic stem cell transplantation in sickle cell patients should be encouraged.

Low growth hormone response to growth hormone-releasing hormone in child depression

BACKGROUND

This study examined growth hormone (GH) response to growth hormone-releasing hormone (GHRH) in a large sample of depressed children compared with normal control children. Within-subject comparisons were also performed in control subjects to examine test-retest reliability and in depressed children comparing episode versus clinical recovery.

METHODS

The sample included depressed children (n = 82) and normal control children (n = 55) group-matched for age, gender, and pubertal status; the mean ages were 11.2 +/- 1.7 and 11.2 +/- 1.8 years, respectively. We gave GHRH (0.1 mcg/Kg) at 9 AM, and serum GH levels were determined every 15 min from -30 min through +90 min of the GHRH infusion. A subgroup of normal control subjects (n = 11) repeated the protocol for test-retest reliability within a 2-month interval. A subgroup of depressed children (n = 20) were restudied off all medications following full clinical remission from depression.

RESULTS

The mean GH response to GHRH was significantly lower in the depressed group (8.7 ng/mL +/- SEM 0.9) compared with normal control children [12.2 ng/mL +/- SEM 1.3; t(135) = 2.59, p =.01 effect size 0.44]. The test-retest reliability of GH response to GHRH was stable (intraclass correlation =.93 for mean post-GH). The GH response to GHRH remained low in subjects restudied during clinical remission from depression.

CONCLUSIONS

Depressed children show low GH response to GHRH. The measure appears to be reliable, and the low GH response continues following clinical remission. Further studies are needed to explore the mechanism and relative specificity of this finding.

2-deoxy 5-azacytidine and fetal hemoglobin induction in sickle cell anemia

Augmentation of the fetal hemoglobin (HbF) levels is of therapeutic benefit in patients with sickle cell anemia. Hydroxyurea (HU), by increasing HbF, lowers rates of pain crisis, episodes of acute chest syndrome, and requirements for blood transfusions. For patients with no HbF elevation after HU treatment, augmentation of HbF levels by 5-aza-2'-deoxycytidine (5-aza-CdR, decitabine) could serve as an alternate mode of treatment. Eight adult patients participated in a dose-escalating phase I/II study with 5-aza-CdR at doses ranging from 0.15 to 0.30 mg/kg given 5 days a week for 2 weeks. HbF, F cell, F/F cell, gamma-globin synthesis ratio, complete blood count, and chemistry were measured. The average gamma-globin synthesis relative to non-alpha-globin synthesis prior to therapy was 3.19% +/- 1.43% and increased to 13.66% +/- 4.35% after treatment. HbF increased from 3.55% +/- 2.47% to 13.45% +/- 3.69%. F cells increased from 21% +/- 14.8% to 55% +/- 13.5% and HbF/F cell increased from 17% to 24%. In the HU nonresponders HbF levels increased from 2.28% +/- 1.61% to 2.6% +/- 2.15% on HU, whereas on 5-aza-CdR HbF increased to 12.70% +/- 1.81%. Total hemoglobin increased by 1 g/dL in 6 of 8 patients with only minor reversible toxicities, and all patients tolerated the drug. Maximum HbF was attained within 4 weeks of treatment and persisted for 2 weeks before falling below 90% of the maximum. Therefore 5-aza-CdR could be effective in increasing HbF in patients with sickle cell anemia who failed to increase HbF with HU. Demonstration of sustained F levels with additional treatment cycles without toxicity is currently being performed.

Transitioning adolescents with sickle cell disease to adult-centered care

Efforts have been made to formalize transitioning of adolescents with chronic health conditions such as sickle cell disease (SCD), from child-centered care (CCC) to adult-centered care (ACC). A dearth of literature exists that examines the transition of adolescents with SCD or offers guidance for transitioning. This study sought to explore concerns, expectations, and needs regarding the transition from CCC to ACC and to generate a framework for transitioning. Separate focus groups were conducted with adolescents (n = 22), their parents (n = 22), and practitioners (n = 8). Focus group interviews revealed that concerns, expectations, and needs for adolescents and their parents were parallel. Adolescents and their parents had concerns about: (a) leaving a familiar setting and physician whom they trusted, (b) going to an adult provider who may or may not be familiar with managing sickle cell disease, and (c) establishing new family roles. Practitioners affirm the need for transitioning that prepares the adolescents and their families for ACC. Findings led to a draft framework for transitioning that which will be tested at a later date. The framework is based on an ecological perspective that includes physiologic, developmental and psychosocial, and educational/vocational components.

