Horticultural Therapy for Patients With Chronic ...

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original research

Horticultural Therapy for Patients With Chronic Musculoskeletal Pain: Results of a Pilot Study Martin L. Verra, MPtSc; Felix Angst, MD, MPH; Trudi Beck, MSc; Susanne Lehmann, RN; Roberto Brioschi, MSc; Renata Schneiter, MSc; André Aeschlimann, MD

Abstract Context • Therapists can use horticultural therapy as an adjuvant therapy in a nonthreatening context, with the intent of bringing about positive effects in physical health, mental health, and social interaction. Very few experimental studies exist that test its clinical effectiveness. Objective • To determine whether the addition of horticultural therapy to a pain-management program improved physical function, mental health, and ability to cope with pain. Design • The research team designed a prospective, nonrandomized, controlled cohort study, enrolling all patients consecutively referred to the Zurzach Interdisciplinary Pain Program (ZISP) who met the study’s criteria. The team divided them into two cohorts based on when medical professionals referred them: before (control group) or after (intervention group) introduction of a horticultural therapy program. Setting • The setting was the rehabilitation clinic (RehaClinic) in Bad Zurzach, Switzerland. Participants • Seventy-nine patients with chronic musculoskeletal pain (fibromyalgia or chronic, nonspecific back pain) participated in the study. Interventions • The research team compared a 4-week, inpatient, interdisciplinary pain-management program with horticultural therapy (intervention, n = 37) with a pain-management

Martin L. Verra, MPtSc, is director at the Physiotherapy Institute, Inselspital, Bern University Hospital, Switzerland, and research assistant at the rehabilitation clinic (RehaClinic), Bad Zurzach, Switzerland. Felix Angst, MD, MPH, is head of research at RehaClinic, Bad Zurzach. Professor Trudi Beck, MSc, is lecturer in the Department of Social Sciences, Zurich University of Applied Sciences, Duebendorf, Switzerland. Susanne Lehmann, RN, is research nurse and Roberto Brioschi, MSc, is clinical psychologist at RehaClinic, Bad Zurzach. Renata Schneiter, MSc, is a professor in the School of Life Sciences and Facility Management, Zurich University of Applied Sciences, Wädenswil, Switzerland. André Aeschlimann, MD, is medical director at RehaClinic, Bad Zurzach. Corresponding author: Martin L. Verra E-mail: [email protected] 44

program without horticultural therapy (control, n = 42). The horticultural therapy program consisted of seven sessions of group therapy, each of 1-hour duration. Outcome Measures • The research team assessed the outcome using the Medical Outcome Study Short Form-36 (SF-36), the West Haven-Yale Multidimensional Pain Inventory (MPI), the Hospital Anxiety and Depression Scale (HADS), the Coping Strategies Questionnaire (CSQ ), and two functional performance tests. The team tested participants on entry to and discharge from the 4-week pain-management program. Results • Between-group differences in sociodemographic and outcome variables were not significant on participants’ entry to the pain-management program. On discharge, the research team measured small to moderate outcome effects (effect size [ES] up to 0.71) within both groups. The study found significantly larger improvements for the horticultural therapy group vs the control group in SF-36 role physical (ES = 0.71 vs 0.22; P = .018); SF-36 mental health (ES = 0.46 vs 0.16; P = .027); HADS anxiety (ES = 0.26 vs 0.03; P = .043); and CSQ pain behavior (ES = 0.30 vs –0.05; P = .032). Conclusion • The addition of horticultural therapy to a painmanagement program improved participants’ physical and mental health and their coping ability with respect to chronic musculoskeletal pain. (Altern Ther Health Med. 2012;18(2):44-50.)

Author Disclosure Statement: The Zurzach Rehabilitation Foundation SPA, Bad Zurzach, Switzerland, supported this study. The Swiss Confederation’s innovation promotion agency (CTI project no. 8047.2 ESPP 2006-2009) provided additional financial support. No author has any conflict of interest to declare.

