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

Healthy eating and lifestyle in pregnancy (HELP): a cluster randomised trial to evaluate the effectiveness of a weight management intervention for pregnant women with obesity on weight at 12 months postpartum

Objective: To assess whether a weight management intervention for pregnant women with obesity was effective in reducing body mass index (BMI) 12 months after giving birth. Methods: Pragmatic, cluster randomised controlled trial (RCT) with embedded cost-effectiveness analysis. 598 women with a BMI of ≥30 kg/m2 (between 12 and 20 weeks gestation) were recruited from 20 secondary care maternity units in England and Wales. BMI at 12 months postpartum was the primary outcome. A range of clinical and behavioural secondary outcomes were examined. Interventions: Women attending maternity units randomised to intervention were invited to a weekly weight management group, which combined expertise from a commercial weight loss programme with clinical advice from midwives. Both intervention and control participants received usual care and leaflets on diet and physical activity in pregnancy. Results: Mean (SD) BMI at 12 months postpartum was 36.0 kg/m2 (5.2) in the control group, and 37.5 kg/m2 (6.7) in the intervention group. After adjustment for baseline BMI, the intervention effect was −0.02 (95% CI −0.04 to 0.01). The intervention group had an improved healthy eating score (3.08, 95% CI 0.16 to 6.00, p < 0.04), improved fibre score (3.22, 1.07 to 5.37, p < 0.01) and lower levels of risky drinking at 12 months postpartum compared to the control group (OR 0.45, 0.27 to 0.74, p < 0.002). The net incremental monetary benefit was not statistically significantly different between arms, although the probability of the intervention being cost-effective was above 60%, at policy-relevant thresholds. Conclusions: There was no significant difference between groups on the primary outcome of BMI at 12 months. Analyses of secondary outcomes indicated improved healthy eating and lower levels of risky drinking. Trial registration: Current Controlled Trials ISRCTN25260464

Sacred turf: the Wimbledon tennis championships and the changing politics of Englishness

© 2015 Taylor & Francis. This article is about ‘Wimbledon’, widely celebrated – not least in its own publicity material – as the world’s premier tennis tournament. It examines ‘Wimbledon’ essentially as a text (hence the inverted commas), viewed politically and historically. In this context, ‘Wimbledon’ is seen as a signifier of a certain kind of Englishness, carefully adapted to meet changing social and economic circumstance. Loose parallels are drawn between the cultural trajectory of ‘Wimbledon’ and that of the British royal family. The transmutations of ‘Wimbledon’ as a tennis championship are also seen as reflecting Britain’s decline as a world power during the twentieth century