An educational program for remote training and supervision of home-based transcranial electrical stimulation: feasibility and preliminary effectiveness

Abstract

Objective:

There has been recent interest in the administration of transcranial electrical stimulation (tES) by a caregiver, family member, or patient themselves while in their own homes (HB-tES). The need to properly train individuals in the administration of HB-tES is essential, and the lack of a uniform training approach across studies has come to light. The primary aim of this paper is to present the HB-tES training and supervision program, a tele-supervised, instructional, and evaluation program to teach laypeople how to administer HB-tES to a participant and provide a standardized framework for remote monitoring of participants by teaching staff. The secondary aim is to present early pilot data on the feasibility and effectiveness of the training portion of the program based on its implementation in 379 sessions between two pilot clinical trials.

Materials and Methods:

The program includes instructional materials, standardized tele-supervised hands-on practice sessions, and a system for remote supervision of participants by teaching staff. Nine laypersons completed the training program. Data on the feasibility and effectiveness of the program were collected.

Results:

No adverse events were reported during the training or any of the HB-tES sessions after the training. All laypersons successfully completed the training. The nine laypersons reported being satisfied with the training program and confident in their tES administration capabilities. This was consistent with laypersons requiring technical assistance from teaching staff very infrequently during the 379 completed sessions. The average adherence rate between all administrators was over 98%, with 7/9 administrators having 100% adherence to the scheduled sessions.

Conclusions:

These findings indicate that the HB-tES program is effective and is associated with participant satisfaction.

Significance:

We hope that the remote nature of this training program will facilitate increased accessibility to HB-tES research for participants of different demographics and locations. This program, designed for easy adaptation to different HB-tES research applications and devices, is also accessible online. The adoption of this program is expected to facilitate uniformity of study methodology among future HB-tES studies, and thereby accelerate the pace of tES intervention discovery.

1. Introduction

Transcranial electrical stimulation (tES) has recently gained popularity as a promising intervention for numerous clinical conditions (For review, please see: ^1,2). tES, which includes transcranial direct current stimulation (tDCS), transcranial alternating current stimulation (tACS), and transcranial random noise stimulation (tRNS), is administered to the patient or participant using a battery-powered device that transmits low-intensity electrical current between two or more electrodes placed on the scalp. This process generates an electric field that penetrates the brain and can interact with neural processing ^3–5. When properly applied, tES has been shown to be safe in laboratory and/or clinical settings^6–8. These settings allow for a well-controlled environment where the interventions and participants are closely monitored and where potential adverse events can be detected and managed rapidly. The mechanisms underlying tES clinical efficacy are thought to be dependent on long-lasting neuroplastic changes in response to repeated exposure over multiple days, weeks, and potentially months ^9–11. Thus, while promising as a therapeutic strategy, tES interventions require significant time and effort by the patients, including planning, traveling, and spending time at clinical or research centers. This may often be burdensome, especially for older adults and those suffering from significant functional limitations. Moreover, in-person interaction between participants and research staff may not be possible for individuals who live far away from research facilities, for those who are immunocompromised, or during periods requiring social isolation such as the COVID-19 pandemic.

The challenges of administering multi-session tES interventions within the laboratory setting have led to the development of home-based tES (HB-tES) in which a caregiver, family member, or the patient themselves administers tES in their own homes. Aside from the many Do-It-Yourself and Direct-to-Consumer tES devices being promoted and sold ^12–15, several ‘medical-grade’ HB-tES devices are now manufactured and commercialized (see table 1). These are classified in the U.S. as investigational devices by the Food and Drug Administration (FDA) and none have yet to receive clearance for a medical application. In our experience, HB-tES has the potential to relieve patients of the need for travelling to and from a clinic or a laboratory that may be far away from their home. Furthermore, because participants can gain access to tES irrespective of where they live, this approach may help prevent geographical selection bias and promote diversity in treatment samples, increase sample sizes, and enable protocols with a greater number of tES sessions (Figure 1).

Table 1.

Major Home-Based-Transcranial Electrical Stimulation Equipment Manufacturing Companies.

