Correspondence: Paul A. Landsbergis, Department of Community and Preventive Medicine, Division of Cardiology, Department of Medicine, Mount Sinai School of Medicine, Box 1043, One Gustave L. Levy Place, New York, NY 10029-6574, USA; (email: paul.landsbergis@mssm.edu).
Recent trends in the organization of work may affect worker health through a variety of pathways--by increasing the risk of stress-related illnesses, such as cardiovascular disease, musculoskeletal disorders, and psychological disorders, by increasing exposure to hazardous substances and violence on the job, or by affecting occupational health services and training programs. Much remains to be learned about the nature of changes in work organization, and how they affect worker health and safety. While available evidence is limited, such evidence suggests that recent trends in work organization may be increasing the risk of occupational illnesses. In a ground breaking publication, the National Institute for Occupational Safety and Health has provided a concise summary of available knowledge and a detailed agenda for research and development.
Effects of vitamin D and calcium supplementation on falls: a randomized controlled trial.
- Bischoff HA, Stahelin HB, Dick W, Akos R, Knecht M, Salis C, Nebiker M, Theiler R, Pfeifer M, Begerow B, Lew RA, Conzelmann M. J Bone Miner Res 2003; 18(2): 343-51.
Correspondence: H.A. Bischoff, Department of Orthopaedics, University of Basel, Basel, SWITZERLAND; (email: hbischof@hsph.harvard.edu).
Specific receptors for vitamin D have been identified in human muscle tissue. Cross-sectional studies show that elderly persons with higher vitamin D serum levels have increased muscle strength and a lower number of falls. We hypothesized that vitamin D and calcium supplementation would improve musculoskeletal function and decrease falls. In a double-blind randomized controlled trial, we studied 122 elderly women (mean age, 85.3 years; range, 63-99 years) in long-stay geriatric care. Participants received 1200 mg calcium plus 800 IU cholecalciferol (Cal+D-group; n = 62) or 1200 mg calcium (Cal-group; n = 60) per day over a 12-week treatment period. The number of falls per person (0, 1, 2-5, 6-7, >7 falls) was compared between the treatment groups. In an intention to treat analysis, a Poisson regression model was used to compare falls after controlling for age, number of falls in a 6-week pretreatment period, and baseline 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D serum concentrations. Among fallers in the treatment period, crude excessive fall rate (treatment - pretreatment falls) was compared between treatment groups. Change in musculoskeletal function (summed score of knee flexor and extensor strength, grip strength, and the timed up & go test) was measured as a secondary outcome. Among subjects in the Cal+D-group, there were significant increases in median serum 25-hydroxyvitamin D (+71%) and 1,25-dihydroxyvitamin D (+8%). Before treatment, mean observed number of falls per person per week was 0.059 in the Cal+D-group and 0.056 in the Cal-group. In the 12-week treatment period, mean number of falls per person per week was 0.034 in the Cal+D-group and 0.076 in the Cal-group. After adjustment, Cal+D-treatment accounted for a 49% reduction of falls (95% CI, 14-71%; p < 0.01) based on the fall categories stated above. Among fallers of the treatment period, the crude average number of excessive falls was significantly higher in the Cal-group (p = 0.045). Musculoskeletal function improved significantly in the Cal+D-group (p = 0.0094). A single intervention with vitamin D plus calcium over a 3-month period reduced the risk of falling by 49% compared with calcium alone. Over this short-term intervention, recurrent fallers seem to benefit most by the treatment. The impact of vitamin D on falls might be explained by the observed improvement in musculoskeletal function.
According to information gathered by the Centers for Disease Control, falling is the leading cause of death in women and the fourth leading cause of death in men between the ages of 65 and 85. It is the leading cause of death for both men and women over the age of 85. The percentage of falls among community-dwelling elderly persons increases from 25 percent at age 70 to 35 percent after age 75. A comprehensive, multidisciplinary treatment plan must be established to address the manifold problem of falls in our elderly patient population. A comprehensive evaluation to include medical history, medications, functional assessment, and home safety must be performed in order to reduce the patient's risk of falls, thereby maximizing safe, functional mobility.
Inadequate supervision as a cause of injury deaths among young children in Alaska and Louisiana.
- Landen MG, Bauer U, Kohn M. Pediatrics 2003; 111(2): 328-331.
Correspondence: Michael G. Landen, New Mexico Department of Health, Santa Fe, New Mexico 87502, USA; (email: michaell@doh.state.nm.us).
OBJECTIVE: Inadequate supervision of children has contributed to injuries. However, the association of inadequate supervision with injury events in children has not been quantified. The purpose of this study was to describe and quantify the role of inadequate supervision of children in injury deaths.
METHODS: Injury deaths among children aged 0 to 6 years in Alaska during 1993 to 1995 and Louisiana during 1994 were classified using 10 child safety standards to assess the role of parent/caregiver supervision in the circumstances of injury death.
FINDINGS: The leading categories of injury death for both states combined were motor vehicle injury and fire-related injury. Of the classifiable injury deaths in both states (157 [77%] of 203 deaths), the most commonly violated safety standard was "children should be supervised by a responsible care provider" (64 deaths [41%]). Of these deaths, the caregiver was absent in 38%, and the caregiver increased the danger to the child in 17%. Male injury deaths more typically involved a supervision standard violation. Drowning and pedestrian deaths typically involved a supervision standard violation, whereas asphyxiation, homicide, and occupant motor vehicle injury deaths did not.
