Abstract
BACKGROUND:
Chronic pain is a complex accumulation of physical, psychological, and social conditions, thus interventions that address pain and promote occupational performance are needed. A holistic intervention, with mind and body components, is likely necessary to best treat the complexities of chronic pain. Thus, we developed and tested a yoga intervention for people with chronic pain.
OBJECTIVES:
In a randomized control trial (RCT), participants with chronic pain were randomized to a yoga intervention or usual care group. Between and within group differences for pre-and post-outcome measure scores were assessed for: occupational performance, completion of activities, and depression.
METHODS:
Pilot RCT with participant allocation to 8 weeks of yoga or usual care. Both groups received ongoing monthly self-management programming. Data were collected before and after the 8-week intervention. Participants were randomized to yoga or usual care after baseline assessments. Demographics were collected and measures included: Canadian Occupational Performance Measure (COPM) to assess occupational performance; the 15-item Frenchay Activities Index (FAI)(activities); and the 9-item Patient Health Questionnaire (PHQ-9) for depression. Independent t-tests were used to assess differences between groups. Paired t-tests were used to assess differences between pre- and post 8-week intervention for both the yoga and the usual care groups. Percent change scores and effect sizes were calculated.
RESULTS:
83 people were recruited for the study and completed baseline assessments; 44 individuals were randomized to yoga and 39 to the control group. The average age of all participants was 51.4±10.5 years, 68% were female; and 60% had at least some college education. There were no significant differences in demographics or outcome measures between groups at baseline or 8 weeks; however, the study was not powered to see such differences. Individuals randomized to the control group did not significantly improve in any outcome measure over the 8 weeks. There were significant improvements in COPM performance and COPM satisfaction scores for individuals randomized to the yoga group; both scores significantly improved. COPM performance improved by 27% with a moderate to large effect size (3.66±1.85 vs 4.66±1.93, p < 0.001, d = 0.76). COPM satisfaction significantly improved by 78% (2.14±2.31 vs. 3.80±2.50, p < 0.001) and had a large effects size (d = 1.02). FAI scores improved, indicating increased activity or engagement in daily occupation during the 8-week intervention. Scores increased by 5% (38.13±8.48 vs. 39.90±8.57, p = 0.024) with a small effect size (d = 0.37). Depression significantly decreased from 13.21±5.60 to 11.41±5.82, p = 0.041, with a small effect size.
CONCLUSION:
Data from this pilot RCT indicate yoga may be an effective therapeutic intervention with people in chronic pain to improve occupational performance, increase engagement in activities, and decrease depression. Occupational therapy practitioners may consider adding yoga as a treatment intervention to address the needs of people with pain.
Introduction
In the United States, at least 100 million individuals are estimated to suffer from chronic pain [1]. The number of people experiencing pain has doubled over the last decade [2] and is likely to continue to increase. Chronic pain is considered a complex condition that may stem from trauma or many different diagnoses. For examples, pain may be secondary to: arthritis; cancer; fibromyalgia; stroke; and other disorders [2]. When individuals experience chronic pain, their pain requires multimodal, comprehensive treatment and management [1]. Furthermore, the complexity of pain is secondary to pain being a physical issue that commonly includes both cognitive and emotional factors [3]. Chronic pain may lead to temporary or permanent disability [4].
Based on current research, it is apparent that chronic pain leads to impairments in occupational performance [5–8]. Occupational performance, or engagement in occupations or activities, is associated with individuals’ choice, motivation, and the meaning of the occupation or the activity [9]. Occupations are everyday activities that are meaningful and important to individuals [9]. For example, Persson and colleagues discovered that the activity of household management (i.e. cooking, gardening, doing the laundry, cleaning) was the most important problem or challenge area for people with chronic pain [6]. It is important to note, all areas of daily activities or occupations were found to be negatively influenced by pain. Furthermore, Nilsen and Anderssen qualitatively examined how people manage their daily chronic pain [10]. Results of their study indicated that both pain and pain management were integrated into daily lives. Coping with the pain on a daily basis required extensive efforts in time and energy among participants.