Companies	Location	Current flow of electric charge	Electrode Type	Multi- or Bichannel
Soterix Medical	New York, NY	tDCS, tACS, tRNS	Saline-based	Bichannel
neuroConn	Ilmenau, Germany	tDCS	Saline-based	Bichannel
Neuroelectrics Corp	Barcelona, Spain	tDCS, tACS, tRNS	Gel-based	Multichannel
Newronika s.r.l	Milan, Italy	tDCS	Saline-based	Bichannel
Sooma	Helsinki, Finland	tDCS	Saline-based	Bichannel

tDCS, transcranial direct current stimulation; tACS, transcranial alternating current stimulation; tRNS, transcranial random noise stimulation.

Figure 1: Advantages of laboratory and home-based administered transcranial electrical stimulation (tES).

Laboratory-based tES interventions are safe, enable standardized administration from qualified clinical and research staff following published tES protocols and guidelines, and may offer faster response times in the unlikely event of an adverse event. HB-tES minimizes travel burden for study participants, reduces geographical selection bias, and may allow for greater flexibility in the scheduling, timing and duration of tES interventions. Made with Canva^® Version 2.0, 2021 ©

The number of published HB-tES trials has rapidly increased over the past decade (see Table 1 in ¹⁶). The first case study was reported in 2013 by Andrade and colleagues who utilized HB-tDCS to suppress auditory hallucinations in a 24-year-old patient ¹⁷. HB-tES has since been found to be feasible and effective at improving function in patients with multiple sclerosis (MS) ¹⁸, Alzheimer’s disease ¹¹, Parkinson’s disease ¹⁹, and major depressive disorder ^16,20. For a comprehensive overview of the current literature please consult the following reviews: ^21–23.

Home-based administration of tES interventions by laypersons, although promising, requires considerable effort to ensure quality control, rigor, and safety. The International Federation of Clinical Neurophysiology (IFCN) recently recommended a set of core competencies that should be achieved by technicians, scientists, and clinicians involved in the administration of tES.²⁴ They also argued that training in the administration of tES should comprise a combination of conceptual education, hands-on training, and supervised practice. Specifically in the context of HB-tES, Charvet et al²⁵ highlighted the critical importance of ensuring that laypersons acquire proficiency in all aspects of HB-tES before administering stimulation by providing training materials to participants and conducting evaluations to verify competency. More recently, Charvet et al²⁶ published thoughtful recommendations for the safe deployment of HB-tES.

Despite the above guidelines, the training of layperson administrators of HB-tES has not been standardized. To date, only a few published studies have allowed completely remote training,^16,27 with most studies providing laboratory-based training to administrators over the course of one to five days.^{11,20,28,29,30,31,32, 33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51} Most have tested administrator and/or participant competency,^{20,32,33,34,36,37,38,39,50,51} yet only some provided training manuals^{16,33,38,48,50} or instructive videos.^{34,35,36,38,41,48,50} Regarding the remote monitoring of participants by research staff, studies were split by either remotely monitoring participants virtually during every session^{16,28,30, 34,35,36,40,41,43,48,49,52} or having research staff “on-call” if assistance was needed.^{20,29,31,33,39,41,42,47,50} Overall, the training approaches currently used in HB-tES investigations differ significantly across studies. Therefore there is an urgent need to develop a training program to ensure rigor and standardization of HB-tES intervention delivery and side-effect reporting across study sites.

We leveraged the experience and knowledge gained from completing multiple clinical studies employing tES interventions to develop the framework of the HB-tES training program in general and the content of the instructional resources specifically. Inspired by the guidelines of the IFCN and the recommendations laid out by Charvet and colleagues, we have created a comprehensive HB-tES training and supervision program with the explicit goal of optimizing rigor within and between clinical trials that utilize tES in the home setting. Here, we aim to describe the program—which includes instructional materials and familiarity quizzes, hands-on practice sessions, and both remote supervision and on-demand research staff assistance thereafter—and provide initial evidence on the feasibility and educational effectiveness of the program based on 379 HB-tES sessions conducted by laypersons who completed the program.

2. Materials and Methods: The home based transcranial electrical stimulation training and supervision program

The Home based transcranial electrical stimulation training program was developed aiming to fulfill the IFCN recommendations on training in the practice of noninvasive brain stimulation ²⁴. The program’s major goal is to provide a layperson administrator (e.g., caregiver, spouse, family member, volunteer) with the skills to safely and appropriately administer tES in the home setting. The program is designed to be implemented remotely, not requiring any in-person sessions. The curriculum includes materials that cover basic knowledge areas relevant to tES application and was designed to be accessible to individuals across a wide range of ages, socioeconomic status, and educational backgrounds. The training portion of the program focuses on preparation and maintenance of the equipment, tES safety in the home setting, and troubleshooting. We used the Starstim^® - Home Kit (Neuroelectrics Corp.) for both of these pilot studies. However, this training program may be adapted to any HB-tES device, and was in fact specifically designed to achieve general competencies that are not tied to the use of one specific HB-tES device.

