Secular trends in ischemic stroke subtypes and stroke risk factors.

BACKGROUND AND PURPOSE: Early diagnosis and treatment of a stroke improves patient outcomes, and knowledge of the cause of the initial event is crucial to identification of the appropriate therapy to maximally reduce risk of recurrence. Assumptions based on historical frequency of ischemic subtypes may need revision if stroke subtypes are changing as a result of recent changes in therapy, such as increased use of statins. METHODS: We analyzed secular trends in stroke risk factors and ischemic stroke subtypes among patients with transient ischemic attack or minor or moderate stroke referred to an urgent transient ischemic attack clinic from 2002 to 2012. RESULTS: There was a significant decline in low-density lipoprotein cholesterol and blood pressure, associated with a significant decline in large artery stroke and small vessel stroke. The proportion of cardioembolic stroke increased from 26% in 2002 to 56% in 2012 (P<0.05 for trend). Trends remained significant after adjusting for population change. CONCLUSIONS: With more intensive medical management in the community, a significant decrease in atherosclerotic risk factors was observed, with a significant decline in stroke/transient ischemic attack caused by large artery atherosclerosis and small vessel disease. As a result, cardioembolic stroke/transient ischemic attack has increased significantly. Our findings suggest that more intensive investigation for cardiac sources of embolism and greater use of anticoagulation may be warranted.

Road safety impact of Ontario street racing and stunt driving law.

OBJECTIVE: The purpose of this study was to conduct a process and outcome evaluation of the deterrent impact of Ontario's street racing and stunt driving legislation which came into effect on September 30, 2007, on collision casualties defined as injuries and fatalities. It was hypothesized that because males, especially young ones, are much more likely to engage in speeding, street racing and stunt driving, the new law would have more impact in reducing speeding-related collision casualties in males when compared to females. METHODS: Interrupted time series analysis with ARIMA modelling was applied to the monthly speeding-related collision casualties in Ontario for the period of January 1, 2002 to December 31, 2010, separately for young male drivers 16-25 years of age (primary intervention group), mature male drivers 26-65 years of age (secondary intervention group), young female drivers 16-25 years of age (primary comparison group) and mature female drivers 26-65 years of age (secondary comparison group). A covariate adjustment using non-speeding casualties was included. RESULTS: A significant intervention effect was found for young male drivers with, on average, 58 fewer collision casualties per month, but not for mature male drivers, when non-speeding casualties were controlled for. No corresponding effect was observed in either comparison (females) group. CONCLUSION: These findings indicate a reduction in speeding-related casualties among young males of 58 fewer casualties per month subsequent to the introduction of Ontario's street racing and stunt driving legislation and suggest the presence of a general deterrent effect.

SPARKLE (Subtypes of Ischaemic Stroke Classification System), incorporating measurement of carotid plaque burden: a new validated tool for the classification of ischemic stroke subtypes.

BACKGROUND: Previous classification systems of acute ischemic stroke (Causative Classification System, CCS, of acute ischemic stroke, Trial of Org 10172 in Acute Stroke Treatment, TOAST) established the diagnosis of large artery disease (LAD) based on the presence or absence of carotid stenosis. However, carotid plaque burden is a stronger predictor of cardiovascular risk than stenosis. Our objective was to update definitions of ischemic stroke subtypes to improve the detection of LAD and to assess the validity and reliability of a new classification system: SPARKLE (Subtypes of Ischaemic Stroke Classification System). METHODS: In a retrospective review of clinical research data, we compared three stroke subtype classifications: CCS, TOAST and SPARKLE. We analyzed a random sample of 275 patients presenting with minor stroke or transient ischemic attack (TIA) in an Urgent TIA Clinic in London, Ont., Canada, between 2002 and 2012. RESULTS: There was substantial overall agreement between SPARKLE and CCS (κ = 0.75), with significant differences in the rate of detection of LAD, cardioembolic and undetermined causes of stroke or TIA. The inter-rater reliability of SPARKLE was substantial (κ = 0.76) and the intra-rater reliability was excellent (κ = 0.91). CONCLUSION: SPARKLE is a valid and reliable classification system, providing advantages compared to CCS and TOAST. The incorporation of plaque burden into the classification of LAD increases the proportion of cases attributable to LAD and reduces the proportion classified as being of 'undetermined' etiology.

Evaluation of deterrent impact of Ontario's Street Racing and Stunt Driving Law on extreme speeding convictions.

OBJECTIVE: The purpose of this study was to conduct a process and outcome evaluation of the deterrent impact of Ontario's street racing and stunt driving legislation, introduced in September 2007, on extreme speeding convictions. It was hypothesized that because males are much more likely to engage in speeding, street racing, and stunt driving, the new law would have more impact in reducing extreme speeding in males compared to females. METHODS: Descriptive statistics and time series plots were used for the suspensions data. Interrupted time series analysis with autoregressive integrated moving average (ARIMA) modeling was applied to the monthly extreme speeding convictions in Ontario for the period of January 1, 2003, to December 31, 2011, to assess the impact of the new legislation, separately for male drivers (intervention group) and female drivers (comparison group). RESULTS: The results indicated that per licensed driver, 1.21 percent of 16- to 24-year-old male drivers and 0.37 percent of 25- to 64-year-old male drivers had their licenses suspended between September 2007 and December 2011. This is in contrast to female drivers: 0.21 percent of 16- to 24-year-old female drivers and 0.07 percent of 25- to 64-year-old female drivers had their licenses suspended during the same time period. A significant intervention effect of reduced extreme speeding convictions was found in the male driver group, though no corresponding effect was observed in the female driver group. The findings of this study are consistent with previous research on demographics of street racers and stunt drivers. CONCLUSIONS: These findings are congruent with deterrence theory that certain, swift, and severe sanctions can deter risky driving behavior and support the hypothesis that legal sanctions can have an impact on the extreme speeding convictions of the intervention group.

