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CLINICAL REVIEW
The effect of meditative movement on sleep quality: A systematic
review
Fang Wang
a
, Othelia Eun-Kyoung Lee
b
, Fan Feng
a
, Michael V. Vitiello
c
,
Weidong Wang
a
,
*
, Herbert Benson
d
, Gregory L. Fricchione
d
, John W. Denninger
d
a
Department of Psychology, Guang'an Men Hospital of China Academy of Chinese Medical Sciences, Beijing, China
b
School of Social Work, University of North Carolina at Charlotte, Charlotte, NC, USA
c
Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, USA
d
Benson Henry Institute for Mind Body Medicine of Massachusetts General Hospital, Boston, MA, USA
article info
Article history:
Received 24 March 2015
Received in revised form
28 November 2015
Accepted 1 December 2015
Available online 12 December 2015
Keywords:
Meditative movement
Sleep quality
Systematic review
summary
The purpose of this systematic review was to identify and assess evidence related to the efficacy of
meditative movement (MM) on sleep quality. We conducted a comprehensive review of relevant studies
drawn from English and Chinese databases. Only randomized controlled trials (RCTs) reporting outcomes
of the effects of MM (tai chi, qi gong, and yoga) on sleep quality were taken into consideration. Twenty-
seven RCTs fulfilled our inclusion criteria and formed the basis for this review. Due to clinical hetero-
geneity, no meta-analysis was performed. Seventeen studies received a Jadad score of 3 and were
considered high-quality studies. Findings of the 17 studies showed that MM has beneficial effects for
various populations on a range of sleep measures. Improvement in sleep quality was reported in the
majority of studies and was often accompanied by improvements in quality of life, physical performance,
and depression. However, studies to date generally have significant methodological limitations. Addi-
tional RCTs with rigorous research designs focusing on sleep quality or insomnia and testing specific
hypotheses are needed to clearly establish the efficacy of MM in improving sleep quality and its potential
use as an intervention for various populations.
©2015 Elsevier Ltd. All rights reserved.
Introduction
Meditative movement (MM), also called complementary/alter-
native exercise or mind-body exercise, is a recently coined term for
gentle exercises that incorporate some form of movement or body
positioning, breathing, and relaxation [1,2]. MM techniques, most
commonly tai chi, qi gong, and yoga, incorporate a number of
common components: a) focusing the mind; b) movements that are
usually slow, relaxed, and flowing, but may range from a high level
of dynamic movement to quiescent static postures, with or without
specific choreography; c) a focus on breathing to rest the mind,
which also “energizes”the body; and d) a deep state of physical and
mental relaxation [3]. Tai chi and qi gong have roots in ancient
China as traditional Chinese medicine practices [4]. Yoga, originally
a spiritual practice, has origins in India [5]. When the
aforementioned components are combined (as they are in tai chi, qi
gong, and yoga), these practices have been shown to produce a
wide range of health benefits that may or may not be achieved with
any single element [6]. A number of randomized controlled trials
have focused on the positive effects of MM in various populations
with specific medical conditions, including fibromyalgia [7], breast
cancer [8], cardiovascular conditions [9], and diabetes [10].
The construct of sleep quality is poorly defined yet widely used
by researchers, clinicians and patients. The term insomnia has been
thought of both as a symptom and as a disorder with certain
diagnostic criteria in the medical literature and popular press. Poor
sleep quality is a key feature of insomnia [11]. Sleep quality is
commonly assessed in studies of MM. However, sleep quality is
usually a secondary outcome. Relatively few studies focus on using
MM to treat insomnia or improve sleep quality.
A previous systematic review of MM found support for
improved sleep quality; however, it focused solely on cancer
patients, the intervention included only yoga, and Chinese liter-
ature was not included [12]. A narrative review of mind-body
*Corresponding author. Tel.: þ86 10 88001178; fax: þ86 10 83114725.
E-mail address: prof_ww2005@hotmail.com (W. Wang).
