AI for Social Work, Public Health, and Medical Decision Making

2021
Aditya Mate*, Lovish Madaan*, Aparna Taneja, Neha Madhiwalla, Shresth Verma, Gargi Singh, Aparna Hegde, Pradeep Varakantham, and Milind Tambe. 12/2021. “Restless Bandits in the Field: Real-World Study for Improving Maternal and Child Health Outcomes.” In MLPH: Machine Learning in Public Health NeurIPS 2021 Workshop.Abstract

The widespread availability of cell phones has enabled non-profits to deliver critical health information to their beneficiaries in a timely manner. This paper describes our work in assisting non-profits employing automated messaging programs to deliver timely preventive care information to new and expecting mothers during pregnancy and after delivery. Unfortunately, a key challenge in such information delivery programs is that a significant fraction of beneficiaries tend to drop out. Yet, non-profits often have limited health-worker resources (time) to place crucial service calls for live interaction with beneficiaries to prevent such engagement drops. To assist non-profits in optimizing this limited resource, we developed a Restless Multi-Armed Bandits (RMABs) system. One key technical contribution in this system is a novel clustering method of offline historical data to infer unknown RMAB parameters. Our second major contribution is evaluation of our RMAB system in collaboration with an NGO, via a real-world service quality improvement study. The study compared strategies for optimizing service calls to 23003 participants over a period of 7 weeks to reduce engagement drops. We show that the RMAB group provides statistically significant improvement over other comparison groups, reducing 30% engagement drops. To the best of our knowledge, this is the first study demonstrating the utility of RMABs in real world public health settings. We are transitioning our system to the NGO for real-world use.

neurips-workshop-mlph-restlessbandits.pdf
Haipeng Chen, Wei Qiu, Han-Ching Ou, Bo An, and Milind Tambe. 7/25/2021. “Contingency-Aware Influence Maximization: A Reinforcement Learning Approach.” In Conference on Uncertainty in Artificial Intelligence. uai21.pdf
Aditya Mate, Andrew Perrault, and Milind Tambe. 5/7/2021. “Risk-Aware Interventions in Public Health: Planning with Restless Multi-Armed Bandits.” In 20th International Conference on Autonomous Agents and Multiagent Systems (AAMAS). London, UK.Abstract
Community Health Workers (CHWs) form an important component of health-care systems globally, especially in low-resource settings. CHWs are often tasked with monitoring the health of and intervening on their patient cohort. Previous work has developed several classes of Restless Multi-Armed Bandits (RMABs) that are computationally tractable and indexable, a condition that guarantees asymptotic optimality, for solving such health monitoring and intervention problems (HMIPs).
However, existing solutions to HMIPs fail to account for risk-sensitivity considerations of CHWs in the planning stage and may run the danger of ignoring some patients completely because they are deemed less valuable to intervene on.
Additionally, these also rely on patients reporting their state of adherence accurately when intervened upon. Towards tackling these issues, our contributions in this paper are as follows: 
(1) We develop an RMAB solution to HMIPs that allows for reward functions that are monotone increasing, rather than linear, in the belief state and also supports a wider class of observations.
(2) We prove theoretical guarantees on the asymptotic optimality of our algorithm for any arbitrary reward function. Additionally, we show that for the specific reward function considered in previous work, our theoretical conditions are stronger than the state-of-the-art guarantees.
(3) We show the applicability of these new results for addressing the three issues pertaining to: risk-sensitive planning, equitable allocation and reliance on perfect observations as highlighted above. We evaluate these techniques on both simulated as well as real data from a prevalent CHW task of monitoring adherence of tuberculosis patients to their prescribed medication in Mumbai, India and show improved performance over the state-of-the-art. The simulation code is available at: https://github.com/AdityaMate/risk-aware-bandits.
