Douglas J. Wiebe

The King–Devick test and sports-related concussion: Study of a rapid visual screening tool in a collegiate cohort

OBJECTIVE Concussion, defined as an impulse blow to the head or body resulting in transient neurologic signs or symptoms, has received increasing attention in sports at all levels. The King-Devick (K-D) test is based on the time to perform rapid number naming and captures eye movements and other correlates of suboptimal brain function. In a study of boxers and mixed martial arts (MMA) fighters, the K-D test was shown to have high degrees of test-retest and inter-rater reliability and to be an accurate method for rapidly identifying boxers and mixed martial arts fighters with concussion. We performed a study of the K-D test as a rapid sideline screening tool in collegiate athletes to determine the effect of concussion on K-D scores compared to a pre-season baseline. METHODS In this longitudinal study, athletes from the University of Pennsylvania varsity football, sprint football, and womens and mens soccer and basketball teams underwent baseline K-D testing prior to the start of the 2010-11 playing season. Post-season testing was also performed. For athletes who had concussions during the season, K-D testing was administered immediately on the sidelines and changes in score from baseline were determined. RESULTS Among 219 athletes tested at baseline, post-season K-D scores were lower (better) than the best pre-season scores (35.1 vs. 37.9s, P=0.03, Wilcoxon signed-rank test), reflecting mild learning effects in the absence of concussion. For the 10 athletes who had concussions, K-D testing on the sidelines showed significant worsening from baseline (46.9 vs. 37.0s, P=0.009), with all except one athlete demonstrating worsening from baseline (median 5.9s). CONCLUSION This study of collegiate athletes provides initial evidence in support of the K-D test as a strong candidate rapid sideline visual screening tool for concussion. Data show worsening of scores following concussion, and ongoing follow-up in this study with additional concussion events and different athlete populations will further examine the effectiveness of the K-D test.

Neighborhoods, daily activities, and measuring health risks experienced in urban environments.

Studies of place and health often classify a subjects exposure status according to that which is present in their neighborhood of residence. Ones neighborhood is often proxied by designating it to be an administratively defined unit such as census tract, to make analysis feasible. Although it is understood that residential space and actual lived space may not correspond and therefore exposure misclassification may result, few studies have the opportunity to investigate the implications of this issue concretely. A population-based case-control study that is currently underway provides one such opportunity. Adolescent victims of assault in Philadelphia, Pennsylvania, USA, and a control sample of adolescents drawn randomly from the community are being enrolled to study how alcohol consumption and time spent nearby alcohol outlets - individual-level and environmental-level risk factors for violence, respectively - over the course of daily activities relate to the likelihood of being assaulted. Data from a rapport-building exercise consist of hand-drawn sketches that subjects drew on street maps when asked to indicate the area considered their neighborhood. The main data consist of self-reported, detailed paths of the routes adolescents traveled from one location to the next over the course of one full day. Having noticed interesting patterns as the data collection phase proceeds, we present here an analysis conducted with the data of 55 control subjects between 15 and 19 years old. We found that hand-drawn neighborhoods and activity paths did not correspond to census tract boundaries, and time subjects spent in close proximity to alcohol outlets during their daily activities was not correlated with the prevalence of alcohol outlets in the census tract of their residence. This served as a useful example demonstrating how classifying subjects as exposed based solely on the prevalence of the exposure in the geographic area of their residence may misrepresent the exposure that is etiologically meaningful.

Postconcussive symptoms in hospitalized pediatric patients after mild traumatic brain injury