Contents lists available at ScienceDirect
Sleep Medicine Reviews
journal homepage: www.elsevier.com/locate/smrv
http://dx.doi.org/10.1016/j.smrv.2015.12.001
1087-0792/©2015 Elsevier Ltd. All rights reserved.
Sleep Medicine Reviews 30 (2016) 43e52
interventions for the treatment of insomnia found that mind-
body interventions could improve sleep quality and reduce the
use of hypnotic drugs in a hypnotic-dependent population.
However, this review included not only tai chi, qi gong, and yoga
but also cognitive behavioral therapy, music therapy, and several
other interventions. In addition, only studies in which the main
objective was to treat insomnia were considered in this review
[13].
The present systematic review comprehensively summarizes
the known effects of MM (specifically tai chi, qi gong, and yoga) for
improving sleep quality in order to guide evidence-based clinical
decision-making and to inform future research.
Methods
Methods of data searches, study selection, data extraction,
quality assessment, and analysis were all specified in advance and
documented according to protocol.
Data searches and study selection
Articles were screened and selected based on the following
study inclusion/exclusion criteria:
Inclusion criteria
a) Investigated tai chi, qi gong, or yoga
b) Measured effects on sleep quality
c) Randomized controlled trials (RCTs)
Exclusion criteria
a) Assessed sleep quality without using recognized scales or
questionnaires specialized for sleep quality, such as the Pitts-
burgh sleep quality index (PSQI) and the Athens insomnia scale
(AIS), or objective measures, such as actigraphy and
polysomnography.
b) Used mixed interventions, such as tai chi with music therapy.
Randomized controlled trials (RCTs) reporting outcomes of the
effects of MM on sleep quality were identified. A study was oper-
ationally defined as an RCT in this review if the allocation of par-
ticipants to treatment and comparison groups was reported to be
randomized.
Since many tai chi and qi gong studies were published in Chi-
nese, we included relevant publications from both Chinese and
English-language databases (our team consists of three researchers
from China and five researchers from the U.S.). Two reviewers
independently searched and screened the titles and abstracts of the
English-language studies identified by the search against the
eligibility criteria, and two reviewers independently searched and
screened the Chinese-language studies.
Research articles that were published in English from the start
date of each database up to December 31st, 2014, and that con-
cerned the effects of MM on sleep quality, were identified from the
following databases: Medline, PubMed, PsycINFO, Cochrane Re-
views, Ovid, EBSCOhost, and all of the journals in the Harvard
Countway Library of Medicine. Using the same search criteria,
studies published in Chinese were identified from the following
databases: CNKI, Wan Fang Med Online, and VMIS. For potentially
eligible studies in both languages, full text versions were obtained
and the search criteria reapplied. Disagreement was resolved by
discussion. For English databases, the key words used included the
following combination of medical subject headings (MeSH) and
free text terms: “Tai-ji/Tai Chi/Chi, Tai/Tai JiQuan/JiQuan, Tai/Quan,
Tai Ji/taiji/Taijiquan/T'ai Chi/Tai Chi Chuan,”“Ch'i Kung, qi gong,”
“yoga,”“sleep quality,”“insomnia,”“sleep complaints,”“sleep
disturbance,”and “sleep disruption”as main subject headings or
text words in titles and abstracts. For Chinese databases, the key
words used included equivalent Chinese terms as main subject
headings and text words in titles and abstracts.
Fig. 1 shows the process used to select studies.
Data extraction and quality assessment
The characteristics of the original research in English and in
Chinese were each independently assessed by two reviewers, who
then extracted the data. A third reviewer checked the extracted
data from both English and Chinese searches. Disagreements were
resolved by discussion and consensus. Relevant information was
collected regarding date of publication, study sites, language of the
publications, and clinical domains (see Table 1). Duplicate publi-
cations, which meant that two or more journals published the same
research data, were represented as a single study in the systematic
review.
