Injury prevention, emergency medicine, and sports medicine on the same playing field

What influences the association between previous and future crashes among cyclists? A propensity score analysis

BACKGROUND

It is known that experience of a previous crash is related to incidence of future crashes in a cohort of New Zealand cyclists. This paper investigated if the strength of such association differed by crash involvement propensity and by the need for medical care in the previous crash.

METHODS

The Taupo Bicycle Study involved 2590 adult cyclists recruited in 2006 and followed over a median period of 4.6 years through linkage to four national databases. The crash involvement propensity was estimated using propensity scores based on the participants' demographic, cycling and residential characteristics. Cox regression modelling for repeated events was performed with multivariate and propensity score adjustments. Analyses were then stratified by quintiles of the propensity score.

RESULTS

A total of 801 (31.0%) participants reported having experienced at least one bicycle crash in the twelve months prior to the baseline survey. They had a higher risk of experiencing crash events during follow-up (hazard ratio (HR): 1.43; 95% CI: 1.28, 1.60) but in the stratified analysis, this association was significant only in the highest two quintiles of the propensity score where the likelihood of having experienced a crash was more than 33%. The association was stronger for previous crashes that had received medical care (HR 1.63; 95% CI: 1.41, 1.88) compared to those that had not (HR 1.30; 95% CI: 1.14, 1.49).

CONCLUSIONS

Previous crash experience increased the risk of future crash involvement in high-risk cyclists and the association was stronger for previous crashes attended medically. What distinguishes the high risk group warrants closer investigation, and the findings indicate also that health service providers could play an important role in prevention of bicycle crash injuries.

The effect of concentrating periods of physical activity on the risk of injury in organized sports in a pediatric population

BACKGROUND

The trend in pediatric sport organizations is to regroup activities into tournaments. Sports-related injuries in children are a public concern.

OBJECTIVE

To evaluate the association between sport injuries and consolidation of physical activity in children.

DESIGN

A case-crossover study.

SETTING

The emergency department of a tertiary care hospital for approximately 1 year in 2006.

PARTICIPANTS

Eligible participants had to be between 8 to 16 years of age, presenting to the emergency department for an acute injury that occurred during a timed organized sport event.

ASSESSMENT OF RISK FACTORS

A standardized questionnaire was used to evaluate the number of hours of organized physical activity, which was defined as a supervised exercise leading to competitions. The number of hours of activity was compared between case periods (48 hours and 7 days) and control periods of same length.

MAIN OUTCOME MEASUREMENTS

An injury was defined as any acute problem with organic tissue that occurred during a sport.

RESULTS

On average, participants performed 136 minutes of organized sport activity in the 48 hours preceding the injury for a mean difference of 8 +/- 18 min. They also performed 356 minutes of organized sports in the 7 days prior the injury. This represented an increase of 40 +/- 31 minutes compared to the control periods.

CONCLUSIONS

More injuries were observed if the athletes had increased the concentration of activity in the 7 days prior. Although small, this difference reflected a minor clinical effect. In our study, we failed to disclose an association for the period of 48 hours.