Time allocation between work and recreation and the associated injury risks among young people.

PROBLEM: The purpose of this study was to examine the relationship between overall risk of injury and time use patterns between work and active recreation among adolescents and young adults. METHODS: Using a representative sample of 9,795 Canadians aged 15-24 years, a multivariate logistic regression on the likelihood of any medically attended injury was conducted, including sociodemographic, individual, and time factors. RESULTS: Young people who engaged in a combination of high work and high activity hours were twice as likely to sustain a medically attended injury compared to those who worked low hours, but did not participate in any recreational activity. Those respondents who were not in school had a 43% increase in injury risk compared to full-time students. SUMMARY: Our findings suggest that injury risk was not a simple function of fatigue and cumulative exposure time. Our findings suggest the importance of considering time use and the associated injury risk tradeoffs. IMPACT ON INDUSTRY: Relevant to state and federal work safety policy makers, our findings suggest the importance of understanding where youth might otherwise spend their time if constraint were placed on their employment opportunities, and the associated injury risk tradeoffs must be taken into consideration.

Gender differences in socioeconomic inequality in mortality.

OBJECTIVES: There is uncertainty about whether position in a socioeconomic hierarchy confers different mortality risks on men and women. The objective of this study was to conduct a systematic review of gender differences in socioeconomic inequality in risk of death. METHODS: This research systematically reviewed observational cohort studies describing all cause or cause specific mortality for populations aged 25-64 in developed countries. For inclusion in the review, mortality had to be reported stratified by gender and by one or more measures of socioeconomic status. For all eligible studies, five absolute and six relative measures of the socioeconomic inequality in mortality were computed for male and female populations separately. RESULTS: A total of 136 published papers were reviewed for eligibility, with 58 studies deemed eligible for inclusion. Of these eligible studies, 20 papers published data that permitted the computation of both absolute and relative measures of inequality. Absolute measures of socioeconomic mortality inequality for men and women generally agreed, with about 90% of studies indicating that male mortality was more unequal than female mortality across socioeconomic groups. In contrast, the pattern of relative inequality results across the 20 studies suggested that male and female socioeconomic inequality in mortality was equivalent. CONCLUSIONS: Inferences about gender differences in socioeconomic inequality in mortality are sensitive to the choice of inequality measure. Wider understanding of this methodological issue would improve the clarity of the reporting and synthesis of evidence on the magnitude of health inequalities in populations.

Ex vivo evaluation of the biomechanical effect of varying monocortical screw numbers on a plate-rod canine femoral gap model.

OBJECTIVE: To compare the biomechanical behaviour of plate-rod constructs with varying numbers of monocortical screws applied to an ex vivo canine femoral-gap ostectomy model. SAMPLE POPULATION: Twenty Greyhound dog cadaveric femurs. METHODS: Bone mineral density (BMD) was assessed with dual x-ray absorptiometry. Bones were assigned to four groups. Bones had a 12-hole 3.5 mm locking compression plate with one bicortical non-locking cortical screw in the most proximal and distal plate holes and an intramedullary Steinmann pin applied across a 20 mm mid-diaphyseal ostectomy. Additionally, one to four monocortical non-locking cortical screws were then placed (Groups 1-4 respectively) in the proximal and distal fragments. Stiffness and axial collapse were determined before and after cyclic axial loading (6000 cycles at 20%, 40%, and 60% of mean bodyweight [total: 18000 cycles]). Constructs subsequently underwent an additional 45000 cycles at 60% of bodyweight (total: 63000 cycles). Loading to failure was then performed and ultimate load and mode of failure recorded. RESULTS: The BMD did not differ significantly between groups. Construct stiffness for group 1 was significantly less than group 4 (p = 0.008). Stiffness showed a linear increase with an increasing number of monocortical screws (p = 0.001). All constructs survived fatigue loading. Load-to-failure was not significantly different between groups. Mean load- to-failure of all groups was >1350N. CLINICAL RELEVANCE: Ex vivo canine large-breed femurs showed adequate stability biomechanically and gradually increasing stiffness with increasing monocortical screw numbers.