Abstract

1. Introduction

Among older adults, chronic pain is a common condition that can have devastating consequences. Chronic pain is associated with depression (Fishbain, Cutler et al. 1997; Bair, Robinson et al. 2003) decreased appetite (Bosley, Weiner et al. 2004), impaired sleep (Benca, Ancoli-Israel et al. 2004) and overall decreased quality of life (Cooper and Kohlmann 2001). Not surprisingly, approximately 1/4-1/3 of older adults suffer from low back pain (Urwin, Symmons et al. 1998; Thomas, Peat et al. 2004). Many older adults’ chronic pain is inadequately treated (Roy 1987; Woo, Ho et al. 1994). This may be due to older adults increased susceptibility to medication side effects and increased number of co-morbidities that prohibit surgical interventions (Gagliese and Melzack 1997).

Approximately 1/3 of older adults have used complementary and alternative medicine (CAM) in the previous year (Foster, Phillips et al. 2000). Chronic pain is one of the top medical conditions for which they seek CAM modalities (Foster, Phillips et al. 2000; Astin 2004). The growing use of CAM presents researchers with the responsibility of studying it scientifically. We were interested in studying a mind-body technique called mindfulness meditation for the treatment of chronic pain in older adults.

Mindfulness meditation was introduced as a clinical intervention for conditions such as chronic pain and anxiety in 1979 (Kabat-Zinn 1982; Kabat-Zinn, Massion et al. 1992). It is currently taught and studied in many clinical trials as the Mindfulness-Based Stress Reduction Program (MBSR) (Kabat-Zinn 1990; Kabat-Zinn 2003). Previous research of Kabat-Zinn showed a significant reduction of chronic pain among 90 patients with a variety of chronic pain conditions (Kabat-Zinn, Lipworth et al. 1985). He then published 4-year follow-up data showing maintenance of pain improvement among 60-72% of 225 chronic pain patients (Kabat-Zinn, Lipworth et al. 1986). The studies did not include a comparison group. Sustained pain reduction up to 4-months after the MBSR intervention was noted in 28 fibromyalgia patients (Creamer, Singh et al. 2000). In a different study, fibromyalgia patients were randomized to an MBSR or an education program, both groups showed improvement in pain self-report, but the differences between the two groups did not reach statistical significance (Astin, Berman et al. 2003). None of these studies targeted older adults or chronic low back pain (CLBP). It is not known if older adults would differ from a younger population in terms of program adherence and effects. A recent review supports the use of meditation training in the older adult (Lindberg 2005; Morone and Greco 2007).

Kabat-Zinn states mindfulness is: “the awareness that emerges through paying attention on purpose, in the present moment, and nonjudgmentally to the unfolding of experience moment by moment” (Kabat-Zinn 2003).

The primary aim of this pilot study was to assess the feasibility of recruitment and adherence to an eight-session mindfulness meditation program for community-dwelling older adults ≥ age 65 with CLBP. The secondary aim was to develop initial estimates of treatment effects on measures of pain, physical function and quality of life.

2. Methods

3. RESULTS

3.1. Recruitment and Follow-up of Participants

Eighty-nine subjects responded to posted flyers or ads and were assessed for eligibility (see figure 1 for trial profile). Thirty-seven were enrolled in the study between May and October 2004. Those who were not enrolled were ineligible, had scheduling conflicts with the day and time of the program or were not interested. Nineteen were randomized to the meditation intervention group and eighteen to the wait-list control group. Thirteen participants completed the 8-week program and were available for assessment. Seventeen subjects in the wait-list control group were available for assessment at week eight. Twelve subjects were available for 3-month follow-up in the meditation intervention group. Thirteen subjects from the control group crossed over and completed the 8-week meditation program and completed 3-month follow-up measures.

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Figure 1

Participant flow diagram

3.2. Baseline Characteristics

The two groups did not differ significantly on demographic factors of age, gender, ethnicity, education, religion, income and marital status as displayed in Table 1. The mean age of the study participants was 75 years (range 65-84), 22 (59%) of the participants had at least some college education and 24 (65%) made $50,000 or less.