BACKGROUND Mild traumatic brain injury (MTBI) is common in the pediatric population. The symptom complex that might be expected in children after MTBI is not well documented. We sought to clarify the frequency and severity of concussive symptoms reported by children who required hospitalization for MTBI. METHODS Pediatric blunt trauma patients (age, 11-17 years) admitted for treatment of MTBI (GCS 14-15) were prospectively enrolled over a 2-year period. Consented patients were administered a 22-question Likert-based concussion symptom scale (normal, total score 0-8). The symptom scale was repeated at the time of routine follow-up trauma clinic visit. The frequency and severity of concussive symptoms were analyzed at both time-points. RESULTS For the 2-year period, 116 children participated in the study including 63 who returned for clinic follow-up. The overall population had mean age of 14.1 years (median 14) and was 69.8% male. The mean symptom score (sum of Likert scores [scale 0-6] for 22 questions) was 27.9 (median, 23.5) at hospitalization and 9.2 (median, 4.0) at follow-up. An abnormal symptom score (>8) was reported in 83.6% of hospitalized patients and 38.1% at follow-up. Girls had a significantly higher mean symptom score at initial testing than boys (33.9 vs 25.3, respectively; P < .05). This difference disappeared by the time of follow-up (girls 9.2 vs boys 9.1, P = .98) The most common initial symptom was headache (71.5% of patients) and most severe (highest mean score) was fatigue (mean, 2.0; median, 2.0). At follow-up, the most common symptom was excess sleep (38.1%) and most severe symptom falling asleep (mean, 1.0; median, 0). There were no significant differences in initial scores based on reported loss of consciousness, prior concussion history, or GCS 14 vs 15. CONCLUSIONS Symptoms after MTBI are quite common at the time of hospitalization. Symptom scores improve to near normal for most by outpatient follow-up. The most common symptom was headache, but the most severe was fatigue, in this hospitalized pediatric population. Thoughtful assessment and follow-up of this patient population are warranted.

Location, Location, Location: Geographic Clustering of Lower-Extremity Amputation Among Medicare Beneficiaries With Diabetes

OBJECTIVE Lower-extremity amputation (LEA) is common among persons with diabetes. The goal of this study was to identify geographic variation and the influence of location on the incidence of LEA among U.S. Medicare beneficiaries with diabetes. RESEARCH DESIGN AND METHODS We conducted a cohort study of beneficiaries of Medicare. The geographic unit of analysis was hospital referral regions (HRRs). Tests of spatial autocorrelation and geographically weighted regression were used to evaluate the incidence of LEA by HRRs as a function of geographic location in the U.S. Evaluated covariates covered sociodemographic factors, risk factors for LEA, diabetes severity, provider access, and cost of care. RESULTS Among persons with diabetes, the annual incidence per 1,000 of LEA was 5.0 in 2006, 4.6 in 2007, and 4.5 in 2008 and varied by the HRR. The incidence of LEA was highly concentrated in neighboring HRRs. High rates of LEA clustered in contiguous portions of Texas, Oklahoma, Louisiana, Arkansas, and Mississippi. Accounting for geographic location greatly improved our ability to understand the variability in LEA. Additionally, covariates associated with LEA per HRR included socioeconomic status, prevalence of African Americans, age, diabetes, and mortality rate associated with having a foot ulcer. CONCLUSIONS There is profound “region-correlated” variation in the rate of LEA among Medicare beneficiaries with diabetes. In other words, location matters and whereas the likelihood of an amputation varies dramatically across the U.S. overall, neighboring locations have unexpectedly similar amputation rates, some being uniformly high and others uniformly low.

Investigating the Link Between Gun Possession and Gun Assault

OBJECTIVES We investigated the possible relationship between being shot in an assault and possession of a gun at the time. METHODS We enrolled 677 case participants that had been shot in an assault and 684 population-based control participants within Philadelphia, PA, from 2003 to 2006. We adjusted odds ratios for confounding variables. RESULTS After adjustment, individuals in possession of a gun were 4.46 (P < .05) times more likely to be shot in an assault than those not in possession. Among gun assaults where the victim had at least some chance to resist, this adjusted odds ratio increased to 5.45 (P < .05). CONCLUSIONS On average, guns did not protect those who possessed them from being shot in an assault. Although successful defensive gun uses occur each year, the probability of success may be low for civilian gun users in urban areas. Such users should reconsider their possession of guns or, at least, understand that regular possession necessitates careful safety countermeasures.

