INTERVENTION DESIGNS

What is a JITAI?

The JITAI is an intervention design that uses mobile and wireless technology to treat individuals in their natural environments. By monitoring moment-to-moment changes in an individual’s internal and contextual state, JITAIs are able to deliver the right type and amount of support at the right time, motivating health behavior change.

Why use JITAIs?

Treatment in the moment is powerful.

Health practitioners have limited opportunities to treat and engage with their patients, but patients’ mobile devices are always with them. Using mobile sensing, JITAIs identify moments in a person’s day when intervention is most likely to make an impact. These include moments of opportunity, in which the potential for positive change is the greatest, and moments of vulnerability, in which health behaviors are most likely to slip. Then, through the same mobile device, JITAIs deliver an intervention, influencing the patient to engage in behaviors that move them towards treatment goals.

JITAIs make treatment at scale simple.

The ubiquity of mobile devices means almost everyone is ready to receive treatment through a JITAI. As global demand for healthcare spreads resources thin, JITAIs offer a way to provide evidence-based, individualized care that scales quickly at a low cost per patient.

What are the key components of a JITAI?

Intervention Options

JITAIs deliver two main types of interventions, known in mobile health (mHealth) as push interventions and pull interventions. When a JITAI delivers an intervention based on a person’s internal and external status, this is called a push intervention. When a JITAI makes a resource available for a person to access at any time, this is a pull intervention. Push interventions may direct patients to interact with pull intervention content in a particular way at a particular time.

Tailoring Variables

A tailoring variable represents information about an individual that determines what conditions trigger the delivery of an intervention and which intervention is delivered in a JITAI. Tailoring variables are measured before and during the course of a JITAI through a combination of self-reporting and passive monitoring with mobile devices. At predetermined thresholds, tailoring variables trigger an intervention.

Proximal and Distal Outcomes

Proximal outcomes are the short-term goals intervention options are intended to achieve. JITAIs measure proximal outcomes shortly after an intervention is delivered to gauge whether the intervention had an effect.

A distal outcome is the long-term goal a JITAI is designed to achieve. Intervention options in a JITAI are designed to impact multiple proximal outcomes as a means of achieving a single distal outcome.

What are the key components of a JITAI?

Intervention Options

JITAIs deliver two main types of interventions, known in mobile health (mHealth) as push interventions and pull interventions. When a JITAI delivers an intervention based on a person’s internal and external status, this is called a push intervention. When a JITAI makes a resource available for a person to access at any time, this is a pull intervention. Push interventions may direct patients to interact with pull intervention content in a particular way at a particular time.

Tailoring Variables

A tailoring variable represents information about an individual that determines what conditions trigger the delivery of an intervention and which intervention is delivered in a JITAI. Tailoring variables are measured before and during the course of a JITAI through a combination of self-reporting and passive monitoring with mobile devices. At predetermined thresholds, tailoring variables trigger an intervention.

Proximal and Distal Outcomes

Proximal outcomes are the short-term goals intervention options are intended to achieve. JITAIs measure proximal outcomes shortly after an intervention is delivered to gauge whether the intervention had an effect.

A distal outcome is the long-term goal a JITAI is designed to achieve. Intervention options in a JITAI are designed to impact multiple proximal outcomes as a means of achieving a single distal outcome.

Where are JITAIs found?

JITAIs have been implemented and pilot tested in several domains of health behavior change.

Psychiatric Care

FOCUS

FOCUS is a smartphone behavioral intervention that provides illness management support to individuals with schizophrenia. FOCUS prompts individuals three times a day (via auditory signals and visual notifications) to assess their status in five target domains: medication adherence, mood regulation, sleep, social functioning, and coping with hallucinations. Once signaled, individuals can engage or ignore the prompt. If they engage, the system launches a brief assessment. When an assessment indicates that the individual is experiencing difficulties, FOCUS recommends self-management strategies to ameliorate the type of difficulties the individual endorsed; otherwise, FOCUS provides feedback and positive reinforcement. No intervention is offered if the individual ignores the prompt.

Substance Use Disorders

ACHESS

ACHESS is a JITAI for supporting recovery from alcohol use disorders. It provides 24-7 access via smartphone to a wide variety of supportive services, including computerized cognitive-behavioral therapy, web-links to addiction-related websites, and information on alcohol-free events in their community. Global positioning system (GPS) technology tracks when an individual approaches a high-risk location, namely a location that the individual pre-specified as a place where s/he regularly obtained or consumed alcohol in the past (e.g., favorite bar). If the individual approaches a high-risk location, ACHESS sends an alert to the individual asking him/her if s/he wanted to be there; otherwise, no alerts are delivered.

Personal Wellness

SitCoach

SitCoach is a JITAI for office workers in which messages encouraging activity are delivered via a smartphone. Software on the worker’s computer records uninterrupted computer time via mouse and keyboard activity. If 30 min of uninterrupted computer time occurs, the smartphone delivers a persuasive message to raise the individual’s awareness of his/her sedentary behavior and encourage a walking activity; otherwise, no messages are delivered. SitCoach does not deliver a message if the individual received a message in the past 2 hours, even if s/he exceeds the computer activity threshold during that time.

Constructing optimized JITAIs.

During the development of a JITAI, researchers must investigate the utility of each component and how well different components work together. The d3center specializes in developing new methods for constructing adaptive interventions, including JITAIs. d3c pioneered the Micro-Randomized Trial, an experimental design for optimizing JITAIs, and methods for conducting and interpreting data from a Micro-Randomized Trial.

Learn more about the Micro-Randomized Trial

JITAI Resources

References

Carpenter, S. M., Menictas, M., Nahum-Shani, I., Wetter, D. W., & Murphy, S. A. Developments in Mobile Health Just-in-Time Adaptive Interventions for Addiction Science. Curr Addict Rep 7, 280–290 (2020).

Hiremath, S. V., Amiri, A. M., Thapa-Chhetry, B., Snethen, G., Schmidt-Read, M., Ramos-Lamboy, M., . . . Intille, S. S. (2019). Mobile health-based physical activity intervention for individuals with spinal cord injury in the community: A pilot study. PloS one, 14(10), e0223762.

Nahum-Shani, I., Hekler, E. B., & Spruijt-Metz, D. (2015). Building health behavior models to guide the development of just-in-time adaptive interventions: A pragmatic framework. Health Psychology, 34(S), 1209.

Nahum-Shani, I., Smith, S. N., Spring, B. J., Collins, L. M., Witkiewitz, K., Tewari, A., & Murphy, S. A. (2018). Just-in-Time Adaptive Interventions (JITAIs) in Mobile Health: Key Components and Design Principles for Ongoing Health Behavior Support. Annals of Behavioral Medicine, 52, 446-462. doi:10.1007/s12160-016-9830-8.

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