H

orticultural therapy is the engagement of a person in gardening-related activities that a trained therapist facilitates to achieve specific treatment goals.1 It is a process through which these therapists use plants, gardening activities, and proximity to nature as vehicles in therapy and rehabilitation programs.2 Horticultural therapy used in physical rehabilitation retrains muscles and improves coordination, balance, and strength. Therapists often use horticultural therapy as an adjuvant therapy in a nonthreatening context in addition to occupational and physical therapies.3-5 Horticultural

ALTERNATIVE THERAPIES, mar/apr 2012, VOL. 18, NO. 2

Horticultural Therapy for Chronic Pain Patients


therapists are specially educated and trained members of rehabilitation teams who involve patients in all phases of gardening. Besides the obvious physical benefits of gardening—such as improvement of lifting capacity, reaching, carrying, working in stooped positions, pushing, pulling, sitting, and prolonged standing—horticultural therapy has other mental and psychosocial therapeutic aspects.1,5 They comprise (1) the enjoyment of the sensations offered by the garden with its beauty, colors, and smells; (2) the encouragement of social activity; and (3) the opportunity to practice active, adaptive pain-coping strategies (eg, ignoring pain, relaxation techniques vs endurance behavior, reduction of catastrophizing). Recently published reviews bear witness to the high number of paraprofessional articles and book chapters on the subject of horticultural therapy, but very few include experimental studies that test its clinical effectiveness.1,5 The current explorative study examines the effects of the addition of horticultural therapy to a standard pain-management program for patients with chronic musculoskeletal pain, investigating whether it improved physical function, mental health, and the ability to cope with chronic pain. A second aim was to calculate sample sizes for a future randomized, controlled trial. MATERIALS AND METHODS Participants The study’s participants were patients in the Zurzach Interdisciplinary Pain Program (ZISP),6 all of whom had suffered from chronic nonspecific back pain or fibromyalgia for at least 6 months.7 Exclusion criteria included the existence of severe somatic illness requiring specific treatment and pain after a recent operation or manifest psychiatric disorder. For pragmatic reasons, the research team conducted a nonrandomized, pretest-posttest, controlled group study from April 2006 to December 2009. During this time, the research team enrolled all patients consecutively referred to ZISP who met the inclusion criteria and divided them into two cohorts. The first cohort, referred from April 2006 to August 2007, was the control group, and that group participated in the pain-management program without horticultural therapy. The research team initiated the newly developed, standardized, horticultural therapy program in the therapy garden and greenhouse in September 2007; all participants from that time until December 2008 took part in the standard pain-management program plus 7 additional standardized sessions of horticultural therapy. This second cohort—pain-management program plus horticultural therapy—was the intervention group. The Swiss Confederation’s Innovation Promotion Office (CTI project no. 8047.2 ESPP 2006-2009) approved the study’s protocol. The research team obtained ethical approval at the Independent Local Ethics Commission (Health Department in Aarau, Switzerland, no. EK AG 2008/026) as well as written, signed, informed consent from all participants. Outcome Measures The research team collected sociodemographic data—eg, age, gender, education, working ability—using a standardized questionnaire from a previous study.8 The West Haven-Yale Multidimensional Pain Inventory (MPI) assesses pain and its consequences in terms of symptoms, disability, activity, behavior, mood, and social relationHorticultural Therapy for Chronic Pain Patients