DISCUSSION: Alaska and Louisiana child injury deaths were mostly attributed to preventable violations of 10 child safety standards, most commonly the supervision standard. The methods in this report were useful in identifying target populations and causes of death, which can be used to plan and implement interventions to improve supervision of children.
A model of the attitudinal outcomes of the occurrence and severity of occupational injuries was developed and tested. The model postulates that workplace accidents result in a perceived lack of influence and a distrust of management, with the former also affecting the distrust of management. Both are hypothesized to predict job dissatisfaction. Exit (turnover intentions) and voice (perceptions of union instrumentality) are hypothesized as outcomes of job dissatisfaction. A sample of 9,908 employees was tested with the 1995 Australian Workplace Industrial Relations Survey database. Structural equation modeling provided strong support for the model with respect to accident occurrence, and the model was replicated across 8 different occupational groups. There was less support for the model with respect to accident severity.
BACKGROUND: Pedestrians and cyclists account for nearly one in three of all road users killed and seriously injured in road traffic crashes. Late detection of other road users is one of the basic driver failures responsible for collisions. Aids to improve pedestrians and cyclist visibility have been used to avert potential collisions. However, the impact of these strategies on drivers' responses, and on pedestrian and cyclist safety is not known.
OBJECTIVES: 1. To quantify the effect of visibility aids vs no visibility aids, and of different visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries.
2. To quantify the effect of visibility aids vs no visibility aids, and of different visibility aids on drivers' detection and recognition responses.
SEARCH STRATEGY: We searched the Cochrane Controlled Trials Register, the Injuries Group Specialised Register, MEDLINE, TRANSPORT, TRANSDOC from ECMT (European Conference of Ministers of Transport), IRRD (International Road Research Documentation), TRIS (Transportation Research Information Services), NRR (National Research Register), PsycInfo and PsycLit.
SELECTION CRITERIA: 1. Randomized controlled trials and controlled before/after trials of the effect of visibility aids on the occurrence of pedestrian and cyclist-motor collisions and injuries. 2. Randomized controlled trials of the effect of visibility aids on drivers' detection and recognition responses. This included trials where the order of presentation of visibility aids was randomized or balanced using a Latin square design.
DATA COLLECTION AND ANALYSIS: Two reviewers independently screened records, extracted data and assessed trial quality.
FINDINGS: We found no trials assessing the effect of visibility aids on the occurrence of pedestrian and cyclist-motor vehicle collisions and injuries. We identified 37 trials assessing the effect of visibility aids on drivers' responses. Fluorescent materials in yellow, red and orange colors improve detection and recognition in the daytime. For night-time visibility, lamps, flashing lights and retroreflective materials in red and yellow colors increase detection and recognition. Retroreflective materials arranged in a 'biomotion' configuration also enhance recognition. Substantial heterogeneity between and within the trials limited the possibility for meta-analysis. Summary statistics and descriptive summaries of the outcomes were presented for individual trials when appropriate.
REVIEWERS' CONCLUSIONS: Visibility aids have the potential to increase visibility and enable drivers to detect pedestrians and cyclists earlier. Public acceptability of these strategies would merit further development. However, the effect of visibility aids on pedestrian and cyclist safety remains unknown. Studies which collect data on simple, meaningful outcomes are required.
The selective tuning model [Artif. Intell. 78 (1995) 507] is a neurobiologically plausible neural network model of visual attention. One of its key predictions is that to simultaneously solve the problems of convergence of neural input and selection of attended items, the portions of the visual neural network that process an attended stimulus must be surrounded by inhibition. To test this hypothesis, we mapped the attentional field around an attended location in a matching task where the subject's attention was directed to a cued target while the distance of a probe item to the target was varied systematically. The main result was that accuracy increased with inter-target separation. The observed pattern of variation of accuracy with distance provided strong evidence in favor of the critical prediction of the model that attention is actively inhibited in the immediate vicinity of an attended location.
Human temporal impulse response speeds up with increased stimulus contrast.
- Stromeyer CF, Martini P. Vision Res 2003; 43(3): 285-298.
Correspondence: Charles F. Stromeyer, Division of Engineering and Applied Sciences, Harvard University, 02138, Cambridge, MA, USA; (email: charles@stokes.harvard.edu).
It is well known that raising mean luminance speeds-up the visual response to temporal change. At higher mean luminance, the temporal impulse response function (IRF) becomes more transient or biphasic. An analogous effect is observed physiologically when stimulus contrast is increased, at constant mean luminance. As stimulus contrast is raised, the temporal response to flicker advances in phase and becomes more transient (bandpass). The MC (magnocellular) retinal ganglion cells manifest this temporal contrast gain control, but the PC (parvocellular) cells do not. We show psychophysically that the temporal response in humans speeds-up in an analogous manner as stimulus contrast is raised. Low spatial-frequency gratings, of suprathreshold contrast, were presented as pairs of pulses, separated by brief delays. Responses became more transient with increasing contrast in both our motion task (direction discrimination) and in our flicker task ('agitation' discrimination), mimicking the temporal contrast gain control seen in the physiological studies. Results could be modeled with a nonlinearity, in which the IRF shortens with increasing contrast.
Temporal asymmetry in motion masking: a shortening of the temporal impulse response function.
