Clustered Multistate Models with Observation Level Random Effects, Mover–Stayer Effects and Dynamic Covariates: Modelling Transition Intensities and Sojourn Times in a Study of Psoriatic Arthritis
研究银屑病关节炎中关节活动（肿胀和疼痛）与损伤过程的关系，使用聚类多状态模型分析个体手关节水平的数据，并考虑观测水平随机效应和动态协变量，提出新参数化方法以解释协变量对停留时间和跳跃概率的影响。
In psoriatic arthritis, it is important to understand the joint activity (represented by swelling and pain) and damage processes because both are related to severe physical disability. The paper aims to provide a comprehensive investigation into both processes occurring over time, in particular their relationship, by specifying a joint multistate model at the individual hand joint level, which also accounts for many of their important features. As there are multiple hand joints, such an analysis will be based on the use of clustered multistate models. Here we consider an observation level random-effects structure with dynamic covariates and allow for the possibility that a subpopulation of patients is at minimal risk of damage. Such an analysis is found to provide further understanding of the activity-damage relationship beyond that provided by previous analyses. Consideration is also given to the modelling of mean sojourn times and jump probabilities. In particular, a novel model parameterization which allows easily interpretable covariate effects to act on these quantities is proposed.