Unintentional injuries at school in China--patterns and risk factors

OBJECTIVE: To describe the rate and pattern of unintentional school injuries among primary and middle school students and to explore the major risk factors involved. STUDY DESIGN: A cross-sectional survey of more than 10,000 students attending 6 primary and 4 middle schools selected randomly from all schools in Maanshan City of Anhui Province in eastern China was conducted to collect information on school injuries occurring in the 12-month period before the survey. Rate ratios for risk factors were estimated using the negative binomial regression analysis. RESULTS: The annual person-based school injury rate was 5.22 (95% CI: 3.90-6.53) percent. The annual event-based injury rate was 5.40 (95% CI: 4.04-6.76) per 100 students. Most injuries in school were relatively mild and only 1.53% (9/590) of the episodes resulted in hospitalization. The most frequent injures were falls (73%), and the most commonly injured sites were the upper limbs (46%). Male sex, primary school grades, poor health status, poor ability to concentrate, bad risk-taking behavior and high study-related stress were important risk factors. CONCLUSION: This study provided useful baseline information on school injuries in China and identified important risk factors that would be important in planning prevention strategies.     

A review of risk factors and patterns of motorcycle injuries

Per vehicle mile traveled, motorcycle riders have a 34-fold higher risk of death in a crash than people driving other types of motor vehicles. While lower-extremity injuries most commonly occur in all motorcycle crashes, head injuries are most frequent in fatal crashes. Helmets and helmet use laws have been shown to be effective in reducing head injuries and deaths from motorcycle crashes. Alcohol is the major contributing factor to fatal crashes. Enforcement of legal limits on the blood alcohol concentration is effective in reducing motorcycle deaths, while some alcohol-related interventions such as a minimal legal drinking age, increased alcohol excise taxes, and responsible beverage service specifically for motorcycle riders have not been examined. Other modifiable protective or risk factors comprise inexperience and driver training, conspicuity and daytime headlight laws, motorcycle licensure and ownership, riding speed, and risk-taking behaviors. Features of motorcycle use and potentially effective prevention programs for motorcycle crash injuries in developing countries are discussed. Finally, recommendations for future motorcycle-injury research are made.     

Incidence rate and risk factors of missed injuries in major trauma patients

This study was designed to determine the incidence rate and risk factors of missed injuries in major trauma patients in the emergency department (ED). Hospital records of all 976 trauma patients visiting the ED and admitted to intensive care units (ICUs) of a medical center in Taiwan from 2006 to 2007 were reviewed. Missed injuries were defined as those not identified in the ED but recognized later in the ICUs. Clinically significant injuries were those with an Abbreviated Injury Scale of ≥2. In the 2-year period, there were 133 missed injuries in 118 patients in the ED, for a prevalence of 12.1%; 87 injuries were clinically significant in 78 patients, for a prevalence of 8.0%. The estimated incidence rate per 100 person-hours was 3.2 for missed injuries and 2.1 for clinically significant missed injuries. The most commonly involved body region of missed injuries was the head/neck, followed by the chest and extremities. Results of a Cox regression analysis showed that a younger age, more-severe injury, polytrauma, and the absence of soft-tissue injuries were significantly associated with missed injuries, while younger ages, more-severe injuries, and the presence of chest and pelvic injuries were also significantly associated with clinically significant missed injuries. In conclusion, a considerable number of injuries, particularly to the head/neck, may be undetected in the ED, while young people and patients with certain injury patterns such as severity levels, polytrauma, and the presence of a chest or pelvic injury are more likely to have missed injuries and/or clinically significant missed injuries.     

Modelling risk factors for injuries from dog bites in Greece: a case-only design and analysis

We conducted a study using a newly developed dataset based on Emergency Departments records of a network of hospitals from Greece on injuries from dog bites. Our goal is three-fold: (a) to investigate if surrogate factors of leisure time are associated with increased risk of injury from bites; (b) to address recently reported contradictory results on putative association of lunar periods and injuries from dog bites; and (c) to offer a general methodology for addressing similar case-only designs with combined factors of which some can exhibit cyclical patterns. To address these goals, we used a case-only design of our dataset, and conducted an analysis where we controlled simultaneously for weekday/weekend effects, season of year (winter, spring/fall, summer), and lunar periods, because any one of these factors can contribute to the degree of exposure to injuries from dog bites. We found that increased risk of injury from bites was associated with weekends versus weekdays (RR=1.19, 95% CI: 1.10-1.29), summer versus winter (RR=1.24, 95% CI: 1.11-1.39), and fall or spring versus winter (RR=1.31, 95% CI: 1.19-1.45). The results support the hypothesis that longer leisure time at these levels of factors does increase the risk of having a bite injury. Moreover, after controlling for these factors, risk of bite injury was not associated with moon periods, thereby also helping settle a longstanding argument.     