The methodological quality of the RCTs was evaluated using the
Jadad scale, which includes the following five questions: 1) Was the
trial described as randomized? (The words random, randomly, or
randomization must be used) 2) Is the method of randomization
appropriate? (The methods used to generate the sequence of
randomization must be described) 3) Was the study described as
double-blind? (The word double-blind must be used) 4) Is the
method of blinding appropriate? (If not, one point is deducted) 5) Is
there a description of withdrawals and dropouts? (The reasons
need to be included, and if there are no withdrawals, it must be
stated as such). Each question is given a maximum score of one
point. The scale awards 1e5 points to RCTs. RCTs with 2 points are
considered low-quality studies, and RCTs with 3 points are
considered high-quality studies [14]. When necessary, additional
information was sought from authors of the study reports (see
Table 2).
The inter-rater agreement between each of the two reviewers
for methodological quality as measured by kappa (k) was 0.802
(p<0.001) for English-language studies and 0.845 (p<0.001) for
Chinese-language studies.
Assessment of heterogeneity
Clinical, methodological, and statistical heterogeneity were
assessed. Clinical heterogeneity generally came from sample char-
acteristics (e.g., age, gender, and disease). Methodological
Abbreviations
AIS Athens insomnia scale
DSM-IV-TR diagnostic and statistical manual, fourth edition,
text revision
ECG electrocardiogram
ESS Epworth sleepiness scale
GSDS general sleep disturbance scale
ISI insomnia severity index
MM meditative movement
PSG polysomnography
PSQI Pittsburgh sleep quality index
RCTs randomized controlled trials
YOCAS yoga for cancer survivors
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e5244
heterogeneity refers to differences between studies in terms of
methodological factors, such as randomization sequence genera-
tion and blinding [15]. If the studies were found to be clinically and
methodologically homogeneous, we planned to conduct a meta-
analysis. However, given the extensive heterogeneity of age,
gender, comparison groups, and measures used across studies, and
the poor quality and reporting of many of the papers, a meta-
analysis was deemed inappropriate and potentially misleading.
Therefore, narrative synthesis was used to describe the strengths
and weaknesses and evaluate the outcomes of the studies.
Results
We identified 1200 papers: 286 from English-language data-
bases and 914 from Chinese-language databases. After excluding
duplicate studies and studies with inappropriate study design or
focus, the final total of acceptable studies was 27: twenty-one in
English and six in Chinese. These studies are listed in Table 1.
Fourteen studies were conducted in the United States, eight in
China, and one each in Brazil, India, Iran, Vietnam, and Japan.
Twelve studies evaluated tai chi, ten yoga, four qi gong, and one
studied tai chi and qi gong combined.
Quality of studies
Seventeen of the acceptable studies described the randomiza-
tion process. The most common method of randomization reported
was computer-generated random numbers. The other ten studies
did not clearly report the process of randomization. Only one study
used double-blinding, where the subjects were blinded by sham
control [2]. The number of dropouts and the reasons for dropping
out were mentioned in all but one study [16].
The statistical methods reported in all studies were considered
appropriate for the analyses performed. Intention-to-treat was
used in 11 studies. Eighteen studies described the methods used to
keep the adherence of patients to the intervention. Two studies
failed to present comprehensive comparisons of demographic and
baseline information [16,21]. Five studies reported that some de-
mographic characteristics were unbalanced among the comparison
groups at baseline [7,22e25].
In summary, 17 studies received a Jadad score of 3 and were
therefore considered high-quality studies (see Table 2). Among
these studies, all described the randomization process and the
methods used to keep the adherence of patients to the intervention.
The number of dropouts and the reasons for dropping out were
mentioned in all these studies. The statistical methods reported in
all of these studies were considered appropriate for the analyses
performed.
The findings of the 17 studies with high quality were tabulated
with respect to sample characteristics (i.e., sample size, age, and
gender), duration and frequency, intervention style, outcome mea-
sures, outcomes related to sleep quality, and follow-up (see Table 3).
