Sex differences in healthcare use before the first multiple sclerosis-related demyelinating event
Amini F, Everett K, Zhu F, Li P, McKay KA, Zhao Y, Maxwell CJ, Marrie RA, Tremlett H. Mult Scler Relat Disord. 2026; Jul 2 [Epub ahead of print].
Analysis of interval-censored data from clustered multistate processes: application to joint damage in psoriatic arthritis
A conditionally Markov multiplicative intensity model is described for the analysis of clustered progressive multistate processes under intermittent observation. The model is motivated by a long-term prospective study of patients with psoriatic arthritis with the aim of characterizing progression of joint damage via an irreversible four-state model.
The model accommodates heterogeneity in transition rates between different individuals and correlation in transition rates within patients. To do this, the authors introduce subject-specific multivariate random effects in which each component acts multiplicatively on a specific transition intensity. Through the association between the components of the random effect, correlations in transition intensities are accommodated.
A Monte Carlo EM algorithm is developed for estimation, which features closed form expressions for estimators at each M-step.
Information
Citation
Sutradhar R, Cook RJ. J R Stat Soc Ser C Appl Stat. 2008; 57(5):553-66.