Jake Olivier

Relative injury severity among vulnerable non-motorised road users: Comparative analysis of injury arising from bicycle–motor vehicle and bicycle–pedestrian collisions

With the expansion of bicycle usage and limited funding and/or space for segregated pedestrian and bicycle paths, there is a need for traffic, road design and local government engineers to decide if it is more appropriate for space to be shared between either cyclists and pedestrians, or between cars and cyclists, and what restrictions need to be applied in such circumstances. To provide knowledge to aid engineers and policy makers in making these decisions, this study explored death and morbidity data for the state of New South Wales, Australia to examine rates and severity of injury arising from collisions between pedestrians and cyclists, and between cyclists and motor vehicles (MVs). An analysis of the severity of hospitalised injuries was conducted using International Classification of Diseases, Version 10, Australian Modification (ICD-10-AM) diagnosis-based Injury Severity Score (ICISS) and the Disability Adjusted Life Year (DALY) was used to measure burden of injury arising from collisions resulting in death or hospitalisation. The greatest burden of injury in NSW, for the studied collision mechanisms, is for cyclists who are injured in collisions with motor vehicles. Collisions between cyclists and pedestrians also result in significant injuries. For all collision mechanisms, the odds of serious injury on admission are greater for the elderly than for those in other age groups. The significant burden of injury arising from collisions of cyclists and MVs needs to be addressed. However in the absence of appropriate controls, increasing the opportunity for conflict between cyclists and pedestrians (through an increase in shared spaces for these users) may shift the burden of injury from cyclists to pedestrians, in particular, older pedestrians.

Impact of telemedicine upon rural trauma care.

OBJECTIVES Only preliminary reports have evaluated the impact of telemedicine in trauma care. This study will analyze outcomes before (pre-TM) and after (post-TM) implementation of telemedicine in the management of rural trauma patients initially treated at local community hospitals (LCH) before trauma center (TC) transfer. METHODS Seven rural hospital emergency departments in Mississippi were equipped with dual video cameras with remote control capability. All trauma patients initially treated at these LCH with TC consultation were reviewed. Data included patient demographics, Injury Severity Score, institutional volume of patients, mode of transportation, length of stay in LCH, transfer time (TT), mortality, and hospital cost. Patients were grouped in the pre-TM and post-TM periods. Statistical testing was with two-sample Students t test or chi analysis as appropriate. RESULTS During 5 years, 814 traumatically injured patients (pre-TM, n = 351; post-TM, n = 463) presented to the LCH. In the pre-TM period, 351 patients were transferred directly from the LCH for definitive management to the TC. In the post-TM period, 463 virtual consults were received, of which 51 patients were triaged to the TC. There were no differences in patient age, sex, or mode of transportation. When comparing post-TM with pre-TM era, patients had a higher Injury Severity Score (18 vs. 10, p < 0.001); less incidence of blunt trauma 35 (68%) versus 290 (82%), p < 0.05; a decrease in length of stay at LCH 1.5 hours versus 47 hours, p < 0.001; as well as TT LCH to TC 1.7 hours versus 13 hours, p < 0.001. After arrival to TC during the post-TM era patients received more units of packed red bed cell 13 units versus 5 units, p < 0.001 but without difference in mortality 4 (7.8%) versus 17 (4.8%), when compared with pre-TM era. Of statistical significance there was a dramatic decrease in hospital cost when comparing post-TM and pre-TM eras (

Stenting of chronically obstructed inferior vena cava filters

1,126,683 vs.

Increased frequency of large local reactions among systemic reactors during subcutaneous allergen immunotherapy

7,632,624, p < 0.001). CONCLUSION Telemedicine significantly improved rural LCH evaluation and management of trauma patients. More severely injured trauma patients were identified and more rapidly transferred to the TC. Total TC hospital costs were significantly decreased without significant changes in TC mortality. Introduction of telemedicine consultation to rural LCH emergency departments expanded LCH trauma capabilities and conserved TC resources, which were directed to more severely injured patients.

Social Anxiety, Reasons for Drinking, and College Students.

