An N-of-1 trial is a multi-period crossover trial performed in a single individual, with a primary goal to estimate treatment effect on the individual instead of population-level mean responses. As in a conventional crossover trial, it is critical to understand carryover effects of the treatment in an N-of-1 trial, especially when no washout periods between treatment periods are instituted to reduce trial duration. To deal with this issue in situations where high volume of measurements is made during the study, we introduce a novel Bayesian distributed lag model that facilitates the estimation of carryover effects, while accounting for temporal correlations using an autoregressive model. Specifically, we propose a prior variance-covariance structure on the lag coefficients to address collinearity caused by the fact that treatment exposures are typically identical on successive days. A connection between the proposed Bayesian model and penalized regression is noted. Simulation results demonstrate that the proposed model substantially reduces the root mean squared error in the estimation of carryover effects and immediate effects when compared to other existing methods, while being comparable in the estimation of the total effects. We also apply the proposed method to assess the extent of carryover effects of light therapies in relieving depressive symptoms in cancer survivors.
翻译:N-Of-1试验是在一个人身上进行的跨期跨期审判,主要目的是估计对个人的治疗影响,而不是人口层面的平均反应。与传统的交叉审判一样,理解N-Of-1试验中治疗的结转影响至关重要,特别是当治疗期之间没有为缩短审判期而规定任何冲洗期时。在研究期间进行大量测量的情况下,为了处理这一问题,我们采用了新的巴伊西亚分布差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差率差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差的差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差差