Research Group Physical Activity and Public Health, Institute of Sports Science, University of Graz, Graz, Austria.
Working Group Social and Health Sciences of Sport, Institute for Sports and Sports Science, Karlsruhe Institute of Technology, Karlsruhe, Germany.
PLoS One. 2018 May 15;13(5):e0197270. doi: 10.1371/journal.pone.0197270. eCollection 2018.
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 [Formula: see text] assessed with the unrelated questionnaire method (UQM) is influenced by changing the probability of receiving the sensitive question p.
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.
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).
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.
为了提高随机响应技术（RRT）作为研究敏感问题工具的价值，本研究探讨了使用无关问卷法（UQM）评估敏感项目[公式：见文本]的患病率估计值是否会受到敏感问题接收概率 p 的变化的影响。
向 1243 名大学生发放了一份简短的纸质问卷，使用两种不同的 UQM 版本（p≈1/3 和 p≈2/3）评估身体和认知兴奋剂的 12 个月患病率。似然比检验用于评估 p≈1/3 和 p≈2/3 时身体和认知兴奋剂的患病率估计值是否有显著差异。问题的顺序（身体兴奋剂和认知兴奋剂）以及敏感问题的接收概率（p≈1/3 或 p≈2/3）在参与者之间平衡。进行了统计功效分析以确定样本量。
p≈1/3 时，身体兴奋剂的患病率估计值为 22.5%（95%CI：10.8-34.1），p≈2/3 时为 12.8%（95%CI：7.6-18.0）。p≈1/3 时，认知兴奋剂的估计患病率为 22.5%（95%CI：11.0-34.1），p≈2/3 时为 18.0%（95%CI：12.5-23.5）。似然比检验表明，p≈1/3 和 p≈2/3 时，身体和认知兴奋剂的患病率估计值没有显著差异（身体兴奋剂：χ2=2.25，df=1，p=0.13；认知兴奋剂：χ2=0.49，df=1，p=0.48）。使用 Savage-Dickey 方法计算的贝叶斯因子倾向于零假设（“p≈1/3 和 p≈2/3 下的患病率估计值相同”）而不是替代假设（“p≈1/3 和 p≈2/3 下的患病率估计值不同”），这对于身体兴奋剂（BF=2.3）和认知兴奋剂（BF=5.3）都是如此。
本研究结果表明，使用 UQM 评估的身体和认知兴奋剂的患病率估计值受敏感问题接收概率 p 的影响不大。