The HB-tES training program has three phases: 1) self-study; 2) hands-on guided practice; and 3) remote supervision (Figure 2). In phase 1, the administrator receives training materials in the form of a written manual and a set of educational videos. The instructional materials are designed to ensure that the administrator achieves a foundational understanding of tES generally and how to properly administer tES in the home environment specifically. The administrator is asked to demonstrate understanding of key concepts by a set of familiarity quizzes before moving on to Phase 2. Phase 2 is comprised of a set of remotely-hosted practice sessions during which a member of the teaching staff guides the administrator step-by-step through the tES administration process. Teaching staff were members of the research team experienced in the method of HB-tES administration. The administrator transitions to Phase 3 once they demonstrate proficiency and report comfort with tES administration. Within Phase 3, the administrator is responsible for carrying out the HB-tES sessions independently with remote monitoring and on-demand assistance provided by teaching staff.

Figure 2: Structure of the home-based transcranial electrical stimulation (HB-tES) training and supervision program.

In phase 1, the administrator is given instructional materials in the form of a manual and six training videos with embedded familiarity quizzes. During phase 2, the administrator practices the delivery of tES under live remote supervision by teaching staff. In phase 3, the administrator leads the HB-tES sessions independently with electronic notification-based remote monitoring and on-demand remote staff assistance. Made with Canva^® Version 2.0, 2021

2.1. Study Population

The HB-tES Training and Remote Supervision Program was implemented within two ongoing pilot clinical research trials. Each trial acquired separate ethical approval from the Hebrew SeniorLife Institutional Review Board and a total of nine administrators across both studies provided informed consent and were enrolled. The complete list of eligibility criteria for both trials are listed at www.clinicaltrials.gov. Briefly, one trial (NCT04732533) focused on improving mobility in older adults over the age of 55 that were ambulatory and non-demented, yet presented with mobility difficulties and a high risk of falling. This trial also included an optional one-year extension of the intervention. The other trial (NCT04799405) focused on improving depressive symptoms in older adults over the age of 55 who were diagnosed with major depressive disorder (MDD). Stimulation montages for both studies are shown in Table 2. Eligibility criteria for tES administrators were the same for both trials. Administrators were included if they were aged 21 or older, scored ≥26 (out of 30) on the Montreal Cognitive Assessment, and reported proficiency with computers as well as intact hearing and vision either with or without corrective devices. The characteristics of each enrolled tES administrator across both studies and their relationship to the participant are presented in Table 2.

Table 2.

Stimulation Parameters for Pilot Studies NCT04799405 and NCT04732533.

Stimulation parameters	NCT04732533 (Mobility)	NCT04799405 (major depressive disorder)
Stimulation target	L-DLPFC	L-DLPFC
Type of stimulation	tDCS	tDCS
NG Pistim electrode positions (10–20 EEG system)	FC5, F3, CP1, FC1, Cz, AF4	F3, FZ, FC5, FP1
Maximum current per electrode	1.00 mA	1.75 mA
Length of session	20 min	30 min

L-DLPFC, left dorsolateral prefrontal cortex.

2.2. Training curriculum

Administrators receive a training manual and a series of training videos that cover instructions on head montage preparation, device set-up, equipment cleaning and storage, troubleshooting, and participant safety. The training manual provides step-by-step written instructions on each component of the tES administration process. The training videos incorporate short video clip demonstrations on how the stimulation session should be conducted. Both the training manual and the training videos are structured into multiple chapters, each discussing a specific aspect of HB-tES. Familiarity quiz questions are posed at the end of each video chapter to test the administrator’s acquisition of knowledge (see Figure 3 for example questions). The purpose of these quizzes is to familiarize administrators with the nomenclature and the appearance of the tES equipment as well as to emphasize the most important aspects of the general tES administration process.

Figure 3: Sample familiarity quiz questions that accompany targeted training videos.

A quiz must be successfully completed at the end of each chapter in order for the administrator to progress to the next chapter. Made with Word 2013, © Microsoft 2022.

