Physical and cognitive doping in university students using the unrelated question model (UQM): Assessing the influence of the probability of receiving the sensitive question on prevalence estimation

Study objectives: In order to increase the value of randomized response techniques (RRTs) as tools for studying sensitive issues, the present study investigated whether the prevalence estimate for a sensitive item π̂$_{s}$ assessed with the unrelated questionnaire method (UQM) is influenced by changing the probability of receiving the sensitive question p. Material and methods: A short paper-and-pencil questionnaire was distributed to 1.243 university students assessing the 12-month prevalence of physical and cognitive doping using two versions of the UQM with different probabilities for receiving the sensitive question (p ≈ 1/3 and p ≈ 2/3). Likelihood ratio tests were used to assess whether the prevalence estimates for physical and cognitive doping differed significantly between p ≈ 1/3 and p ≈ 2/3. The order of questions (physical doping and cognitive doping) as well as the probability of receiving the sensitive question (p ≈ 1/3 or p ≈ 2/3) were counterbalanced across participants. Statistical power analyses were performed to determine sample size. Results: The prevalence estimate for physical doping with p ≈ 1/3 was 22.5% (95% CI: 10.8-34.1), and 12.8% (95% CI: 7.6-18.0) with p ≈ 2/3. For cognitive doping with p ≈ 1/3, the estimated prevalence was 22.5% (95% CI: 11.0-34.1), whereas it was 18.0% (95% CI: 12.5-23.5) with p ≈ 2/3. Likelihood-ratio tests revealed that prevalence estimates for both physical and cognitive doping, respectively, did not differ significantly under p ≈ 1/3 and p ≈ 2/3 (physical doping: χ2 = 2.25, df = 1, p = 0.13; cognitive doping: χ2 = 0.49, df = 1, p = 0.48). Bayes factors computed with the Savage-Dickey method favored the null (‟the prevalence estimates are identical under p ≈ 1/3 and p ≈ 2/3“) over the alternative (‟the prevalence estimates differ under p ≈ 1/3 and p ≈ 2/3“) hypothesis for both physical doping (BF = 2.3) and cognitive doping (BF = 5.3). Conclusion: The present results suggest that prevalence estimates for physical and cognitive doping assessed by the UQM are largely unaffected by the probability for receiving the sensitive question p

Absolute Accelerometer-Based Intensity Prescription Compared to Physiological Variables in Pregnant and Nonpregnant Women

Estimation of the intensity of physical activity (PA) based on absolute accelerometer cut points (Cp) likely over- or underestimates intensity for a specific individual. The purpose of this study was to investigate the relationship between absolute moderate intensity Cp and the first ventilatory threshold (VT1). A group of 24 pregnant and 15 nonpregnant women who performed a submaximal incremental walking test with measures of ventilatory parameters and accelerations from three different accelerometers on the wrist (ActiGraph wGT3X-BT, GENEActiv, Axivity AX3) and one on the hip (Actigraph wGT3X-BT) were analyzed. Cp were determined corresponding to 3 metabolic equivalents of task (MET), using the conventional MET definition (Cp3.5) (3.5 mL/kg×min) and individual resting metabolic rate (Cpind). The ventilatory equivalent (VE/VO2) was used to determine VT1. Accelerations at VT1 were significantly higher (p < 0.01) compared to Cp3.5 and Cpind in both groups. Cp3.5 and Cpind were significantly different in nonpregnant (p < 0.01) but not in pregnant women. Walking speed at VT1 (5.7 ± 0.5/6.2 ± 0.8 km/h) was significantly lower (p < 0.01) in pregnant compared to nonpregnant women and correspondent to 3.8 ± 0.7/4.9 ± 1.4 conventional METs. Intensity at absolute Cp was lower compared to the intensity at VT1 independent of the device or placement in pregnant and nonpregnant women. Therefore, we recommend individually tailored cut points such as the VT1 to better assess the effect of the intensity of PA

Distribution of the different questionnaire versions.