Fisher et al. used a qualitative approach to study the experiences of people with chronic pain [11]. These researchers found that pain impacted occupations, and chronic pain elicited emotional distress. In this study, depression commonly co-occurred with chronic pain. The researchers concluded that the depression may have begun when the pain prevented engagement in activities or occupations. Some study participants were depressed because they knew the pain would interfere with their day and the daily occupations. Still other participants felt emotional distress related to the fear of never being free of pain. Loneliness and despair have been experienced by people with pain. The isolation that may occur with pain has been shown to be associated with depression and decreased community integration [10]. After an injury or disability, community re-integration is considered the ultimate goal of rehabilitation [12]. Pain and depression are strongly related, and it is common for people with chronic pain to become depressed [13, 14]. Opioid therapy is a common pharmacological treatment for pain that has become increasingly more controversial. Recently, the duration of treatment time using opioid drugs was linked to onset of depression [15]. The risk of overuse of opioids elicits the need for non-pharmacological pain interventions to manage pain.
Yoga is a non-pharmacological intervention that, like occupational therapy, is intended to be a holistic approach to treat the whole person [16]. Yoga addresses the physical, cognitive, and emotional needs of individuals. Mind-body interventions, such as yoga, are an aspect of complementary and integrative medicine (CIM) or complementary and integrative therapy (CIT). Yoga typically includes: asana or physical poses of stretching and strengthening [17, 18]; pranayama, diaphragmatic breathing and breath with movement [17]; mantras or positive affirmations repeated during the yoga session; and dhyana, meditation with relaxation [18]. Yoga is an established intervention for some people with chronic pain that improves pain severity, pain-related disability [19–21], as well as depression [22]. For one example, both pain and occupational performance among people with diabetic peripheral neuropathy were improved after an 8-week yoga intervention [23, 24]. However, at this time, there is no research that examines the use of yoga to improve occupational performance, daily activity, depression, and other occupational therapy relevant outcomes in people with chronic pain. Therefore, the purpose of this study was to assess the impact of an 8-week yoga intervention in people with chronic pain as compared to a usual care control group, and to comparatively assess outcome measures for occupational performance, completion of activities, depression, and community re-integration.
Methods
Design
These are analyses of secondary outcomes of data derived from a small pilot randomized controlled trial (RCT) comparing yoga to usual care for people with chronic pain [25]. Occupational therapy (OT) relevant outcome measures were completed before and after the 8-week intervention and data were compared with-in and between groups.
Participants
Data collection and the intervention were completed at an outpatient pain clinic (‘Pain Clinic’) that acts as a safety net facility providing pain-related care for individuals in need. Study participants were recruited with phone calls by the clinic nurse and the study staff. To be included, participants met the following inclusion criteria: current patient at the Pain Clinic; at least 6 months of chronic pain; >18 years old; no restriction on physical activity; no consistent yoga in the past year; and willingness to provide consent to enter and participate in the study. Approval from the University Institutional Review Board was received before participants were recruited for the study.
Yoga group or usual care control group
Details describing the yoga intervention for this study have been previously published [25]. Hour-long yoga sessions were offered twice a week for eight weeks (16 sessions). The yoga protocol was a standardized and progressive intervention that included sitting, standing, and floor postures. Yoga sessions included physical postures, breath work (to connect the movement to the breath), mantras, and meditation/relaxation. (See Table 1 for physical postures.) The yoga teacher was an occupational therapist or a physical therapist to allow for enhanced modification of postures to best meet pain and disability-related needs of study participants.
Yoga postures and description of postures
Yoga postures and description of postures
Usual care included: monthly physician visits; vital sign monitoring and recording (i.e. blood pressure, heart rate, pulse oxygen); management of pain medication; goal setting; nutritional counseling; a limited number of visits to a massage therapist or acupuncturist; and monthly self-management sessions. Self-management education sessions led by the Pain Clinic nurse focused on health and wellness programming.
Data were collected on basic demographics and pain characteristics (e.g. time since pain onset, reason for pain). When possible, assessments were completed outside of the clinic. Study participants returned the assessments within two weeks of the yoga intervention beginning or ending. The Canadian Occupational Performance Measure (COPM) was completed while in the clinic. Study staff reviewed the assessments at this time, and helped the participant complete any missing items. After the pre-assessment was complete a different study staff member randomized the participant to the yoga or usual care control group. The initial study staff assessor was blinded to study aim.
