Assessing Fidelity in Yoga Interventions for Chemotherapy-Induced Peripheral Neuropathy: Decision-Making to Enhance Protocol Quality Adherence

Abstract

Background:

Yoga interventions need fidelity monitoring to standardize the trial process and ensure adherence. We examined fidelity measures of current yoga trials and developed a fidelity assurance process in a phase III randomized clinical trial addressing chemotherapy-induced peripheral neuropathy among cancer survivors.

Methods:

We qualitatively analyzed the fidelity monitoring components in published clinical trials on yoga therapy for chemotherapy-induced peripheral neuropathy through a literature search in PubMed from inception to February 2023. Leveraging fidelity measures for community-based, complex interventions and yoga therapy reporting guidelines, we developed an instructor/participant-oriented fidelity checking approach in an ongoing phase III trial evaluating yoga for improving chemotherapy-induced peripheral neuropathy in cancer survivors. Two researchers independently assessed 4 of 8 video recordings of yoga instructor-led training sessions (50%) and participant-kept home practice logs using a developed fidelity checklist.

Results:

None of the 4 eligible yoga trials specifically have intervention fidelity measures. We prospectively incorporated yoga instructor training, virtual delivery, and participant engagement strategies in the phase III trial protocol following guidelines. All trial yoga instructors were trained under study protocol to ensure compliance and participant engagement. There was high intervention fidelity in all instructor-led virtual sessions: an average of 100% adherence to class structure and three-thirds on specific skills. Assessment of participant adherence to the established home yoga protocol was 63%.

Conclusion:

Yoga trials for chemotherapy-induced peripheral neuropathy need adequate fidelity measures. Our study provides a feasible fidelity-monitoring approach to ensure trial intervention delivery and protocol adherence by instructors and participants in oncological settings.

Introduction

Yoga is a multi-component, mind-body practice combining physical postures (asana), breathwork (pranayama), ethical principles (yamas and niyamas), and meditation (dharana, dhyana) practices. ¹ Prior yoga interventions have improved chemotherapy-induced peripheral neuropathy,^{2 -4} including hatha yoga and restorative yoga. However, over 20 different styles of yoga exist. ⁵ Considering the heterogeneity of yoga practice, it is difficult to standardize yoga treatment in clinical trial settings, leading to decreased methodological rigor, inconsistent findings, and poor generalizability among yoga trials. ⁶ Recent initiatives established standardized reporting guidelines for yoga interventions in clinical trials, that is, the “CheckList Standardizing the Reporting of Interventions For Yoga” (CLARIFY). ⁷ There is a pressing need for intervention fidelity monitoring to ensure the delivery of yoga intervention as developed in trial protocols for the compliance and subsequent real-world implementation.

One crucial aspect of standardizing trial yoga interventions focuses on fidelity measures: the degree to which an intervention is delivered as described in the protocol or as intended by the study planners. ⁸ Evaluating treatment fidelity and ensuring the yoga intervention is consistent with the planned intervention improves the validity of interventions and the internal and external validity of study results, otherwise may generate type I, II, and III errors.^{8 -11} Current fidelity approaches include models for behavioral change studies (Bellg et al ¹² model), complex health interventions (PRIDE model ¹³ ), and community-based interventions. Yet, there is no specific validated model to monitor yoga therapy fidelity for clinical trials.

Individual studies in noncancer populations incorporate varied fidelity metrics to ensure standard and adequate yoga intervention delivery.^14,15 For yoga trials in the oncological setting, how intervention fidelity was measured remains unknown. To inform the fidelity monitoring in a phase III yoga trial for chemotherapy-induced peripheral neuropathy (CIPN), we qualitatively analyzed existing trials to examine the fidelity measures employed in CIPN symptom management. We further developed an intervention fidelity monitoring process in the phase III yoga trial, following the fidelity measures for complex health interventions and community-based interventions, and the CLARIFY yoga therapy reporting checklist.^7,13,16

Methods

Literature Review

We conducted a literature search in the PubMed database using the terms “yoga” and “chemotherapy-induced peripheral neuropathy” to evaluate fidelity practices in yoga study designs specific to CIPN. While several yoga studies address global side effects of chemotherapy, ¹⁷ we specifically focused on CIPN. We used the following inclusion criteria: (1) clinical trials using yoga as the intervention; (2) participants with CIPN; and (3) results published in peer-reviewed journals in English from inception through February 2023. Trials were excluded if the intervention was focused on patients’ caretakers or if the outcome was pain medication adherence.

Our Randomized Control Trial

Our randomized control trial (RCT) was part of a phase III trial approved by our institution’s Institutional Review Board (NCT05121558). Participants gave written informed consent to engage in all study activities. The clinical trial evaluated gentle therapeutic yoga versus education versus waitlist control for CIPN symptom severity and fall prevention among cancer survivors at a large cancer center in the eastern United States.