Alcohol consumption, alcohol outlets, and the risk of being assaulted with a gun

BACKGROUND We conducted a population-based case-control study to better delineate the relationship between individual alcohol consumption, alcohol outlets in the surrounding environment, and being assaulted with a gun. METHODS An incidence density sampled case-control study was conducted in the entire city of Philadelphia from 2003 to 2006. We enrolled 677 cases that had been shot in an assault and 684 population-based controls. The relationships between 2 independent variables of interest, alcohol consumption and alcohol outlet availability, and the outcome of being assaulted with a gun were analyzed. Conditional logistic regression was used to adjust for numerous confounding variables. RESULTS After adjustment, heavy drinkers were 2.67 times as likely to be shot in an assault when compared with nondrinkers (p < 0.10) while light drinkers were not at significantly greater risk of being shot in an assault when compared with nondrinkers. Regression-adjusted analyses also demonstrated that being in an area of high off-premise alcohol outlet availability significantly increased the risk of being shot in an assault by 2.00 times (p < 0.05). Being in an area of high on-premise alcohol outlet availability did not significantly change this risk. Heavy drinkers in areas of high off-premise alcohol outlet availability were 9.34 times (p < 0.05) as likely to be shot in an assault. CONCLUSIONS This study finds that the gun assault risk to individuals who are near off-premise alcohol outlets is about the same as or statistically greater than the risk they incur from heavy drinking. The combination of heavy drinking and being near off-premise outlets resulted in greater risk than either factor alone. By comparison, light drinking and being near on-premise alcohol outlets were not associated with increased risks for gun assault. Cities should consider addressing alcohol-related factors, especially off-premise outlets, as highly modifiable and politically feasible approaches to reducing gun violence.

Characteristics of Prolonged Concussion Recovery in a Pediatric Subspecialty Referral Population

OBJECTIVE To identify pre-existing characteristics associated with prolonged recovery from concussion in a sample of patients referred to a pediatric sports medicine clinic. STUDY DESIGN This was a retrospective, exploratory cohort study of 247 patients age 5-18 years with concussion referred to a tertiary pediatric hospital-affiliated sports medicine clinic from July 1, 2010, through December 31, 2011. A random sample of all eligible patient visits (3740) was chosen for further review and abstraction. Statistical comparisons between subsets of patients were conducted using exact χ(2) tests, logistic regression, quantile regression, and Kaplan-Meier survival curves. RESULTS The median time until returning to school part-time was 12 days (IQR 6-21); until returning to school full-time without accommodations was 35 days (IQR 11-105); until becoming symptom-free was 64 days (IQR 18-119); and until being fully cleared to return to sports was 75 days (IQR 30-153). Furthermore, 73% of all patients were symptomatic for >4 weeks, 73% were prescribed some form of school accommodation, and 61% reported a decline in grades. Characteristics associated with a prolonged recovery included a history of depression or anxiety; an initial complaint of dizziness; abnormal convergence or symptom provocation following oculomotor examination on physical examination; and history of prior concussion. CONCLUSIONS Pediatric and adolescent patients with concussion may experience cognitive and emotional morbidity that can last for several months following injury. Clinicians should consider specific pre-existing characteristics and presenting symptoms that may be associated with a more complicated recovery for concussion patients.

Variation in Pediatric and Adolescent Firearm Mortality Rates in Rural and Urban US Counties

OBJECTIVE: We examined whether firearm mortality rates among children varied across US counties along a rural-urban continuum. METHODS: US vital statistics data were accessed for all pediatric (age: 0–19 years) firearm deaths from 1999 through 2006. Deaths were analyzed according to a modified rural-urban continuum code (based on population size and proximity to metropolitan areas) assigned to each county (3141 counties). RESULTS: In the 8-year study period, there were 23649 pediatric firearm deaths (15190 homicides, 7082 suicides, and 1377 unintentional deaths). Pediatric nonfirearm mortality rates were significantly higher in the most-rural counties (adjusted rate ratio: 1.36 [95% confidence interval [CI]: 1.13–1.64]), compared with the most-urban counties. The most-rural counties demonstrated virtually identical pediatric firearm mortality rates (adjusted rate ratio: 0.91 [95% CI: 0.63–1.32]), compared with the most-urban counties. The most-rural counties had higher rates of pediatric firearm suicide (adjusted rate ratio: 2.01 [95% CI: 1.43–2.83]) and unintentional firearm death (adjusted rate ratio: 2.19 [95% CI: 1.27–3.77]), compared with the most-urban counties. Pediatric firearm homicides rates were significantly higher in the most-urban counties (adjusted rate ratio: 3.69 [95% CI: 2.00–6.80]), compared with the most-rural counties. CONCLUSIONS: Children in the most-rural US counties had firearm mortality rates that were statistically indistinguishable from those for children in the most-urban counties. This finding reflects a greater homicide rate in urban counties counterbalanced by greater suicide and unintentional firearm death rates in rural counties. Nonfirearm mortality rates were significantly greater outside the most-urban US counties.