Table 1

Demographic Characteristics of Study Participants

	Treatment Condition
Variable	Meditation n=19	Control n=18	P-value
Age, mean ± SD	74.1 ± 6.1	75.6 ± 5.0	.41
Gender, n
Male	9	7	.63
Female	10	11
Ethnicity, n
White	17	16	.98
African American	1	1
Asian	1	1
Education, n
High School Graduate	5	5	.96
Technical School	2	3
Some College	3	2
College	6	4
Master’s or greater	3	4
Religion, n
Catholic	10	8	.97
Jewish	6	7
Protestant	2	2
Other	1	1
Income, n
$10,000-$19,999	4	5	.80
$20,000-$29,999	2	1
$30,000-$39,999	3	6
$40,000-49,999	2	1
$50,000-$59,999	0	0
$60,000-$69,999	1	1
Marital status, n
Single	1	2	.22
Married	14	9
Separated/divorced	0	3
Widowed	4	4
Low back pain cause, n
Osteoarthritis	17	16	.26
Injury	0	1
Fibromyalgia	0	1
Not sure	2	0
Medications, n
Opioids	4	3	.84
Other analgesics	13	12
None	2	3
*CAM use in last year, n
Yes	8	10	.86
No	9	10
Folstein Mini-Mental State
Examination, mean ± SD	29.2 ±1.1	29.3 ± .7	.56

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^*CAM = Complementary and Alternative Medicine; SD = standard deviation. Use of any one or more of the following CAM treatments in the previous 12 months for any reason: acupuncture/acupressure, chiropractic, herbal medicine, yoga, tai chi, homeopathy, magnets, guided imagery or relaxation techniques such as progressive muscle relaxation.

3.4. Post-Intervention Outcomes

Table 2 compares the intervention and control groups change scores on study measures completed before and after the 8-week program. None of the baseline measures were significantly different from each other between the intervention and control groups. Although on visual inspection some of the baseline measures appear quite different from each other, because of the large variance in this small sample, they are not statistically different.

Table 2

Comparison of the Effects of Meditation versus Wait-List Control in Outcomes During the 8-Week Trial and 3-Month Follow-Up

Outcome Measure	Groupa	Baseline mean ± SD	8-Week mean ± SD	Effect Size db	P- value	3-Month follow-up, meditation group only mean ± SD
Pain
McGill Pain Questionnaire- Short Formc	Meditation	15.5 ± 10.0	13.7 ± 7.9	0.32	0.16	16.5 ± 11.6 d
	Control	15.2 ± 7.0	15.7 ± 9.1
SF-36 Pain Scale	Meditation	35.5 ± 6.0	39.9 ± 7.7	0.16	0.31	39.9 ± 8.4 d
	Control	35.7 ± 7.2	38.8 ± 8.3
Physical Function
Roland Disability Questionnairec	Meditation	11.5 ± 3.7	9.4 ± 5.1	0.35	0.25	8.9 ± 5.7 d
	Control	11.8 ± 4.6	10.6 ± 5.3
SF-36 Physical Function Scale	Meditation	42.0 ± 10.9	45.7 ± 9.2	0.46	0.03	45.8 ± 11.5 d
	Control	45.1 ± 9.5	44.5 ± 10.1
Pain Acceptance
Chronic Pain Acceptance Questionnaire Total Score	Meditation	72.2 ± 13.4	75.5 ± 16.0	0.83	0.008	74.5 ±15.9 d
	Control	68.1 ± 20.3	64.8 ± 23.0
Chronic Pain Acceptance Questionnaire Activities Engagement	Meditation	47.7 ± 8.9	50.3 ± 12.3	0.95	0.004	48.1± 9.4 d
	Control	47.9 ± 12.3	43.4 ± 13.5
Quality of Life
SF-36 Physical Health Composite	Meditation	41.4 ± 8.7	43.9 ± 8.4	0.13	0.36	44.6 ± 10.4 d
	Control	41.2 ± 6.8	42.9 ± 9.0
SF-36 Global Health Composite	Meditation	40.4 ± 9.0	44.7 ± 8.9	0.21	0.27	43.9 ± 9.8 d
	Control	40.3 ± 10.4	42.9 ± 10.7
SF-36 Mental Health Composite	Meditation	41.7 ± 11.3	45.7 ± 10.3	0.17	0.30	45.1 ± 11.2 d
	Control	40.8 ± 13.7	43.2 ± 12.4