Qualification of Yoga Instructors

Yoga therapy is the therapeutic application of yogic practices to help individuals manage specific symptoms or conditions, with a special emphasis on safety precautions. ¹⁸ Two skilled and experienced yoga instructors delivered our intervention: one is an internationally accredited and certified yoga therapist [Master of Science (MS), Certified International Association of Yoga Therapists (C-IAYT)] and the second instructor will earn their MS and apply to become a certified C-IAYT in July 2024. Both instructors have received their training at the Maryland University of Integrative Health (MUIH, the only Master of Science in Yoga Therapy in the United States at the time of publication), have a minimum of 500 hours in Yoga Alliance accreditation hours, and have received Yoga Alliance Continuing Education Provider (YACEP) credentials. Our instructors have extensive experience working with cancer patients through the yoga4cancer ¹⁹ program and participated in our pilot study to help develop the study protocol based on previous pilot studies.^{2 -4}

Delivery of Yoga

Each yoga class was 60 minutes in length, delivered twice weekly via Zoom. A virtual platform was used due to the COVID-19 pandemic. The yoga intervention duration was 8 weeks, for a total of 16 yoga classes. The classes involved gentle therapeutic yoga based on previously published pilot studies^{2 -4} and were taught in small groups of 2 to 6 participants. Instructors used both visual demonstration and verbal guidance. The yoga sessions consisted of the same supine, seated, standing postures, and restorative postures along with breathwork (pranayama), and meditation (dharana, dhyana) practices every time. Each session consisted of approximately 10 minutes of breathwork, 45 minutes of postures, and 5 minutes of debriefing and re-enforcement of home practice to end class. Appropriate modifications were provided as needed in real-time by class instructors for participant needs and comfort. For example, a participant given a diagnosis of spondylolisthesis before the start of the study was not able to practice prone postures (asana) as they are contraindicated. Therefore, appropriate modifications were given, such as keeping the bottom leg knee bent during supta padangusthasana, taking constructive rest during sphinx and locust pose, and stacking blocks and blankets under the knees during savasana. Instructors recorded participant attendance. The yoga protocol was based on our team’s prior pilot studies, qualitative feedback from participants, and analysis of best outcomes based on significant findings.^{2 -4}

Development of Intervention Fidelity Monitoring Process for Our Study

We conducted a literature review to understand pre-existing research before developing our own yoga arm fidelity assessment. We created a plan for our fidelity checks using Walton et al’s ¹³ five-step approach to develop robust and high-quality fidelity measures in complex health interventions. We obtained permission from Breitenstein et al ¹⁶ to adopt the validated Fidelity Checklist as a basis for our checklist (Table 1), including instructor competence in intervention delivery and instructor adherence to the intervention protocol. As such, our process included (1) modification of the “Adherence to Class Structure” section, (2) adaptation of the “Skill” section to assess leader competence, and (3) discussion of the modified checklist drafts among key stakeholders with revisions completed through an iterative process. This included in depth discussions during weekly research meetings and solicited feedback from our fellow research team members, including medical oncologists, physical therapists, yoga instructors, and clinical researchers. We repeated this process 3 times until we had a fidelity checklist vetted via consensus. Previously published yoga trials helped guide our development of intervention fidelity.^14,20 Of note, our intervention fidelity process began while our study was underway; this was after multiple IRB modifications moving the yoga intervention from in-person to a virtual platform due to the unforeseen COVID-19 pandemic. Our first participant was recruited in October of 2021 and we are expected to complete recruitment by December of 2025.

Table 1.

Yoga Group Fidelity Checklist. This table includes our fidelity checklist, adapted with permission from Dr. Susan M. Breitenstein’s “The Fidelity Checklist.” It includes a section on instructor adherence to class structure and a section on instructor skills. It also evaluates the overall tone of the yoga session and elicits additional qualitative comments and feedback from the reviewer.

Observer/Coder:  Group Instructor:  

Date of group:  Number of participants:  

Modification with permission of The Fidelity Checklist, originally published by Dr. Susan M. Breitenstein and obtained with permission to use and modify.

Please answer yes or no to evaluate if the group instructor completes the following actions.

