Changes in Physiology before, during, and after Yawning

The ultimate function of yawning continues to be debated. Here, we examine physiological measurements taken before, during, and after yawns in humans, in an attempt to identify key proximate mechanisms associated with this behavior. In two separate studies we measured changes in heart rate, lung volume, eye closure, skin conductance, ear pulse, respiratory sinus arrhythmia, and respiratory rate. Data were depicted from 75 s before and after yawns, and analyzed at baseline, during, and immediately following yawns. Increases in heart rate, lung volume, and eye muscle tension were observed during or immediately following yawning. Patterns of physiological changes during yawning were then compared to data from non-yawning deep inhalations. In one study, respiration period increased following the execution of a yawn. Much of the variance in physiology surrounding yawning was specific to the yawning event. This was not the case for deep inhalation. We consider our findings in light of various hypotheses about the function of yawning and conclude that they are most consistent with the brain cooling hypothesis

Quality of Cohort Studies Reporting Post the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) Statement

The quality of reporting of cohort studies published in the most prestigious scientific medical journals was investigated to indicate to what extent the items in the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) checklist are addressed. Six top scientific medical journals with high impact factor were selected including New England Journal of Medicine, Journal of the American Medical Association, Lancet, British Medical Journal, Archive of Internal Medicine, and Canadian Medical Association Journal. Ten cohort studies published in 2010 were selected randomly from each journal. The percentage of items in the STROBE checklist that were addressed in each study was investigated. The total percentage of items addressed by these studies was 69.3 (95% confidence interval: 59.6 to 79.0). We concluded that reporting of cohort studies published in the most prestigious scientific medical journals is not clear enough yet. The reporting of other types of observational studies such as case-control and cross-sectional studies particularly those being published in less prestigious journals expected to be much more imprecise

Accuracy of the WHO Haemoglobin Colour Scale for the diagnosis of anaemia in primary health care settings in low-income countries: a systematic review and meta-analysis.

BACKGROUND: Anaemia is a major cause of morbidity and mortality in low-income countries. Primary health-care workers in resource-poor settings usually diagnose anaemia clinically, but this is inaccurate. The WHO Haemoglobin Colour Scale (HCS) is a simple, cheap quantitative method to assess haemoglobin concentration outside of the laboratory. We systematically reviewed the literature to assess the accuracy of the HCS in primary care to diagnose anaemia, and compared this with clinical assessment. METHODS: We searched the electronic databases including MEDLINE, EMBASE, SCOPUS, Web of Science, Cochrane library, CINAHL plus, Popline, Reproductive Health Library, and Google Scholar and regional databases up to Nov 14, 2014, "haemoglobin colour scale" in alternative spellings published in any language. Two reviewers independently screened studies, extracted data, and assessed quality using the QUADAS-2 instrument. Statistical analyses were carried out in STATA using the bivariate model. FINDINGS: Of 141 records and abstracts screened, 14 studies were included. The pooled sensitivity of the HCS to diagnose anaemia was 80% (95% CI 68-88) compared with 52% for clinical assessment ([95% CI 36-67]; p=0·008). Specificity was similar between the HCS (80% [95% CI 59-91]) and clinical assessment (75% [56-88]; p=0·8250). For severe anaemia, diagnostic accuracy was again higher overall for the HCS (p<0·0001); sensitivity was 57% (36-76) for the HCS and 45% (95% CI 12-83) for clinical assessment, but specificity was 99·6% (95% CI 95-99·9) versus 92% (62-99). Combining clinical assessment and the HCS could result in higher sensitivity (anaemia: 91% [95% CI 81-96]); severe anaemia 83% (33-98), but at the expense of specificity (anaemia: 59% [35-79]; severe anaemia 90% [40-99]). Individual studies were highly heterogeneous but pooled results did not differ substantially in a series of sensitivity analyses for indicators of study robustness. INTERPRETATION: In so-called real-life primary health-care conditions, HCS can significantly reduce misdiagnosis of anaemia compared with clinical assessment alone. Future research is required to optimise training, and assess clinical outcomes and cost-effectiveness. FUNDING: None