Chapter 1: Equipment Overview

Administrators are provided with an overview of all the equipment and a set of instructions on how to care for the equipment. First, a visual inventory of the equipment is presented. This includes the stimulator, headgear, gel-based or saline-based electrodes. The administrator is instructed on best practices for equipment storage and on how to correctly handle the equipment in order to decrease unnecessary wear and tear.

Chapter 2: Stimulation Set-up

Administrators are provided with a step-by-step demonstration of the HB-tES administration process. The administrator is instructed to ensure before each session that the participant’s hair is dry, that there are no open lesions or wounds on the participant’s scalp, and that the participant uses the restroom if needed. The administrator then receives guidance on how to assemble the stimulation equipment, prepare the electrodes with electro conductive gel or saline solution, position the headgear, and create good impedance between the scalp and electrodes. For example, administrators are informed that too much gel or saline solution can cause bridging between neighboring electrodes and thus affect the efficacy of tES stimulation, whereas too little gel or saline solution might not be enough to lower electrode impedance.

Chapter 3: Troubleshooting

Administrators are provided with knowledge of how to tackle common challenges that may come up during HB-tES. One common issue is high impedance between the electrodes and the scalp. In such a situation, administrators are instructed to move the hair to the side of the electrode to optimally expose the scalp for better contact, add more conductive gel or saline to enhance connectivity, and to ensure tight and secured contact between the electrodes and scalp.

Chapter 4: Disassembly, Cleaning, and Charging

This chapter teaches administrators how to disassemble and store equipment after use to ensure functioning. The administrator is instructed to clean the electrodes using lukewarm water and leave them to dry. Participants should avoid using any harsh chemicals to clean and prevent using rough materials to brush the electrode surface. Administrators are instructed to charge the stimulator after use so that the equipment is fully charged for the next session.

Competency Chapter 5: Safety

In this chapter, administrators are taught about potential side effects of tES and what to do when participants experience one or more side effects. tES is considered very safe with only minimal side effects ⁶. Common reported side effects include itching, tingling, headache, burning, and discomfort. Before and after each tES session, participants complete a questionnaire that inquiries about the degree to which the participant is experiencing specific side effects. Such a questionnaire can be incorporated into the study design by embedding it into the tES controlling system, contacting participants before and after each session by phone or email, or through paper-based questionnaires that can be mailed to teaching staff. Administrators are instructed to not start a session (or stop it immediately) if the participant is experiencing severe symptoms before or during a stimulation session, and to notify their study team immediately.

For examples of our training materials, please see our webpage: https://www.marcusinstituteforaging.org/research/neurostimulation-research-program/hb-tes-trainingand-supervision-program

2.3. Tele-supervised hands-on practice sessions

Once all familiarity quiz questions have been completed, administrators advance to phase 2, which consists of a set of remotely hosted hands-on practice sessions. The purpose of these sessions is for the administrator to gain practical experience delivering HB-tES while in the virtual presence of teaching staff who can provide guidance in real time. The practice sessions are hosted via the administrator’s preferred videoconferencing platform. It is suggested that the administrator uses a smartphone for the videoconference so that the camera can be easily positioned to visualize specific parts of the HB-tES setup as needed.

A minimum of three practice sessions are hosted, each with a different instructional purpose: guidance, rehearsal, and evaluation. Should an administrator not achieve proficiency and pass the evaluation at the end of the third practice session, additional guidance and rehearsal is provided as needed.

Hands-on Practice Session 1: Guidance

The administrator receives detailed instructions from the teaching staff on how to carry out each operation in the HB-tES process. The administrator is instructed on, among other things, how to prepare the participant for stimulation, secure the stimulation montage to the scalp, check for acceptable impedance metrics, and initiate the stimulation. The teaching staff instructs the administrator to remind the participant to rest comfortably and to avoid unnecessary movements or conversation. Finally, the administrator is guided through the disassembling, cleaning, and stowing of the equipment. The teaching staff also provides recommendations for how to troubleshoot and solve commonly encountered issues. For example, the teaching staff describes techniques for how to efficiently decrease impedance values. During the first session, the administrator is encouraged to ask the staff member as many clarifying questions as desired.

Hands-on Practice Session 2: Rehearsal

The administrator conducts the HB-tES process as independently as possible, but is allowed to ask questions to the teaching staff when needed. Further, teaching staff corrects the administrator should they commit any errors and provide subsequent coaching in order to help minimize the likelihood of committing the same error in the future.