Study samples
Among the 17 high quality studies, sample sizes ranged from 18
to 410. Most studies had between 30 and 60 subjects, and 10 studies
had over 100. The total number of study participants across the 17
articles was 1880; of those, 927 participants received active MM
interventions.
Most studies recruited research participants aged 18 y and up.
Five studies targeted older adults (60 y) [22,23,25,27,31]. One
study recruited young adults aged from 16 to 25 [20]. The majority
of studies included mixed-gender groups, although two studies
included women only [2,32].
Diagnosis of insomnia
Among the 17 high quality studies, two studies included peo-
ple with diagnoses of uncomplicated insomnia [26,27].Ofthese,
only one study [26] used the criteria both for primary insomnia in
the diagnostic and statistical manual, fourth edition, text revision
Fig. 1. Flow chart of the study selection process.
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e52 45
(DSM-IV-TR) and for general insomnia in the International clas-
sification of sleep disorders, second edition [26]. The other study
included older adults who had reported moderate sleep com-
plaints, which was defined as ratings of three or higher on two of
three sleep items drawn from the sleep questionnaire and
assessment of wakefulness or a rating of four or higher on any one
of three sleep items that assessed the problem of falling asleep at
night, waking up during the night, and waking and getting up in
the morning. The exclusion criteria included the following con-
ditions: a clinically diagnosed or clinically significant sleep dis-
order (e.g., sleep apnea); a medical or psychiatric condition (e.g.,
chronic pain, clinical depression) responsible for sleep com-
plaints; use of prescription sleep medication more than once a
week for the duration of the study; use of other psychotropic
medication; and a current recipient of sleep disorder treatment
[27].
Two studies focused on people with co-morbid insomnia, such
as cancer with insomnia [28], and type 2 diabetes with insomnia
[10]. In the study featuring cancer patients, sleep disturbance was
indicated by a response of three or above on a clinical symptom
inventory using an 11-point scale anchored by zero (no sleep
disturbance) and 10 (worst possible sleep disturbance) [28]. As for
the study featuring the co-morbidity of insomnia and type 2 dia-
betes, this Chinese-language study counted a score above sixon the
AIS as insomnia [10].
The remaining 13 studies, which did not explicitly include a
diagnosis of insomnia, targeted individuals either with a variety of
health conditions or from specific demographic groups. Eight of
these studies targeted illnesses: four reported on cancer
[2,21,32,34], two on fibromyalgia [7,35], one on chronic heart failure
[9], and one on stroke [25]. Five studied healthy people: four re-
ported on older adults [22,23,31,37], and one on college students
[20].
Study design
Among the 17 high quality studies, the greater majority (n ¼14)
were two-armed with one intervention and one control arm. Three
studies utilized either no treatment or usual care controls
[20,28,31],five utilized waitlist controls [9,21e23,34], and three
utilized health education controls [32,35,37]. The other three 2-
armed studies reported the following control conditions: low-
impact exercise [27], wellness education and stretching [7], and
sham qi gong [2].
Table 1
Summary of characteristics of meditative movement and sleep studies.
Year of publication Number of
studies
Authors, reference number
Before 2006 2 Cohen L et al. 2004 [21]; Li F et al. 2004 [27]
2006e2010 9 Chandwani KD et al. 2010 [33]; Chen K-M et al. 2009 [22]; Danhauer SC et al. 2009 [8]; Hosseini H et al.
2011 [18]; Irwin MR et al. 2008 [37]; Wang C et al. 2010 [7]; Wang F 2008 [10]; Wang W et al. 2010
[36]; Yeh GY et al. 2008 [9]
After 2010 16 Afonso RF et al. 2012 [30]; Bower JE et al. 2012 [32]; Chen MC et al. 2012 [31]; Cui X, Bo Z [17]; Dhruva A
A et al. 2012 [34]; Hariprasad VR et al. 2013 [23]; Irwin MR et al. 2014 [26]; Jones KD et al. 2012 [35];
Larkey LK et al. 2014 [2];LiC[19]; Mustian KM et al. 2013 [28]; Nguyen MH et al. 2012 [24]; Rao T 2014
[20]; Song Z et al. 2011 [16]; Taylor-Piliae RE et al. 2014 [25]; Yang L [29]
Study sites
US 14 Bower JE et al. 2012 [32]; Cohen L et al. 2004 [21]; Chandwani KD et al. 2010 [33]; Danhauer SC et al.
