The association between 2D:4D digit ratio and sex-typed play in children with and without siblings.

The 2D:4D digit ratio is commonly used as a surrogate possibly reflecting prenatal testosterone levels. Indirect evidence comes from studies investigating the association between 2D:4D and human characteristics that likely relate to prenatal testosterone. In children, sex-typed play reveals large sex differences early in development and an influence of prenatal testosterone is likely. Findings on the association between 2D:4D and children's sex-typed play are heterogeneous and other influences on the development of sex-typed play have been suggested, most of all social influences like siblings, their sex and birth order. The current study examined the association between right and left 2D:4D, a proposed surrogate for prenatal testosterone exposure, which was assessed in right and left hands of N = 505 6-month-old children, and sex-typed play behavior, which was evaluated 3.5 years later using the Pre-School Activities Inventory (PSAI), and the influence of siblings. To capture differential effects of siblings' sex and birth order, dummy-coded variables were used reflecting having no siblings as well as older or younger sisters or brothers. Multiple regression models were used to investigate the association between PSAI scores and sex, right and left 2D:4D, being a singleton as well as having an older or younger sister or brother. It was shown that sex and having an older brother were significant predictors for sex-typed play. Effects were further disentangled by conducting separate regression analyses in boys and girls. In boys, a significant association between PSAI scores and having an older brother was revealed, in girls, no significant associations were found. Results are discussed highlighting the non-significant association between 2D:4D and children's sex-typed play, which weakens the applicability of 2D:4D as a surrogate reflecting influences of prenatal T. Further, the importance of social factors like siblings on children's sex-typed play is discussed.

The association of prenatal amniotic sex hormones and digit ratio (2D:4D) in children aged 5 to 70 months: A longitudinal study.

The sex difference of the 2D:4D digit ratio (female > male)-a proposed marker for prenatal testosterone exposure-is well established. Studies suggest it already exists in utero and is of moderate effect size in adulthood. However, evidence for the claim that 2D:4D reflects prenatal androgen action is limited, and the sex difference may exhibit lability during childhood. In the present study, 244 mothers were recruited in the course of an amniocentesis examination (performed between gestational weeks 14 and 18). Prenatal testosterone (T) and estradiol (E) levels were determined from amniotic fluid for boys and girls. The majority (97.4%, n = 114) of available female T levels (n = 117) were found below the level of quantification. Therefore, only male amniotic fluid data (n = 117) could be included for the analysis of associations between amniotic sex hormones (T levels and T to E ratio (T/E)) and 2D:4D. The families were then invited to each of the five consecutive follow-ups (ages: 5, 9, 20, 40, and 70 months) where children's 2D:4D was measured for both hands. The alternative marker D[r-l] reflects the directional asymmetry of 2D:4D (right subtracted by left 2D:4D) and was subsequently calculated as an additional measure for prenatal T exposure. No significant correlations between amniotic T or the T/E ratio (measured between week 14 and 18 of gestation) with 2D:4D respectively D[r-l] were observed for any time point. There was a significant sex difference (females > males) and a significant age effect with moderate correlations of 2D:4D between time points. 2D:4D increased between 20 and 40 months and between 40 and 70 months of age. The findings raise questions regarding the applicability of 2D:4D as a marker for prenatal androgen action and are discussed in terms of the reliability of obtained digit ratio data as well as in terms of the developmental timing of amniocentesis.

Effectiveness of interprofessional communication skills training for oncology teams: study protocol for a three-arm cluster randomised trial (KommRhein Interpro).

INTRODUCTION: Patient-provider communication is an important factor influencing the quality of care in oncology. The study examines the comparative effectiveness of a 10-hour interprofessional communication skills training (CST) programme for physicians and nurses in cancer centres. METHODS AND ANALYSIS: KommRhein Interpro is a cluster-randomised trial sponsored by the German Cancer Aid (Deutsche Krebshilfe, DKH) and conducted at the cancer centres of the university hospitals of Aachen, Bonn, Cologne and Düsseldorf. Thirty oncology teams of four cancer centres are randomly assigned to three study arms, providing healthcare professionals with either (a) only written information on patient-centred communication or (b) written information plus CST for physicians or (c) written information plus interprofessional CST for physicians and nurses. For summative evaluation, standardised surveys from three measurement points for patients (T0pat: study enrollment; T1pat: after discharge; T2pat: 3 months' follow-up) and two measurement points for physicians and nurses (T0hcp: before the intervention; T1hcp: after the intervention) are used. N=1320 valid patient cases are needed for data evaluation. The primary endpoint is fear of progression in patients with cancer after discharge. Data will be analysed according to the intention-to-treat principle using a mixed model for repeated measurement. Secondary outcome is the providers' self-efficacy in patient centeredness. Individual confounders and possible moderating effects of organisational factors will be considered. Secondary analysis will be performed by means of multilevel analysis and structural equation modelling. ETHICS AND DISSEMINATION: A vote of approval has been obtained from the ethics committees of the medical faculties of RWTH Aachen University (EK325/20), University of Bonn (391/20), University of Cologne (20-1332) and Heinrich Heine University Düsseldorf (2019-796). Data protection regulations are adhered to for all processed data. The conduct of the study will be monitored. Dissemination strategies include a transfer workshop with cancer teams and distribution of the final study report to participants. TRIAL REGISTRATION NUMBER: DRKS00022563; DRKS (German Clinical Trials Register).

Investigating the reliability and sex differences of digit lengths, ratios, and hand measures in infants.

Hands and digits tend to be sexually dimorphic and may reflect prenatal androgen exposure. In the past years, the literature introduced several hand and digit measures, but there is a lack of studies in prepubertal cohorts. The available literature reports more heterogeneous findings in prepubertal compared to postpubertal cohorts. The comparability of the available studies is further limited by the study design and different measurement techniques. The present study compared the reliability and sex differences of available hand and digit measures, namely digit lengths of 2D, 3D, 4D, 5D, digit ratios 2D:4D, 2D:5D, 3D:4D, 3D:5D, 4D:5D, relative digit lengths rel2, rel3, rel4, rel5, directional asymmetry of right and left 2D:4D (Dr-l), hand width, length, and index of 399 male and 364 female 6-month-old German infants within one study using only indirect and computer-assisted measurements. The inter-examiner reliability was excellent while the test-retest reliability of hand scans was only moderate to high. Boys exhibited longer digits as well as wider and longer hands than girls, but smaller digit ratios, with ratios comprising the fifth digit revealing the largest effect sizes. Other hand and digit ratios revealed sex differences to some extent. The findings promote the assumption of sexual dimorphic hand and digit measures. However, by comparing the results of the available literature, there remains an uncertainty regarding the underlying hypothesis. Specifically in prepubertal cohorts, i.e. before the influence of fluctuating hormones, significant effects should be expected. It seems like other factors than the influence of prenatal androgens contribute to the sexual dimorphism in hand and digit lengths.