Multiple outcome measures were included in this study and all measures were completed before and after the 8-week yoga intervention or usual care period. Occupational performance and occupational performance satisfaction were assessed with the COPM. The COPM was completed by the participant with the assistance of an occupational therapist using a semi-structured guide. As directed in the COPM, the participant identified problems or areas of concern in regards to productivity, self-care, and leisure [26]. The particpant then rated the importance of each problem (1–10). The five most important problems were rated on a 1–10 scale for the ability to perform the activity and the satisfaction of the performance of the activity. Higher scores are indicative of greater occupational performance and greater satisfaction with performance. The COPM has been successfully used with people with pain [27].
The Frenchay Activities Index (FAI) was included to assess completion of daily activities [28]. The three domains of domestic activities, leisure or work, and outdoor activities were addressed. Ten items ask about activities (i.e. light housework, social occasions, pursuing hobbies) completed over the prior three months. An additional five items address other activities (i.e. traveling, gainful employment) completed over the last 6 months. Scoring ranges from 15 to 45 with higher scores demonstrating increased activity or occupation. The FAI is commonly used in stroke rehabilitation, but it has also been used with good reliability with people with other chronic conditions [29–31].
Depression was assessed with the Patient Health Questinnaire-9 (PHQ-9) [32]. The PHQ-9 includes 9 items with a score range of 0–27. Items address depression-related problems that have occurred in the last 2 weeks. Higher scores indicate increased depression. Kroenke et al. found the PHQ-9 to be a reliable and valid measure of depression [32] and the assessment tool has been used in multiple diagnostic populations. Cut points have been established for the PHQ-9:5 = mild, 10 = moderate, 15 = moderately severe, and 20 = severe depression.
The 11-item Reintegration to Normal Living Index (RNLI) was used to assess participants’ perception and satisfaction related to community reintegration, daily functioning, and perception of self [33]. Scores range between 0 and 110 and higher scores represent enhanced reintegration. In a study of people with mixed diagnoses, the RNLI showed moderate concurrent validity and acceptable test-retest reliability [34].
Improvements in pain-related disability using the Brief Pain Inventory were previously reported [25]. Pain severity did not improve, but pain-related disability, or the interference of pain on everyday life significantly improved for participants randomized to the yoga group. The newly developed Occupational Impact of Pain Screening Tool (OIPS) was used to assess the impact of pain on occupational performance and everyday life. The OIPS includes 9 items and each item was rated from a 0 to a 10. Items measured include: the level of pain interference on personal tasks, time spent with important people, and participation in leisure activities or hobbies. Higher scores are indicative of higher pain interference on occupational performance and everyday life. Reliability and validity of the OIPS has not yet been demonstrated in people with chronic pain.
Statistical analysis
The Shapiro-Wilk test was used to assess normality of data. Means with standard deviations or frequencies and proportions were used to describe demographic data. T-tests (or non-parametric Mann-Whitney U) or chi-square analyses were used to compare demographic data between yoga and control groups. Paired-t tests (or non-parametric Wilcoxon Signed) were completed to assess within group differences between baseline and post 8-weeks for both the yoga and the usual care control group. The Cohen d (d Cohen ) effect size was calculated for each outcome measure [35] and the following thresholds were used: 0.20 = small; 0.50 = moderate; 0.80 = large; and 1.30 = very large [36, 37]. The percent change was calculated for each variable (Time 1 – Time 2 divided by Time 1, multiplied by 100) to examine trends in the data. T-tests (or non-parametric Mann-Whitney U) were completed to compare baseline and 8-week data between the yoga group and usual care control group.
Results
Demographics and comparison between baseline and 8-week data
Over approximately 5 months, of the 83 individuals recruited for the study, 44 participants were randomized to yoga and 39 to the control group. Based on t-tests and chi-square, there were not significant differences in any demographics between groups (see Table 2 for the full demographic details). The majority of the sample was female (68%), Caucasian (70%), not part of a couple (52%), and had some college level education (60%). Pain started over 10 years ago for 64% of the study participants and the pain was most often related to trauma (46%) as compared to illness or other injury. All but two individuals were using opioids for pain management and, as a group, participants took an average of nearly 10 medications a day. There were not any significant differences in any outcome measure scores at baseline between yoga and usual care control groups. This sample has been previously described in detail [25].
Demographic data between groups
Demographic data between groups
SD = standard deviation. ∧= Fisher’s Exact Test.
The study was not adequately powered to detect differences in outcome measures at 8-weeks, and as we expected, there were no significant differences for any outcome measure between the yoga group and usual care control group.