ships.9 The German version of the MPI is a self-reported, 51-item inventory with 9 subscales: (1) pain severity; (2) interference with pain (ie, interference in the individual’s life); (3) life control; (4) affective distress (synonymously described as negative mood); (5) support (from partner, family, or friends); (6) punishing responses (from partner or spouse); (7) solicitous responses (from partner or spouse); (8) distracting responses (from partner or spouse); and (9) general activities.10,11 The Medical Outcome Study Short Form-36 (SF-36) is a selfadministered, generic instrument that assesses health-related quality of life (QOL).12,13 It consists of 4 physical scales (physical functioning, role physical, bodily pain, and general health) and 4 mental scales (vitality, social functioning, role emotional, and mental health). The Hospital Anxiety and Depression Scale (HADS) is a short self-rating of anxiety and depression (each 7 items), anxiety and depression being two of the most important affective health dimensions for people with chronic musculoskeletal pain.14,15 The questionnaire has a long history of application in chronic pain management. The Coping Strategies Questionnaire (CSQ ) is a self-report instrument to assess active and passive coping strategies that individuals with chronic pain use.16,17 It consists of 48 items that assess 6 cognitive strategies (diverting attention, reinterpreting pain sensations, coping self-statements, ignoring pain sensations, praying or hoping, and catastrophizing) and 2 behavioral coping strategies (increasing activity level and increasing pain behaviors). The CSQ also includes 2 one-item scales that assess participants’ subjective abilities to control or decrease their pain. To assess specific features of construct validity (known groups), the research team used the Back Performance Scale (BPS) for participants with chronic back pain and the 6-minute Walk Test (6-MWT) for participants with fibromyalgia. The BPS is a specific performance measure of observed mobility-related activities, extensively validated for people with chronic back pain.18 The BPS consists of 5 physical performance tests: (1) the sock test (touching the toes of one foot with both hands); (2) the pick-up test; (3) the roll-up test (sitting upright from a supine position); (4) the fingertip-tofloor test; and (5) the lift test. The 16-point, BPS sum score ranges from 0 (=no activity limitation) to 15 (=major activity limitation).19 The 6-MWT is a performance-based test that Butland and colleagues derived from the 12-minute Walk Test.20 The test measures and reports the distance walked in 6 minutes in meters. A greater distance indicates a better performance.21 Data Analyses The research team performed assessments upon a participant’s admission to (baseline) and discharge from (1-month follow-up) the clinic. To ease comparison with scores obtained from other instruments, the research team rescaled the descriptive statistics for all instrument scores from 0 = worst to 100 = best health/function in accordance with the original scoring of the SF-36.7 The research team quantified the effects within groups by the effect size (ES), which is the difference between the baseline and the follow-up scores, divided by the sample’s standard deviation at baseline.22,23 The research team considered an ES of 0.20 to 0.49 to be a small effect, 0.50 to 0.79 to be a moderate effect, and 0.80 or more to be a large effect.22 The team stratified and listed absolute


45


effects—ie, score differences between follow-up and baseline within groups—for both the intervention and control groups, and then the team applied the nonparametric, frequency-distribution, independent Wilcoxon test for bivariate comparison of effects. The main analysis was the comparison of effects between the control and intervention groups. Covariates may affect the outcome of physical health if they are different for the two groups at baseline. To control for confounders, the research team performed an effect comparison between groups using multivariate logistic regression, with group allocation as the dependent variable and the score difference from baseline to follow-up (eg, for pain) as one of the independent variables.23 The team included any assessed parameters that were likely to confound the main outcome variables as independent covariates in the regression analysis. These covariates were outcome score at entry (eg, pain), depression, age, gender, working capacity, education, and social status (living alone/with partner). ESΔ, which measures the ES of the difference, is a standardized, unit-free measure of the difference in score changes (baseline to follow-up) between the intervention and the control groups. The measure reflects the difference between two ESs as described above.22,23 The research team performed all analyses using the statistical software package SPSS 17.0 for Windows® (SPSS Inc, Chicago, Illinois). Interventions Pain-management Program. ZISP is a 4-week, in-house, standardized, interdisciplinary pain-management program. The program has three main components: (1) medical care including adapted drug therapy, (2) exercise therapy, and (3) psychotherapy, mainly cognitive and operant behavioral therapy.24-30 As recommended by Gatchel and Okifuji, the program is intensive, consisting of over 100 hours of therapy.27 Over the course of treatment, participants receive an average of 6 daily sessions of the following treatments: (1) physiotherapy; (2) aerobic endurance training; (3) qigong/tai chi exercises; (4) individual psychotherapy, including cognitive behavioral therapy; (5) participation in a coping-withpain group; (6) relaxation therapy; (7) humor therapy; (8) information and education about the pathophysiology of pain mechanisms and management of chronic disabling pain; (9) nursing care; and (10) regular medical consultations, including drug therapy. The members of the pain-management team identify, adapt, and evaluate individual treatment strategies during the interdisciplinary meetings of the pain-management team (2 hours per week for 6 patients). The team discusses every patient weekly. In the first and last weeks of the pain-management program, the patient participates in the planning and review of his or her individual treatment strategies. Several studies, published in diverse peer-reviewed journals over the past few years, have demonstrated the outcomes of different aspects of this pain-management program.6,31,32 Horticultural Therapy Program. The intervention group received horticultural therapy in addition to the pain-management program; ie, horticultural therapy did not replace a part of the normal program. The horticultural therapy program consisted of 7 sessions of group therapy, each of 1-hour duration, held twice a week for 4 weeks. Per session, the standardized content included an average of 10 minutes of theoretical information about plants (to increase motivation), 10 minutes perception training (to reduce 46

