The ideal trial: defining causal estimands that balance relevance and feasibility in target trial emulations and actual randomized trials
理想试验:在目标试验模拟与随机试验中平衡因果目标的相关性和可行性
Causal inference is the goal of randomized trials and many observational studies. The first step in a formal causal inference framework is to define the causal estimand, and in both types of study this can be intuitively defined as the effect in an ideal trial: a hypothetical perfect randomized experiment (with representative sample, perfect adherence, etc.). The target trial framework is increasingly used for causal inference in observational studies, but clarity is lacking…