Radiance-irradiance inversion algorithm for estimating the absorption and backscattering coefficients of natural waters: vertically stratified water bodies

A full multiple-scattering algorithm for inverting profiles of the upwelling and downwelling irradiances to yield profiles of the absorption and backscattering coefficients in a vertically stratified water body is described and tested with simulated data. The algorithm does not require knowledge of the scattering phase function of the medium. The results are better the closer the phase function assumed in the retrievals is to the true phase function, although excellent retrievals of the absorption coefficient can still be obtained with an inaccurate phase function. Simulations show that the algorithm is capable of determining the vertical structure of a stratified water body and usually provides the absorption coefficient profile with an error ?2% and the backscattering coefficient profile with an error ?10%, as long as the spacing between pseudodata samples is sufficiently small that the necessary derivatives of the irradiances can be accurately computed. The performance is only slightly degraded when the upwelling radiance (nadir viewing) is substituted for the upwelling irradiance.     

Crash risk factors related to individuals sustaining and drivers following traumatic brain injuries

Objective

Some crashes result in drivers experiencing (or sustaining) a traumatic brain injury (TBI) while other crashes involve drivers that have already experienced a TBI. The objective of this study is to examine the factors that influence these two TBI crash groups.

Methods

Data from the Iowa Department of Public Health's Brain Injury Registry and Department of Transportation's crash records were linked together and used in logistic regression models to predict the likelihood of a driver sustaining a TBI in a crash and those who drive after a TBI.

Results

Between 2001 and 2006, there were 2382 crashes in which an individual sustained a TBI. As expected, a higher likelihood of sustaining a TBI was observed for motorcycle drivers who did not wear a helmet and in crashes that resulted in total or disabling vehicle damage. Focusing specifically on the post-TBI drivers (and not occupants), 1583 were involved in crashes. These post-TBI drivers were less likely to wear seatbelts or have passengers in the vehicle at the time of the crash, and were more likely to crash at night. Post-TBI drivers were also involved in significantly more multiple crashes (about 14%) when compared to drivers who have not experienced a TBI (about 10%) during the study period. When controlling for gender, date of injury, and severity of TBI (using Glasgow Coma Scale), individuals that sustained a TBI when they were younger were more likely to be involved in multiple crashes.

Conclusions

Different factors influence the crash likelihood for those that sustain a TBI in a crash and those that crash following a TBI. In general, post-TBI drivers have a higher occurrence of multiple crashes and this should be further explored to guide driver rehabilitation, evaluation, and training.     

Trapping of water waves by moored bodies

Certain types of floating bodies are known to support trapped modes, with oscillatory fluid motion near the body and no energy radiation in the far field. Previous work has considered either fixed bodies, where the boundary conditions are homogeneous, or bodies which are freely floating and moving without any exciting force. For a fixed body the existence of a trapped mode implies that there is no unique solution of the boundary-value problem for the velocity potential with a prescribed body motion. For a free body which supports a trapped mode, the solution of the coupled problem for the motions of the fluid and body does not have a unique solution. A more general case is considered here, of a body with a linear restoring force such as an elastic mooring. The limiting cases of a fixed and free body correspond to infinite or zero values of the corresponding spring constant. A variety of body shapes are found including cylinders in two dimensions and axisymmetric bodies in three dimensions, which illustrate this more general case of trapping and provide a connection between the fixed and free cases.     

