To the Rescue: Optimally Locating Trauma Hospitals and Helicopters

Injury (trauma) is the leading cause of death in the United States for people younger than 45 years of age. Each day, more than 170,000 men, women, and children are injured severely enough to seek medical care. About 400 of these people will die and another 200 will sustain a long-term disability as a result of their injuries. An estimated 20-40% of trauma-related deaths could be prevented if all Americans lived in communities that were served by a well-organized system of trauma care. This Issue Brief describes a new computer model that can help State and regional policymakers decide where to place designated trauma hospitals and helicopter depots to maximize their residents’ access to trauma care

Causal Inference in Observational Studies with Outcome-Dependent Sampling

In this paper, we consider estimation of the causal effect of a treatment on an outcome from observational data collected in two phases. In the first phase, a simple random sample of individuals are drawn from a population. On these individuals, information is obtained on treatment, outcome, and a few low-dimensional confounders. These individuals are then stratified according to these factors. In the second phase, a random sub-sample of individuals are drawn from each stratum, with known, stratum-specific selection probabilities. On these individuals, a rich set of confounding factors are collected. In this setting, we introduce four estimators: (1) simple inverse weighted, (2) locally efficient, (3) doubly robust and (4)enriched inverse weighted. We evaluate the finite-sample performance of these estimators in a simulation study. We also use our methodology to estimate the causal effect of trauma care on in-hospital mortality using data from the National Study of Cost and Outcomes of Trauma

PRINCIPAL STRATIFICATION DESIGNS TO ESTIMATE INPUT DATA MISSING DUE TO DEATH

We consider studies of cohorts of individuals after a critical event, such as an injury, with the following characteristics. First, the studies are designed to measure “input” variables, which describe the period before the critical event, and to characterize the distribution of the input variables in the cohort. Second, the studies are designed to measure “output” variables, primarily mortality after the critical event, and to characterize the predictive (conditional) distribution of mortality given the input variables in the cohort. Such studies often possess the complication that the input data are missing for those who die shortly after the critical event because the data collection takes place after the event. Standard methods of dealing with the missing inputs, such as imputation or weighting methods based on an assumption of ignorable missingness, are known to be generally invalid when the missingness of inputs is nonignorable, that is, when the distribution of the inputs is different between those who die and those who live. To address this issue, we propose a novel design that obtains and uses information on an additional key variable – a treatment or externally controlled variable, which if set at its “effective” level, could have prevented the death of those who died. We show that the new design can be used to draw valid inferences for the marginal distribution of inputs in the entire cohort, and for the conditional distribution of mortality given the inputs, also in the entire cohort, even under nonignorable missingness. The crucial framework that we use is principal stratification based on the potential outcomes, here mortality under both levels of treatment. We also show using illustrative preliminary injury data, that our approach can reveal results that are more reasonable than the results of standard methods, in relatively dramatic ways. Thus, our approach suggests that the routine collection of data on variables that could be used as possible treatments in such studies of inputs and mortality should become common

Investigating the foraging, guarding and drifting behaviors of commercial Bombus terrestris

Social insects have high levels of cooperation and division of labor. In bumble bees this is partly size-based, with larger bees performing tasks outside the nest and smaller bees remaining inside, although bumble bees still display considerable behavioral plasticity. The level of specialization in tasks outside the colony, including foraging, guarding and drifting (entering a foreign colony), is currently unknown for bumble bees. This study aimed to assess division of labor between outside tasks and the degree of specialization in foraging, guarding, and switching colonies in commercially reared bumble bees placed in the field. Nine factory-bought Bombus terrestris colonies were placed on three farms in Sussex, UK, between June and August 2015. Forty workers from each colony were radio-tagged and a reader on the colony entrance recorded the date, time and bee ID as they passed. The length and frequency of foraging trips and guarding behavior were calculated, and drifting recorded. The mean (±SD) length of foraging trips was 45 ± 36 min, and the mean number of foraging trips per day was 7.75 ± 7.71. Low levels of specialization in guarding or foraging behavior were found; however, some bees appeared to guard more frequently than others, and twenty bees were categorized as guards. Five bees appeared to exhibit repeated “stealing” behavior, which may have been a specialist task. The division of labor between tasks was not size-based. It is concluded that commercial bumble bees are flexible in performing outside nest tasks and may have diverse foraging strategies including intra-specific nest robbing

Development and pilot implementation of a locally developed Trauma Registry: lessons learnt in a low-income country

