27 citations · 84 across the 22 of their papers we have counts for
22 papers
A Continuous-Time Dynamic Factor Model for Intensive Longitudinal Data Arising from Mobile Health Studies
Madeline R. Abbott, Walter H. Dempsey, Inbal Nahum-Shani +3
Intensive longitudinal data (ILD) collected in mobile health (mHealth) studies contain rich information on multiple outcomes measured frequently over time that have the potential t…
Exploring the big data paradox for various estimands using vaccination data from the global COVID-19 Trends and Impact Survey (CTIS)
Youqi Yang, Walter Dempsey, Peisong Han +4
Selection bias poses a challenge to statistical inference validity in non-probability surveys. This study compared estimates of the first-dose COVID-19 vaccination rates among Indi…
A Meta-Learning Method for Estimation of Causal Excursion Effects to Assess Time-Varying Moderation
Jieru Shi, Walter Dempsey
Advances in wearable technologies and health interventions delivered by smartphones have greatly increased the accessibility of mobile health (mHealth) interventions. Micro-randomi…
Estimating Time-Varying Direct and Indirect Causal Excursion Effects with Longitudinal Binary Outcomes
Jieru Shi, Zhenke Wu, Walter Dempsey
Construction of just-in-time adaptive interventions, such as prompts delivered by mobile apps to promote and maintain behavioral change, requires knowledge about time-varying moder…
Node-level community detection within edge exchangeable models for interaction processes
Yuhua Zhang, Walter Dempsey
Scientists are increasingly interested in discovering community structure from modern relational data arising on large-scale social networks. While many methods have been proposed…
Recurrent event analysis in the presence of real-time high frequency data via random subsampling
Walter Dempsey
Digital monitoring studies collect real-time high frequency data via mobile sensors in the subjects' natural environment. This data can be used to model the impact of changes in ph…
Kernel Deformed Exponential Families for Sparse Continuous Attention
Alexander Moreno, Supriya Nagesh, Zhenke Wu +2
Attention mechanisms take an expectation of a data representation with respect to probability weights. This creates summary statistics that focus on important features. Recently, (…
SMART Binary: Sample Size Calculation for Comparing Adaptive Interventions in SMART studies with Longitudinal Binary Outcomes
John J. Dziak, Daniel Almirall, Walter Dempsey +2
Sequential Multiple-Assignment Randomized Trials (SMARTs) play an increasingly important role in psychological and behavioral health research. This experimental approach enables re…
Assessing Time-Varying Causal Effect Moderation in the Presence of Cluster-Level Treatment Effect Heterogeneity
Jieru Shi, Zhenke Wu, Walter Dempsey
The micro-randomized trial (MRT) is a sequential randomized experimental design to empirically evaluate the effectiveness of mobile health (mHealth) intervention components that ma…
Addressing selection bias and measurement error in COVID-19 case count data using auxiliary information
Walter Dempsey
Coronavirus case-count data has influenced government policies and drives most epidemiological forecasts. Limited testing is cited as the key driver behind minimal information on t…
A Robust Functional EM Algorithm for Incomplete Panel Count Data
Alexander Moreno, Zhenke Wu, Jamie Yap +5
Panel count data describes aggregated counts of recurrent events observed at discrete time points. To understand dynamics of health behaviors, the field of quantitative behavioral…
Hierarchical network models for structured exchangeable interaction processes
Walter Dempsey, Brandon Oselio, Alfred Hero
Network data often arises via a series of structured interactions among a population of constituent elements. E-mail exchanges, for example, have a single sender followed by potent…
Exchangeable, Markov multi-state survival process
Walter Dempsey
We consider exchangeable Markov multi-state survival processes -- temporal processes taking values over a state-space with at least one absorbing failure state $\flat…
Relational exchangeability
Harry Crane, Walter Dempsey
A relationally exchangeable structure is a random combinatorial structure whose law is invariant with respect to relabeling its relations, as opposed to its elements. Aside from ex…
Edge exchangeable models for network data
Harry Crane, Walter Dempsey
Exchangeable models for countable vertex-labeled graphs cannot replicate the large sample behaviors of sparsity and power law degree distribution observed in many network datasets.…
Vital variables and survival processes
Walter Dempsey, Peter McCullagh
The focus of a survival study is partly on the distribution of survival times, and partly on the health or quality of life of patients while they live. Health varies over time, and…
Community detection for interaction networks
Harry Crane, Walter Dempsey
In many applications, it is common practice to obtain a network from interaction counts by thresholding each pairwise count at a prescribed value. Our analysis calls attention to t…
Atypical scaling behavior persists in real world interaction networks
Harry Crane, Walter Dempsey
Scale-free power law structure describes complex networks derived from a wide range of real world processes. The extensive literature focuses almost exclusively on networks with po…
A framework for statistical network modeling
Harry Crane, Walter Dempsey
Basic principles of statistical inference are commonly violated in network data analysis. Under the current approach, it is often impossible to identify a model that accommodates k…
The pilgrim process
Walter Dempsey, Peter McCullagh
Pilgrim's monopoly is a probabilistic process giving rise to a non-negative sequence that is infinitely exchangeable, a natural model for time-to-event data. The…
Weak continuity of predictive distribution for Markov survival processes
Walter Dempsey, Peter McCullagh
We explore the concept of a consistent exchangeable survival process - a joint distribution of survival times in which the risk set evolves as a continuous-time Markov process with…
Survival models and health sequences
Peter McCullagh, Walter Dempsey
Medical investigations focusing on patient survival often generate not only a failure time for each patient but also a sequence of measurements on patient health at annual or semi-…