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^aMeditation n = 19, control n= 18.

^bd=M _t -M _c / σ_pooled. M _t = mean change score for the treatment group, M _c = mean change score for the control group, ${\mathrm{\sigma }}_{\mathrm{pooled}}=\surd [{\mathrm{\sigma }}_{\mathrm{t}}^2+{\mathrm{\sigma }}_{\mathrm{c}}^2/2]$, σ_t = standard deviation of change score for treatment group, σ_c = standard deviation of change score for control group.

^cLower scores indicate improvement.

^dNo statistically significant difference (P>.05) between 8-week and 3-month scores with one sample t-test.

Pain acceptance as measured with the Chronic Pain Acceptance Questionnaire total score significantly improved for the meditation group while the control group worsened over the 8-week period (P =.008). The Activities Engagement subscale of the CPAQ was also significantly improved (P = .004).

Mean pain scores changed in the expected direction for the meditation group as compared to the control group at 8-week follow-up for the McGill Pain Questionnaire and SF-36 Pain Scale, though not significantly.

Physical function showed significant improvement for the meditation group (P =.03) in the Physical Function Scale of the SF-36. Disability due to low back pain as measured by the Roland Disability Questionnaire changed in the expected direction for the meditation group as compared to the control group but this change did not reach statistical significance. There was no significant change between the two groups on the Short Physical Performance Battery on the Mann-Whitney U test at 8-weeks. Because of space considerations these data are not included in the outcome tables.

QOL as reflected in the summary scores and scales of the SF-36 were not improved to a statistically significant extent (P>.05) relative to the control group, but changes in each scale were in the expected direction for the MBSR group.

3.7. Control Subjects Who Completed MBSR

Table 3 presents the data from the control group after they had crossed over into the mindfulness meditation program. These data are presented because of the exploratory nature of the clinical trial and allows the reader to evaluate the changes in this group independently of the intervention group. All the measures were in the expected direction at 8-weeks but did not reach statistical significance. Although the McGill Pain Questionnaire, Chronic Pain Acceptance Questionnaire Total Score and Activities Engagement subscale trended toward improvement as compared to the participants’ pre-intervention scores. A significant improvement at 3-months is seen in the McGill Pain Questionnaire but not in the other measures.

Table 3

Outcomes for the Wait-List Control Group After They Completed the Mindfulness Meditation Program at 8-Weeks and 3-Months Follow-Up

Outcome Measure	Baselinea mean ± SD n=18	8-Week mean ± SD n=18	3-Month mean ± SD n=18	P-Value Baseline to 8-Weeks	P-Value Baseline to 3-Months
Pain
McGill Pain Questionnaire- Short Formb	15.7 ± 9.1	12.4 ± 8.5	11.4 ± 6.5	0.098	0.03
SF-36 Pain Scale	38.8 ± 8.3	41.0 ± 10.0	39.5 ± 8.4	0.16	0.66
Physical Function
Roland Disability Questionnaireb	10.6 ± 5.3	8.8 ± 6.5	9.4 ± 5.5	0.17	0.35
SF-36 Physical Function Scale	44.5 ± 10.1	45.8 ± 9.3	46.8 ± 10.7	0.38	0.11
Pain Acceptance
Chronic Pain Acceptance Questionnaire Total Score	64.8 ± 23.0	69.3 ± 20.9	68.0 ± 16.8	0.07	0.19
Chronic Pain Acceptance Questionnaire Activities Engagement	43.4 ± 13.5	47.2 ± 14.2	42.7 ± 11.5	.057	0.71
Quality of Life
SF-36 Physical Health Composite	42.9 ± 9.0	44.7 ± 9.5	43.9 ± 9.0	0.21	0.50
SF-36 Global Health Composite	42.9 ± 10.7	45.3 ± 10.9	42.2 ± 9.6	0.17	0.67
SF-36 Mental Health Composite	43.2 ± 12.4	45.4 ± 12.1	41.5 ± 10.7	0.30	0.42