Driver stress and performance on a driving simulator

Effects of stress on driving performance can depend on the nature of driver's stress reactions and on the traffic environment. In an experimental study, we assessed multiple dimensions of vulnerability to driver stress by a questionnaire that was validated in previous field studies and related those dimensions to performance on a driving simulator. Results were broadly consistent with prediction. A dimension of habitual dislike of driving was associated with reduced control skills, greater caution, and disturbance of moods. A measure of aggressive driving predicted more frequent and more error-prone overtaking, which are effects attributed to the use of confrontive coping strategies in interaction with other vehicles. An alertness measure predicted speed of reaction to pedestrian hazards. This research has practical applications for system design, automated monitoring of driver performance, selection and assessment of drivers, and training.

Continuing care for adult patients with sickle cell disease

Continuing services for patients with sickle cell disease focuses on holistic care. Participation in preventive medicine principles of health management, avoidance of risk behaviors and seeking appropriate counseling for education, employment, healthy lifestyles, and productive living are beneficial to the patient.

Age and gender differences in perceived accident likelihood and driver competences

Road traffic accident involvement rates show clear age and gender differences which may in part be accounted for by differences in risk perception and perceptions of driving competence. The present study extends and replicates that of Matthews and Moran (1986). Young (18-30 years) and older (45-60 years) male and female drivers responded to a questionnaire on perceived accident risk and driving competence (judgment and skill) with respect to themselves and four target groups, and also rated a series of videotaped driving sequences with respect to likelihood of accident occurrence and perceived driving competence. Results showed that effects of rater characteristics were generally confined to the questionnaire. Younger males were perceived as most likely to experience an accident and were judged to be lower than other groups in driving competence. Younger groups showed little bias against older groups and vice versa, but gender-related bias was apparent. The findings of Matthews and Moran were generally confirmed. The results are discussed with reference to four main issues: (1) demographic bias effects--which are generally weak; (2) stereotyping on the basis of gender and/or age of driver; (3) group-specific bias; (4) self-appraisal bias.

Health insurance status and the use of emergency and other outpatient services by adults with sickle cell disease

STUDY OBJECTIVE

To evaluate insurance status and frequency of use of emergency services in adults with sickle cell disease.

DESIGN

Retrospective analysis of visits.

SETTING

Emergency department and outpatient clinics of an urban university hospital.

PARTICIPANTS

One hundred seventy-two subjects, who made 771 visits to the ED during 1990.

RESULTS

Of the 172 subjects, 31 were covered by commercial insurance, 32 were covered by Medicare, and 109 were covered by Medicaid or were uninsured. Insurance status and frequency of use of emergency services were independent (P > .05). On discriminant analysis, Medicaid-covered and uninsured subjects were correctly classified, but commercially insured and Medicare subjects were not. Medicaid and uninsured subjects were more likely to be younger and to live closer to the hospital (P < .00005). High-frequency users of emergency services were discriminated from low-frequency users. High-frequency users were more likely to be younger, to be users of primary-care services, and to live closer to the hospital (P = .0004).

CONCLUSION

Provision of primary-care services or stable insurance in the form of commercial insurance or Medicare did not decrease use of emergency services in subjects with sickle cell disease in a group of patients selected from one urban academic ED.

Evaluation and Management of Sickle Cell Disease in the Emergency Department (An 18-year Experience): 1974--1992

Painful episodes are the most frequent complaints of patients with sickle cell disease. The Emergency Department (ED) has provided management for acute events using the usual triage format for emergencies. A prospective study evaluated the role of the ED in the care of adults with sickle cell disease (SCD). The protocol, thus, addressed issues of acute events related to SCD and provided better care for patients with SCD in the ED. Approximately 37% of ED visits were for painful events. An inciting cause was identified in 35% of painful events and 75% of these required admission to the hospital. A 15-year follow-up prospectively showed similar results and that uncomplicated pain crisis can be treated with ED protocols. Outpatient clinics and urgent centers could reduce these visits. Absolute indications for admission include sepsis, fever >102 degreeF, white cell counts >20 000, worsening anemia, hypoxemia, acute chest syndrome and new CNS events. Patient database in the ED must be revised annually to avoid extensive workup in the ED and a complete history/physical examination, and a CBC could be sufficient for triage in an uncomplicated pain crisis. An acceptable protocol for care should be available at all EDs and a registry and information system for SCD will discourage overutilization of investigational tests and visits to multiple EDs.

Management of pain in sickle cell disease using biofeedback therapy: a preliminary study

Fifteen patients with a history of painful episodes of sickle cell disease were given training in progressive relaxation, thermal biofeedback, cognitive strategies, and self-hypnosis to help them develop self-management skills to relieve pain. Results show a 38.5% reduction in the number of emergency room visits, a 31% reduction in the number of hospitalizations, and a 50% reduction in the inpatient stay during the 6 months since the beginning of therapy compared to 6 months prior to therapy. Analgesic intake was reduced by 29% for those who were using it regularly. This is a preliminary study, and the results are considered only as suggestive of the potential use of biofeedback therapy and behavioral management in alleviating painful episodes in sickle cell disease.