Research objectives
Objective 1:
To compare the impact of, separately, MBSR, the Daily Examen, and Stress Proofing with a waitlist control condition, on stress outcomes at 12 weeks.
Hypotheses 1–2. When randomly assigned to waitlist vs non-waitlist, MBSR, the Daily Examen, and/or Stress Proofing will be superior to the waitlist control on stress symptoms (Hypothesis 1) and HRV (Hypothesis 2) at 12 weeks (co-primary outcomes).
Objective 2:
To compare the impact of, separately, MBSR, the Daily Examen, and Stress Proofing with a waitlist control condition, on anxiety symptoms at 12 weeks.
Hypothesis 3
When randomly assigned to waitlist vs non-waitlist, MBSR, the Daily Examen, and/or Stress Proofing will be superior to the waitlist control on anxiety symptoms at 12 weeks (secondary outcome).
Objective 3:
To compare the impact of, separately, MBSR, the Daily Examen, and Stress Proofing with a waitlist control condition, on stress and anxiety symptoms at 24 weeks.
Hypotheses 4–5. When randomly assigned to waitlist vs non-waitlist, MBSR, the Daily Examen, and/or Stress Proofing will be superior to the waitlist control on stress symptoms (Hypothesis 4) and anxiety symptoms (Hypothesis 5) at 24 weeks (exploratory outcomes).
Objective 4:
To determine whether having a preference, and that preference being honored, was associated with better outcomes on stress symptoms, HRV, and anxiety symptoms.
Hypotheses 6–8. Participants who had a stated preference and received that intervention (i.e. MBSR, the Daily Examen, and Stress Proofing combined) will experience larger between-arm (waitlist vs non-waitlist) differences in improvements on stress symptoms (Hypothesis 6), HRV (Hypothesis 7), and anxiety symptoms (Hypothesis 8) at 12 weeks when compared to no-preference participants randomly assigned across interventions and waitlist (exploratory outcomes).
Study design: Partially randomized waitlist-controlled preference trial
This study’s timing crossed the start of the COVID-19 pandemic, which necessitated changes in the original design registered with clinicaltrials.gov (see Fig. 1). In this manuscript, we report the pandemic-adapted design (see Fig. 1), a partially randomized waitlist-controlled preference trial with assignment into non-waitlist (i.e. intervention) vs waitlist arms. Preference-based trials are a kind of pragmatic clinical trial design that recognizes individuals have treatment preferences that are likely to affect outcomes and result in “preference effects.”[12] These preference effects may be due to expectancy effects or degree of engagement, which are particularly important in behavioral interventions. In conventional randomized controlled trials, participant choice is removed to create high internal validity between the intervention and treatment effects.[13] Blinding participants to the allocated intervention can be challenging in behavioral trials, making participant preferences more salient.
We enacted a partially randomized preference design to assign participants into particular interventions.[12] Prior to March 1, 2020 and the COVID-19 pandemic, participants read descriptions of the three stress management interventions and provided preference ratings using the Treatment Acceptability and Preferences Scale[14] to help them think through their preferences. In addition, participants were asked whether they preferred any of the three interventions or if the interventions were equally appealing to them (i.e. no preference). Those with a preference were asked whether they had one or two equal first choice(s). Participants who preferred one intervention were assigned to their preferred intervention and randomized to a non-waitlist vs waitlist condition; the waitlist condition participants provide control data prior to intervention receipt. Upon completing the waitlist condition, participants were allowed to update their preference and receive their currently preferred intervention while providing data. Participants who stated no preference (or equally preferred two interventions over the third) were randomized to receive one of three (or, if applicable, two) interventions in a non-waitlist condition or to the waitlist condition (Fig. 1).
During a time of heightened stress due to COVID-19, stress reduction research seemed particularly important, and we sought more participants to maximize statistical power should others withdraw.[15] For those reasons, after March 1, 2020 we continued to recruit participants and assigned them to their preferred intervention in a non-waitlist condition (Fig. 1). These additional recruits will provide observational, as-treated data.
Study setting
Clergy from the United Methodist Church (UMC) appointed to positions in North Carolina (NC) will be recruited. There are approximately 1600 active UMC clergy in this potential study group. The majority serve as congregational leaders, but some work in nonprofit and denominational settings in rural, suburban, and urban environments. The average age is 53, 66% are men, and 90% are white and non-Hispanic.[16]
Patient and public involvement
The material introduced in the interventions was pilot-tested by 78 clergy prior to the final development of the intervention protocols.