OBJECTIVES A protective inferior vena cava (IVC) filter may later be incorporated into a chronic postthrombotic ilio-caval obstruction (occlusive, requiring recanalization, or nonocclusive). This study aims to assess the safety and stent-related outcome following stenting across an obstructed filter. METHODS From 1997 to 2009, 708 limbs had stenting for postthrombotic ilio-caval outflow obstruction (occlusion in 121 limbs). In 25 patients, an IVC filter was obstructed (Group X). The site was crossed by a guidewire and balloon dilated. The filter was markedly displaced sidewise or remodeled. A stent was placed across the IVC filter and redilated. In 28 other patients, the cephalad stenting terminated below a patent IVC filter (Group B). The remaining 655 patients had no previous IVC filter placement (Group no IVC filter present [NF]). The patients were followed to assess patency. The types of reintervention were noted. RESULTS The stenting maneuver through a variety of previously inserted IVC filters was safely performed without an apparent tear of the IVC, no clinical bleeding or abdominal symptoms, or pulmonary embolism. Mortality was nil; morbidity minimal. The primary and secondary cumulative patency rates at 54 months for limbs with postthrombotic obstruction were with and without IVC filter (38% and 40%; P = .1701 and 79% and 86%; P = .1947, respectively), and for limbs with stenting across the filter (Group X) and stent termination below the filter (Group B; 32% and 42%; P = .3064 and 75% and 84%; P = .2788, respectively), not statistically different. When Group X alone was compared with Group NF, the secondary patency rate was, however, significantly lower (75% vs 86%; P = .0453), suggesting that crossing of the stent was associated with reduced patency. Occlusive postthrombotic disease requiring recanalization was more frequent in Group X than in Group B and Group NF (68%, 25%, and 15%, respectively; P = .004). A comparison was therefore performed only between limbs stented for recanalized occlusions with (n = 23) and without IVC filters (n = 92) showing no difference (cumulative primary and secondary patency rates 30% and 35%; P = .9678 and 71% and 73%; P = .9319, respectively). Multiple logistic regression analysis also supported a significant association between patency rate and occlusive disease (odds ratio, 6.9; 95% confidence interval, 3.4-13.9; P < .0001), but not between patency rate and presence of an IVC filter (P = .5552). CONCLUSIONS Stenting across an obstructed IVC filter is safe. It appears that patency is not influenced by the fact that an IVC filter is crossed by a stent, but is related to the severity of postthrombotic disease (occlusive or nonocclusive obstruction) and the associated recanalization procedure.

The logarithmic transformation and the geometric mean in reporting experimental IgE results: what are they and when and why to use them?

BACKGROUND Large local reactions are not uncommon during allergen immunotherapy (AIT). Dosage adjustments after large local reactions are commonly instituted despite literature that suggests individual large local reactions do not seem to predict subsequent systemic reactions. OBJECTIVE To investigate the relationship between large local reactions and the risk of systemic reactions to AIT. METHODS Retrospective review of the AIT database of a large, multicenter allergy practice group was conducted between June 1, 2003, and May 31, 2005. Numbers of large local reactions in 258 patients who experienced systemic reactions to AIT were compared with 299 age-, sex-, and sensitivity-matched control patients who did not experience systemic reactions during AIT. RESULTS A total of 283 systemic reactions occurred in 258 patients during the surveillance period, which included 661,123 patient visits for 1,108,621 allergy injections. The systemic reaction rate was 0.043% of visits and 0.025% of injections. The large local reaction rate was 35.2% of visits and 19.5% of injections among systemic reactors compared with 8.9% of visits and 5.3% of injections in the controls (P < .001 each). Thus, the odds of experiencing large local reactions were significantly increased among systemic reactors. CONCLUSIONS Although AIT is a safe and effective immunomodulatory therapeutic option for the treatment of allergic diseases, patients with increased frequency of large local reactions may have increased risk for future systemic reactions. Identifying additional risk factors remains viable. Recognizing the relevance of frequent large local reactions is important for designing safer protocols for successful AIT in these patients.