Within group differences
There was a significant improvement in the COPM satisfaction score for the control group (2.29±2.05 vs. 3.22±2.32, p = 0.009), with a small effect size (0.46). Otherwise, there were no significant improvements in any other outcome measure scores for participants in the usual care control group. Except for the COPM satisfaction, scores were maintained between baseline and 8-weeks. See Table 3 for additional outcome measure data.
Occupational therapy outcome measure scores between baseline and 8 weeks (mean and standard deviation)
Occupational therapy outcome measure scores between baseline and 8 weeks (mean and standard deviation)
COPM = Canadian Occupational Performance Measure. FAI = Frenchay Activities Index. RNLI = Reintegration to Normal Living Index. OIPS = Occupational Impact of Pain Screening Tool.
Significant improvements from baseline were found in multiple outcome measures for individuals randomized to the yoga group. Both COPM performance and COPM satisfaction scores significantly improved. COPM performance improved by 27% with a moderate to large effect size (3.66±1.85 vs 4.66±1.93, p < 0.001, d = 0.76). COPM satisfaction significantly improved by 78% (2.14±2.31 vs. 3.80±2.50, p < 0.001) and had a large effects size (d = 1.02). FAI scores improved, indicating increased activity or engagement in daily occupation during the 8-week intervention. Scores increased by 5% (38.13±8.48 vs. 39.90±8.57, p = 0.024) with a small effect size (d = 0.37). Depression significantly decreased from 13.21±5.60 to 11.41±5.82, p = 0.041, with a small effect size. Of note, the group members were still considered moderately depressed, even after a significant improvement in PHQ-9 scores [32]. OIPS scores significantly improved (50.67±16.62 vs. 45.88±18.24, p = 0.010) with a decrease in scoring by 9% and a moderate effect size (d = 0.50). See Table 3 for additional data, including p values, percent change calculations, add effect sizes for all outcome measures.
The purpose of this study was to examine changes in people with chronic pain after 8 weeks of yoga when measuring occupational performance, engagement in activity, feelings of depression, and community re-integration. Results indicate that people randomized to the yoga intervention demonstrated: significant improvement in occupational performance and occupational satisfaction, increased completion of daily activities, decreased depression, and lessened interference of pain on occupational performance.
Satisfaction with occupational performance significantly improved for both the yoga and the usual care control group, with a small effect size in the control group and a large effect size after 8 weeks of yoga. The usual care control group included a higher level of care than what is likely seen in most pain management venues [38] and this may have influenced performance and perception of satisfaction with performance. When participants in both groups were asked to identify problems or areas of concern, they commented on needing to address problems in regards to productivity, self-care, and leisure skills. Potentially, just identifying the problems participants had at baseline helped the participants focus on a problem area, and this might have facilitated the 12% improvement in COPM performance scores and the 40% improvement in COPM satisfaction scores in the control group.
We believe this is the first study to assess change in occupational performance after a yoga intervention for people with chronic pain. Previously, a small study tested yoga with people with diabetic peripheral neuropathy [24]. Results from that study showed 8 weeks of group yoga led to similar improvements in COPM performance and satisfaction scores, with large effect sizes. In both the current study and the neuropathy study, larger changes were demonstrated in satisfaction with performance rather than actual performance scores. FAI scores improved in the current study, but only by 5%, and with a small effect size. The change in FAI score indicates some improvement in completion of daily activities. This may indicate that while yoga improves ability to perform activities, there may be a greater impact on the belief about the activity or the performance of the activity. Yoga seems to improve the self-efficacy of doing things, and not only the act of completing tasks. This could be related to the idea that yoga improves the connection between the mind and the body, allowing the mind to be happier or more satisfied or content with what the body is able to accomplish. A foundation objective of yoga is to practice contentment, and some of the mantras introduced during the yoga intervention emphasized being content with the body and recognizing what the body could do instead of what it cannot accomplish. Perhaps these mantras, or affirmations, played a role in improving satisfaction with performance of activities.