Correspondence: Charles F. Stromeyer, Division of Engineering and Applied Sciences, Harvard University, 02138, Cambridge, MA, USA; (email: charles@stokes.harvard.edu).
A striking temporal asymmetry in motion masking has been reported. Motion was produced with a two-frame sequence of gratings presented in spatial quadrature phase; the second grating (100 ms) was presented immediately after the first grating (100 ms), with no temporal overlap. The contrast threshold for detecting the direction of motion of the stimulus pair was facilitated when the first grating was of low-contrast and the second grating was of high-contrast, but strong masking occurred when the order was reversed, so the high-contrast grating came first. We replicated this result, but showed that the masking mostly disappeared when the two gratings temporally overlapped only slightly. The high sensitivity to the precise temporal pattern of the stimulus can be explained by a small temporal 'shortening' of the temporal impulse response function (IRF) as stimulus contrast is increased. The IRF is biphasic with a negative inhibitory lobe. When the first grating has high-contrast, its flash response (owing to the shortening of the IRF) may be in a fairly strong negative phase by the time that the positive response to the second, lower-contrast grating has reached appreciable strength--this reduces the magnitude of the motion signal generated by the two flashes and can account for the masking. A shortening of the IRF with increased contrast (a nonlinearity) is supported by psychophysical studies in humans and by recordings of magnocellular retinal ganglion cells in macaque, and the present results bolster this concept.
Upper and lower limits of vulnerability to sudden arrhythmic death with chest-wall impact (commotio cordis).
- Link MS, Maron BJ, Wang PJ, VanderBrink BA, Zhu W, Estes NA. J Am Coll Cardiol 2003; 41(1): 99-104.
Correspondence: Mark S. Link, Center for the Cardiovascular Evaluation of Athletes and the Cardiac Arrhythmia Service, New England Medical Center, Tufts University School of Medicine, Boston, Massachusetts, USA; (email: MLink@Lifespan.org).
In an animal model of commotio cordis, sudden death with chest-wall impact, we sought to systematically evaluate the importance of impact velocity in the generation of ventricular fibrillation (VF) with baseball chest-wall impact.Sudden cardiac death can occur with chest-wall blows in recreational and competitive sports (commotio cordis). Analyses of clinical events suggest that the energy of impact is often not of unusual force, although this has been difficult to quantify.Juvenile swine (8 to 25 kg) were anesthetized, placed prone in a sling to receive chest-wall strikes during the vulnerable time window during repolarization for initiation of VF with a baseball propelled at 20 to 70 mph.Impacts at 20 mph did not induce VF; incidence of VF increased incrementally from 7% with 25 mph impacts, to 68% with chest impact at 40 mph, and then diminished at >/=50 mph (p < 0.0001). Peak left ventricular pressure generated by the chest blow was related to the incidence of VF in a similar Gaussian relationship (p < 0.0001).The energy of impact is an important variable in the generation of VF with chest-wall impacts. Impacts at 40 mph were more likely to produce VF than impacts with greater or lesser velocities, suggesting that the predilection for commotio cordis is related in a complex manner to the precise velocity of chest-wall impact.
Injuries among world-class professional beach volleyball players: the federation internationale de volleyball beach volleyball injury study.
Correspondence: Roald Bahr, Oslo Sports Trauma Research Center, University of Sport and Physical Education, PO Box 4014 Ullevaal Stadion, 0406 Oslo, NORWAY; (email: roald@nih.no).
BACKGROUND: Very little is known about the injury characteristics of beach volleyball. PURPOSE: To describe the incidence and pattern of injuries among professional male and female beach volleyball players.
STUDY DESIGN: Cohort study-retrospective injury recall and prospective registration.
METHODS: Injuries occurring over a 7.5-week interval of the summer season were retrospectively registered by interviewing 178 of the 188 participating players (95%) in the 2001 Beach Volleyball World Championships. Injuries were also cataloged prospectively during five of the tournaments held during this interval.
FINDINGS: Fifty-four acute injuries was recorded, of which 23 (43%) resulted in 1 or more days of missed practice or competition. The incidence of acute time-loss injuries was estimated to be 3.1 per 1000 competition hours and 0.8 per 1000 training hours. Knee (30%), ankle (17%), and finger injuries (17%) accounted for more than half of all acute time-loss injuries. In addition, 67 players reported 79 overuse injuries for which they received medical attention during the study period. The three most common overuse conditions were low back pain (19%), knee pain (12%), and shoulder problems (10%). Similar results were observed in the prospective portion of the study.
DISCUSSION: The rate of acute time-loss injuries in beach volleyball is considerably lower than that in most other team sports, but overuse injuries affecting the low back, knees, and shoulder represent a significant source of disability and impaired performance for professional beach volleyball players.
Using US data for 1986-1998 fatal crashes, we employed matched-pair analysis methods to estimate that the relative risk of death among belted compared with unbelted occupants was 0.39 (95% confidence interval (CI) 0.37-0.41). This differs from relative risk estimates of about 0.55 in studies that used crash data collected prior to 1986. Using 1975-1998 data, we examined and rejected three theories that might explain the difference between our estimate and older estimates: (1) differences in the analysis methods; (2) changes related to car model year; (3) changes in crash characteristics over time. A fourth theory, that the introduction of seat belt laws would induce some survivors to claim belt use when they were not restrained, could explain part of the difference in our estimate and older estimates; but even in states without seat belt laws, from 1986 through 1998, the relative risk estimate was 0.45 (95% CI 0.39-0.52). All of the difference between our estimate and older estimates could be explained by some misclassification of seat belt use. Relative risk estimates would move away from 1, toward their true value, if misclassification of both the belted and unbelted decreased over time, or if the degree of misclassification remained constant, as the prevalence of belt use increased. We conclude that estimates of seat belt effects based upon data prior to 1986 may be biased toward 1 by misclassification.