2009 [8]; Dhruva A A et al. 2012 [34]; Irwin MR et al. 2008 [37]; Irwin MR et al. 2014 [26]; Jones KD et al.
2012 [35]; Larkey LK et al. 2014 [2]; Li F et al. 2004 [27]; Mustian KM et al. 2013 [28]; Taylor-Piliae RE
et al. 2014 [25]; Wang C et al. 2010 [7]; Yeh GY et al. 2008 [9]
China, Hong Kong, and Taiwan 8 Cui X, Bo Z [17]; Chen K-M et al. 2009 [22]; Chen MC et al. 2012 [31];LiC[19]; Rao T 2014 [20]; Song Z
et al. 2011 [16]; Wang F 2008 [10]; Yang L [29]
Others 5 Afonso RF et al. 2012 [30] (Brazil); Hariprasad VR et al. 2013 [23] (India); Hosseini H et al. 2011 [18]
(Iran); Nguyen MH et al. 2012 [24] (Vietnam); Wang W et al. 2010 [36] (Japan)
Language of study
Chinese 6 Cui X, Bo Z [17];LiC[19]; Rao T 2014 [20]; Song Z et al. 2011 [16]; Wang F 2008 [10]; Yang L [29]
English 21 Afonso RF et al. 2012 [30]; Bower JE et al. 2012 [32]; Chandwani KD et al. 2010 [33]; Chen K-M et al.
2009 [22]; Chen MC et al. 2012 [31]; Cohen L et al. 2004 [21]; Danhauer SC et al. 2009 [8]; Dhruva A A
et al. 2012 [34]; Hariprasad VR et al. 2013 [23]; Hosseini H et al. 2011 [18]; Irwin MR et al. 2008 [37];
Irwin MR et al. 2014 [26]; Jones KD et al. 2012 [35]; Larkey LK et al. 2014 [2]; Li F et al. 2004 [27];
Mustian KM et al. 2013 [28]; Nguyen MH et al. 2012 [24]; Taylor-Piliae RE et al. 2014 [25]; Wang C et al.
2010 [7]; Wang W et al. 2010 [36]; Yeh GY et al. 2008 [9]
Clinical domains
Cancer Breast cancer 4 Bower JE et al. 2012 [32]; Chandwani KD et al. 2010 [33]; Danhauer SC et al. 2009 [8]; Larkey LK et al.
2014 [2]
Lymphoma 1 Cohen L et al. 2004 [21]
General 1 Dhruva A A et al. 2012 [34]
General with
insomnia
1 Mustian KM et al. 2013 [28]
Cerebral vascular disorder 1 Wang W et al. 2010 [36]
Chronic heart failure 1 Yeh GY et al. 2008 [9]
Fibromyalgia 2 Jones KD et al. 2012 [35]; Wang C et al. 2010 [7]
Insomnia 5 Cui X, Bo Z [17]; Hosseini H et al. 2011 [18]; Irwin MR et al. 2014 [26]; Li F et al. 2004 [27]; Song Z et al.
2011 [16]
Stroke 1 Taylor-Piliae RE et al. 2014 [25]
Type 2 diabetes with insomnia 2 Yang L [29]; Wang F 2008 [10]
Postmenopausal women
with insomnia
1 Afonso RF et al. 2012 [30]
Geriatrics 5 Chen K-M et al. 2009 [22]; Chen MC et al. 2012 [31]; Hariprasad VR et al. 2013 [23]; Irwin MR et al. 2008
[37]; Nguyen MH et al. 2012 [24]
Pregnant woman 1 Li C [19]
College student 1 Rao T 2014 [20]
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e5246
The three remaining studies were 3-armed. Two compared MM
to: 1) cognitive behavioral therapy or education [26], and 2) group-
based exercise or written materials plus resources and weekly
phone call [25]. Finally, one study compared two kinds of qi gong to
usual care [10].