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^aThe most proximal pre-treatment data was used as the control group’s baseline.

^bLower scores indicate improvement.

4.0 DISCUSSION

This is the first published study to show the feasibility of an 8-week mindfulness-based meditation program for older adults with CLBP. Other studies of MBSR have included older adults, but the mean age is much younger. A recent review of mindfulness-based interventions reported the mean age for 18 studies ranged from 38-51 years (Baer 2003). In this pilot study, not only were older adults interested in meditation, with recruitment requiring only six months, but they were enthusiastic about the program, attended most of the classes and adhered to the daily meditation homework assignments. The program appeared to have a beneficial effect on pain acceptance and physical function as measured by the CPAQ and SF-36 Physical Function scale. Additionally, the majority of participants continued to meditate at 3-month follow-up, suggesting they found enough benefit in meditation to continue it on their own.

This study adds to previous studies on the possible benefits of the MBSR program to reduce chronic pain (Kabat-Zinn 1982; Kabat-Zinn, Lipworth et al. 1985; Kabat-Zinn, Lipworth et al. 1986; Randolph, Tacone et al. 1999; Creamer, Singh et al. 2000). It is also consistent with the early work of Kabat-Zinn who found significant improvements in measures of pain and psychological function in subjects with varied chronic pain conditions and a large age range. We particularly view acceptance of pain as measured by the CPAQ as an important outcome. There is growing evidence for acceptance-based approaches to suffering vs. control or avoidance techniques (McCracken, Carson et al. 2004). Letting go of struggle and accepting one’s condition without judgment is a critical concept in the MBSR program. Other non-pharmacologic approaches to pain management also teach patients how to “live” with pain, but may not place as much emphasis on the concepts of letting go or acceptance. This approach was easily grasped by participants and encouraged them to take a fresh look at their pain condition. This may have led them to change their behavior or perception of pain, which may have resulted in improvement of their pain experience. A program participant stated it best “Mindfulness meditation has a quieting effect on me. It gives me a peaceful feeling while doing it and I am able to reduce my back and leg pain by deflecting the pain and by focusing on other parts of my body”. Interestingly, there is evidence from EEG studies that meditation can result in a shift to a more positive affect (Davidson, Kabat-Zinn et al. 2003).

We believe the lower completion rate in the intervention group (i.e., 68%) was largely due to factors not related to the intervention itself. This is because two participants never attended any classes and 3 had unexpected health or family obligations. Taking this into consideration, if we exclude the two participants who dropped out before the 8-week program began the true dropout rate was 4/17 (24%) for a completion rate of 76%. We cannot state with certainty that the other three participants simply gave the excuse of unexpected health or family obligations to please the investigators. However, two of these participants gave detailed descriptions of their obligations. This is not an unusual scenario in the older adult population, and we will take this into consideration when determining sample size for future planned studies. Because of the pilot nature of this study we were constrained by the day of the week and time of day we could offer the MBSR program. This also impacted both recruitment and dropouts, since scheduling conflicts came up frequently as a barrier to recruitment and was one of the reasons cited for discontinuing the program. A future larger trial will offer more scheduling flexibility. Other potential reasons for the differential dropout rate between the intervention and control groups could be the time demand of the class and homework assignments or dissatisfaction with the program itself. The dropouts were less educated than completers, which reduces the generalizability of the study findings, but were otherwise not different from completers in demographic characteristics.

