Department of Psychology, University of Essex, Colchester, Essex, UK.
Med Decis Making. 2019 Jan;39(1):32-40. doi: 10.1177/0272989X18814256.
Prior research found that "1-in-X" ratios led to higher and less accurate subjective probability than "N-in-X*N" ratios or other formats, even though they featured the same mathematical information. It is unclear, however, whether the effect transfers into health decisions, and the practical significance of the effect is undetermined. Based on previous findings and risk communication theories, we hypothesized that the 1-in-X effect would occur and transfer into relevant decisions. We also tested whether age, gender, and education differences would moderate the 1-in-X effect on decision making. We conducted 3 well-powered experiments ( n = 1912) using a sample from the general adult UK population to test our hypotheses, estimated the effect, and excluded a possible methodological explanation for such a transfer. In hypothetical scenarios, participants decided whether to travel to Kenya given the chance of contracting malaria (experiment 1) and whether to take recommended steroids given the side effects (experiments 2 and 3). Across the experiments, we replicated a small to medium 1-in-X effect on the perceived probability (Hedge's g = -0.36; 95% confidence interval [CI], -0.47 to -0.24; z = -6.18; P < 0.001) and found a small effect on subsequent decisions (odds ratio = 1.32; 95% CI, 1.10-1.59; z = 2.99; P = 0.003). The perceived probability fully mediated the effect of the ratio format on decision. Age, gender, and education did not moderate the 1-in-X effect on decision. We argue that a high prevalence of 1-in-X ratios in medical communication makes these small changes clinically relevant. Therefore, to communicate information accurately, 1-in-X ratios should not be used or at least used cautiously in medical communication.
先前的研究发现，“1-in-X”的比例比“N-in-X*N”的比例或其他格式更能导致更高和更不准确的主观概率，尽管它们具有相同的数学信息。然而，目前尚不清楚这种影响是否会转移到健康决策中，并且这种影响的实际意义尚不确定。基于先前的研究结果和风险沟通理论，我们假设“1-in-X”效应会发生并转移到相关决策中。我们还测试了年龄、性别和教育差异是否会调节“1-in-X”对决策的影响。我们使用来自英国一般成年人群体的样本进行了 3 项强有力的实验（n = 1912），以检验我们的假设，估计影响，并排除这种转移的可能方法学解释。在假设的情景中，参与者根据感染疟疾的机会决定是否前往肯尼亚（实验 1），并根据副作用决定是否服用推荐的类固醇（实验 2 和 3）。在所有实验中，我们复制了一个小到中等的“1-in-X”效应，即在感知概率上（Hedge's g = -0.36；95%置信区间[CI]，-0.47 至 -0.24；z = -6.18；P < 0.001），并在随后的决策中发现了一个小的影响（优势比= 1.32；95%CI，1.10-1.59；z = 2.99；P = 0.003）。感知概率完全中介了比例格式对决策的影响。年龄、性别和教育并没有调节“1-in-X”对决策的影响。我们认为，在医学沟通中，1-in-X 比例的高患病率使得这些小的变化具有临床意义。因此，为了准确传达信息，不应该在医学沟通中使用 1-in-X 比例，或者至少要谨慎使用。