South Asian ethnicity and risk of childhood accidents: an ecological study at enumeration district level in Leicester.
- Tobin MD, Milligan J, Shukla R, Crump B, Burton PR. J Public Health Med 2002; 24(4): 313-318.
Correspondence: M. Tobin, Department of Epidemiology and Public Health, University of Leicester, 22-28 Princess Road West, Leicester LE1 6TP, UNITED KINGDOM; (email: mt47@leicester.ac.uk).
BACKGROUND: Surveys of 'self-reported' accidents suggest that South Asian children in the United Kingdom may have lower rates of childhood accidents, but little is known about their susceptibility to severe accidents compared with white children.
METHODS: We conducted an ecological study at the level of Census enumeration districts to compare hospital utilization as a result of childhood accidents according to White, South Asian, Black or 'Other' ethnic grouping and Townsend deprivation score in Leicester. Enumeration districts were assigned to postcoded data for fracture clinic attendances between 1997 and 1999 and in-patient admissions and in-patient stays of longer than 3 days as a result of accidents between 1995 and 1999 in children under 16 years.
FINDINGS: South Asian children were less likely than white children to attend fracture clinic, be admitted or to have a prolonged stay as a result of an accident. Having adjusted for deprivation score, for a 10 per cent increase in the proportion of South Asian residents in an enumeration district, the odds ratio for an in-patient stay of longer than 3 days was 0.95 (95 per cent confidence interval (CI) 0.91-1.00, p = 0.035), for an accident admission the odds ratio was 0.93 (95 per cent CI 0.92-0.94, p < 0.001) and for attendance at fracture clinic the odds ratio was 0.94 (95 per cent CI 0.92-0.96, p < 0.001). For a district with 70 per cent of its children from South Asian groups (as observed in one-fifth of Leicester's enumeration districts), this represents a 40 per cent lower rate of accident admissions.
DISCUSSION: South Asian children were significantly less likely to utilize hospital services as a result of an accident. This may well be explained by differential exposure to accident hazards across ethnic groups, rather than by different thresholds of hospital attendance, given that hospital utilization was also lower for serious accidents in South Asian children.
Childhood behavior disorders and injuries among children and youth: a population-based study.
- Brehaut JC, Miller A, Raina P, McGrail KM. Pediatrics 2003; 111(2): 262-269.
Correspondence: J. Brehaut, Ottawa Health Research Institute, Ottawa Hospital, Ottawa, Ontario, CANADA; (email: jbrehaut@ohri.ca).
BACKGROUND: While an association between pediatric behavioral disorders and injuries is generally acknowledged, no studies have measured the risk for injury in the context of a large, population-based study that is free of cohort biases.
OBJECTIVES: To examine the association between childhood behavior disorders ([CBDs] as indicated by prescription for methylphenidate [MPH]) and a variety of injury outcomes, and to evaluate the risk for injury among these children after controlling for known demographic correlates.
METHODS: Population-based database analysis of all children in British Columbia (BC) under the age of 19 as of December 31, 1996; comparison of those who had been prescribed MPH and therefore placed in the CBD group (n = 16, 806) and those who were not (n = 1,010,067). Demographic information collected was as follows: age, sex, measures of socioeconomic status, and region of residence.
OUTCOME MEASURES: Common types of childhood injury in BC: International Classification of Diseases, Ninth Revision N-codes (fractures, open wounds, poisoning/toxic effect, concussion, intracranial, burns) and E-codes (falls, postoperative complications, motor vehicle accidents, struck by object, adverse effects of drugs, suffocation, drowning).
DATA SOURCE: BC Linked Health Data Set and the BC Triplicate Prescription Program.
FINDINGS: After controlling for known demographic correlates, odds for injury was greater among those treated with MPH and presumed to have a behavioral disorder, when injury was characterized either by type (1.67; 99% confidence interval: 1.54-1.81) or cause (1.52; 99% confidence interval: 1.40-1.66) of injury. This increased risk extended to unexpected categories of injury such as postoperative complications and adverse effects of drugs.
DISCUSSION: Children with CBDs have >1.5 times the odds of sustaining injuries of a variety of types from a variety of causes, even after controlling for known demographic correlates, than those without behavioral disorders. The risks for these children extend beyond those that might be directly associated with impulsivity and overactivity. Injury prevention strategies aimed at this group of children and youth would be beneficial. Policy-makers should account for increased risk of a wide variety of injuries in this group of children and youth.
A prospective study of absence for illness and injury in child care children.
Correspondence: L.M. Slack-Smith, School of Population Health, University of Western Australia, Nedlands,AUSTRALIA; (email: lindas@cyllene.uwa.edu.au).
OBJECTIVES: This population-based study investigated prospectively collected absence episodes to describe patterns and rates of absences for illness and other reasons in two types of formal childcare.
METHODS: Center day care and family day care homes were selected at random from licensing lists. All centers (n = 11) and 95% of family day care caregivers (n = 130) agreed to participate. The results are based on absence information from carers and on questionnaires to the parents of participating children (n = 846).