Interventions
All 17 high quality studies reported the duration and frequency
of the intervention. The length of duration was from four weeks to
six months; the most common was 12 wk. The frequency was from
five times a week to daily; the most common was twice a week. The
length of interventions ranged from 30 min to 90 min; the most
common was 60 min.
Only two studies did not report the style or philosophy of MM
[2,26]. The vast majority (82%) of the studies report details about
the teacher's qualifications or style. Six studies specified encour-
aging home practice, usually daily. An instructional DVD, CD, or
videotape was employed in four studies. Seven studies described
periods of follow-up, ranging from nine weeks to 12 months.
Tai chi was implemented in eight studies [7,9,20,25e27,35,37].
The most common style, Yang style tai chi, was used in five studies.
Other interventions included 24-style tai chi, tai chi easy, and 8-
form easy tai chi.
Two studies used qi gong as the intervention, including
Baduanjin (qi gong), Liuzijue (qi gong), and relaxation qi gong
[10,31]. One study used both tai chi and qi gong [2].
Yoga in various forms was used in six trials, including Iyengar
yoga, silver yoga, Tibetan yoga, pranayama (yoga), and yoga for
cancer survivors (YOCAS) [21e23,28,32,34].
Outcome measures
The most frequently used sleep measure, used in 15 of the 17
studies, was the PSQI, a well validated and commonly used in-
strument that measures the quality and patterns of sleep [38,39].
Other measures included the general sleep disturbance scale
(GSDS) [34], AIS [26], actigraphy [28], electrocardiogram (ECG) [9],
and polysomnography (PSG) [26]; each was employed in one study,
respectively. The Epworth sleepiness scale (ESS) was employed in
two studies [26,27]. In summary, most studies used subjective
measurements, such as different kinds of self-report question-
naires, to evaluate outcomes. Only a few studies used objective
measurements, such as actigraphy, ECG, or PSG.
Outcomes
Table 3 summarizes the effects of MM on sleep quality outcomes
as reported in the 17 high quality studies. Of them, 10 used sleep
quality as a primary outcome. Three studies, related to cancer [2,32]
and fibromyalgia [7], used sleep quality as a secondary outcome.
Other studies did not clearly mention sleep quality as a primary or a
secondary outcome but did report on sleep. These studies targeted
the following four populations: 1) subjects with uncomplicated
insomnia, 2) subjects with co-morbid insomnia, 3) subjects with
chronic illnesses, and 4) healthy subjects.
Studies using sleep quality as a primary outcome
Subjects with uncomplicated insomnia. Both of the two studies in
this population reported significant improvement in the total score
of PSQI in the MM groups compared to control groups (including
education and low-impact exercise) [26,27]. Significant improve-
ment in the following sleep domains was reported: subjective sleep
quality, sleep efficiency, sleep latency, sleep duration, sleep dis-
turbances and daytime sleepiness (all as measured by the PSQI, the
ESS score, and the AIS score). The significant improvement in the
total score of PSQI and the AIS score, compared to the education
control, was not sustained at 12 months follow-up [26]. Other
benefits of MM practice, compared to control groups, included
improvements in depression, physical performance, and exercise
capacity.
Table 2
Methodological quality of meditative movements studies reviewed using Jadad scoring criteria.