Participant eligibility
Inclusion criteria
Participants must have had a current appointment in the 2019–2020 or 2020–2021 appointment cycle of the NC Annual Conference or the Western NC Annual Conference of the UMC to be included in the study. Participants are eligible if they are 18 years of age or older, and willing to participate in the survey and HRV data collection and commit to completing their assigned stress management intervention. There are no stress- or health-related inclusion criteria.
Exclusion criteria
In an attempt to increase ecological validity, no exclusion criteria were set for participation in the trial. Participants with underlying medical conditions which could seriously impact the integrity of their HRV data were excluded from HRV data collection, including a diagnosis of tachycardia; being pregnant or becoming pregnant during the course of data collection; being diagnosed with COVID-19; having a pacemaker; and documentation of other cardiovascular-related chronic or acute morbidities.
Procedures
Screening, recruitment and enrollment
Recruitment is expected to benefit from the 12-year partnership that the Duke Clergy Health Initiative and the two UMC conferences in NC have enjoyed. Participants will be recruited primarily via email addresses provided by the denomination. Additionally, all eligible clergy will receive a program brochure in the mail. Study staff, including a recruitment coordinator who is well-known to the population, will promote the study and answer questions at in-person gatherings. Participants will be directed to the study website (spiritedlife.org) to learn more about the interventions and study details. The web-based registration form will guide participants through a series of questions that will culminate in indicating their preferred intervention(s) and study consent. Participants will be compensated $20 for each of the first two surveys and $25 for the final survey, as well as $25 for each occasion of heart rate tracking submitted (possible total=$115).
Randomization and blinding
All participants recruited before March 1, 2020 were randomly assigned to non-waitlist vs waitlist arms. Data on participants’ preference on the three interventions were collected before randomization. Table 1 reports assignment and randomization allocations for each preference scenario. The analysis statistician wrote the randomization codes in Stata version 16. To keep the analysis statistician blinded, a research staff member ran the Stata program. A secondary recruitment period was initiated after March 1, 2020 that did not include random assignment; data from those participants will be included in a secondary as-treated analysis. The analysis statistician will be blinded to intervention allocation. It is not possible to blind participants, interventionists, or outcome assessors.
Table 1
Study assignment approach for each preference and enrollment date scenario
Preference Scenario
|
Assignment Approach
|
Enrolled prior to March 1, 2020
|
|
No preference between interventions
|
Randomly assigned to one of the four study arms: three interventions without waitlist and the waitlist arm, with a 1:1:1:1 ratio
|
Preferred two interventions equally and over the third intervention
|
Randomly assigned to one of the two interventions with a 1:1 ratio, and then a fraction was randomly assigned to the waitlist arm, with a 3:1 non-waitlist vs waitlist ratio for MBSR and Stress Proofing and a 5:4 non-waitlist vs waitlist ratio for the Daily Examen (DE was preferred by more participants and this allowed the same number of participants to be randomized into each study arm)
|
Preferred one intervention among the three
|
Assigned to their preferred intervention and combined with participants with two top preferences who had been randomized to that intervention, and then randomly assigned to non-waitlist vs waitlist arms, with a 3:1 non-waitlist vs waitlist ratio for MBSR and Stress Proofing and a 5:4 non-waitlist vs waitlist ratio for the Daily Examen
|
Any of the above scenarios and are part of a married or cohabitating couple who both meet study criteria and enrolled
|
To avoid spillover effects, each couple was treated as if they were one person, i.e., assigning both spouses to the same intervention and randomizing them into a non-waitlist vs waitlist arm. When a couple had different preferences, one preference was randomly chosen as the couple’s preference.
|
Seven clergy with an established meeting group (a covenant group)
|
The seven clergy jointly chose a single preferred intervention and were randomized together to the non-waitlist vs waitlist arm.
|
Enrolled after March 1, 2020
|
|
All enrollees after March 1, 2020 with no preference, two equal preferences, or one preference, and whether a clergy couple or not
|
Participants answered treatment preference survey items but regardless of their answers, self-selected the intervention with intervention dates they most wanted from the full list of workshop options. None were randomized to the non-waitlist vs waitlist arms; they all were assigned to non-waitlist.
|
Study Arms: Non-waitlist interventions and waitlist
This trial includes three non-waitlist study arms (Mindfulness Based Stress Reduction, Daily Examen, and Stress Proofing) and one waitlist arm that includes two conditions: first providing control data and then participating in any intervention condition. Originally, participants were to be trained in small workshop formats delivered across NC between April 2020 and May 2021. Due to the global pandemic, all workshops were converted to online-delivery formats and delivered during the same anticipated months. Interventions will be delivered in small groups of 10–25 participants. Survey data will be collected online and HRV data will be collected by the participants in their respective personal settings.