Risk-Aware-Bandits.pdf
Beyond "To Act or Not to Act": Fast Lagrangian Approaches to General Multi-Action Restless Bandits
Jackson A Killian, Andrew Perrault, and Milind Tambe. 5/2021. “Beyond "To Act or Not to Act": Fast Lagrangian Approaches to General Multi-Action Restless Bandits.” In 20th International Conference on Autonomous Agents and Multiagent Systems. multi_action_bandits_aamas_2021_preprint.pdf
2020
Aditya Mate*, Jackson A. Killian*, Haifeng Xu, Andrew Perrault, and Milind Tambe. 12/5/2020. “Collapsing Bandits and Their Application to Public Health Interventions.” In Advances in Neural and Information Processing Systems (NeurIPS) 12/5/2020. Vancouver, Canada. Publisher's VersionAbstract
We propose and study Collapsing Bandits, a new restless multi-armed bandit (RMAB) setting in which each arm follows a binary-state Markovian process with a special structure: when an arm is played, the state is fully observed, thus “collapsing” any uncertainty, but when an arm is passive, no observation is made, thus allowing uncertainty to evolve. The goal is to keep as many arms in the “good” state as possible by planning a limited budget of actions per round. Such Collapsing Bandits are natural models for many healthcare domains in which health workers must simultaneously monitor patients and deliver interventions in a way that maximizes the health of their patient cohort. Our main contributions are as follows: (i) Building on the Whittle index technique for RMABs, we derive conditions under which the Collapsing Bandits problem is indexable. Our derivation hinges on novel conditions that characterize when the optimal policies may take the form of either “forward” or “reverse” threshold policies. (ii) We exploit the optimality of threshold policies to build fast algorithms for computing the Whittle index, including a closed form. (iii) We evaluate our algorithm on several data distributions including data from a real-world healthcare task in which a worker must monitor and deliver interventions to maximize their patients’ adherence to tuberculosis medication. Our algorithm achieves a 3-order-of-magnitude speedup compared to state-of-the-art RMAB techniques, while achieving similar performance.
collapsing_bandits_full_paper_camready.pdf
Ankit Bhardwaj*, Han Ching Ou*, Haipeng Chen, Shahin Jabbari, Milind Tambe, Rahul Panicker, and Alpan Raval. 11/2020. “Robust Lock-Down Optimization for COVID-19 Policy Guidance.” In AAAI Fall Symposium. robust_lock-down_optimization_for_covid-19_policy_guidance.pdf
Bryan Wilder, Marie Charpignon, Jackson A Killian, Han-Ching Ou, Aditya Mate, Shahin Jabbari, Andrew Perrault, Angel Desai, Milind Tambe, and Maimuna S. Majumder. 9/24/2020. “Modeling between-population variation in COVID-19 dynamics in Hubei, Lombardy, and New York City.” Proceedings of the National Academy of Sciences. Publisher's Version pnas_full.pdf
Evaluating COVID-19 Lockdown and Business-Sector-Specific Reopening Policies for Three US States
Jackson A. Killian, Marie Charpignon, Bryan Wilder, Andrew Perrault, Milind Tambe, and Maimuna S. Majumder. 8/24/2020. “Evaluating COVID-19 Lockdown and Business-Sector-Specific Reopening Policies for Three US States.” In KDD 2020 Workshop on Humanitarian Mapping. Publisher's VersionAbstract
Background: The United States has been particularly hard-hit by COVID-19, accounting for approximately 30% of all global cases and deaths from the disease that have been reported as of May 20, 2020. We extended our agent-based model for COVID-19 transmission to study the effect of alternative lockdown and reopening policies on disease dynamics in Georgia, Florida, and Mississippi. Specifically, for each state we simulated the spread of the disease had the state enforced its lockdown approximately one week earlier than it did. We also simulated Georgia's reopening plan under various levels of physical distancing if enacted in each state, making projections until June 15, 2020.

Methods: We used an agent-based SEIR model that uses population-specific age distribution, household structure, contact patterns, and comorbidity rates to perform tailored simulations for each region. The model was first calibrated to each state using publicly available COVID-19 death data as of April 23, then implemented to simulate given lockdown or reopening policies.