Scattering of water waves by axisymmetric bodies in a channel

Methods are presented for the calculation of wave forces on a vertically axisymmetric body arbitrarily placed within a channel. Integral representations of singular solutions of the Helmholtz equation, called channel multipoles here, are derived and these allow straightforward solution of the scattering problem for a vertical cylinder extending throughout the depth. In contrast to previous methods there is no need to sum series of images. These multipoles are also used in deriving an approximate solution valid when the radius of the cylinder is small relative to the wavelength and channel width.To solve for arbitrary shaped axisymmetric bodies, a plane-wave approximation is developed based on the assumption that the wavelength is much less than the channel width. Comparisons with the accurate solution for a vertical cylinder suggest that this approximate method performs well even when this assumption is clearly violated. The results of calculations of wave forces on a truncated cylinder are also given.All of the methods described may be applied just as easily to the case of an off-centre body as to a centrally-placed body.     

Neck injuries in frontal impacts: influence of crash pulse characteristics on injury risk

AIS1 neck injuries are the most frequent disabling injuries among car occupants in road traffic accidents. Although neck injury is mostly regarded as resulting from rear end collisions, almost one third of all neck injuries occur in frontal impacts. The injury mechanisms in both rear-end and frontal impacts are still not known, although different hypotheses exist. Since 1992, approx. 100,000 vehicles on the Swedish market have been equipped with crash recorders to measuring frontal impacts. This paper analyses the influence of different characteristics derived from the acceleration time history on the risk of short- and long-term disability to the neck in frontal impacts. The study includes injury outcomes from 187 restrained front seat occupants in 143 frontal collisions with an overlap exceeding 25%, where the crash pulses have been recorded using crash pulse recorders. The results show that the shape of the crash pulse influences the risk of long-term disability to the neck. The vehicle accelerations in the mid and last third of the crash pulse seem to be important. It is also shown how change of velocity and mean and peak accelerations influence the neck-injury risk. It is suggested that the risk of sustaining an AIS1 neck injury in frontal impacts could be reduced by using more effective pretensioners and more advanced belt-load limiters. These results may also have implications for neck injury mechanisms in rear-end impacts.     

Multi-attribute risk assessment for risk ranking of natural gas pipelines

The paper presents a decision model for risk assessment and for risk ranking of sections of natural gas pipelines based on multi-attribute utility theory. Pipeline hazard scenarios are surveyed and the reasons for a risk assessment model based on a multi-attribute approach are presented. Three dimensions of impact and the need to translate decision-makers’ preferences into risk management decisions are highlighted. The model approaches these factors by using a multi-attribute utility function, in order to produce multi-dimensional risk measurements. By using decision analysis concepts, this model quantitatively incorporates the decision-maker's preferences and behavior regarding risk within clear and consistent risk measurements. In order to support the prioritizing of critical sections of pipeline in natural gas companies, this multi-attribute model also allows sections of pipeline to be ranked into a risk hierarchy. A numerical application based on a real case study was undertaken so that the effectiveness of the decision model could be verified.     

Risk factors and prevention for spinal cord injury from diving in swimming pools and natural sites in Quebec, Canada: a 44-year study

BACKGROUND: Diving is the most frequent cause of spinal cord injury (SCI) from recreation and sport in Canada. This study was done to identify risk factors for SCI from diving in the province of Quebec. METHODS: An interview survey was done for a target population of 203 subjects with a SCI from diving treated in the two specialized rehabilitation centers in Quebec during 1961-2004. Telephone interviews of consenting individuals were used to collect pertinent personal, equipment, and environmental factors for each incident. RESULTS: Response was 44% (89/203); 92% were male and 85% <35 years old. Only 37% were aware prior to injury of the risk of SCI from diving, and only 33% had received water safety training. Swimming pools were the site of 51% (n=45) and natural bodies of water for 49% (n=44). 87% (n=39) of pools were single-unit home pools and 57% (n=26) above-ground. Depth indicators were absent for 100% of above-ground and 74% of in-ground pools. For SCI in in-ground pools, 63% resulted from striking the up-slope between deep and shallow ends. For dives at natural sites, a dock or wharf was the most frequent location, 36% (n=16). In 52% of pools and 79% of natural sites, depth was <1.4m (4.6ft). Signs prohibiting diving were absent in 96% of above-ground and 89% of in-ground pools. Alcohol was reported in 47% of SCIs. INTERPRETATION: The target for prevention of diving SCI is male youths and young adults. Above-ground pools are too shallow and small for diving. Deep ends of many in-ground pools are excessively shallow and short since many SCIs resulted from striking the up-slope. Prevention of SCI from diving needs to focus on education of potential victims, pool vendors and manufacturers, and regulations for safety norms in private pools. Water safety should highlight diving as a high-risk activity, and emphasize that most home pools and natural sites are unsafe. Safer evidence-based pool designs and more effective warnings need to be implemented.     