Background Trauma registries (TRs) play an integral role in the assessment of trauma care quality. TRs are still uncommon in developing countries owing to awareness and cost. We present a case study of development and pilot implementation of “Karachi Trauma Registry” (KITR), using existing medical records at a tertiary-care hospital of Karachi, Pakistan to present results of initial data and describe its process of implementation. Methods KITR is a locally developed, customized, electronic trauma registry based on open source software designed by local software developers in Karachi. Data for KITR was collected from November 2010 to January 2011. All patients presenting to the Emergency Department (ED) of the Aga Khan University Hospital (AKUH) with a diagnosis of injury as defined in ICD-9 CM were included. There was no direct contact with patients or health care providers for data collection. Basic demographics, injury details, event detail, injury severity and outcome were recorded. Data was entered in the KITR and reports were generated. Results Complete data of 542 patients were entered and analysed. The mean age of patients was 27 years, and 72.5% were males. About 87% of patients had sustained blunt injury. Falls and motor vehicle crashes were the most common mechanisms of injury. Head and face, followed by the extremities, were the most frequently injured anatomical regions. The mean Injury Severity Score (ISS) was 4.99 and there were 8 deaths. The most common missing variables in the medical records were ethnicity, ED notification prior to transfer, and pre-hospital IV fluids. Average time to review each chart was 14.5 minutes and entry into the electronic registry required 15 minutes. Conclusion Using existing medical records, we were able to enter data on most variables including mechanism of injuries, burden of severe injuries and quality indicators such as length of stay in ED, injury to arrival delay, as well as generate injury severity and survival probability but missed information such as ethnicity, ED notification. To make the data collection process more effective, we propose provider based data collection or making a standardized data collection tool a part of medical records

The impact of trauma-center care on mortality and function following pelvic ring and acetabular injuries

ABSTRACT Background: Lower mortality and improved physical function following major polytrauma have been associated with treatment at level-1 trauma centers (TC) compared with that at non-trauma centers (NTC). This study investigates the impact of TC care on outcomes after pelvic and acetabular injuries. Methods: Mortality and quality of life-related measures were compared among patients treated in 18 hospitals with level-1 trauma centers and 51 hospitals without trauma centers in 14 U.S. states. Complete data were obtained on 829 adult trauma patients (18-84 years old) with at least one pelvic ring or acetabular injury (OTA 61 or 62). We used inverse probability of treatment weighting to adjust for observable confounding. Results: After adjustment for case mix, in-hospital mortality was significantly lower at TC versus NTC (RR 0.10, 95% CI 0.02-0.47), as was death by 90 days (RR 0.10, 95% CI 0.02-0.47), and one year (RR 0.21, 95% CI 0.06-0.76) for patients with more severe acetabular injuries (OTA 62-B or 62-C). Patients with combined pelvic ring and acetabular injuries treated at TC had lower mortality by 90 days (RR 0.34, 95% CI 0.14-0.82) and one year (RR 0.30 95% CI 0.14-0.68). Care at TC was also associated with mortality risk reduction for those with unstable pelvic ring injuries (OTA 61-B or 61-C) at one year (RR 0.21, 95%CI 0.06-0.76). Seventy-eight percent of included subjects discharged alive was available for interview at twelve months. Average absolute differences in SF-36 physical functioning and Musculoskeletal Functional Assessment at one year were 11.4 (95%CI 5.3 – 17.4) and 13.2 (1.7 – 24.7) respectively, indicating statistically and clinically significant improved outcomes with TC treatment for more severe acetabular injuries. Conclusions: Mortality is reduced for patients with unstable pelvic and severe acetabular injuries when care is provided in a TC compared to NTC. Moreover, those with severe acetabular fractures experience improved physical function at one year. Patients with these injuries represent a well-defined subset of trauma patients that should be preferentially triaged or transferred to a Level-1 trauma center

Monitoring the introduction of pneumococcal conjugate vaccines into West Africa: design and implementation of a population-based surveillance system.

