Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Nonparametric analysis of nonhomogeneous multi-state processes based on
  clustered observations   Frequently, clinical trials and observational studies involve complex event
history data with multiple events. When the observations are independent, the
analysis of such studies can be based on standard methods for multi-state
models. However, the independence assumption is often violated, such as in
multicenter studies, which makes the use of standard methods improper. In this
work we address the issue of nonparametric estimation and two-sample testing
for the population-averaged transition and state occupation probabilities under
general multi-state models based on right-censored, left-truncated, and
clustered observations. The proposed methods do not impose assumptions
regarding the within-cluster dependence, allow for informative cluster size,
and are applicable to both Markov and non-Markov processes. Using empirical
process theory, the estimators are shown to be uniformly consistent and to
converge weakly to tight Gaussian processes. Closed-form variance estimators
are derived, rigorous methodology for the calculation of simultaneous
confidence bands is proposed, and the asymptotic properties of the
nonparametric tests are established. Furthermore, we provide theoretical
arguments for the validity of the nonparametric cluster bootstrap, which can be
readily implemented in practice regardless of how complex the underlying
multi-state model is. Simulation studies show that the performance of the
proposed methods is good, and that methods that ignore the within-cluster
dependence can lead to invalid inferences. Finally, the methods are applied to
data from a multicenter randomized controlled trial.

5
The categories of this paper are: gr-qc
18
The categories of this paper are: econ
4
The categories of this paper are: cond-mat
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
13
The categories of this paper are: quant-ph
17
The categories of this paper are: q-fin
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
28
The categories of this paper are: alg-geom
25
The categories of this paper are: patt-sol
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The categories of this paper are: physics
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
12
The categories of this paper are: nucl-th