stress and tension), 25 to 30 minutes of physical activity (working with plants and various elements of gardening with increasing physical effort), and a 10 to 15–minute break (to practice individually adapted pain coping strategies). The research team designed the program as a progression of activities. A physiotherapist assisted by a horticulturalist instructed and supervised a group of chronic pain patients (maximum of six). Session 1 focused on walking through the garden and the greenhouse (rediscovering the beauty and fascination of nature and discussing the wide range of horticultural activities) and on working with a stereomicroscope (observing the structure of seeds and small parts of plants). Session 2 consisted of sowing seeds (engaging in light physical activity in an upright position) and a “seed quiz.” Session 3 dealt with potting of houseplants in the greenhouse (standing to use a larger range of movements with heavier objects). Session 4 consisted of vegetable gardening in a raised bed at waist height (engaging in outdoor activity). Session 5 was a practical session of planting flowers in a flowerbed (bending to ground level and squatting as an outdoor activity). Session 6 consisted of digging and kneeling as a moderately hard physical activity. Finally, in the last session, the therapist instructed the participants to make a bouquet of flowers (providing sensory stimulation and reducing stress and tension) and distributed written information that dealt with easy and ergonomically correct gardening activities that allowed for continued participation at home. During the sessions, the horticultural therapists participated in the activities and closely observed the pain behaviors of the patients. For example, if during progression of horticultural activities a patient responded with withdrawal or pain catastrophizing, the therapist gave that patient some guidance: eg, motivated him or her to do mental or physical relaxation exercises as learned in the individual physiotherapy or psychotherapy sessions and told him or her to continue the activities despite the pain. The research team formulated the objectives of the horticultural therapy interventions according to the International Classification of Functioning, Disability, and Health.33 RESULTS Study Flow and Participants at Baseline The Figure depicts the flow chart of the study’s patients. The study started in April 2006 with the inclusion of the first particiFigure. Flow Chart of Participants in the Study Pain-management program plus horticultural therapy (Intervention)

Pain-management program without horticultural therapy (Control)

Included at entry:

n = 41

Included at entry:

n = 47

Refused to participate: Premature discharge: Data lost: Totally lost to follow-up:

n = 2 n = 1 n = 1 n = 4

Refused to participate: Acute hospitalization: Other reasons: Totally lost to follow-up:

n = 2 n = 1 n = 2 n = 5

Analyzed at discharge:

n = 37

Analyzed at discharge: n = 42




Table 1. Between-group Comparison at Study Entrya

Dimension

Diagnosis fibromyalgia Diagnosis chronic back pain Average age, y (min-max) Average onset of symptoms, y Education: grade 10-12, % Education: high school graduate, % Education: college graduate, % Education: university graduate, % Employment status: unemployed, % Employment status: part-time, % Employment status: full-time, % Depressionb, % SF-36 physical component summary, mean (SD) SF-36 mental component summary, mean (SD) MPI pain severity, mean (SD) MPI interference with pain, mean (SD) MPI working in garden, 1 item CSQ catastrophizing, mean (SD) CSQ ability to control pain, mean (SD) BPS (0 = best; 15 = worst), mean (SD) 6-MWT, m, mean (SD) a b

Control (n = 42)

Intervention (n = 37)

P

21 21 47.1 (20.4-66.9) 9.7 35.7 42.9 16.7 4.8 54.8 23.8 21.4 57.1 31.1 (6.0) 31.3 (12.7) 20.8 (12.7) 22.8 (13.7) 47.6 (n = 14) 41.4 (20.9) 46.4 (19.3) 6.7 (3.7) 382 (105)

15 22 49.0 (27.6-76.2) 10.7 37.8 43.3 13.5 5.4 68.6 11.4 20.0 73.0 31.0 (4.1) 30.7 (13.9) 21.2 (17.6) 21.4 (19.3) 35.4 (n = 16) 39.7 (20.9) 42.3 (22.8) 8.4 (4.1) 372 (105)

.400 .400 .694 .569 .394 .394 .394 .394 .132 .132 .132 .142 .746 .768 .710 .236 .608 .980 .794 .573 1.000

Scaling (except BPS and 6-MWT): 0 = worst to 100 = best health/function. Hospital Anxiety and Depression Scale (HADS) depression score above cut-off point of 9 out of 21 points.