A case-control study of child bicycle injuries: relationship of risk to exposure

In order to assess the relationship of the risk of injury requiring hospital attendance in children riding bicycles to sociodemographic factors and to measures of exposure, a population-based case-control study is being undertaken in a large area of suburban Melbourne, Australia. Particular attention is given to the measurement of individual exposure in several dimensions. Analysis of interim data from 109 cases and 118 controls shows that 51% of injuries occurred while the child was playing rather than making a trip on the bicycle and only 22% involved another vehicle. Boys used bicycles more commonly than girls but there was minimal evidence of an increased risk of injury in boys, adjusting for exposure. There was no evidence for an age trend in injury risk, but children from families in the lowest income category were at significantly increased risk. Exposure measures showed complex patterns of association with injury risk. Estimated time spent riding was more closely associated with risk than distance travelled, with an odds ratio of 2.2 (95% confidence interval 1.1–4.2) for children riding for more than 3 hours per week compared to children riding less than 1 hour. Riding more than 5 km on the sidewalk was also associated with increased risk (odds ratio 3.1, 95% CI 1.1–8.5). The elevated risk associated with sidewalk riding may be due to difficulties in negotiating uneven surfaces. The case-control study provides an ideal design for this type of investigation but valid and reliable measurement of exposure is difficult.     

Thulium hydroxide: a new coprecipitant for speciation of chromium in natural water samples

A coprecipitation procedure has been established for chromium speciation in natural water samples. The procedure is based on the coprecipitation of Cr(III) on thulium hydroxide precipitate. After reduction of Cr(VI) to Cr(III) by using potassium iodide, the presented method was applied to the determination of the total chromium. The level of Cr(VI) is calculated by difference of total chromium and Cr(III) levels. The procedure was optimized for some analytical parameters including pH, sample volume, matrix effects, etc. The detection limits based on 3sigma criterion were 0.87 microg L(-1) for Cr(III) and 1.18 microg L(-1) for Cr(VI). The procedure presented was validated by the analysis of BCR-144R Sewage Sludge (domestic origin). The presented method was applied for the speciation of chromium in environmental sample with satisfactory results (recoveries>95%, R.S.D.s<10%).     

Alcohol and driving factors in collision risk

In this study we examine the effect of several alcohol-related measures on self-reported collision involvement within the previous 12 months while controlling for demographic and driving exposure factors based on a large representative sample of adults in Ontario. Data are based on the 2002–2006 Centre for Addiction and Mental Health Monitor, an ongoing cross-sectional telephone survey of Ontario adults aged 18 and older (n = 8542). Three logistic regressions of self-reported collision involvement in the past 12 months were implemented, each consisting of 3 steps: (1) demographic factors and driving exposure entered, (2) driving after drinking within the last 12 months entered, and (3) one of three alcohol-related measures (AUDIT subscales of alcohol consumption, dependence and problems) entered. In each step, measures from the preceding step were included in order to control for those variables. In Step 1, age (OR = 0.989), region overall, Central East region (OR = 0.71), West region (OR = 0.67), and North region (OR = 0.67), income overall and those who did not state income (OR = 0.64), marital status overall and those married or living common law (OR = 0.60), and number of kilometers driven in a typical week (OR = 1.00) were found to be significant predictors of collision involvement. The analyses revealed that driving after drinking was a significant predictor of collision involvement in Step 2 (OR = 1.51) and each of the Step 3 models (ORs = 1.52, 1.37, 1.34). The AUDIT Consumption subscale was not a significant factor in collision risk. Both the AUDIT Dependence and AUDIT Problems subscales were significantly related to collision risk (ORs = 1.13 and 1.10, respectively). These findings suggest that alcohol, in addition to its effects on collision risk through its acute impairment of driving skills, may also affect collision risk through processes involved when individuals develop alcohol problems or alcohol dependence.     