Hands-on Practice Session 3: Evaluation

Teaching staff observe the administrator as they lead the tES session in order to complete a formal evaluation of the administrator’s proficiency. To pass this evaluation check, administrators must adequately perform all operations included in the tES administration process, including setting up the equipment, monitoring the participant during the stimulation, disassembling the equipment and cleaning, as well as troubleshooting.

2.4. Remote evaluation of competencies in administering HB-tES

To guarantee that all administrators acquire a high level of competence in the HB-tES process, multiple assessment points throughout this training program maintain a continuous evaluation of the administrator’s level of understanding and proficiency.

Specifically, in Phase 1, administrators are presented with a familiarity quiz comprising three to five multiple-choice questions at the end of each Competency Chapter. The main purpose of these quizzes is to ensure that administrators have become generally familiar with the tES equipment and the HB-tES administration process. They must score an 80 percent on each chapter quiz to progress from Phase 1 to Phase 2. Administrators are provided with a review of the correct responses to those questions that they incorrectly answered for each quiz. At the end of Phase 2, the administrator’s proficiency in carrying out tES is formally assessed during the third training session. We utilize a competency evaluation checklist adapted from Charvet and colleagues ²⁵. This checklist details all operations required for the successful administration of HB-tES. The administrator passes the evaluation check if they adequately perform each operation on this list. This is done by the administrator demonstrating their knowledge by a hands-on HB-tES administration and oral explanation of the process while observed by teaching staff. If the administrator fails the evaluation check they are offered an explanation on how to prevent the same error in the future. They then repeat the evaluation phase on subsequent sessions until they achieve proficiency and self-report comfort in the HB-tES administration process.

2.5. Remote supervision and assistance in administering HB-tES

Administrators enter Phase 3 of the training program only after passing Phase 1 and 2. In this phase the administrator conducts HB-tES without the real-time virtual presence of a member of the teaching staff. However, teaching staff are available and can be called upon for remote assistance as needed.

The importance of remote supervision has been highlighted by Charvet and colleagues ^{25, 26}. Remote supervision ensures that the teaching staff control when tES is administered, allows for the monitoring of treatment progress and compliance, provides the staff with oversight over participant’s experience of side effects, and allows for the identification of when remote technical guidance is needed.

Our remote supervision framework is comprised of two key elements. Firstly, supervision of the overall HB-tES intervention is enabled by an online scheduling portal. Only staff has access to this portal. When staff and the participant mutually agree on a time for the tES session, the staff member schedules the session on the online portal. Secondly, the remote supervision framework leverages a notification system that uses both email and text notifications. Email notifications generate an overview of each HB-tES session from start to finish and are utilized for tracking. Emails are sent to designated staff when the session is started, when an impedance check is initiated, when the outcome of the impedance check is calculated, and when a session is completed. Responses of side effects questionnaires are also sent to staff via this platform.

3. Results: Implementation of the HB-tES training and supervision program

Here, we present initial evidence on the feasibility and effectiveness of the program as implemented in two pilot clinical research trials (NCT04799405 and NCT04732533). See Table 2 for relevant demographic and other characteristics of the nine layperson administrators.

We examined the training program’s feasibility by recording administrator satisfaction levels and data on the adherence to the tES schedule after training was complete. Effectiveness of the training program was evaluated by the number of practice sessions that administrators required to complete the training program, as well as their stated level of confidence in the acquisition of troubleshooting skills and the number of adverse events that occurred.

i). Self-report of confidence in acquired troubleshooting skills.

A total of 379 HB-tES sessions (of 405 scheduled sessions) have been completed by administrators who underwent the tele-supervised HB-tES training and remote supervision program. These sessions were completed after the three practice sessions described in the HB-tES training and remote supervision program. After completion of the training program, administrators were asked to report how much they agreed to the following statement: “If I made a mistake during the stimulation set-up, I felt confident that I could figure it out and correct it on my own” by indicating that they ‘strongly agreed’, ‘agreed’, ‘neither agreed nor disagreed’, ‘disagreed’, or ‘strongly disagreed’. Eight of the nine administrators indicated that they strongly agreed, and one administrator said they agreed.

ii). Number of hands-on practice sessions required for administrators to be proficient and comfortable in tES administration.

