Partially ordered Markov models (POMMs) are Markov random elds (MRFs) with neighborhood structures derivable from an associated partially ordered set. The most attractive feature of POMMs is that their joint distributions can be written in closed and product form. Therefore, simulation and maximum likelihood estimation for the models is quite straightforward, which is not the case in general fo...

The changes occurring in the field of rheumatoid arthritis (RA) over the past decade or two have encompassed new therapies and, in particular, a new look at the clinical characteristics of the disease in the context of therapeutic improvements. It has been shown that composite disease activity indices have special merits in following patients, that disease activity governs the evolution of join...