Routine use of pneumococcal conjugate vaccines (PCVs) in developing countries is expected to lead to a significant reduction in childhood deaths. However, PCVs have been associated with replacement disease with non-vaccine serotypes. We established a population-based surveillance system to document the direct and indirect impact of PCVs on the incidence of invasive pneumococcal disease (IPD) and radiological pneumonia in those aged 2 months and older in The Gambia, and to monitor changes in serotype-specific IPD. Here we describe how this surveillance system was set up and is being operated as a partnership between the Medical Research Council Unit and the Gambian Government. This surveillance system is expected to provide crucial information for immunisation policy and serves as a potential model for those introducing routine PCV vaccination in diverse settings

An assessment of the aversive nature of an animal management procedure (clipping) using behavioral and physiological measures

Animal management often involves procedures that, while unlikely to cause physical pain, still cause aversive responses. The domestic horse ( Equus caballus ) regularly has excessive hair clipped off to facilitate its use as a riding/driving animal and this procedure causes adverse behavioral responses in some animals. The aim of this study was to compare behavioral and physiological measures to assess the aversive effect of this procedure. Ten horses were selected on the basis of being either compliant (C: n = 5) or non-compliant (NC: n = 5) during this procedure. The horses were subjected to a sham clipping procedure (SC: where the blades had been removed from the clippers) for a period of ten minutes. Measures were taken pre, during and post SC (−10 min to +30 min) and mean values calculated for ALL horses and for C and NC separately. Behavioral activity was scored (scale 1-5) by twenty students from video footage in (phase/group-blind scoring). Heart rate (HR), salivary cortisol and eye temperature were monitored throughout the procedure. The NC horses were found to be significantly more behaviorally active/less relaxed throughout the trial than C horses(p b 0.05) with the greatest difference occurring during the SC procedure (p b 0.01). NC horses were more active/less relaxed during, compared with pre or post SC (p b 0.05), but showed no behavioral difference pre and post SC. HR of the NC horses was higher than that of the C horses throughout the trial but only significantly so after 10 min of SC (p b 0.01). ALL horses showed significant increase in HR between +5 and +10 min into the procedure (p b 0.05). There was a significant increase in salivary cortisol concentration in ALL horses post procedure (p b 0.01) with levels peaking at 20 minute post SC. No significant differences in salivary cortisol concentration between C and NC were found at any stage of the trial. Eye temperature increased significantly in ALL horses during SC, peaking at +10 min into the procedure (p b 0.05) and then decreased substantially when SC had ceased (p b 0.01). Although no significant differences were found between C and NC per se, there was a significant interaction between group and phase of trial (p b 0.05) with the NC group showing a greater decrease in eye temperature post SC. There was a significant positive correlation between changes in salivary cortisol concentration and eye temperature (p b 0.01) but no correlation between any of the other measures. Although the behavioral response of C and NC to this procedure was significantly different the physiological responses indicated that ALL horses found the procedure aversive. Eye temperature could be used as an objective and immediate measure of how an animal is responding to a specific situation in order to evaluate management procedures and adapt them where appropriate to reduce the negative impact on animal health and welfare

Safety and efficacy of botox injection in alleviating post-operative pain and improving quality of life in lower extremity limb lengthening and deformity correction

<p>Abstract</p> <p>Background</p> <p>Distraction osteogenesis is the standard treatment for the management of lower limb length discrepancy of more than 3 cm and bone loss secondary to congenital anomalies, trauma or infection. This technique consists of an osteotomy of the bone to be lengthened, application of an external fixator, followed by gradual and controlled distraction of the bone ends. Although limb lengthening using the Ilizarov distraction osteogenesis principle yields excellent results in most cases, the technique has numerous problems and is not well tolerated by many children. The objective of the current study is to determine if Botulinum Toxin A (BTX-A), which is known to possess both analgesic and paralytic actions, can be used to alleviate post-operative pain and improve the functional outcome of children undergoing distraction osteogenesis.</p> <p>Methods/Design</p> <p>The study design consists of a multi centre, randomized, double-blinded, placebo-controlled trial. Patients between ages 5–21 years requiring limb lengthening or deformity correction using distraction will be recruited from 6 different sites (Shriners Hospital for Children in Montreal, Honolulu, Philadelphia and Portland as well as DuPont Hospital for Children in Wilmington, Delaware and Hospital for Sick Children in Toronto, Ont). Approximately 150 subjects will be recruited over 2 years and will be randomized to either receive 10 units per Kg of BTX-A or normal saline (control group) intraoperatively following the surgery. Functional outcome effects will be assessed using pain scores, medication dosages, range of motion, flexibility, strength, mobility function and quality of life of the patient. IRB approval was obtained from all sites and adverse reactions will be monitored vigorously and reported to IRB, FDA and Health Canada.</p> <p>Discussion</p> <p>BTX-A injection has been widely used world wide with no major side effects reported. However, to the best of our knowledge, this is the first time BTX-A is being used under the context of limb lengthening and deformity correction.</p> <p>Trial Registration</p> <p>NCT00412035</p