FINDINGS: The major reason for absence was respiratory illness with 48% of all children absent at least once during the year with some form of respiratory illness. Although the absence rate for children in center care was higher than that in family care (3.34 episodes per 52 child-weeks compared with 2.41), the difference was not statistically significant.
DISCUSSION: Investigating patterns of absences from child care allows a better understanding of needs in child care. The major reason for absence for illness was respiratory illness.
Paraoxonase and susceptibility to organophosphorus poisoning in farmers dipping sheep.
- Mackness B, Durrington P, Povey A, Thomson S, Dippnall M, Mackness M, Smith T, Cherry N. Pharmacogenetics 2003; 13(2): 81-88.
Correspondence: Bharti Mackness, University Department of Medicine, Manchester Royal Infirmary, Oxford Road, Manchester M13 9WL, UK; (email: bmack@central.cmht.nwest.nhs.uk).
OBJECTIVES: Human serum paraoxonase (PON1) hydrolyses organophosphate pesticides (OPs) entering the blood circulation and tissue fluid thus limiting toxicity. The PON1 coding region has two polymorphisms involving the amino acids at position 55 (Lt<--M) and 192 (Qt<--R), giving rise to isoenzymes which differ in their catalytic rate for the hydrolysis of OPs. We therefore hypothesized that individuals inheriting low activity isoforms of PON1 would be more liable to report symptoms of OP toxicity.
METHODS: We have therefore investigated the relationship between PON1 genetic polymorphisms and PON1 activity in farmers reporting chronic ill health which they attributed to OP exposure whilst sheep dipping (cases) and farmers who carried out similar activities, but remained well (controls). Diazoxon, paraoxon and phenylacetate were used as substrates for PON1. Diazoxon is the active metabolite of diazinon, the sheep dip most commonly used in the UK.
FINDINGS: Cases were found to be more likely to have the R192 allele ( 0.01) and to have the L55 allele ( 0.05) than the controls. This combination of R and L genotypes was associated with lower PON1 activity towards diazoxon in both cases and controls. Farmers in the lowest quintile for the rate of serum diazoxon hydrolysis had a greater risk of being a case i.e. of reporting ill health (odds ratio 2.47 (95% CI 1.35-2.82)), than the other four quintiles of diazoxon hydrolysis. The rate of serum hydrolysis of paraoxon was greatest in cases and controls with the R/L haplotype (both 0.001).
DISCUSSION: The farmers reporting chronic ill health due to organophosphate exposure have a higher proportion of the PON1-192R polymorphism associated with lower rates of diazoxon hydrolysis and lower rates of diazoxon hydrolysis than the controls and that their ill health may be explained by a lower ability to detoxify diazoxon.
In addressing an issue rarely explored in research literature, the prevalence and severity of the risk of being bullied at school was measured in 100 children with specific language impairment (SLI). Participants attended a range of different educational placement types and these were compared for bullying risk. Furthermore, the risk encountered by children with SLI was compared with that of normally developing age-matched peers. Each participant completed a questionnaire and it was found that 36% of participants with SLI considered themselves at risk of being bullied in school compared with only 12% of the normally developing cohort. No statistically significant difference was found between the risk experienced by participants with SLI attending mainstream education and that by participants attending special education placements. Possible explanations for the results are offered and the relevance of the findings in the context of optimizing the educational experience of children with SLI is highlighted.
Correspondence: Pedro.R. Portes, Department of Educational and Counseling Psychology, University of Louisville, Kentucky 40292, USA; (email: prport01@athena.louisville.edu
).
Adolescent suicide remains an international tragedy, yet a common denominator continues to elude researchers. Some adolescents internalize rejection and respond with suicide; other troubled adolescents engage in homicide before ending their own lives. One factor underlying suicide concerns the failure to construct a healthy identity. Using Erikson's theories on identity development as a framework, this paper examines the motives for and contexts of suicide among preadolescents, adolescents, and young adults, identifies specific school-age populations that are vulnerable to suicide, and discusses implications.
An exploratory investigation of suicide and occupational exposure.
This exploratory study evaluated the association between suicide and occupational exposure to electromagnetic fields, pesticides, and hydrocarbon solvents. The study population comprised 11,707 suicide deaths and 132,771 eligible controls identified from United States death certificate files for the years 1991 and 1992. Exposure assignment was based on job title reported on the death certificates. Exposure to electromagnetic fields and pesticides was weakly associated with suicide risk, while little evidence for an increased risk was seen for hydrocarbon solvents. The association for electromagnetic field exposure was highest for suicide between the ages 20 and 35 (odds ratio; OR = 1.5), while the highest risk of suicide for pesticide exposure was seen between the ages of 35 and 49 years (OR = 1.5). Further investigation to replicate these findings seems warranted, using higher quality occupational data.
Self-reported suicidal and help seeking behaviors in the general population in Latvia.
BACKGROUND: The aims of this study were to assess the prevalence of suicidal behaviors in the general population in Latvia, to identify risk groups for suicidal behavior, to examine a possible continuous sequence of suicidal behaviors with underlying gradient of severity, to assess patterns of help seeking behaviors and preferences of different types of services for suicidal persons.
METHOD: A postal survey of a stratified proportional sample of the general population aged 18 and older was carried out.