1. Mindfulness Based Stress Reduction (MBSR)
MBSR teaches several different kinds of meditation and attitudes. The specific course for this study is a synchronous web-based videoplatform course with certified instructors from Duke Integrative Medicine and content based on Jon Kabat-Zinn's model.[16, 17] It includes exercises in awareness of breath, body scans, walking meditation, "choiceless" open awareness, Loving Kindness Meditation, and bringing awareness to the present moment. The course consists of 8 weekly sessions confined to study participants held via video conference with meditation instruction, periods of guided practice, and group discussion. Participants are also offered a 4-hour online “Day of Mindfulness” which includes both participants and community members not enrolled in the study.
2. The Daily Examen Prayer Practice (DE)
The Daily Examen is a Jesuit reflective prayer practice that was first developed by Ignatius of Loyola and widely practiced by Christians from many traditions. We used a modern adaptation of the Daily Examen.[18]
The Daily Examen guides the person through a five-step prayer.
1. Become aware of God’s presence.
2. Review the events of the past 24 hours, recalling 2–3 things for which you are grateful.
3. Review the events of the past 24 hours, guided by the Holy Spirit, noticing where you experienced God’s presence.
4. Review what stands out and pay attention to what emotions arise. With the guidance of the Holy Spirit, pray through these emotions, noticing which are drawing you closer to God or pulling you away from God.
5. Look forward to the next 24 hours. What is one thing you should do? Where do you need God’s assistance?
The Daily Examen is designed to help the supplicant reflect on positive emotions, move past negative emotions, and align their work with God's work. Instructors trained in Ignatian spirituality and regular practitioners of the Daily Examen developed workshop content that included three occasions of practicing the Daily Examen, lecture instruction, and small group discussion. Topics covered included a history of Ignatian spirituality, the emotions and the spiritual life, and practicalities of developing a daily prayer practice. We asked participants to conduct the Daily Examen as a daily practice, requiring a 10-15-minute commitment for 6 months following their workshop. Participants were also offered the opportunity to meet with their instructors in an online small group format two and also six weeks following their workshop to address any issues arising from their practice.
3. Stress Proofing inoculation combination (SP)
Stress Proofing is a set of stress reduction skills with aspects of stress inoculation training,[19] selected and organized by the founder of an organization called NC Systema. The founder designed and led a weekly, synchronous, web-based workshop for four weeks. Consistent with stress inoculation training, the workshop began with education on the stress response and physical awareness of one’s own stress response.[19, 20] The training diverges from traditional stress inoculation training and goes on to focus on physical activities to undo the stress response. These activities include walking with diaphragmatic breathing, triangle and rectangle breathing, tension control, stretching, and massage. Stress inoculation training is discussed and participants are encouraged during periods of less stress to allow themselves a degree of physical discomfort to learn to tolerate discomfort in the future.[21] The training recommends a variety of beneficial lifestyle practices, including prioritizing nutrition and sleep and disengaging from technology for several hours before sleep. The daily practice plan emphasized stress awareness and diaphragmatic breathing, with encouragement to try the lifestyle adjustments for a week at a time.
4. Waitlist condition
Participants allocated to the waitlist arm will undergo a 24-week waiting period with the purpose of providing control data, during which they will respond to surveys (0, 12, and 24 weeks). Those who are eligible will also provide a 48-hour continuous ambulatory heart rate recording at 0 and 12 weeks. Upon completing the waiting period, participants will be informed that they can update their intervention preference and receive that preferred intervention while providing intervention data.