Adherence to class structure	Yes (1)	No (0)	Comments
Seated: Verbal check in, address questions/concerns/awareness, bring attention to the breath and notice the body (5 min)	Yes	No
Supine gentle movements (10 min)	Yes	No
Seated dandasana with deep breath awareness (5 min)	Yes	No
Seated crossed legged positions (5 min)	Yes	No
Tabletop with additional postures (5 min)	Yes	No
Standing poses (10 min)	Yes	No
Prone poses (5 min)	Yes	No
Cool down poses and pranayama (5 min)	Yes	No
Supine poses (10 min)	Yes	No
General: Starts and stops the group on time	Yes	No

Scoring (goal of >80%):

Please rate the group instructor using the following scale:

1 = Skill rarely or never demonstrated (skill demonstrated < 25% of the time)

2 = Skill sometimes or occasionally demonstrated (skill demonstrated 25%-75% of the time)

3 = Skill consistently demonstrated (skill demonstrated > 75% of the time)

Skill	<25% of the time	25 to 75% of the time	>75% of the time
If applicable, introduces new group members	1	2	3
Actively engages all participants in the yoga class	1	2	3
Ensures participants have appropriate yoga materials	1	2	3
Offers appropriate modifications to participants as needed	1	2	3
Communicates with all participants in a respectful, positive, non-judgmental manner	1	2	3
Facilitates problem solving as needed	1	2	3
Starts and stops group on time	1	2	3
Actively listens when a participant is talking	1	2	3
Offers time for questions and concerns	1	2	3

Overall tone of this group:

Negative Neutral Positive

Average scoring (goal of >2.5):

Additional comments (use this section to describe specific actions of the group instructor that are strengths or specific areas of growth):

The “CheckList Standardizing the Reporting of Interventions for Yoga” (CLARIFY) guideline is a 21-item tool that outlines the details necessary for high-quality yoga research reporting. ⁷ We used this checklist to ensure elements of yoga therapy essential in clinical trial reporting covered in our fidelity process, that is, yoga activities, yoga instructor expertise, delivery, dose, and home practice. Both Fidelity Checklist ¹⁶ and CLARIFY ⁷ were used to comprehensively assess various domains of the protocol, delivery and important areas of participant adherence to home practice.

Measurement of Intervention Fidelity and Analysis Procedure

Our 2 yoga instructors recorded 8 yoga therapy sessions (between November and December 2022) and 4 recordings (50%) were randomly chosen for review. Two study members (KS and MLG) served as independent reviewers for fidelity checks in the yoga intervention. Both reviewers have a strong background in yoga knowledge as registered 200-hour yoga instructors. Neither reviewer accessed IRB/RedCap records to bias the findings. One reviewer (KS) reviewed 4 recorded sessions, while the second reviewer (MLG) reviewed 2 recorded sessions. Reviewers assessed intervention fidelity using Breitenstein’s revised checklist (Table 1) and compared results to assess findings and inter-rater reliability. Fidelity scores were calculated for each evaluated session using 2 subcategories: (1) adherence to class structure scored numerically 1 = yes and 2 = no and (2) demonstrated skills scored via 1 = rarely or never demonstrated, 2 = sometimes or occasionally demonstrated, and 3 = consistently demonstrated.

Participant Home Practice Facilitation

Our study participants were encouraged to continue a 30-minute home yoga practice 5-days a week during the 8-week yoga intervention for 40 total sessions. Recorded yoga videos were available to participants during the intervention and follow-up period to use for home practice sessions. Participants self-recorded their home practice data in a diary collected by research coordinators after the 8-week intervention.

Results

Literature Review—Yoga Study Characteristics

We identified 4 eligible RCTs from our literature review: 2 pilot RCTs with an 8-week yoga intervention group and wait-list control group^2,21, two single-arm feasibility studies using an 8-week yoga intervention.^3,4 Samples included patients with breast, gynecological, or colorectal cancers. All 4 trials were conducted with participants who had already completed chemotherapy treatment and reported persistent CIPN symptoms. The yoga interventions consisted of breathwork (pranayama) and physical postures (asana). None of the 4 publications addressed nor evaluated intervention fidelity.

Fidelity Checks in the Present Randomized Clinical Trial

All 4 evaluated sessions met the benchmark scores (goal of >2.5 of 3 points on class skills and >80% on class structure adherence, consistent with Breitenstein et al ¹⁶ and Martin et al ²² ). Reviewers agreed on all evaluated session scores. Study instructors were provided compiled feedback based on results. This included both positive feedback and constructive feedback based on session reviewing. Constructive feedback included discussion of differences between the protocol outlined and actual delivery of yoga intervention.

Participant Home Practice Adherence

Our study participants completed an average of 25 of 40 home practice sessions (63% adherence) during the 8-week intervention period. Participants were encouraged to continue the yoga home practice at the end of 8 weeks; however, we did not ask them to track their home practice after this time. The instructors encouraged continuance of the home program practice to assure adherence to improvement made during the intervention. Clinical research coordinators were encouraged to remind participants to continue with home practice.

