Graduated driver licensing for reducing motor vehicle crashes among young drivers.

BACKGROUND: Graduated driver licensing (GDL) has been proposed as a means of reducing crash rates among novice drivers by gradually introducing them to higher risk driving situations. OBJECTIVES: To examine the effectiveness of GDL systems in reducing crash rates of young drivers. SEARCH STRATEGY: Studies were identified through searches of MEDLINE, EMBASE, CINAHL, Healthstar, Web of Science, NTIS Bibliographic Database, TRIS Online, SIGLE, the World Wide Web, relevant conference proceedings, consultation with experts and authors, and reference lists. The search was not restricted by language or publication status. SELECTION CRITERIA: Studies were included if: 1) they compared outcomes pre- and post-implementation of a GDL program within the same jurisdiction, 2) comparisons were made between jurisdictions with and without GDL, or 3) both. Studies had to report at least one objective, quantified outcome. Two reviewers independently screened searches and assessed the full text of potentially relevant studies for inclusion using a standard form. DATA COLLECTION AND ANALYSIS: Data were extracted by one reviewer and checked by a second. Additional data were requested from authors. Results were not pooled due to substantial heterogeneity between studies. Percentage change was calculated for each year after the intervention, using one year prior to the intervention as the baseline rate. Results were adjusted by internal controls. Analyses were stratified by different denominators (population, licensed drivers). Results were calculated for the different crash types (overall, injury, fatal, night-time, alcohol, and those resulting in hospitalization). Results were presented for 16 year-olds alone and all teenage drivers combined. MAIN RESULTS: We included 13 studies evaluating 12 GDL programs that were implemented between 1979 and 1998 in the US (n=7), Canada (3), New Zealand (1), and Australia (1). Programs varied in their restrictions during the intermediate stage: e.g. night curfews (8); limitations of extra passengers (2); roadway restrictions (1). Based on the Insurance Institute for Highway Safety classification scheme, no programs were good, six were acceptable, five were marginal, and one was poor. Reductions in crash rates were seen in all jurisdictions and for all crash types. Among 16 year-old drivers, the median decrease in per population overall crash rates during the first year was 31% (range 26-41%). Per population injury crash rates were similar (median 28%, range 4-43%). Results for all teenage drivers, rates per licensed driver, and rates adjusting for internal controls were generally reduced when comparing within jurisdictions. REVIEWERS' CONCLUSIONS: The existing evidence shows that GDL is effective in reducing the crash rates of young drivers, although the magnitude of the effect is unclear. The conclusions are supported by consistent direction of the findings, and the temporal relationship and plausibility of the association. The reviewers have made recommendations for primary research on GDL (e.g. study methods, standardized reporting of outcomes and results, long-term follow-up). The project has also shown what is needed to carry out systematic reviews of observational studies (e.g. quality assessment instruments).

Fatal asphyxiations in children involving drawstrings on clothing.

Injuries account for more deaths and hospital admissions among children and adolescents than all diseases combined. The authors report two deaths by asphyxiation that resulted from drawstrings on the children's clothing becoming entangled on slides. Although such incidents are not common, they are preventable. The authors urge physicians to counsel parents and guardians to remove drawstrings from children's clothing, and they call upon the government and the clothing industry to work toward improving the safety standards for the design, manufacture and importation of children's clothing and banning the sale of children's clothing with drawstrings in Canada. In addition, they provide several resources for readers interested in helping reduce playground hazards in their communities.

[Effect of stimulation of adrenergic beta receptors on electrophysiologic properties of the bundle of Kent in patients with intermittent Wolff-Parkinson-White syndrome]. / Wplyw stymulacji receptorów beta-adrenergicznych na wlasciwosci elektrofizjologiczne peczka Kenta u chorych z intermitujacym zespolem Wolffa-Parkinsona-White'a.

In 15 patients with intermittent ventricular preexcitation symptoms the effect of intravenously administered dobutamine (10 mcg/kg b.w./min) on the ecg tracing, effective atrial, a-v nodal and Kent bundle refractions as well as the incidence of cardiac arrhythmias were assessed basing on results of the electrophysiologic examination. Pharmacological stimulation of the adrenergic system resulted in highly statistically significant shortening of examined refraction periods (p less than 0,02 for effective Kent bundle refraction and p less than 0,001 for the rest parameters) and improved the conduction via the accessory pathway as well as exacerbated cardiac arrhythmias.

[Effect of pharmacologic blockade of the autonomic nervous system on electrophysiologic properties of the accessory pathway and atrioventricular node in patients with Wolff-Parkinson-White syndrome]. / Wplyw blokady farmakologicznej wegetatywnego ukladu nerwowego na wlasciwosci elektrofizjologiczne drogi dodatkowej i wezla przedsionkowo-komorowego u chorych z zespolem Wolffa-Parkinsona-White'a.

In 17 patients aged 21-61 (mean 32) with WPW syndrome the transoseophageal stimulation was performed before and after intravenous administration of propranolol (0.1 mg/kg b.w.) and atropine (0.02 mg/kg b.w.). Pharmacological blockade of the autonomic nervous system resulted in statistically significant increase of heart rate (from 81 to 111/min), shortening of a-v nodal and atrial refraction (from 298 to 272 ms) as well as in shortening of stimuli cycle length revealing Wenckebach's point (from 324 to 291 ms). The Kent bundle refraction did not at the average change (333 and 324 ms), while in individuals great differences were observed. Generally, pharmacological blockade of the autonomic nervous system improves a-v nodal conduction, but in patients with WPW syndrome does not significantly effect on the accessory pathway.