Overview of critical risk factors in Power-Two-Wheeler safety

Power-Two-Wheelers (PTWs) constitute a vulnerable class of road users with increased frequency and severity of accidents. The present paper focuses of the PTW accident risk factors and reviews existing literature with regard to the PTW drivers’ interactions with the automobile drivers, as well as interactions with infrastructure elements and weather conditions. Several critical risk factors are revealed with different levels of influence to PTW accident likelihood and severity. A broad classification based on the magnitude and the need for further research for each risk factor is proposed. The paper concludes by discussing the importance of dealing with accident configurations, the data quality and availability, methods implemented to model risk and exposure and risk identification which are critical for a thorough understanding of the determinants of PTW safety.     

Individual and occupational factors related to fatal occupational injuries: a case-control study

This study has been designed in order to identify factors increasing the risk of a fatal outcome when occupational accidents occur. The aim is to provide further evidence for the design and implementation of preventive measures in occupational settings. The Spanish Ministry of Labour registry of occupational injuries causing absence from work includes information on individual and occupational characteristics of injured workers and events. Registered fatal occupational injuries in 2001 (n = 539) were compared to a sample of non-fatal injuries in the same year (n = 3493). Risks for a fatal result of occupational injuries, adjusted by individual and occupational factors significantly associated, were obtained through logistic regression models. Compared to non-fatal injuries, fatal occupational injuries were mostly produced by trapping or by natural causes, mostly related to elevation and transport devices and power generators, and injured parts of body more frequently affected were head, multiple parts or internal organs. Adjusted analyses showed increased risk of fatality after an occupational injury for males (adjusted odds ratio aOR = 10.92; 95%CI 4.80–24.84) and temporary workers (aOR = 5.18; 95%CI 2.63–10.18), and the risk increased with age and with advancing hour of the work shift (p for trends <0.01). Injuries taking place out of the usual occupational setting (aOR = 2.85, 95%CI 2.27–3.59), or carrying out atypical tasks (aOR = 2.08; 95%CI 1.27–3.39) showed increased risks of a fatal result too, as occupational accidents in agricultural or construction companies. These data can help to select and define priorities for programmes aimed to prevent fatal consequences of occupational injuries.     

Sleep apnea in hemodialysis patients: risk factors and effect on survival

Sleep disorders are common in patients with end-stage renal disease (ESRD). Using a simple questionnaire, we estimate the probability of sleep apnea in ESRD patients, determine the factors associated with a higher probability of sleep apnea, and determine the association between the probability of sleep apnea and cardiovascular and all-cause mortality. Study design: Prospective cohort study. Setting and participants: prevalent hemodialysis patients (n=270) in 7 urban outpatient hemodialysis units. Predictor: Probability of sleep apnea as quantified by the Flemons questionnaire. Outcomes and measurements: Clinical, demographic, and dialysis-related characteristics were obtained at baseline. Total and cardiovascular mortality was ascertained after a median follow-up of 34 months. The probability of sleep apnea was low in 79 (29%) patients, moderate in 116 (43%) patients, and high in 75 (28%) patients. Male gender (odds ratio [OR] 5.13, p<0.001), obesity (BMI >30, OR 7.58, p<0.01), and interdialytic weight gain (OR 1.72/kg change, p<0.004) were independently associated with a high probability of sleep apnea. A high probability of sleep apnea at baseline did not predict total (hazard ratio [HR] 0.81, p=NS) or cardiovascular mortality (HR 0.9, p=NS). The Flemons questionnaire is validated in the general population, but has not been tested specifically in hemodialysis patients. The study may not be adequately powered to detect a difference in mortality. A high proportion of hemodialysis patients are likely to have sleep apnea; a simple bedside questionnaire can be used for screening to identify these patients. Excessive interdialytic weight gain is a potentially modifiable factor that increases the likelihood of sleep apnea. Despite the presence of a strong association between sleep apnea and mortality in the general population, a similar association could not be demonstrated in ESRD patients with a high prevalence of this condition.     

An influence function for stress intensity factors of bimaterial notched bodies

The problem of a notch at a bimaterial interface is considered. An influence function is developed for determining the stress intensity factors for all notch angles in infinite bodies. Particular solutions are obtained for cracks in homogeneous and bimaterial bodies and for bonded strips. Comparison with solutions in the literature is excellent. This revised version was published online in July 2006 with corrections to the Cover Date.