The impact of compulsory cycle helmet legislation on cyclist head injuries in New South Wales, Australia

Recent research suggests that social anxiety may be associated with higher rates of alcohol problems in women, yet may be associated with lower levels of drinking in men. The current study investigated putative mechanisms that may underlie potential gender differences in the social anxiety-alcohol relationship. One hundred and eighteen college students (61.0% women) completed an interview assessing drinking behaviors and questionnaires measuring social anxiety, drinking motives, and drinking situations. Although college men and women both reported similar frequencies of drinking in positive situations and to enhance positive emotions, women reported drinking more often in negative situations and to cope with aversive emotions than men. Mediated moderation analyses suggested that women with social anxiety may be at greater risk of encountering adverse consequences because of their likelihood to drink to conform or to cope with the aversive affect they experience in negative situations. Conversely, when men experience high rates of adverse consequences, it may be due to drinking greater quantities of alcohol in positive situations. Highly socially anxious college men may drink less alcohol and experience fewer adverse consequences than their nonanxious or mildly anxious counterparts because they may find themselves in positive situations and drinking to enhance positive feelings less often, potentially due to avoidant behavior. These findings may help to explain why social anxiety serves as a potential risk factor for alcohol-related problems for college women, but a protective factor for college men.

Effect Sizes for 2×2 Contingency Tables

BACKGROUND Immunologic data, such as IgE and interleukin 4, tend to have positively skewed distributions with a long tail of larger values. This renders analyses based on normal distribution theory questionable (eg, t tests and analysis of variance) and distorts the sample mean as a measure of central tendency. These problems can be addressed through analysis of log-transformed data. Data analyzed in this fashion are summarized with the geometric mean. OBJECTIVE To elucidate the use of the logarithmic transform and the geometric mean in the analysis of immunologic data. METHODS The analysis may be conducted by transforming the data to a logarithmic scale to achieve a bell-shaped (approximately normal) distribution. The bell-shaped distribution needed to validate statistical inferences is only achieved in the transformed scale. In summarizing the research findings, the statistical analyst usually will transform means and confidence intervals from the logarithmic scale back to the original scale of measurement. Statistical inferences in the log scale remain valid for the data. The result of back transforming the mean of logarithmic values to the original scale is the geometric mean. This statistic is less subject to distortion by the unusually large values in the tail of the positively skewed distribution of the data. RESULTS A brief example is used to illustrate this type of analysis. CONCLUSIONS Logarithmic transformation permits valid statistical inference for positively skewed immunologic data. A result of this analysis is the geometric mean, which is a better measure of central tendency of this data type than the usual sample mean.

Activity of a heptad of transcription factors is associated with stem cell programs and clinical outcome in acute myeloid leukemia

The study aimed to assess the effect of compulsory cycle helmet legislation on cyclist head injuries given the ongoing debate in Australia as to the efficacy of this measure at a population level. We used hospital admissions data from New South Wales, Australia, from a 36 month period centred at the time legislation came into effect. Negative binomial regression of hospital admission counts of head and limb injuries to cyclists were performed to identify differential changes in head and limb injury rates at the time of legislation. Interaction terms were included to allow different trends between injury types and pre- and post-law time periods. To avoid the issue of lack of cyclist exposure data, we assumed equal exposures between head and limb injuries which allowed an arbitrary proxy exposure to be used in the model. As a comparison, analyses were also performed for pedestrian data to identify which of the observed effects were specific to cyclists. In general, the models identified a decreasing trend in injury rates prior to legislation, an increasing trend thereafter and a drop in rates at the time legislation was enacted, all of which were thought to represent background effects in transport safety. Head injury rates decreased significantly more than limb injury rates at the time of legislation among cyclists but not among pedestrians. This additional benefit was attributed to compulsory helmet legislation. Despite numerous data limitations, we identified evidence of a positive effect of compulsory cycle helmet legislation on cyclist head injuries at a population level such that repealing the law cannot be justified.

Bicycle injuries and helmet use: a systematic review and meta-analysis

Sample size calculations are an important part of research to balance the use of resources and to avoid undue harm to participants. Effect sizes are an integral part of these calculations and meaningful values are often unknown to the researcher. General recommendations for effect sizes have been proposed for several commonly used statistical procedures. For the analysis of tables, recommendations have been given for the correlation coefficient for binary data; however, it is well known that suffers from poor statistical properties. The odds ratio is not problematic, although recommendations based on objective reasoning do not exist. This paper proposes odds ratio recommendations that are anchored to for fixed marginal probabilities. It will further be demonstrated that the marginal assumptions can be relaxed resulting in more general results.