FINDINGS: The last year and lifetime prevalence of any type of suicidal behaviors was 52.6 and 60.2 %. The incidence of self-reported suicide attempts was 1.8 and 5.1 %, respectively. Females reported significantly less serious types (includes ideation, plans and/or attempts) of suicidal behaviors (OR 0.04, p = 0.001) during last year than males. Younger age, lower level of education, urban residency and Latvian ethnicity were identified as risk factors for serious types of suicidal behaviors in both genders. Non-cohabitation status (OR 5.3, p = 0.01) and lower level of education for males, but higher levels of education for females were identified as significant risk factors for mild types (solely life-weariness and/or death wishes) of suicidal behaviors. The results indicated no simple cumulative relationship between the suicidal behaviors. Age, gender, previous help seeking experience and severity of self-reported suicidal behaviors influenced help seeking behaviors. The overall acceptance of professional services was high, but people who reported suicidal behaviors ranked them lower.
DISCUSSION: A postal survey can provide a reasonable coverage of suicidal behaviors and description of risk groups in the general population. Higher prevalence of suicidal behaviors among males might indicate that nowadays males are under certain stress in Latvia.
Area-wide traffic calming for preventing traffic related injuries (Cochrane Review).
- Bunn F, Collier T, Frost C, Ker K, Roberts I, Wentz R. Cochrane Database Syst Rev 2003; (1): CD003110.
Correspondence: F. Bunn, Centre for Research in Primary and Community Care (CRIPACC), University of Hertfordshire, College Lane, Hatfield, Hertfordshire AL10 9PN, UK; (email: f.bunn@herts.ac.uk).
This is an abstract of a regularly updated, systematic review prepared and maintained by the Cochrane Collaboration.
BACKGROUND: It is estimated that by 2020 road traffic crashes will have moved from ninth to third in the world disease burden ranking, as measured in disability adjusted life years, and second in developing countries. The identification of effective strategies for the prevention of traffic related injuries is of global health importance. Area-wide traffic calming schemes that discourage through traffic on residential roads is one such strategy.
OBJECTIVES: To evaluate the effectiveness of area-wide traffic calming in preventing traffic related crashes, injuries, and deaths.
SEARCH STRATEGY: We searched the following electronic databases: Cochrane Injuries Group's Specialised Register, Cochrane Controlled Trials Register, MEDLINE, EMBASE and TRANSPORT (NTIS, TRIS, TRANSDOC). We searched the web sites of road safety organizations, hand searched conference proceedings, checked reference lists of relevant papers and contacted experts in the area. The search was not restricted by language or publication status.
SELECTION CRITERIA: Randomized controlled trials, and controlled before-after studies of area-wide traffic calming schemes.
DATA COLLECTION AND ANALYSIS: Two reviewers independently extracted data on type of study, characteristics of intervention and control areas, and length of data collection periods. Before and after data were collected on the total number of road traffic crashes, all road user deaths and injuries, pedestrian-motor vehicle collisions and road user deaths. The statistical package STATA was used to calculate rate ratios for each study, which were then pooled to give an overall estimate using a random effects model.
FINDINGS: We found no randomized controlled trials, but 16 controlled before-after trials met our inclusion criteria. Seven studies were done in Germany, six in the UK, two in Australia and one in the Netherlands. There were no studies in low or middle income countries. Eight trials reported the number of road traffic crashes resulting in deaths. The pooled rate ratio was 0.63 (0.14, 2.59 95% CI). Sixteen studies reported the number of road traffic crashes resulting in injuries (fatal and non fatal). The pooled rate ratio was 0.89 (0.80, 1.00 95% CI). Nine studies reported the total number of road traffic crashes. The pooled rate ratio was 0.95 (0.81, 1.11 95% CI). Thirteen trials reported the number of pedestrian-motor vehicle collisions. The pooled rate ratio was 1.00 (0.84, 1.18). There was significant heterogeneity for the total number of crashes and deaths and injuries.
REVIEWERS' CONCLUSIONS: The results from this review suggest that area-wide traffic calming in towns and cities may be a promising intervention for reducing the number of road traffic injuries, and deaths. However, further rigorous evaluations of this intervention are needed.
Risk of Injury to Restrained Children from Passenger Air Bags
- Durbin DR, Kallan M, Elliott M, Cornejo RA, Arbogast KB, Winston FK. Traf Inj Prev 2003; 4(1): 58-63.
Correspondence: Kristy B. Arbogast, Department of Pediatrics, The Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; (email: arbogast@email.chop.edu)
The objectives of this study were to estimate the prevalence of children's exposure to passenger air bag (PAB) deployments and to determine the relative risk of both minor and more serious nonfatal injuries to restrained children exposed to PABs in frontal impact collisions. Data were collected from 1 December 1998 to 30 November 2001 from a large-scale, child-specific crash surveillance system based on insurance claims, a telephone survey, and on-site crash investigations. Vehicles qualifying for inclusion were State Farm-insured, model year 1990 or newer, and involved in a crash with at least one child occupant h15 years of age. Qualifying crashes were limited to those that occurred in 15 states and the District of Columbia. A stratified cluster sample was designed in order to select vehicles (the unit of sampling) for the conduction of a telephone survey with the driver. For cases in which child occupants were seriously injured or killed, in-depth crash investigations were performed. The prevalence of exposure to PABs was calculated as the number of children occupying the right front seat in a PAB deployment crash among all children occupying the right front seat in vehicles equipped with PABs. Complete interview data were obtained on 9,779 vehicles involving 15,341 children. Among PAB-exposed children, 175 (14%) suffered serious injuries versus 41 (7.5%) of those in the comparison group (OR 2.0; 95% CI, 1.1-3.7). The overall risk of any injury (both minor and serious) was 86% among children exposed to PABs, compared to 55% among the comparison group (OR 5.3; 95% CI, 2.1-13.4). Exposure to PABs increased the risk of both minor injuries, including facial and chest abrasions, and more serious injuries, particularly upper extremity fractures.
