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.

中文翻译：

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具有观察水平随机效应、移动者-停留者效应和动态协变量的聚类多状态模型：对银屑病关节炎研究中的转变强度和停留时间进行建模。

在银屑病关节炎中，了解关节活动（以肿胀和疼痛为代表）和损伤过程非常重要，因为两者都与严重的身体残疾有关。本文旨在通过在单手关节层面指定联合多状态模型，对随时间发生的这两个过程（特别是它们的关系）进行全面的研究，这也解释了它们的许多重要特征。由于存在多个手关节，此类分析将基于聚类多状态模型的使用。在这里，我们考虑具有动态协变量的观察水平随机效应结构，并考虑到患者亚群受到损害的风险最小的可能性。人们发现，这种分析可以提供对活动与损害关系的进一步理解，超出了以前的分析。还考虑了平均停留时间和跳跃概率的建模。特别是，提出了一种新颖的模型参数化，它允许容易解释的协变量效应作用于这些量。