Original Contributions SELF-REPORTED ALCOHOL USE IS AN INDEPENDENT RISK FACTOR FOR HEAD AND BRAIN INJURY AMONG CYCLISTS BUT DOES NOT CONFOUND HELMETS’ PROTECTIVE EFFECT Pat Crocker, DO,* Ben King, BA,*† Hassie Cooper, BS,† and T. J. Milling, MD*† *Dell Children’s Medical Center of Central Texas, Austin, Texas, and †University Medical Center at Brackenridge, Austin, Texas Reprint Address: Ben King, BA, Department of Emergency Medicine, Dell Children’s Medical Center of Central Texas, 601 E. 15th Street, Austin, TX 78701 , Abstract—Background: Head and brain injury ac- counts for most morbidity and mortality related to bicycle accidents, much of which can be mitigated by helmet use; but other factors, such as alcohol use and type of accident, also correlate with injury. Objective: To examine the corre- lation between alcohol use, helmet use, riding environment, and rider characteristics, with the presence of head and severity of brain injury in a group of bicycle riders present- ing to a regional trauma center after an accident. Methods: Data were collected at the bedside and from the medical records for all bicycle accident victims presenting during a 2 ½-year period to a regional trauma center. Data were analyzed in Stata version 10 (StataCorp LP, College Station, TX) using chi-squared, analysis of variance, Kruskal-Wallis, or Wilcoxon rank-sum where appropriate. Results: There were 427 patients enrolled, of which 82% were male, with a median age of 31 years. Two factors cor- related with presence of head injury and severity of brain injury among bicycle riders presenting to the emergency department (ED) after an accident. For any head or brain injury, the odds ratios for helmet use and alcohol use were 0.5 (95% confidence interval [CI] 0.32–0.78) and 2.68 (95% CI 1.66–4.33). Of accidents presenting to the ED, helmeted riders were less likely to sustain a head or brain injury, and riders who reported alcohol use were more likely to sustain a head or brain injury. Conclusions: Helmet use was pro- tective for head or brain injury in non-drinking cyclists, but had a confounding effect in drinking riders. Ó 2012 Elsevier Inc. , Keywords—alcohol; head and brain injury; bicycle accident; helmet use INTRODUCTION The National Safety Council estimates that 35.6 million Americans ride bicycles (1). About 480,000 of those end up in emergency departments (EDs) for injuries, and 20,000 are admitted to the hospital (1,2). Head injury accounts for about a third of bicycle-related injuries, and these victims are more likely to die (3). Those that survive suffer more long-term sequelae (3). We recently examined the impact of alcohol use on bicycle-related head injury, but our data set was too small to examine other correlates, so we continued to collect data using the same instrument and also examining com- puted tomography (CT) results of injured riders. We reported data on the first 200 patients confirming the correlation between head or brain injury and alcohol use in this population (4). This relationship has been dem- onstrated in a variety of ways in the past as well (5–14). Our goal was to study a group of bicycle accident vic- tims presenting to a regional trauma center and further elucidate the relationship between alcohol use, helmet use, and head or brain injury and positive CT findings. RECEIVED: 24 June 2010; FINAL SUBMISSION RECEIVED: 15 November 2010; ACCEPTED: 23 May 2011 244 The Journal of Emergency Medicine, Vol. 43, No. 2, pp. 244–250, 2012 Copyright Ó 2012 Elsevier Inc. Printed in the USA. All rights reserved 0736-4679/$ - see front matter doi:10.1016/j.jemermed.2011.05.029