Results: Our model estimated that imposing lockdowns one week earlier could have resulted in hundreds fewer COVID-19-related deaths in the context of all three states. These estimates quantify the effect of early action, a key metric to weigh in developing prospective policies to combat a potential second wave of infection in each of these states. Further, when simulating Georgia’s plan to reopen select businesses as of April 27, our model found that a reopening policy that includes physical distancing to ensure no more than 25% of pre-lockdown contact rates at reopened businesses could allow limited economic activity to resume in any of the three states, while also eventually flattening the curve of COVID-19-related deaths by June 15, 2020.
covid_19_us_states.pdf
Aniruddha Adiga, Lijing Wang, Adam Sadilek, Ashish Tendulkar, Srinivasan Venkatramanan, Anil Vullikanti, Gaurav Aggarwal, Alok Talekar, Xue Ben, Jiangzhuo Chen, Bryan Lewis, Samarth Swarup, Milind Tambe, and Madhav Marathe. 6/5/2020. “Interplay of global multi-scale human mobility, social distancing, government interventions, and COVID-19 dynamics”. Publisher's Version merrxiv.pdf
Han-Ching Ou, Arunesh Sinha, Sze-Chuan Suen, Andrew Perrault, Alpan Raval, and Milind Tambe. 5/9/2020. “Who and When to Screen Multi-Round Active Screening for Network Recurrent Infectious Diseases Under Uncertainty.” In International Conference on Autonomous Agents and Multiagent Systems (AAMAS-20). who_and_when_to_screen.pdf
Aditya Mate, Jackson A. Killian, Bryan Wilder, Marie Charpignon, Ananya Awasthi, Milind Tambe, and Maimuna S. Majumder. 4/13/2020. “Evaluating COVID-19 Lockdown Policies For India: A Preliminary Modeling Assessment for Individual States.” SSRN. Publisher's VersionAbstract
Background: On March 24, India ordered a 3-week nationwide lockdown in an effort to control the spread of COVID-19. While the lockdown has been effective, our model suggests that completely ending the lockdown after three weeks could have considerable adverse public health ramifications. We extend our individual-level model for COVID-19 transmission [1] to study the disease dynamics in India at the state level for Maharashtra and Uttar Pradesh to estimate the effect of further lockdown policies in each region. Specifically, we test policies which alternate between total lockdown and simple physical distancing to find "middle ground" policies that can provide social and economic relief as well as salutary population-level health effects.

Methods: We use an agent-based SEIR model that uses population-specific age distribution, household structure, contact patterns, and comorbidity rates to perform tailored simulations for each region. The model is first calibrated to each region using publicly available COVID-19 death data, then implemented to simulate a range of policies. We also compute the basic reproduction number R0 and case documentation rate for both regions.

Results: After the initial lockdown, our simulations demonstrate that even policies that enforce strict physical distancing while returning to normal activity could lead to widespread outbreaks in both states. However, "middle ground" policies that alternate weekly between total lockdown and physical distancing may lead to much lower rates of infection while simultaneously permitting some return to normalcy.
ssrn-covid_lockdown_policies_india.pdf
2019
Jackson Killian, Bryan Wilder, Amit Sharma, Vinod Choudhary, Bistra Dilkina, and Milind Tambe. 8/4/2019. “Learning to Prescribe Interventions for Tuberculosis Patients Using Digital Adherence Data.” In The 25th ACM SIGKDD Conference on Knowledge Discovery and Data Mining (KDD), 8/4/2019. Abstract
Digital Adherence Technologies (DATs) are an increasingly popular method for verifying patient adherence to many medications.