Few researchers have used the COPM in studies of chronic pain, and there are limited options proven to be effective occupational therapy interventions for chronic pain. The COPM was included as an outcome measurement tool in a group-based interdisciplinary musculoskeletal pain rehabilitation program [5]. The 5-week intervention was based on principles of cognitive behavioral therapy (CBT). The results, after the group CBT intervention, show there were significant improvements in both COPM performance and satisfaction scores. The recent literature indicates a Lifestyle Redesign® program, developed and delivered by occupational therapists, significantly improved COPM scores but did not improve pain severity or pain-related disability [39]. Results of this current study showed improvements in COPM scores, as well as pain-related disability as assessed by both the Brief Pain Inventory [25] and the newly developed occupation-based OIPS. In our study, yoga was not intended to directly address performance and satisfaction of the chosen problem areas in the way Lifestyle Redesign® Programming does, and yet we found significant improvement in COPM scores. This may be due to changes in the physical body, cognitive abilities, and emotional stability leading to enhanced performance of activities as well as a resultant satisfaction with performance.
Our study team has completed multiple studies on the use of yoga for people with disabilities, and we have always included the PHQ-9 to assess change in depression. We find it interesting that this study of people with chronic pain shows for the first time there have been significant change in depression scores. This may be due to depression scores indicating that the group, as a whole, were moderately depressed with baseline PHQ-9 scores above 10 points [32]. These higher scores allowed for improvement, and in people randomized to the yoga group there was a 14% decrease in PHQ-9 scores (small effect size). Unfortunately, while depression scores significantly decreased with yoga, mean 8-week scores of 11.41 indicate continued depression. Other researchers have found depression is linked to chronic pain [40] and depression may increase the subjective stigma of chronic pain (and possibly influence opioid use) [41]. It is important that non-pharmacological interventions be utilized to improve outcomes for both pain and depression because chronic use of opioids is linked to onset of depression [15]. All but two of the study participants were prescribed opioids and are at risk for an opioid use disorder with increased depression. The addition of yoga to the management protocol for chronic pain interventions may be a part of the solution for a multimodal, comprehensive, and non-pharmacological intervention for recovery from depression. Chronic pain is an unpredictable condition; and leads to loneliness for some people. It is possible that the group intervention positively influenced the feeling of loneliness and allowed for improvements in depression [10].
Community re-integration scores (RNLI) improved, but not significantly. The yoga intervention was delivered in a group format; and individuals were required to go to the Pain Clinic to participate in yoga. While not collected or recorded data, participants planned activities outside of the yoga class and participants discussed their ability to do more activities in general. The group intervention may have alleviated some levels of loneliness associated with depression. The group format might have helped participants get back to activities in their own communities, and enjoy old friends and make new friends. Of note, community re-integration scores in the control group remained steady, perhaps indicating that the once a month self-management education group was not sufficient to influence community re-integration.
Yoga may be used as a coping mechanism [42]. People with chronic pain shared coping with pain requires daily time and energy [10]. The yoga intervention may not have improved the severity of pain, but it may have improved the ability to cope with the pain, thus decreasing the interference of pain on daily life [25]. Among the participants in the current study, scores on the OIPS significantly decreased by 9% with a moderate effect size. Decreased scoring on the OIPS represents a decrease of the impact of pain on occupational performance. It may be useful to combine interventions likely to decrease pain severity with interventions likely to create Improvement in the occupational performance scores. Yoga may help decrease the interference of pain on occupational performance and day to day life.
A limitation of this study is that it was planned as a small pilot RCT, and it was not adequately powered to detect differences between groups. All participants were recruited from the same Pain Clinic located in a relatively small city and our results cannot be generalized to other individuals living with chronic pain. Participants in our study attended, on average, 50% (8 classes) of the yoga classes [25], which is poorer attendance than the 75% average (12 classes) attendance reported in the study about yoga interventions for neuropathy [23, 24]. Lower class attendance may have influenced our results. Yoga has not been adequately studied by researchers and this research should be considered an important next step in CIT science. This study used an eight week intervention, other studies have required additional weeks of exercise training to obtain similar results [43]. Perhaps, the study of yoga will contribute to a decreasing population of individuals experiencing chronic pain and other serious symptoms. Perhaps, the study of yoga will allow an earlier discharge from the pain intervention services, sooner than when we use more traditional exercise programs.
Conclusion
Yoga, along with CIT in general, is becoming a more accepted intervention for treatment by occupational therapists and other health care providers in the management of chronic pain. Stronger evidence for including yoga in practice must be established. The results of our study shows 8-weeks of group yoga sessions contributed to improvements in multiple occupation-based outcomes in people who are living with chronic pain. Occupational therapists, and other therapists on the rehabilitation team, can consider yoga to be an integral part of chronic pain management.
Conflict of interest
None to report.
Funding
Colorado State University Prevention Research Center.