<p>Distribution of the different questionnaire versions.</p

Holistic physical exercise training improves physical literacy among physically inactive adults: a pilot intervention study

Abstract Background Physical literacy (PL), given as a multidimensional construct, is considered a person’s capacity and commitment to a physically active lifestyle. We investigated the effect of a holistic physical exercise training on PL among physically inactive adults. Methods A non-randomised controlled study was conducted. Thirty-one physically inactive adults in the intervention group (IG; 81% females, 44 ± 16 years) participated in a holistic physical exercise training intervention once weekly for 15 weeks. A matched, non-exercising control group (CG) consisted of 30 physically inactive adults (80% female, 45 ± 11 years). PL, compliance and sociodemographic parameters were measured. PL was evaluated by a questionnaire, covering five domains: physical activity behaviour, attitude towards a physically active lifestyle, exercise motivation, knowledge and self-confidence/self-efficacy. Data were analysed using ANCOVA models, adjusted for age, gender and BMI at baseline. Results At post-training intervention, the IG showed significant improvements in PL (p = 0.001) and in the domains physical activity behaviour (p = 0.02) and exercise self-confidence/self-efficacy (p = 0.001), with no changes overserved for the CG regarding PL and those domains. No intervention effect were found for the other three domains, i.e. attitude, knowledge and motivation. Additionally, for the IG baseline BMI was identified to be positively correlated with physical exercise-induced improvements in PL (β = 0.51, p = 0.01). Conclusions The results from this study are very useful for further public health activities, which aim at helping physically inactive adults to adopt a physically active lifestyle as well as for the development of further PL intervention strategies. This pilot-study was a first attempt to measure PL in inactive adults. Yet, a validated measurement tool is still not available. Further research is necessary to determine the psychometric properties for this PL questionnaire. Trial registration German Clinical Trials Register (DRKS), DRKS00013991, date of registration: 09.02.2018, retrospectively registered

Tree diagram of the unrelated question method (UQM).

<p><i>p</i> denotes the probability of receiving the sensitive question; <i>π</i>_<i>n</i> denotes the probability of answering the neutral question with “yes”; <i>π_s</i> denotes the prevalence for the sensitive question.</p

Estimated 12-month prevalences for physical and cognitive doping using the UQM for <i>p</i> ≈ 1/3 and <i>p</i> ≈ 2/3^*.

<p>Estimated 12-month prevalences for physical and cognitive doping using the UQM for <i>p</i> ≈ 1/3 and <i>p</i> ≈ 2/3^{<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0197270#t004fn001" target="_blank">*</a>}.</p

Characteristics of the respondents.

<p>Characteristics of the respondents.</p

Mediators of lifestyle intervention effects on neonatal adiposity:are we missing a piece of the puzzle?

We evaluated possible mediators underlying lifestyle intervention effects on neonatal adiposity, assessed with sum of skinfolds and cord blood leptin. This is a secondary analysis of the DALI study, a randomised controlled trial in nine European countries. Pregnant women with a pre-pregnancy body mass index of ≥29 kg/m2 were randomly assigned to counselling for healthy eating (HE), physical activity (PA), HE&amp;PA combined, or to usual care. We considered five maternal metabolic factors at 24–28 and 35–37 weeks of gestation, and four cord blood factors as possible mediators of the effect of combined HE&amp;PA counselling on neonatal adiposity. From all potential mediators, the intervention only affected cord blood non-esterified fatty acids (NEFA), which was higher in the HE&amp;PA group compared to UC (0.068 (mmol/L), 95% CI: 0.004 to 0.133). Cord blood NEFA did not mediate the HE&amp;PA intervention effects on neonatal sum of skinfolds or cord blood leptin, based on an indirect effect on skinfolds of 0.018 (mm), 95% CI: −0.217 to 0.253 and an indirect effect on leptin of −0.143 (μg/l), 95% CI: −0.560 to 0.273. The Dali study observed reductions in neonatal adiposity in pregnant women with obesity, but we were not able to identify the underlying metabolic pathway.</p