Feedback Process to Improve Fidelity in Our Trial

Our yoga instructors were provided with compiled, anonymous reviewer feedback after completed fidelity checks. Examples of reviewer feedback include: “Good use of the blocks for hip extension with focused feedback for each leg. . . Verbal cues are helpful throughout the session and [instructor] demonstrated facing forward and also from the side to provide the 3-dimensional aspects of chair pose.” And “[Instructor] demonstrates optimal posture with encouragement for participants.” “Truly engaged and clearly compassionate providing adaptations as needed; good use of blocks..” In addition: “[Instructor A] talks through snow angel while [Instructor B] did the poses to further demonstrate. It is only at 12 minutes into the instruction that [Instructor A] then demonstrates accordingly.” This finding prompted conversations among our research team if it is best for instructors to physically demonstrate postures versus simply use verbal cues; we determined as long as the instructors were closely monitoring study participants for accurate and safe demonstration of the postures, they could use either method. Modifications using chair yoga were implemented for safety purposes.

Discussion

In this study, the initial literature review of yoga interventions for CIPN revealed a lack of intervention fidelity described among published yoga clinical trials. As a result, we developed a yoga instructor/participants-oriented fidelity check process with a fidelity checklist, adapted from international guidelines, in our ongoing phase III yoga for CIPN trial. Our model will encourage consistency and foster accountability for future yoga trials through the use of a checklist to assist investigators in the design of clinical trials. This may ensure fidelity as part of the research design and implementation and translate into the community for sustainability of yoga protocols to manage specific conditions.

Our findings combined validated PRIDE fidelity checklists for community-based and complex health interventions^13,16 which was feasible to evaluate fidelity in our ongoing Yoga for CIPN phase III RCT. Bellg et al’s ¹² model is considered the “gold” standard of fidelity check in behavioral change trials. Although our trial addresses yoga practice as a health behavior, we deemed the fidelity models by Breitenstein et al ¹⁶ and Walton et al ¹³ more appropriate to assess yoga as a complex, group-delivered intervention in our trial. Breitenstein et al ¹⁶ and Walton et al ¹³ originally created the fidelity checklist for use in community-based and complex health interventions, but it has insufficient details of yoga therapy. Adding those points to the fidelity checklist in our trial ensured high yoga intervention fidelity on instructor adherence to class structure and demonstrated skills, consistent with our trial protocol aims, and acceptable home practice adherence.

Our study demonstrated the importance of combining elements required for transparent reporting of yoga trials in developing intervention fidelity protocol. The CLARIFY checklist Item 4, “Instructor Expertise,” prompted our research team to provide robust description of our instructors’ expertise and prior experience to help contextualize our study’s yoga intervention. ⁷ Item 7, “Home Practice,” helped us measure and reinforce home practice adherence. Finally, Item 10, “Instructor Fidelity,” outlines the importance of describing intervention fidelity by assessing protocol fidelity, differences between what was planned and actually delivered, and the reasons for any deviation from the study plan. ⁸ These items were key guidelines for our current study as we developed a methodology to report our own intervention fidelity.

Our results provide important feasibility data for fidelity checks in video-based virtual yoga therapy delivery in RCTs in the oncological setting. Sohl et al provided fidelity assessment strategies for a yoga intervention protocol to treat worry, anxiety and stress among older adults based on previous checklists from cognitive behavioral therapy.^12,23,24 Similar to our model, they video-recorded yoga sessions and evaluated the first yoga session of an instructor with new participants, and randomly checked 10% of the remaining session recordings. Another study by Adair et al ²⁰ measured protocol fidelity through evaluating 10% of videotaped yoga sessions for its consistency with the protocol description by an external yoga consultant. Both Adair et al’s ²⁰ and our study provided constructive feedback to the instructors based on video review, specifically focused on being more open-ended, more permissive, and less directive. Further, Sohl et al’s ¹⁴ trial yoga instructors self-described how well they were able to follow each session checklist. We did not have yoga instructors self-evaluate as we sought to evaluate intervention fidelity from an independent reviewer perspective. In addition, Sohl et al’s ¹⁴ and our study rather than Adair et al’s ²⁰ also evaluated home practice completion by checking in with group members during class. Future virtual yoga trials may incorporate these fidelity metrics in their trial design.

Limitations

This study has limitations. Our study modified with permission, Breitenstein et al’s ¹⁶ previously published manual to develop a fidelity checklist accordingly for our phase III trial. While there are several published fidelity steps and standards used in various clinical trials, our team modified our fidelity assurance process at post-hoc. Second, our fidelity checking focuses on individuals with chemotherapy induced peripheral neuropathy and thus, only specific corresponding yoga therapy was addressed in this study, which limits the generalizability of the study findings to other clinical populations or settings. Future research is warranted to validate our fidelity monitoring process and develop standard fidelity assurance strategy applicable to more general clinical oncology research.

Conclusion

Our study evaluated the intervention fidelity of an ongoing yoga trial for chemotherapy-induced peripheral neuropathy. We provide an approach to fidelity monitoring to ensure protocol adherence that can be adapted to other studies to ensure consistent intervention delivery in oncological settings.