Cervical spine injury in young children: a National Trauma Data Bank review.

BACKGROUND Blunt cervical spine injury (CSI) is rare in the pediatric population. The objective of this study was to better characterize the incidence and type of CSI in young children (age <3 years) using a large, trauma center-based data set. METHODS The National Trauma Data Bank (NTDB) was reviewed for the period January 2001 to December 2005 for patients younger than 3 years of age with a blunt CSI (International Classification of Diseases, Ninth Revision, 805x, 806x, 952x). Demographic, injury, and outcome information were reviewed. Data management was performed using SAS (SAS, Cary, NC) and Stata (Stata Corp, College Station, TX). Patients with CSI were compared to patients without CSI of similar age. Means were compared with the Wilcoxon rank sum test, medians were compared with a nonparametric test, and count data were compared with the chi(2) test, with significance set at <.05. RESULTS For the period of review, 95,654 young children (age <3 years) with blunt trauma were identified in the NTDB. The overall population had a median Injury Severity Score (ISS) of 4, and most patients (77.01%) had a Glasgow Coma Score (GCS) of 15. There were 1523 (1.59%) patients with a CSI (spinal cord and/or column), including 366 patients (0.38%) with a spinal cord injury (with or without column injury) and 182 (0.19%) with an isolated spinal cord injury (SCIWORA). The CSI and non-CSI populations did not differ regarding median GCS (15 for both groups), but the CSI population had a significantly higher median ISS (14 vs 4, respectively; P < .001). Compared to patients without CSI, the CSI population was more likely to die in the emergency department (2.04% vs 1.25%; P = .007) or be admitted to the intensive care unit (45.3% vs 16.9%; P < .001). Nearly half of all cervical spine fractures (48%) and more than half of cervical spinal cord injuries (53%) were in the lower cervical spine (C5-7). MVCs were the most common injury mechanism (66%) followed by falls (15%). A CSI was observed in 3.2% of all motor vehicle crashes (MVCs). CONCLUSIONS In this trauma center population, these findings confirm the infrequency of blunt CSI in the youngest (age <3 years) trauma patients. The frequency of injuries to the lower cervical spine is higher than previously appreciated. MVCs are the most likely injury mechanism for this potentially devastating injury.

Navigating the time–space context of HIV and AIDS:: daily routines and access to care

Geographers have shown that daily activities and social networks are constrained by time-space, but there are also enabling facets or opportunities created by daily routines for accessing material and emotional resources, improving quality of life, and even challenging existing power relations. Time-geography in this paper is taken as a starting point to assess how individuals living with HIV and AIDS navigate the complex and often difficult time space contexts defining their access to services. The concept of time space windows of access is offered as a way to understand the opportunities created by daily routines and social network interaction even in highly marginalized social, economic, and political circumstances. Survey data and in-depth interviews conducted with a diverse group of persons living with HIV and AIDS are used to illustrate this conceptual argument. Results indicate that the time space characteristics of daily routines, such as frequency of activities, variety or heterogeneity in activities, and whether activities are self- or social network-oriented, serve to define the availability of temporal and spatial windows of access to services. In addition, daily routines seem to matter for specific types of services, and have a limited role to play in terms of primary medical services or those associated with basic needs. The implications of these findings for theorizing and for enhancing access to services are provided.