We analyze data from one city served by 99DOTS, a phone-callbased DAT deployed for Tuberculosis (TB) treatment in India where
nearly 3 million people are afflicted with the disease each year. The
data contains nearly 17,000 patients and 2.1M dose records. We lay
the groundwork for learning from this real-world data, including
a method for avoiding the effects of unobserved interventions in
training data used for machine learning. We then construct a deep
learning model, demonstrate its interpretability, and show how it
can be adapted and trained in three different clinical scenarios to
better target and improve patient care. In the real-time risk prediction setting our model could be used to proactively intervene with
21% more patients and before 76% more missed doses than current
heuristic baselines. For outcome prediction, our model performs
40% better than baseline methods, allowing cities to target more
resources to clinics with a heavier burden of patients at risk of failure. Finally, we present a case study demonstrating how our model
can be trained in an end-to-end decision focused learning setting to
achieve 15% better solution quality in an example decision problem
faced by health workers.
killian-kdd-2019.pdf
Aida Rahmattalabi, Anamika Barman Adhikari, Phebe Vayanos, Milind Tambe, Eric Rice, and Robin Baker. 2019. “Social Network Based Substance Abuse Prevention via Network Modification (A Preliminary Study).” In Strategic Reasoning for Societal Challenges (SRSC) Workshop at International Conference on Autonomous Agents and Multiagent Systems (AAMAS-19).Abstract
Substance use and abuse is a significant public health problem in the
United States. Group-based intervention programs offer a promising
means of preventing and reducing substance abuse. While effective,
unfortunately, inappropriate intervention groups can result in an
increase in deviant behaviors among participants, a process known
as deviancy training. This paper investigates the problem of optimizing the social influence related to the deviant behavior via careful
construction of the intervention groups. We propose a Mixed Integer Optimization formulation that decides on the intervention
groups to be formed, captures the impact of the intervention groups
on the structure of the social network, and models the impact of
these changes on behavior propagation. In addition, we propose
a scalable hybrid meta-heuristic algorithm that combines Mixed
Integer Programming and Large Neighborhood Search to find nearoptimal network partitions. Our algorithm is packaged in the form
of GUIDE, an AI-based decision aid that recommends intervention groups. Being the first quantitative decision aid of this kind,
GUIDE is able to assist practitioners, in particular social workers, in
three key areas: (a) GUIDE proposes near-optimal solutions that are
shown, via extensive simulations, to significantly improve over the
traditional qualitative practices for forming intervention groups;
(b) GUIDE is able to identify circumstances when an intervention
will lead to deviancy training, thus saving time, money, and effort;
(c) GUIDE can evaluate current strategies of group formation and
discard strategies that will lead to deviancy training. In developing
GUIDE, we are primarily interested in substance use interventions
among homeless youth as a high risk and vulnerable population.
GUIDE is developed in collaboration with Urban Peak, a homelessyouth serving organization in Denver, CO, and is under preparation
for deployment.
2019_5_teamcore_aida_aamas2019_workshop_substance_abuse.pdf
2018
Lily Hu, Bryan Wilder, Amulya Yadav, Eric Rice, and Milind Tambe. 2018. “Activating the 'Breakfast Club': Modeling Influence Spread in Natural-World Social Networks.” In International Conference on Autonomous Agents and Multiagent Systems (AAMAS-18).Abstract
While reigning models of diffusion have privileged the structure of a given social network as the key to informational exchange, real human interactions do not appear to take place on a single graph of connections. Using data collected from a pilot study of the spread of HIV awareness in social networks of homeless youth, we show that health information did not diffuse in the field according to the processes outlined by dominant models. Since physical network diffusion scenarios often diverge from their more well-studied counterparts on digital networks, we propose an alternative Activation Jump Model (AJM) that describes information diffusion on physical networks from a multi-agent team perspective. Our model exhibits two main differentiating features from leading cascade and threshold models of influence spread: 1) The structural composition of a seed set team impacts each individual node’s influencing behavior, and 2) an influencing node may spread information to non-neighbors. We show that the AJM significantly outperforms existing models in its fit to the observed node-level influence data on the youth networks. We then prove theoretical results, showing that the AJM exhibits many well-behaved properties shared by dominant models. Our results suggest that the AJM presents a flexible and more accurate model of network diffusion that may better inform influence maximization in the field.