The majority of participants continued to meditate at 3-month follow-up suggesting that they had incorporated meditation into their daily lives and may indicate that they experienced ongoing benefit from mindfulness meditation. Other studies have similarly found that participants continue to practice meditation 6 months-4 years after program completion (Kabat-Zinn, Lipworth et al. 1986; Carlson, Ursuliak et al. 2001). Nearly one half of the participants reported reduction in pain and sleep medications 3 months after completing the study, which is a notable benefit in a group that may be prone to side effects.

In response to the mindfulness meditation program both the intervention and the control group (after cross-over into the program) showed similarities in their response to the measures as they were in the expected direction for most measures in both groups. At 3-month follow-up there was less stability in the control group’s maintenance of a positive response after receiving the program as compared to the intervention group. The one exception, however, was for the MPQ which continued to improve over the follow-up period, with the benefit reaching statistical significance bSSSy 3 months.

Overall, effect sizes varied from small to large. Previously reported effect sizes have been in the medium range (Baer 2003; Grossman, Niemann et al. 2004). Effect sizes should be interpreted with caution because of the small sample size and the increased variability in the control group data as compared to the intervention group. Although this variability might be expected given that the control group was not monitored for therapy changes during the study, it nevertheless makes the effect sizes more difficult to interpret, since the latter are calculated taking change relative to the control group into account. A more difficult question to answer is whether the findings have clinical significance. Measures where values for a clinically important difference (CID) have been reported include the SF-36. A CID on the SF-36 has been proposed to be a change of 3-5 points (Stewart, Greenfield et al. 1989), whereas others would argue a minimum of 5 points is required (Wyrwich, Tierney et al. 2005). The physical function subscale had an overall improvement of 4.1 points at 8-weeks for the intervention group, which would suggest it was clinically relevant. Anecdotally, two of the participants in our trial stopped using their canes by the end of the 8-week program.

During the 8-week program participants were required to fill out a daily diary of minutes spent in meditation and record comments related to their experience. Since participants readily admitted to not meditating, the diaries were likely an accurate reflection of their daily meditation and not simply filled out to please the class instructors. The diary comments revealed a depth and richness of experience that could not be captured with the quantitative measures of this study.

There are many challenges facing psychological interventions as pointed out in a recent editorial (Morley and Williams 2006). We recognize the limitations of our study, many due to its pilot nature. The study is limited by its small sample size and is not powered to detect between-group differences. Additionally, the wait-list control group design did not control for face-to-face time subjects spent in class with the instructors or the total time spent in class. As a result there could be an effect on subjects simply from being present in class with the instructors or from the support of the other class participants. Additionally, controls could worsen during the waiting period, simply due to the distress of waiting for the program to begin. An attention-control would be a more appropriate control for future studies. Treatment effect may be biased by possible regression to the mean. No data were collected about change in therapy during the initial 8-weeks for the wait-list control group and during the 3-month follow-up period for both groups, therefore, self-reported improvement in physical function and pain may reflect other treatments. We crossed over the control group to the meditation program immediately after the intervention group completed the program. Future studies should wait to cross-over the control group until after all follow-up has occurred, to preserve the integrity of the control group. Although we were concerned about dropouts and recruitment of subjects if they had to wait many months to receive the meditation program, participants showed enough enthusiasm for the program that this is of less concern to us for future studies. Finally, measures of mindfulness, such as the Kentucky Inventory of Mindfulness Skills (Baer, Smith et al. 2004; Baer, Smith et al. 2006) or the Mindful Attention Awareness Scale (Brown and Ryan 2003) should be included in future studies.

In summary, an 8-week mindfulness meditation program is feasible among community dwelling older adults with CLBP. Three-month follow-up suggested sustained benefit from the program as measured by continued meditation by program participants and sustained improvement in physical function and pain acceptance. Mind-body therapies such as the MBSR program are a promising non-pharmacologic adjunct to current pain treatment for older adults. However, larger more rigorous trials must be undertaken to convincingly demonstrate their effectiveness.

Acknowledgments

Footnotes

References