A novel application of a data mining technique to study intersections in the social determinants of mental health among young Canadians.

OBJECTIVES: Adolescent mental health is an emergent clinical and public health priority in Canada. Gender-based differences in mental health are well established. The objective of this study was to evaluate a new data mining technique to identify social locations of young Canadians where differences in mental health between adolescent males and females were most pronounced. METHODS: We examined reports from 21,221 young Canadians aged 11-15 years (10,349 males, 10,872 females) who had responded to a 2018 national health and health behaviours survey. Using recursive partitioning for subgroup identification (SIDES), we identified social locations that were associated with the strongest differences between males and females for three reported mental health outcomes: positive psychosomatic health, symptoms of depression, and having a diagnosed mental illness. RESULTS: The SIDES algorithm identified both established and new intersections of social factors that were associated with gender-based differences in mental health experiences, most favouring males. DISCUSSION: This analysis represents a novel proof-of-concept to demonstrate the utility of a subgroup identification algorithm to reveal important differences in mental health experiences between adolescent males and females. The algorithm detected new social locations (i.e., where gender intersected with other characteristics) associated with poor mental health outcomes. These findings set the stage for further intersectional research, involving both quantitative and qualitative analyses, to explore how axes of discrimination may intersect to shape potential gender-based health inequalities that emerge during childhood.

In vivo skin absorption and distribution of the nerve agent VX (O-ethyl-S-[2(diisopropylamino)ethyl] methylphosphonothioate) in the domestic white pig.

The purpose of this study was to characterize the skin absorption and distribution of VX (O-ethyl-S-[2 (diisopropylamino)ethyl] methylphosphonothioate) in the domestic pig in order to evaluate the animal as a potential model for assessing pretreatments against toxic anti-cholinesterase compounds. A liquid droplet (equivalent to a 2 x LD50 dose) of radiolabelled VX was applied to the inner ear-skin of each anaesthetized animal. Blood and tissue samples (liver, lung, kidney, heart and skin exposure sites) were obtained post-mortem. The amount of radioactivity in each sample was measured by liquid scintillation counting, from which the skin absorption rate and dose distribution of VX were calculated. A substantial proportion (22 +/- 3%) of the applied dose remained within the skin at the site of application. It is conceivable that strategies to minimize or remove this reservoir may be of benefit in the early treatment of VX-exposed casualties. Image analysis of autoradiographs of exposed skin sites indicated that each milligram of radioactive VX covered an area of 1.2 +/- 0.5 cm2. The average skin absorption rate of 14C-VX was 661 +/- 126 microg/cm2 per hour. Comparison of these data with previous studies suggests that human skin is less permeable to VX than pig skin, but VX spreads over a greater surface area when applied to human skin. Thus, paradoxically, while pig-ear skin is more permeable than human skin, the difference in skin surface spreading may lead to the absorption of an equivalent systemic dose.

Hematocrit as a predictor of significant injury after penetrating trauma.

A study was undertaken to determine if there are differences in hematocrit (HCT) during the initial evaluation of patients with and without significant visceral intrathoracic or intraabdominal injury after penetrating trauma and, if so, the predictive value of this parameter. Sixty consecutive adults with potentially significant penetrating trauma who presented to an urban municipal trauma center during a 10-week period were studied. Diagnostic variables were recorded for all patients at risk for significant injury, defined as intrathoracic or intraabdominal injury requiring surgical intervention. Patients were ultimately grouped on the basis of operative findings or observation to discharge. Acquired variables included vital signs, initial HCT (HCT-0), HCT at 15 minutes (HCT-15), HCT at 30 minutes (HCT-30), and fluid administered. Twenty-one patients had significant injuries (INJ), and 39 did not (NO-INJ). INJ patients had lower HCT values than NO-INJ on presentation (35% +/- 6% and 41% +/- 5%, respectively). At presentation, a low HCT was predictive of significant injury, but a normal HCT did not preclude injury. The changes in HCT from arrival to 15 minutes, between INJ and NO-INJ patients, were similar (-1.5% +/- 3% and -0.6% +/- 3% respectively). Only when the decrease in HCT was > or =6.5% from presentation measurements was it predictive of injury. During the first 15 minutes a decrease in HCT of > or =6.5% had a positive predictive value and specificity of 1.0. The change in HCT between 15 and 30 minutes was less useful. There was a large difference between the amounts of fluid given to injured and uninjured patients, which may have been responsible for some of the differences in HCT between the two groups. These results show that HCT may have some diagnostic utility during the early management of penetrating trauma. Presentation with an HCT below normal, or an early decrease in HCT, is an indicator of potential injury. Although many patients with serious internal injuries do not manifest large decreases early after presentation, those who do have a high probability of internal injury. The lower the HCT, or the greater the decrease, the greater the probability that a significant injury exists.

Arterial oxygen saturation during upper gastrointestinal endoscopy in elderly patients: the role of endoscope diameter.

The effect of endoscope diameter upon arterial oxygen saturation was investigated in 52 elderly patients by comparing two groups of 26 patients examined with different diameter endoscopes (PQ20 and Q10). In the group of 26 patients examined with the larger endoscope (Q10), the baseline oxygen saturation values and those during intubation were significantly higher than in the group examined with the smaller instrument (PQ20). There was no significant difference in oxygen saturation between the two groups after sedation or during the procedure as a whole. Our findings suggest that the examination of elderly patients using a standard diameter endoscope does not pose any greater risk.