Influence of driver sex on road accidents is assessed in this article. Accident records for 3 years and for three different income regions were analyzed. Annual distance traveled, social and economic participation, and effect of public vehicle accidents were considered. Effects of environmental factors and driver age were also included. Driver faults analysis identified possible reasons for accident differences. Analysis of accident severity was used to assess degree of harm. Statistical analysis at the 5% significance level was used to evaluate all differences. The results show that male accident rates are significantly higher. This trend is consistent through all the analyses. Accident differences are significant only in normal driving conditions. Drivers over age 50 had the lowest accident rates. Accident rate differences were caused by lack of attention and impatience among male drivers. Appropriate means of communication should alert concerned populations to these findings.
Age and sex differences in the risk of causing vehicle collisions in Spain, 1990 to 1999.
Correspondence: Pablo Lardelli Claret, Department of Preventive Medicine and Public Health, Facultad de Farmacia, University of Granada, Campus de Cartuja s/n, 18071, Granada, SPAIN; (email: lardelli@ugr.es).
This retrospective, paired case-control study was designed to estimate crude and adjusted effects of age and sex on the risk of causing collisions between vehicles with four or more wheels in Spain during the period from 1990 to 1999. We selected all 220,284 collisions registered from 1990 to 1999 in the Spanish Direccion General de Trafico (DGT) traffic crash database in which only one driver committed any infraction. Information was collected about age, sex and several confounding factors for both the responsible and paired-by-collision nonresponsible drivers. Crude and adjusted odds ratios (aORs) were calculated for each age and sex category. For men, the lowest risk was seen for drivers aged 25-49 years. Below the age of 35 years the crude odds ratio (cOR) was highest in the 18-24-year-old group (1.61; CI: 1.57-1.65). The risk increased significantly and exponentially after the age of 50 years, to a maximum odds ratio of 3.71 (3.43-4.00) for drivers aged >74 years. In women, the lowest risk values were found for the 25-44-year-old age group. In older women the risk increased significantly with age to a maximum odds ratio of 3.02 (2.31-3.97) in the oldest age group. aOR estimates tended to be lower than crude estimates for drivers younger than 40 years of age, but the opposite was seen for drivers 40 years old and older. Regarding sex differences, among younger drivers crude and aORs for men were higher than for women. Our results suggest that the risk of causing a collision between vehicles with four or more wheels is directly dependent on the driver's age.
Organization of truck-driver training for the transportation of dangerous goods in Europe and North America.
Correspondence: Rolanda Kuncyt�, Department of Social and Preventive Medicine, Laboratory on Transportation Safety of the Centre of Research on Transportation (CRT), Universite de Montreal, Pavillon Andre-Aisenstadt, C.P. 6128 Succursale Centre-Ville, Que., H3C 3J7, Montreal, CANADA; (email: rolanda@crt.umontreal.ca).
In Canada, as in several other countries, truck drivers involved in the transportation of dangerous goods must be trained. However, given the many differences in vehicles, substances transported and driving conditions, international guidelines are very open-ended. This article outlines the domestic training requirements in Canada, the United States, The Netherlands and Sweden, and examines the manner in which the training is provided. In both Canada and the United States, the responsibility for assuring a driver is adequately trained rests with the employer. It is the employer who determines the duration and content of any training program. In addition, the assessment of a driver is also an employer responsibility. In practice, possibility in light of liability issues, many employers use commercial training firms. However, generally speaking there is no national or regional accreditation program for such commercial firms. In Europe, where training is conducted in response to the European Agreement concerning the International Carriage of Dangerous Goods by Road, training and testing must receive national accreditation, although the specific details of such accreditation are not spelled out. Sweden places its emphasis on careful accreditation of those providing training, while in The Netherlands more importance is placed on examinations to be used to test the results of the training. The intent of this article is to show that the same goal in four different countries has resulted in four different schemes, each of which appears to be accepted in the country of use. A comparison of safety achieved in the transportation of dangerous goods in each country is beyond the scope of this article. International evaluation studies would be necessary to draw scientifically-based conclusions on the effectiveness of truck-driver training systems for the safe transportation of dangerous goods.
Risk perception of traffic participants.
- de Blaeij AT, van Vuuren DJ. Accid Anal Prev 2003; 35(2): 167-175.
Correspondence: Daniel J. van Vuuren, Department of Spatial Economics, Vrije Universiteit, De Boelelaan 1105, 1081 HV, Amsterdam, THE NETHERLANDS; (email: dvuuren@tinbergen.nl).
This article analyzes the risk perception of traffic participants by making use of Prospect Theory. This methodology makes a conceptual distinction between the perception of risk and the perception of the outcome of an uncertain event. In the field of transport safety such a distinction is desirable, because risks are typically very low and thus sensitive to misperception by traffic participants. Taking into account such misperception will significantly improve estimates of the valuation of transport safety. The first empirical results show that the valuation of losses is well represented by a utility function that is concave in shape. Secondly, our preliminary results show that individuals base their choice mainly on the possible outcomes and not so much on probabilities whenever there are very small probabilities (say </=1/100) and "bad outcomes" involved.