We recognize that a waitlist control condition sets a “low bar” for evaluating efficacy among interventions.[22] We decided not to use an active control condition because two of our three stress management interventions have not been evaluated as a strategy to improve stress symptoms relative to a no-treatment control group, the recommended first step in intervention evaluation. As such, it is premature to invest considerable resources and compare the Daily Examen and Stress Proofing to an active control before demonstrating efficacy over a waitlist control group.
Qualification of Interventionists
Instructors for each of the three interventions were hired based on their certifications and knowledge of the specific content area. Mindfulness Based Stress Reduction instructors are certified instructors who have been vetted and hired by Duke Integrative Medicine’s MBSR program. Stress Proofing is delivered by the founder of a North Carolina-based health coaching business. While the program has been offered to a variety of local employers, significant changes were made to it to adapt it to a clergy population. The Daily Examen instructors are certified spiritual directors trained in Ignatian Spirituality with experience working with clergy and religious professionals.
Study Measures (see Table 2)
Primary Outcomes
The Calgary-Symptoms of Stress Inventory (C-SOSI) is a 56-item, 8-subscale measure of self-reported stress symptoms.[23] We included the subscales of anger (8 items), muscle tension (8 items), cardiopulmonary arousal (6 items), neurological/gastroenterological (10 items), and cognitive disorganization (9 items) that total 41 items. Validation studies have shown convergent validity with specific subscales and overall divergent validity with anxiety.[23] Response options for each item range 0–4. We will use continuous mean scores of all subscales combined; higher mean scores indicate worse symptoms.
Heart rate
A subset of participants will be provided with an ambulatory heart rate monitoring device to wear for a 48-hour period during week 0 and week 12, during which time participants proceeded with their usual daily routines, including exercising, bathing, and sleep activities.
Heart rate will be measured using continuous electrocardiographic (ECG) recording sampled at a rate of 1,000 Hz and used to calculate heart rate variability. Participants will be fitted with an eMotion Faros 180 ambulatory heart rate recording device (Bittium) connected by electrode leads to two pre-gelled (Ag/AgCl) disposable Ambu BlueSensor wet-gel ECG electrodes attached beneath the right clavicle and left ribcage. The 48-hour ECG recording will be imported to Kubios HRV Premium V3.4.1 software,[24] partitioned into 5-minute segments, visually inspected to allow for manual correction of ectopic beats, detrended, and subject to Kubios’ automatic artefact correction algorithm.[25] Heart rate variability will be indexed using the time-domain metric Root Mean Square of Successive RR Differences (RMSSD) given that it is less affected by breathing and a better suitable outcome measure in ambulatory studies than frequency-domain measures.[26]
Following recommendations for the detection of circadian rhythmicity,[27] 5-minute segments across 24 hours of recording will be subject to a cosinor analysis using the Cosinor package for R. Two individual-level cosine function parameters will be estimated by linear models with ordinary least square estimations to quantify the circadian variability parameters: i) Midline Estimating Statistic Of Rhythm (MESOR), defined as the rhythm adjusted 24-hour mean, and ii) amplitude, defined as the distance between MESOR and the maximum of the cosine curve (i.e. half the extent of rhythmic change in a cycle).
Secondary Outcome
Symptoms of anxiety will be measured using the Generalized Anxiety Disorder-7 (GAD-7),[28] a self-report measure of the extent to which respondents have been bothered by 7 symptoms of generalized anxiety, corresponding to DSM-IV criteria, over the past two weeks using a 4-point Likert scale from 0 “not at all” to 3 “nearly every day”. Sum scores range from 0 to 21 with scores of ≥ 5, ≥10, and ≥ 15, representing mild, moderate, and severe levels of anxiety, respectively. Psychometric properties of the GAD-7 are well documented.[29]
Pertinent demographics measures
A demographics questionnaire was designed to measure sex (male/female); age (in years); race; ethnicity; self-reported physical and mental health conditions; marital status; and having children living at home. To capture work-related characteristics that may relate to stress, we will measure bi-vocational status (i.e. job in addition to serving as clergy) and clergy appointment, i.e., whether they serve in a church or not.
