no code implementations • 27 Feb 2024 • Susobhan Ghosh, Yongyi Guo, Pei-Yao Hung, Lara Coughlin, Erin Bonar, Inbal Nahum-Shani, Maureen Walton, Susan Murphy
The escalating prevalence of cannabis use, and associated cannabis-use disorder (CUD), poses a significant public health challenge globally.
no code implementations • 3 Feb 2024 • Xueqing Liu, Kyra Gan, Esmaeil Keyvanshokooh, Susan Murphy
We propose two online approximation algorithms for this problem, one with and one without learning augmentation, and provide rigorous theoretical performance guarantees for them using competitive ratio analysis.
no code implementations • 26 Jan 2024 • Eura Nofshin, Siddharth Swaroop, Weiwei Pan, Susan Murphy, Finale Doshi-Velez
Many important behavior changes are frictionful; they require individuals to expend effort over a long period with little immediate gratification.
2 code implementations • 15 Aug 2023 • Shuangning Li, Lluis Salvat Niell, Sung Won Choi, Inbal Nahum-Shani, Guy Shani, Susan Murphy
This presents opportunities in mobile health to design interventions that target the dyadic relationship -- the relationship between a target person and their care partner -- with the aim of enhancing social support.
no code implementations • 26 Jul 2023 • Yongyi Guo, Ziping Xu, Susan Murphy
When the context error is non-vanishing, classical bandit algorithms fail to achieve sublinear regret.
no code implementations • 19 Jun 2023 • Sorawit Saengkyongam, Niklas Pfister, Predrag Klasnja, Susan Murphy, Jonas Peters
A major challenge in policy learning is how to adapt efficiently to unseen environments or tasks.
no code implementations • 29 May 2023 • Kyra Gan, Esmaeil Keyvanshokooh, Xueqing Liu, Susan Murphy
Contextual bandit algorithms are commonly used in digital health to recommend personalized treatments.
1 code implementation • 11 Apr 2023 • Susobhan Ghosh, Raphael Kim, Prasidh Chhabria, Raaz Dwivedi, Predrag Klasnja, Peng Liao, Kelly Zhang, Susan Murphy
We use a working definition of personalization and introduce a resampling-based methodology for investigating whether the personalization exhibited by the RL algorithm is an artifact of the RL algorithm stochasticity.
no code implementations • 1 Dec 2022 • Eura Shin, Siddharth Swaroop, Weiwei Pan, Susan Murphy, Finale Doshi-Velez
Mobile health (mHealth) technologies empower patients to adopt/maintain healthy behaviors in their daily lives, by providing interventions (e. g. push notifications) tailored to the user's needs.
no code implementations • 25 Nov 2022 • Raaz Dwivedi, Katherine Tian, Sabina Tomkins, Predrag Klasnja, Susan Murphy, Devavrat Shah
We consider a matrix completion problem with missing data, where the $(i, t)$-th entry, when observed, is given by its mean $f(u_i, v_t)$ plus mean-zero noise for an unknown function $f$ and latent factors $u_i$ and $v_t$.
no code implementations • 14 Feb 2022 • Raaz Dwivedi, Katherine Tian, Sabina Tomkins, Predrag Klasnja, Susan Murphy, Devavrat Shah
Our goal is to provide inference guarantees for the counterfactual mean at the smallest possible scale -- mean outcome under different treatments for each unit and each time -- with minimal assumptions on the adaptive treatment policy.
no code implementations • 21 Jul 2021 • Eura Shin, Pedja Klasnja, Susan Murphy, Finale Doshi-Velez
Motivated by the need for efficient and personalized learning in mobile health, we investigate the problem of online kernel selection for Gaussian Process regression in the multi-task setting.
no code implementations • 21 Dec 2020 • Marianne Menictas, Sabina Tomkins, Susan Murphy
We propose an algorithm for providing physical activity suggestions in mHealth settings.
no code implementations • 31 Jul 2020 • Sabina Tomkins, Peng Liao, Predrag Klasnja, Susan Murphy
In this work we are concerned with the following challenges: 1) individuals who are in the same context can exhibit differential response to treatments 2) only a limited amount of data is available for learning on any one individual, and 3) non-stationary responses to treatment.
no code implementations • 23 Jul 2020 • Peng Liao, Zhengling Qi, Runzhe Wan, Predrag Klasnja, Susan Murphy
The performance of the method is illustrated by simulation studies and an analysis of a mobile health study promoting physical activity.
1 code implementation • 13 Apr 2020 • Jiayu Yao, Emma Brunskill, Weiwei Pan, Susan Murphy, Finale Doshi-Velez
However, when bandits are deployed in the context of a scientific study -- e. g. a clinical trial to test if a mobile health intervention is effective -- the aim is not only to personalize for an individual, but also to determine, with sufficient statistical power, whether or not the system's intervention is effective.
no code implementations • 23 Feb 2020 • Sabina Tomkins, Peng Liao, Predrag Klasnja, Serena Yeung, Susan Murphy
In mobile health (mHealth), reinforcement learning algorithms that adapt to one's context without learning personalized policies might fail to distinguish between the needs of individuals.
no code implementations • 30 Dec 2019 • Peng Liao, Predrag Klasnja, Susan Murphy
The mHealth intervention policies, often called just-in-time adaptive interventions, are decision rules that map an individual's current state (e. g., individual's past behaviors as well as current observations of time, location, social activity, stress and urges to smoke) to a particular treatment at each of many time points.
no code implementations • 8 Sep 2019 • Peng Liao, Kristjan Greenewald, Predrag Klasnja, Susan Murphy
In this paper, we develop a Reinforcement Learning (RL) algorithm that continuously learns and improves the treatment policy embedded in the JITAI as the data is being collected from the user.
no code implementations • 2 Dec 2018 • Sabina Tomkins, Predrag Klasnja, Susan Murphy
In many mobile health interventions, treatments should only be delivered in a particular context, for example when a user is currently stressed, walking or sedentary.