The Influence of the Age and Sex Distributions of Drivers on the Reduction of Impaired Crashes: Ontario, 1974-1999
Legislative changes and public media campaigns to prevent impaired driving are often cited as explanations for the reduction in the rate of impaired crashes over the past 25 years in most of the industrialized world. Other factors may have contributed to these reductions, such as changes in the age and sex distribution of the driver population. The primary purpose of this article is to assess the extent to which the reduction in impaired crashes in Ontario, Canada, may be attributable to the changing age and sex distribution of drivers. In Ontario, the rate of impaired crashes declined by 78.1% from 1974 to 1999. During this time period, the average age of drivers increased from 39.4 years in 1974 to 43.2 in 1999. Similarly, from 1974 to 1999 the percentage of all drivers that were women increased from 39.6% to 46.8%. Since statistics show the likelihood of impaired crashes is lower for both older drivers and women, the reduction of impaired crashes is partially due to these demographic changes. Using indirect standardization, the aging population accounted for an 8.6% decline in the rate of impaired crashes. The changing sex distribution of drivers accounted for a 9.4% decline in impaired crashes. Other global factors may also help to explain the reduction of impaired crashes, such as general road safety improvements and reductions in per adult consumption of alcohol.
Modeling Accident Occurrence at Signalized Tee Intersections with Special Emphasis on Excess Zeros
In implementing effective remedial treatments at hazardous intersections, it often is necessary to identify the geometric and traffic factors that lead to accident occurrence. However, one particular problem frequently encountered in accident studies is how to distinguish virtually safe intersections with little likelihood of accident occurrence from those that have happened to have no accident due to the random process. To deal with this problem, the "excess" records of zero accident, the zero-inflated negative binomial was used to assign the probability to the accident outcome. Accident data at 104 signalized tee intersections in Singapore over a period of 9 years were employed for model development. The model indicates that uncontrolled left-turn slip road, permissive right-turn phase, existence of a horizontal curve, short sight distances, large number of signal phases, total approach volume, and left-turn volume may increase accident occurrence. On the other hand, right-turn channelization, acceleration section on the left-turn lane, median railings, and more than 5% approach gradient may reduce accident occurrence. Moreover, there is a trend of reducing accidents over the years.
This article examines the relationships among experiences of childhood abuse, psychiatric disorders, self-reported victimization, and violent behavior, with a focus on gender differences. Data were obtained from treatment entry and 5-year post-treatment interviews of 446 adolescent clients in therapeutic community (TC) drug treatment programs throughout the United States and Canada. Fifty-eight percent of the sample indicated that they engaged in serious violent behaviors (e.g., beatings, threatening or using weapons against other people, or violent crimes such as assaults, rapes, murders) in the 5 years following their separation from TC treatment. Multivariate logistic regression analyses revealed that victimization in the posttreatment period was the most significant factor associated with violent behavior, and pretreatment childhood abuse experiences and psychiatric disorders were not significantly related to the odds of violent behavior. There were significant gender differences in self-reported victimization and violent behavior. The findings suggest that violence in young adulthood for males is related to increasing involvement in violent lifestyles that include drug trafficking, while violence among females is associated with the social and psychological consequences of drug involvement and victimization. High rates of violent involvement and victimization among former adolescent clients suggests the utility of incorporating interventions such as safety-oriented strategies for females or interventions that address involvement in the drug use lifestyles (i.e., use and dealing) for both males and females into residential treatment to reduce the likelihood of future violence.
Fatal firearm injuries in Finland: a nationwide survey.
- Makitie I, Pihlajamaki H. Scand J Surg 2002;91(4): 328-31.
BACKGROUND: Treatment of life-threatening firearm injuries represents major challenges to the involved medical staff. The aim of the study was to assess numbers, natures and injury patterns of fatal incidents by firearms in Finland over a 10-year period.
METHODS: Retrospective analysis of all firearm-related deaths during the 10-year period from January 1990 to December 1999. Death certificates were obtained and reviewed with detailed analysis of non-suicidal deaths.
FINDINGS: Over the 10-year period 1990 to 1999, 452 individuals (equivalent to 1.8 cases per 100 000 person-years) died in Finland as a result of accidental or violent shooting. There were no significant changes in numbers of cases from year to year. The male-female ratio was 7:3. The mean age of the victims was 32 years. The shooting incident had been classified as an assault in 78% of cases. Its nature was unspecified in 13% of cases and clearly accidental in 9%. The predominant anatomical site of fatal injury following assault was the chest in 43%, the head in 42% and the abdomen in 8% of the cases. After accidental or unspecified nature shooting, the predominant site of injury was the head in 68%, followed by the chest in 16% and the abdomen in 10% of the cases. Most victims (86%) died at the scene of the shooting. Only 14% were alive at hospital admittance. Most hospitalized victims died within 24 hours of admission.
DISCUSSION: The annual incidence of fatal non-suicidal firearm injuries did not change significantly in Finland between 1990 and 1999. Victims of such injuries required only minimal hospital resources because in most cases they died at the scene of the shooting. The results of the study reported indicate that efforts to prevent fatal injuries from use of firearms or diminish their number should be focused mainly on prevention of firearm related assault.