2018_23_teamcore_aamas_ajm.pdf
Amulya Yadav, Bryan Wilder, Eric Rice, Robin Petering, Jaih Craddock, Amanda Yoshioka-Maxwell, Mary Hemler, Laura Onasch-Vera, Milind Tambe, and Darlene Woo. 2018. “Bridging the Gap Between Theory and Practice in Influence Maximization: Raising Awareness about HIV among Homeless Youth.” In International Joint Conference on Artificial Intelligence (IJCAI).Abstract
This paper reports on results obtained by deploying HEALER and DOSIM (two AI agents for social influence maximization) in the real-world, which assist service providers in maximizing HIV awareness in real-world homeless-youth social networks. These agents recommend key ”seed” nodes in social networks, i.e., homeless youth who would maximize HIV awareness in their real-world social network. While prior research on these agents published promising simulation results from the lab, the usability of these AI agents in the real-world was unknown. This paper presents results from three real-world pilot studies involving 173 homeless youth across two different homeless shelters in Los Angeles. The results from these pilot studies illustrate that HEALER and DOSIM outperform the current modus operandi of service providers by ∼160% in terms of information spread about HIV among homeless youth.
2018_14_teamcore_bridging_gap_theory.pdf
Bryan Wilder, Laura Onasch-Vera, Juliana Hudson, Jose Luna, Nicole Wilson, Robin Petering, Darlene Woo, Milind Tambe, and Eric Rice. 2018. “End-to-End Influence Maximization in the Field.” In International Conference on Autonomous Agents and Multiagent Systems (AAMAS-18).Abstract
This work is aims to overcome the challenges in deploying influence maximization to support community driven interventions. Influence maximization is a crucial technique used in preventative health interventions, such as HIV prevention amongst homeless youth. Drop-in centers for homeless youth train a subset of youth as peer leaders who will disseminate information about HIV through their social networks. The challenge is to find a small set of peer leaders who will have the greatest possible influence. While many algorithms have been proposed for influence maximization, none can be feasibly deployed by a service provider: existing algorithms require costly surveys of the entire social network of the youth to provide input data, and high performance computing resources to run the algorithm itself. Both requirements are crucial bottlenecks to widespread use of influence maximization in real world interventions. To address the above challenges, this innovative applications paper introduces the CHANGE agent for influence maximization. CHANGE handles the end-to-end process of influence maximization, from data collection to peer leader selection. Crucially, CHANGE only surveys a fraction of the youth to gather network data and minimizes computational cost while providing comparable performance to previously proposed algorithms. We carried out a pilot study of CHANGE in collaboration with a drop-in center serving homeless youth in a major U.S. city. CHANGE surveyed only 18% of the youth to construct its social network. However, the peer leaders it selected reached just as many youth as previously field-tested algorithms which surveyed the entire network. This is the first real-world study of a network sampling algorithm for influence maximization. Simulation results on real-world networks also support our claims.
2018_26_teamcore_aamas_deployment.pdf
Bryan Wilder, Nicole Immorlica, Eric Rice, and Milind Tambe. 2018. “Maximizing Influence in an Unknown Social Network.” In AAAI conference on Artificial Intelligence (AAAI-18).Abstract
In many real world applications of influence maximization, practitioners intervene in a population whose social structure is initially unknown. This poses a multiagent systems challenge to act under uncertainty about how the agents are connected. We formalize this problem by introducing exploratory influence maximization, in which an algorithm queries individual network nodes (agents) to learn their links. The goal is to locate a seed set nearly as influential as the global optimum using very few queries. We show that this problem is intractable for general graphs. However, real world networks typically have community structure, where nodes are arranged in densely connected subgroups. We present the ARISEN algorithm, which leverages community structure to find an influential seed set. Experiments on real world networks of homeless youth, village populations in India, and others demonstrate ARISEN’s strong empirical performance. To formally demonstrate how ARISEN exploits community structure, we prove an approximation guarantee for ARISEN on graphs drawn from the Stochastic Block Model.