A tale of two cities: the effect of extended drinking hours in licensed establishments on impaired driving and assault charges.

OBJECTIVES: On May 1, 1996, Ontario, Canada, amended the Liquor Licence Act to extend the hours of alcohol sales and service in licensed establishments from 1 to 2 a.m. The purpose of this study was to examine the effect of extended drinking hours on two cities in southwestern Ontario, Canada, one of which (London) would be affected by the alcohol control policy of extended drinking hours and the second city (Windsor) would be affected by two alcohol policies, extended drinking hours, and cross-border legal drinking age differences between Ontario and Michigan. Specifically, this study tested whether there were differences in impaired driving and assault charges in London and Windsor, Ontario, concomitant with the extended drinking hour amendment. METHODS: A quasi-experimental design using interrupted time series was used to assess changes. The analyzed data sets were monthly police impaired driving and assault charges data for Ontario, for the 11-12 p.m., 12-1 a.m., 1-2 a.m., 2-3 a.m. and 3-4 a.m. time windows, for 4 years pre- and 3 years post-policy change. RESULTS: Overall, London and Windsor exhibited significant overall reductions in impaired driving charges and no changes for assault charges aggregated over the 11 p.m.-4 a.m. time period after the drinking hours were extended. Within the different time windows, London showed significant decreases for the 1-2 a.m. Sunday-Wednesday and Thursday-Sunday time periods and a significant increase for the Sunday-Wednesday 3-4 a.m. time period, while Windsor demonstrated significant decreases in impaired driving charges for 1-2 a.m. Sunday-Wednesday and Thursday-Saturday time periods and significant increases for Sunday-Wednesday 2-3 and 3-4 a.m. and for Thursday-Saturday 2-3 a.m. For assault charges, no overall pre-post differences were found for the aggregated 11 p.m.-4 a.m. time period for either city. When the data were disaggregated by hour, a significant decrease was found in London for Thursday-Saturday 1-2 a.m. and significant increases for Sunday-Wednesday 2-3 a.m. and Thursday-Saturday 3-4 a.m. time periods, while no significant decreases were found in Windsor during the 1-2 a.m. time periods and one significant increase occurred during the Thursday-Saturday 2-3 a.m. time period. CONCLUSIONS: These findings, based on police data, suggest no overall effect on charges aggregated over the 11 p.m. to 4 a.m. time window, although some differences were observed for the different hours after 2 a.m., with a possible effect of the one hour extension of drinking in licensed establishments.

Power computations in time series analyses for traffic safety interventions.

The evaluation of traffic safety interventions or other policies that can affect road safety often requires the collection of administrative time series data, such as monthly motor vehicle collision data that may be difficult and/or expensive to collect. Furthermore, since policy decisions may be based on the results found from the intervention analysis of the policy, it is important to ensure that the statistical tests have enough power, that is, that we have collected enough time series data both before and after the intervention so that a meaningful change in the series will likely be detected. In this short paper, we present a simple methodology for doing this. It is expected that the methodology presented will be useful for sample size determination in a wide variety of traffic safety intervention analysis applications. Our method is illustrated with a proposed traffic safety study that was funded by NIH.

Impact of extended drinking hours in Ontario on motor-vehicle collision and non-motor-vehicle collision injuries.

OBJECTIVE: On May 1, 1996, Ontario, Canada, amended the Liquor Licence Act to extend the hours of alcohol sales and service in licensed establishments from 1 am to 2 am. The purpose of this study was to evaluate the impact of extended drinking hours in Ontario on motor-vehicle collision (MVC) and other injuries admitted to regional trauma units based on Ontario Trauma Registry data. METHOD: A quasi-experimental design using interrupted time series was used to assess changes in admissions to Ontario trauma units. The analyzed data sets were monthly data on number of admissions from MVC and other causes of injury during the 11 pm-12 am, 12-1 am, 1-2 am, and 2-3 am time windows for 4 years before and 3 years after the policy change (May 1992-April 1999). RESULTS: For MVC injuries, no significant pre-post increases were found for the 2-3 am period commensurate with the introduction of the extended drinking hours, but decreases were found for the 11 pm-12 am and 1-2 am periods. For non-MVC injuries, a significant increase was found for the 2-3 am period. CONCLUSIONS: The data sets suggest that increased availability of alcohol as a result of extension of closing hours had an impact on non-MVC injuries presenting to Ontario trauma units, but road safety initiatives may have mediated the effects of the extension on MVC injuries. These observations are consistent with those of other studies of small changes in alcohol availability.