Abbreviations: 6-MWT, 6-minute Walk Test; BPS, Back Performance Scale; CSQ, Coping Strategies Questionnaire; MPI, West Haven-Yale Multidimensional Pain Inventory; P, P-values (type I error) of significance tests (Wilcoxon test); SD, standard deviation; SF-36, Medical Outcome Study Short Form 36.

pants in the control group and ended in December 2008 with the discharge of the last participants in the intervention group. During that period, 175 patients participated in ZISP, and the research team assessed them for eligibility. A total of 88 patients met the inclusion criteria. The research team analyzed a complete data set of 79 participants (nine participants, 7.9%, dropped out). As this percentage of dropouts was below 20%, the research team decided that the study did not require a post hoc analysis. Table 1 presents the participants’ (n = 79) demographic and medical data upon entry to the pain-management program. Because this study’s design was not that of a randomized, controlled trial, the research team felt it was important to look for possible differences between groups at study entry. Several prognostic factors—diagnosis, age, gender, education, employment status, observed and self-reported physical capacity, mental health, pain, catastrophizing, and self-efficacy— did not show significant differences between the control and intervention groups at study entry. None of the comparisons of scores from the scales of the SF-36, HADS, MPI, and the CSQ


showed significant differences between groups (data not all shown). In summary, based on between-group analysis, the 35 comparisons between the control group and the intervention group did not yield any significant differences with regard to baseline scores (P = .073 to P = 1.000). Biopsychosocial Health and Activity Level Table 2 presents the effects within the control and intervention groups and the differences in effects between groups. The participants in the control group described small to moderate improvements for 15 out of 25 dimensions on the questionnaires (eg, CSQ catastrophizing: ES = 0.20 and MPI interference with pain: ES = 0.70). Measurements on seven scales showed significant improvement in the control group: SF-36 physical functioning (ES = 0.30; P = .043); SF-36 bodily pain (ES = 0.67; P = .015); SF-36 vitality (ES = 0.63; P = .005); SF-36 social functioning (ES = 0.51; P = .001); SF-36 physical component summary (ES = 0.38; P = .018); BPS (ES = 0.64; P = .003); and 6-MWT (ES = 0.45; P = .003). In the dimensions MPI support (ES = –0.14), CSQ increasing activity level (ES = –0.20), CSQ pain behaviors (ES = –0.05), and CSQ abil-


47


Table 2. Comparison of Pain-management Program Without Horticultural Therapy (Control, n = 42) and of Pain-management Program With Horticultural Therapy (Intervention, n = 37) From Entry to Discharge Change Within Groups Effect Comparison Entry Discharge at Discharge Between Groups

Dimension

Control

Intervention

Control

Intervention

Control

Intervention

P

mean (SD)

mean (SD)

mean (SD)

mean (SD)

ES

P

ES

P

(multivariate)

SF-36 physical functioning SF-36 role physical SF-36 bodily pain SF-36 general health SF-36 vitality SF-36 social functioning SF-36 role emotional SF-36 mental health SF-36 physical component summary SF-36 mental component summary HADS anxiety HADS depression MPI pain severity MPI interference with pain MPI affective distress MPI support MPI life control MPI general activities CSQ catastrophizing CSQ increasing activity CSQ pain behaviors CSQ ability to control pain CSQ ability to reduce pain BPS (0 = best; 15 = worst) 6-MWT, m

40.5 (18.6) 27.5 (13.4) 15.9 (10.8) 35.3 (13.2) 23.9 (11.9) 38.0 (24.3) 38.3 (28.4) 43.5 (20.7)

36.8 (19.0) 21.7 (17.3) 16.2 (14.9) 42.4 (18.3) 26.8 (19.1) 34.0 (26.3) 35.5 (30.2) 41.8 (24.9)