At the end of phase 2, all nine administrators passed the formal proficiency evaluation and self-reported comfort with tES administration after three hands-on practice sessions.

iii). Self-Report of satisfaction with training and educational materials.

Administrators were asked how satisfied they were with the training and educational materials that were provided, by reporting that they were either ‘not satisfied’, ‘somewhat satisfied’, or ‘very satisfied’. Eight out of nine administrators responded they were very satisfied, and one administrator was somewhat satisfied.

iv). Remote assistance required from staff.

Once administrators started to independently lead the HB-tES sessions, remote assistance from staff was required infrequently. The two common issues that participants had were either difficulty connecting the device to their home Wi-Fi network or difficulty achieving sufficient electrode impedance.

v). tES session schedule adherence rate.

Across all participants, >93% of schedule sessions were completed successfully; only 26 of 405 scheduled sessions were missed. Of the missed sessions, 73% (19 sessions) were due to scheduling conflicts (e.g., the administrator was unexpectedly busy or out of town), 11% (3 sessions) were due to medical issues unrelated to the study (e.g., recovery from a surgery or vaccine), 11% (3 sessions) were due to a tES device malfunction, and 4% (1 session) was missed due to an argument between the participant and administrator. Additionally, of the 26 sessions that were missed, 24 were missed by a single participant/administrator pair (Table 2). In this case, the administrator was still working full-time and had unexpected schedule conflicts. The average adherence rate between all administrators was over 98%, with 7/9 administrators having 100% adherence to the scheduled sessions.

vi). Occurrence of adverse events

No adverse events occurred during the training program or during the administration of the tES at home by laypersons after the completion of the training program.

4. Discussion

The HB-tES training and supervision program was designed to help ensure effectiveness and rigor of tES administration by lay persons in remote settings. Results of our initial pilot studies, which were focused on older adults, indicate that the HB-tES training and supervision program is feasible and effective. This program was developed following the IFCN guidelines for providing tES training to technicians, scientists, and clinicians ²⁴, as well as the recommendations for remotely supervised tDCS administration published by Charvet and colleagues^{25, 26}. The IFCN guidelines suggest that any training program incorporate three pillars: tES education, hands-on training, and supervised practice²⁴. We have not only included these three essential pillars in our first two phases of this program, but also created a remote supervision and support system for participants during the entirety of the study. We have brought the above guidelines and recommendations from the laboratory to the homes of participants to be used by a layperson. Our training program described here provides not only guidelines but materials (manual, videos, quizzes, competency checklist, and more) that may be used to facilitate standardization of participant/administrator training for HB-tES across research and clinical groups. Our early preliminary data indicates that our program is feasible to implement, at least when using laypersons with relatively strong baseline computer proficiency, and was effective at training administrators to achieve proficiency in tES concepts and techniques. While dedicated future work is still needed to optimize the educational program, we believe that our program can be used—with supplemental training and instruction on devices and intervention characteristics specific to a given trial—to help ensure rigor of home-based delivery of tES interventions.

Here, we presented pilot data from a small sample of adults across a wide range of ages (age range, 31–80 years). These preliminary data suggest that it is feasible for laypersons, with self-reported computer competency at baseline, to use our training program to achieve proficiency and confidence in tES administration in a relatively short time. Our results further suggest that it is possible to successfully deliver multisession tES interventions within clinical trials using the home-based approach. Average adherence to the HB-tES protocol was very high and similar to other HB-tES study adherence rates^23,51 (and comparable to laboratory-based tES intervention adherence). Moreover, administrators training for tES contacted research staff for technical assistance infrequently, and no unexpected side effects or adverse events were reported.

We developed the HB-tES training and supervision program with the intention for it to be adapted and utilized by other research groups (please contact the corresponding author for a copy of the materials). While we found success in training laypersons across a wide range of ages to administer tES to individuals with depression or mobility impairment, additional training elements and/or safeguards may need to be designed and implemented in order to use this program for other patient populations; e.g., individuals with brain damage due to stroke, neurodegenerative movement disorders, etc. Specific elements of the program may also need to be adapted to fit the needs of research studies with different patient populations, tES equipment, and specific protocols (e.g., stimulation montage, stimulation parameters, etc.). Further, given that ongoing neural activity induced by changing task demands or endogenous network fluctuations can significantly influence how brain stimulation affects neural activity and behavior, future use of our training and supervision program could be expanded to include training for administration of HB-tES with the patient completing a concurrent cognitive or other functional task. The primary purpose of this paper and our training program, therefore, is to help ensure rigor of intervention delivery within such future trials.

