Stressful life-events exposure is associated with 17-year mortality, but it is health-related events that prove predictive

Objectives Despite the widely-held view that psychological stress is a major cause of poor health, few studies have examined the relationship between stressful life-events exposure and death. The present analyses examined the association between overall life-events stress load, health-related and health-unrelated stress, and subsequent all-cause mortality.\ud \ud Design This study employed a prospective longitudinal design incorporating time-varying covariates.\ud \ud Methods Participants were 968 Scottish men and women who were 56 years old. Stressful life-events experience for the preceding 2 years was assessed at baseline, 8–9 years and 12–13 years later. Mortality was tracked for the subsequent 17 years during which time 266 participants had died. Cox's regression models with time-varying covariates were applied. We adjusted for sex, occupational status, smoking, BMI, and systolic blood pressure.\ud \ud Results Overall life-events numbers and their impact scores at the time of exposure and the time of assessment were associated with 17-year mortality. Health-related event numbers and impact scores were strongly predictive of mortality. This was not the case for health-unrelated events.\ud \ud Conclusions The frequency of life-events and the stress load they imposed were associated with all-cause mortality. However, it was the experience and impact of health-related, not health-unrelated, events that proved predictive. This reinforces the need to disaggregate these two classes of exposures in studies of stress and health outcomes.\u

Stressful life events are associated with low secretion rates of immunoglobulin A in saliva in the middle aged and elderly

Whether chronic stress experience is related to down-regulation of secretory immunoglobulin A (S-IgA) was tested in two substantial cohorts, one middle-aged (N = 640) and one elderly (N = 582), comprising similar numbers of men (N = 556) and women (N = 666) and manual (N = 606) and non-manual (N = 602) workers. Participants indicated from a list of major stressful life events up to six they had experienced in the previous two years. They also rated how disruptive and stressful the events were, at the time and now, as well as their perceived seriousness; the products of these impact values and event frequency were adopted as measures of stress load. From unstimulated 2-minute saliva samples, saliva volume and S-IgA concentration were measured, and S-IgA secretion rate determined as their product. There was a negative association between the stress load measures and S-IgA secretion rate, still evident following adjustment for such variables as smoking and saliva volume. The associations also withstood adjustment for sex, cohort, and household occupational status. Although these associations are small in terms of the amount of variance explained, they nonetheless suggest that chronic stress experience either decreases IgA production by the local plasma cells or reduces the efficiency with which S-IgA is transported from the glandular interstitium into saliva. Given the importance of S-IgA in immune defence at mucosal surfaces and the frequency with which infections are initiated at these surfaces, S-IgA down-regulation could be a means by which chronic stress increases susceptibility to upper respiratory tract infection

Hyperdense artery sign, symptomatic infarct swelling and effect of alteplase in acute ischaemic stroke

Alteplase improves functional outcomes of patients with acute ischaemic stroke, but its effects on symptomatic infarct swelling, an adverse complication of stroke and the influence of CT hyperdense artery sign (HAS) are unclear. This substudy of the Third International Stroke Trial aimed to investigate the association between HAS and symptomatic infarct swelling and effect of intravenous alteplase on this association. We included stroke patients whose prerandomisation scan was non-contrast CT. Raters, masked to clinical information, assessed baseline (prerandomisation) and follow-up (24-48 hours postrandomisation) CT scans for HAS, defined as an intracranial artery appearing denser than contralateral arteries. Symptomatic infarct swelling was defined as clinically significant neurological deterioration ≤7 days after stroke with radiological evidence of midline shift, effacement of basal cisterns or uncal herniation. Among 2961 patients, HAS presence at baseline was associated with higher risk of symptomatic infarct swelling (OR 2.21; 95% CI 1.42 to 3.44). Alteplase increased the risk of swelling (OR 1.69; 95% CI 1.11 to 2.57), with no difference between patients with and those without baseline HAS (p=0.49). In patients with baseline HAS, alteplase reduced the proportion with HAS at follow-up (OR 0.67; 95% CI 0.50 to 0.91), where HAS disappearance was associated with reduced risk of swelling (OR 0.25, 95% CI 0.14 to 0.47). Although alteplase was associated with increased risk of symptomatic infarct swelling in patients with or without baseline HAS, it was also associated with accelerated clearance of HAS, which in return reduced swelling, providing further mechanistic insights to underpin the benefits of alteplase

Baseline Predictors of Visual Acuity and Retinal Thickness Outcomes in Patients with Retinal Vein Occlusion. SCORE Study Report 10

To investigate baseline factors significantly associated with visual acuity and central retinal thickness outcomes in patients with macular edema secondary to retinal vein occlusion in the Standard Care versus COrticosteroid for REtinal Vein Occlusion (SCORE) Study

High impact = high statistical standards? Not necessarily so.

What are the statistical practices of articles published in journals with a high impact factor? Are there differences compared with articles published in journals with a somewhat lower impact factor that have adopted editorial policies to reduce the impact of limitations of Null Hypothesis Significance Testing? To investigate these questions, the current study analyzed all articles related to psychological, neuropsychological and medical issues, published in 2011 in four journals with high impact factors: Science, Nature, The New England Journal of Medicine and The Lancet, and three journals with relatively lower impact factors: Neuropsychology, Journal of Experimental Psychology-Applied and the American Journal of Public Health. Results show that Null Hypothesis Significance Testing without any use of confidence intervals, effect size, prospective power and model estimation, is the prevalent statistical practice used in articles published in Nature, 89%, followed by articles published in Science, 42%. By contrast, in all other journals, both with high and lower impact factors, most articles report confidence intervals and/or effect size measures. We interpreted these differences as consequences of the editorial policies adopted by the journal editors, which are probably the most effective means to improve the statistical practices in journals with high or low impact factors