46.1 (18.2) 30.4 (18.8) 23.1 (16.5) 40.1 (17.2) 31.4 (16.7) 50.5 (23.5) 41.7 (27.2) 46.8 (20.9)

41.4 (21.5) 33.9 (20.4) 22.7 (17.5) 43.0 (20.3) 35.5 (19.1) 44.1 (33.4) 43.9 (30.3) 53.2 (21.6)

0.30 0.22 0.67 0.37 0.63 0.51 0.12 0.16

.043 NS .015 NS .005 .001 NS NS

0.24 0.71 0.43 0.03 0.46 0.38 0.28 0.46

NS .001 .016 NS .005 .018 NS .001

NS .018 NS NS NS NS NS .027

31.1 (6.0)

31.0 (4.1)

33.4 (6.4)

32.4 (6.4)

0.38

.018

0.33

NS

NS

31.3 (12.7) 48.1 (22.5) 52.4 (22.0) 20.8 (12.7) 22.8 (13.7) 39.0 (22.3) 67.5 (32.0) 53.0 (21.8) 39.6 (19.6) 41.4 (20.9) 53.4 (15.2) 56.7 (12.1) 46.4 (19.3) 32.9 (16.3) 6.7 (3.7) 382 (105)

30.7 (30.9) 48.8 (23.7) 48.5 (21.8) 21.2 (17.6) 21.4 (19.3) 38.4 (26.7) 66.2 (33.1) 45.5 (23.7) 32.0 (16.6) 39.7 (20.9) 46.0 (18.0) 57.0 (14.2) 42.3 (22.8) 35.6 (20.8) 8.4 (4.1) 372 (105)

34.2 (12.2) 48.6 (24.0) 55.7 (24.2) 28.4 (18.7) 32.4 (18.0) 42.9 (22.3) 62.8 (32.7) 58.6 (20.5) 41.3 (17.6) 45.3 (21.1) 50.4 (13.9) 56.2 (12.5) 40.9 (17.3) 36.9 (17.5) 4.3 (4.0) 430 (120)

36.5 (12.7) 55.0 (20.3) 56.4 (23.1) 29.9 (20.3) 26.0 (20.6) 53.1 (23.1) 67.4 (31.2) 56.2 (23.7) 34.8 (17.2) 43.4 (18.7) 47.4 (21.4) 61.3 (17.5) 42.3 (19.9) 37.8 (21.7) 6.4 (3.9) 421 (80)

0.23 0.03 0.15 0.60 0.70 0.17 –0.14 0.26 0.08 0.20 –0.20 –0.05 –0.29 0.24 0.64 0.45

.075 NS NS NS NS NS NS NS NS NS NS NS .071 NS .003 .003

0.41 0.26 0.36 0.50 0.24 0.55 0.04 0.45 0.17 0.18 0.08 0.30 0.00 0.11 0.49 0.47

.001 .016 .002 .003 .018 .001 NS .003 NS NS NS .058 NS NS .002 .016

NS .043 NS NS NS .091 NS NS NS NS NS .032 .061 NS NS NS

ESa

0.49

0.30

0.23

0.38

0.35 0.29

Abbreviations: 6-MWT, 6-minute Walk Test; BPS, Back Performance Scale; CSQ, Coping Strategies Questionnaire; ES, effect size; ES Δ, effect size of the differences between groups, equals (mean change intervention group minus mean change control group) divided by the pooled standard deviation of the baseline scores; HADS, Hospital Anxiety and Depression Scale; MPI, West Haven-Yale Multidimensional Pain Inventory; NS, not significant; P, P-values (type I error) of significance tests (Wilcoxon test); P multivariate, P-value of score differences after logistic regression; SD, standard deviation; SF-36, Medical Outcome Study Short Form 36.

ity to control pain (ES = –0.29), the participants without horticultural therapy had poorer scores at discharge from the program, although these differences were not significant. The participants in the intervention group described small to moderate improvements in 18 out of 25 dimensions on the questionnaires (eg, MPI interference with pain: ES = 0.24 and SF-36 role physical: ES = 0.71). Measurements on 14 out of 25 scales showed significant improvements (P