Additional measures
Physical activity levels will be measured using the Godin-Shephard Leisure-Time Physical Activity Questionnaire,[30] a self-report measure of how often in the past seven days and for how many minutes per time one has engaged in physical activity, measured separately for strenuous, moderate, and mild exercise. We will use self-reported weight and height to assess body mass index.[31] We will use single items to assess average daily caffeine intake, average weekly alcohol consumption, financial stress (How stressful is your current financial situation for you? Not at all-extremely), number of hours worked per week, and preference for online vs in-person intervention. Depressive symptoms will be measured using the self-report eight-item Patient Health Questionnaire (PHQ-8) which asks about the frequency of specific depressive symptoms experienced within the past two weeks.[32, 33]
Table 2
Measures by study objective and time point
Measure
|
Objectivea
|
At consent
|
0 weeksb
|
12 weeks
|
24 weeks
|
Primary Outcomes
|
|
|
|
|
|
Calgary Symptoms of Stress Inventory (adapted)
|
1, 3, 4
|
|
X
|
X
|
X
|
48-hour ambulatory heart rate
|
1, 4
|
|
X
|
X
|
|
Secondary Outcome
|
|
|
|
|
|
General Anxiety Disorder-7
|
2, 3, 4
|
|
X
|
X
|
X
|
Other Pertinent Measures
|
|
|
|
|
|
Gender, age, race, Hispanic ethnicity, bi-vocational status
|
Covariates for primary, secondary, and exploratory analyses
|
|
X
|
X
|
X
|
Godin-Shephard Leisure-Time Physical Activity Questionnaire, body mass index, caffeine intake, alcohol consumption
|
Additional covariates for HRV analyses
|
|
X
|
X
|
X
|
Preference for online vs in-person interventions, marital status, children living at home, clergy appointment
|
Covariates for sensitivity analyses
|
|
X
|
|
|
Financial stress, Patient Health Questionnaire-8 (depressive symptoms), marital status, number of hours worked per week as clergy, morale of congregants
|
Covariates for sensitivity analyses
|
|
X
|
|
|
Treatment Acceptability and Preferences Scale
|
Inform their preference decision; covariate for sensitivity analyses
|
X
|
|
|
|
a See “research objectives” in the manuscript
b 0 weeks for controls; immediately pre-intervention for intervention group
|
Timeline of Assessments
Surveys
Participants will complete study measures immediately before starting intervention (baseline), 12 weeks after commencing intervention, and 24 weeks after commencing intervention (see Fig. 2). Participants will be prompted to complete surveys via email and given a link to an online survey whose data are securely stored in REDCap. The data collection window will be from 1 week prior to 3 weeks after the time point.
Texting
Participants will receive daily text messages at noon that inquire their practice from the previous day. In the case of Stress Proofing, the text asks how many daily resets were performed; for MBSR, the number of minutes of formal meditation practiced; and for the Daily Examen, whether they have prayed the Examen prayer or not. Participants who have not responded by 4 p.m. will receive a reminder. Text messages will be distributed through an automated system generated by programmers at Duke Digital Health.
Qualitative interviews
Purposive samples of participants from each intervention group will be invited to participate in in-depth interviews about their experience. Interviews will be performed between 5 and 15 weeks after starting the intervention with the goal of evaluating acceptability, perceived value, benefits, unintended consequences, and intervention delivery. We will select up to three participants in early workshop groups as we refine intervention delivery, and 1–2 participants in later workshop groups. Participants will be selected using their text message engagement data, to include both high- and low-practice participants. Interviews will be conducted using semi-structured interview guides and audio-recorded. The interviewer will take comprehensive notes and complete a post-interview debrief form. Interview notes will be coded in qualitative software using a pre-defined book of index codes.[34] Content analysis will be conducted to achieve the goals stated above.
Participant engagement
Participant engagement will be encouraged through multiple methods. Participants will acknowledge their understanding of the three core aspects of participation (workshop attendance, surveys, and heart rate tracking), and commit to participate in all aspects. Second, participants will be oriented to the study as they prepare to begin their intervention (or ask questions via phone, email, or Zoom for controls). At this time, participants are given program materials and study-branded items such as coffee mugs, water bottles, and pens, plus information about compensation for completing each of three surveys and two occasions of Heart Rate tracking. Course instructors and the research team will contact participants via email to remind them of upcoming class sessions and surveys. Participants will have the opportunity to engage further with their instructors in online follow-up sessions (2 weeks and 6 weeks for DE; 1-month for SP). The daily text message to collect amount of practice also serves as a daily engagement prompt. Lastly, the participants will receive “thank you” correspondence in the mail prior to being invited to complete their final survey.