Our data on feasibility and effectiveness of the training program were acquired from a small cohort of laypersons who were mostly Caucasian, self-reportedly proficient with computers, and held at least some collegiate education. In addition, perhaps because most caregivers of older adults are women,^53,54,55 most of the administrators recruited for tES in this work were women. We recognize the limitations of our small sample size and emphasize that further research is needed to test (and optimize) the described training and supervision program in larger, more diverse samples. Participants and administrators of tES were not involved during the development of the training program. Thus, although we did obtain retrospective feedback, future studies are needed to optimize the program by directly including end users in an iterative design process. We plan to continue collecting feedback from future participants in our program and to apply all their feedback through consistent updates to our training materials available on our website. Although we observed rather high participant adherence to the intervention and training program in both pilot trials, future efforts are still needed to determine the degree of research staff time and effort required to troubleshoot and answer participant questions on an ongoing basis, to minimize missed sessions due to technical problems and maximize intervention adherence over time. Future investigations also are warranted to explore the extent to which individuals with relatively low levels of technologic experience or with limitations in cognition, sensory function, and motor control can successfully learn to administer tES. Such efforts are expected to further optimize the program’s applicability and effectiveness.

Finally, we envision that future upgrades to the training and supervision program will be needed to more fully ensure uniformity of tES administration within and between trials. As just one example, in the current pilot studies, accurate placement of the montage/headcap by administrators was taught during the training program and subsequently presented visually on the device tablet during each session. In the future, for example, the requirement for photographic or video evidence of correct set-up may help to ensure proper delivery and induction of electric fields to the brain target of interest. Nevertheless, we contend that the described program is a necessary first step with promise to facilitate uniformity of study methodology among HB-tES trials.

Table 3.

Demographic Characteristics, Computer Proficiency, and Session Compliance of Layperson Administrators

Age (y)	Sex	Race	Relationship to corresponding participant	Education	Computer comfortability	No. of sessions administered	No. of sessions missed	Diagnosis of corresponding participant
68	F	White/Caucasian	Spouse	≥3 y of graduate school	Extremely comfortable	151*,**	24 (86% compliant)	Major depressive disorder, Parkinson’s disease
58	F	White/Caucasian	Spouse	Bachelor’s degree	Extremely comfortable	22	0 (100% compliant)	Mobility difficulties, high risk of falling
52	F	Black/African American	Geriatric Care Manager	High school/GED	Somewhat comfortable	88*	2 (98% compliant)	Mobility difficulties, high risk of falling
56	M	White/Caucasian	Spouse	Bachelor’s degree	Somewhat comfortable	37	0 (100% compliant)	Major depressive disorder
34	F	White/Caucasian	Child	Bachelor’s degree	Extremely comfortable	37	0 (100% compliant)	Major depressive disorder
79	F	White/Caucasian	Spouse	≥3 y of graduate school	Extremely comfortable	22	0 (100% compliant)	Mobility difficulties, high risk of falling
64	F	White/Caucasian	Spouse	-	Somewhat comfortable	22	0 (100% compliant)	Mobility difficulties, high risk of falling
34	F	White/Caucasian	Child	Bachelor’s degree	Extremely comfortable	22	0 (100% compliant)	Mobility difficulties, high risk of falling
30	F	White/Caucasian	Child	Master’s degree	Extremely comfortable	22	0 (100% compliant)	Mobility difficulties, high risk of falling

^*These administrators participated in an extension of their pilot study that lasted up to one year.

^**This participant participated in both pilot studies mentioned and the year-long extension, hence the higher number of total sessions administered.

Table 4.

Administrator Demographics for the Implementation of the HB-tES Training and Supervision Program.

Administrator demographic details
Patient participant condition	Geriatric depression, memory impairment, and mobility deficits.
Total no. of sessions completed	379
Sample size	9
Age range(y)	31–80
Sex	8 women, 1 man
Electronic device use frequency	8/9 >once/d 1/9 once/d
Self-report of satisfaction	8/9 very satisfied 1/9 somewhat satisfied
Self-report of troubleshooting skills	8/9 strongly agree 1/9 agree
Mean no. of practice sessions	3
No. of sessions not completed	26