2018_30_teamcore_aaai_unknown_network_final.pdf
Bryan Wilder, Han Ching Ou, Kayla de la Haye, and Milind Tambe. 2018. “Optimizing network structure for preventative health.” In International Conference on Autonomous Agents and Multiagent Systems (AAMAS-18).Abstract
Diseases such as heart disease, stroke, or diabetes affect hundreds of millions of people. Such conditions are strongly impacted by obesity, and establishing healthy lifestyle behaviors is a critical public health challenge with many applications. Changing health behaviors is inherently a multiagent problem since people’s behavior is strongly influenced by those around them. Hence, practitioners often attempt to modify the social network of a community by adding or removing edges in ways that will lead to desirable behavior change. To our knowledge, no previous work considers the algorithmic problem of finding the optimal set of edges to add and remove. We propose the RECONNECT algorithm, which efficiently finds high-quality solutions for a range of different network intervention problems. We evaluate RECONNECT in a highly realistic simulated environment based on the Antelope Valley region in California which draws on demographic, social, and health-related data. We find the RECONNECT outperforms an array of baseline policies, in some cases yielding a 150% improvement over the best alternative.
2018_27_teamcore_aamas_network_optimization.pdf
Bryan Wilder, Han Ching Ou, Kayla de la Haye, and Milind Tambe. 2018. “Optimizing network structure for preventative health.” In International Conference on Autonomous Agents and Multiagent Systems (AAMAS-18).Abstract
Diseases such as heart disease, stroke, or diabetes affect hundreds of millions of people. Such conditions are strongly impacted by obesity, and establishing healthy lifestyle behaviors is a critical public health challenge with many applications. Changing health behaviors is inherently a multiagent problem since people’s behavior is strongly influenced by those around them. Hence, practitioners often attempt to modify the social network of a community by adding or removing edges in ways that will lead to desirable behavior change. To our knowledge, no previous work considers the algorithmic problem of finding the optimal set of edges to add and remove. We propose the RECONNECT algorithm, which efficiently finds high-quality solutions for a range of different network intervention problems. We evaluate RECONNECT in a highly realistic simulated environment based on the Antelope Valley region in California which draws on demographic, social, and health-related data. We find the RECONNECT outperforms an array of baseline policies, in some cases yielding a 150% improvement over the best alternative.
2018_27_teamcore_aamas_network_optimization.pdf
Eric Rice, Amanda Yoshioka-Maxwell, Robin Petering, Laura Onasch-Vera, Jaih Craddock, Milind Tambe, Amulya Yadav, Bryan Wilder, Darlene Woo, Hailey Winetrobe, and Nicole Wilson. 2018. “Piloting the Use of Artificial Intelligence to Enhance HIV Prevention Interventions for Youth Experiencing Homelessness.” Journal of the Society for Social Work and Research, Volume 9, Number 4., 9, 4.Abstract
Youth experiencing homelessness are at risk for HIV and need interventions to prevent risky sex behaviors. We tested the feasibility of using artificial intelligence (AI) to select peer change agents (PCAs) to deliver HIV prevention messages among youth experiencing homelessness. Method: We used a pretest– posttest quasi-experimental design. In the AI condition (n 5 62), 11 PCAs were selected via AI algorithm; in the popularity comparison (n 5 55), 11 PCAs were selected 6 months later based on maximum degree centrality (most ties to others in the network). All PCAs were trained to promote HIV testing and condom use among their peers. Participants were clients at a drop-in center in Los Angeles, CA. HIV testing and condom use were assessed via a self-administered, computer-based survey at baseline (n 5 117), 1 month (n 5 86, 74%), and 3 months (n 5 70, 60%). Results: At 3 months, rates of HIV testing increased among participants in the AI condition relative to the comparison group (18.8% vs. 8.1%), as did condom use during anal sex (12.1% vs. 3.3%) and vaginal sex (29.2% vs. 23.7%). Conclusions: AI-enhanced PCA intervention is a feasible method for engaging youth experiencing homelessness in HIV prevention
piloting_the_use_of_artificial_intelligenceto_enhance_hiv_prevention_interventionsfor_youth_experiencing_homelessness.pdf

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