Incongruence between test statistics and <it>P </it>values in medical papers

<p>Abstract</p> <p>Background</p> <p>Given an observed test statistic and its degrees of freedom, one may compute the observed <it>P </it>value with most statistical packages. It is unknown to what extent test statistics and <it>P </it>values are congruent in published medical papers.</p> <p>Methods</p> <p>We checked the congruence of statistical results reported in all the papers of volumes 409–412 of <it>Nature </it>(2001) and a random sample of 63 results from volumes 322–323 of <it>BMJ </it>(2001). We also tested whether the frequencies of the last digit of a sample of 610 test statistics deviated from a uniform distribution (i.e., equally probable digits).</p> <p>Results</p> <p>11.6% (21 of 181) and 11.1% (7 of 63) of the statistical results published in <it>Nature </it>and <it>BMJ </it>respectively during 2001 were incongruent, probably mostly due to rounding, transcription, or type-setting errors. At least one such error appeared in 38% and 25% of the papers of <it>Nature </it>and <it>BMJ</it>, respectively. In 12% of the cases, the significance level might change one or more orders of magnitude. The frequencies of the last digit of statistics deviated from the uniform distribution and suggested digit preference in rounding and reporting.</p> <p>Conclusions</p> <p>This incongruence of test statistics and <it>P </it>values is another example that statistical practice is generally poor, even in the most renowned scientific journals, and that quality of papers should be more controlled and valued.</p

Does engaging in a group-based intervention increase parental sense of competence in parents of pre-school children?:A Systematic Review of the Current Literature

As the preschool years are a formative period for long-term physical and mental health, this period is recognised as an important window for early effective intervention. Parenting behaviour is a key factor to target in order to optimise child development. Group-based interventions for parents are considered efficient and cost effective methods of early intervention and have been found to improve child behaviour and adjustment. Self-efficacy is key to behaviour change and as such parental self-efficacy should be a consideration in interventions aimed at influencing parenting behaviour. Therefore, the purpose of this systematic review was to examine the impact of group-based early interventions for parents of preschool children on parental self-efficacy. Nine databases were searched (ASSIA, CINAHL, EMBASE, Maternity and Infant Care, Ovid Medline, PsycINFO, Pubmed, Science Direct and Web of Science). Studies were included if they were a randomised controlled trial of a group-based intervention for parents of preschool children and measured change in parental self-efficacy. Fifteen studies were identified. Although changes in parental self-efficacy following a group-based intervention were noted in the majority of studies reviewed, the methodological quality of the studies included in the review means these findings have to be interpreted with caution; only seven studies were rated to be methodologically adequate. Further research is needed to understand the mechanisms by which these interventions may improve parental self-efficacy. Studies specifically examining the impact of such interventions on paternal self-efficacy are also warranted