Authors, reference number Was the trial
described
as randomized
Is the method of
randomization
appropriate
Was the study described
as double-blind
Is the method of
blinding appropriate
Is there a description
of withdrawals and
dropouts
Jadad
score
Afonso RF et al. 2012 [30] 10 0 0 1 2
Bower JE et al. 2012 [32] 11 0 0 1 3
Chandwani KD et al. 2010 [33] 10 0 0 1 2
Chen K-M et al. 2009 [22] 11 0 0 1 3
Chen MC et al. 2012 [31] 11 0 0 1 3
Cohen L et al. 2004 [21] 11 0 0 1 3
Cui X, Bo Z [17] 10 0 0 1 2
Danhauer SC et al. 2009 [8] 10 0 0 1 2
Dhruva A A et al. 2012 [34] 11 0 0 1 3
Hariprasad VR et al. 2013 [23] 11 0 0 1 3
Hosseini H et al. 2011 [18] 10 0 0 1 2
Irwin MR et al. 2008 [37] 11 0 0 1 3
Irwin MR et al. 2014 [26] 11 0 1 1 4
Jones KD et al. 2012 [35] 11 0 0 1 3
Larkey LK et al. 2014 [2] 11 1 1 1 5
Li C [19] 10 0 0 1 2
Li F et al. 2004 [27] 11 0 0 1 3
Mustian KM et al. 2013 [28] 11 0 1 1 4
Nguyen MH et al. 2012 [24] 10 0 0 1 2
Rao T 2014 [20] 11 0 0 1 3
Song Z et al. 2011 [16] 10 0 0 0 1
Taylor-Piliae RE et al. 2014 [25] 11 0 0 1 3
Wang C et al. 2010 [7] 11 0 0 1 3
Wang F 2008 [10] 11 0 0 1 3
Wang W et al. 2010 [36] 10 0 0 1 2
Yang L [31] 10 0 0 1 2
Yeh GY et al. 2008 [9] 11 0 0 1 3
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e52 47
Table 3
Effects of meditative movements on sleep quality in high quality studies (Jadad scores of 3).
Authors,
reference
number
Sample characteristics
(sample size, age,
gender)
Duration and frequency Intervention style Outcome measures Outcomes Follow-up
Bower JE et al.
2012 [32]
31, G1 ¼16, G2 ¼15;
mean age ¼54 y;
female only
12 wk, twice/wk G1. Iyengar Yoga
(Yoga)
G2. Health
education (control)
Pittsburgh sleep quality
index (PSQI)
No significant
difference between
groups.
3mo
No significant
difference between
groups.
Chen K-M et al.
2009 [22]
128, G1 ¼62, G2 ¼66;
aged 60 y or above; 35
males, 93 females
6 mo, 3 times/wk G1. Silver Yoga
program (Yoga)
G2. Waitlist
(control)
PSQI The total score**,
subjective sleep
quality**, sleep
latency** and
daytime
dysfunction**
improved in G1 vs.
G2.
No
Chen MC et al.
2012 [31]
55, G1 ¼27, G2 ¼28;
aged 60 y or above;
19males, 36 females
12 wk, 3 times/wk G1. Baduanjin (Qi
Gong)
G2. Routine daily
activities (control)
PSQI The total score**
and all subscales*
to
** improved in G1
vs. G2.
No
Cohen L et al.
2004 [21]
38, G1 ¼G2 ¼19; mean
age ¼51 y; 26males,
12females
7 wk, once/wk G1. Tibetan Yoga
(Yoga)
G2. Waitlist
(control)
PSQI The total score**,
subjective sleep
quality*, sleep
latency*, sleep
duration* and sleep
medications*
improved in G1 vs.
G2.
3mo
Effect sustained.
Dhruva A A
et al. 2012
[34]
18, G1 ¼G2 ¼9; mean
age ¼54 y; 2males,
16females
two consecutive cycles
of chemotherapy,
once/wk
G1. Pranayama
(Yoga)
G2. Waitlist
(control)
General sleep
disturbance scale
(GSDS)
No significant
difference between
groups.
No
Hariprasad VR
et al. 2013
[23]
120, G1 ¼62, G2 ¼58;
aged 60 y or above; 48
males, 72 females
6 mo, once/d, once/d
with supervision (1 mo),
once/wk with supervision
(2 mo), practicing without
supervision (3 mo)
G1. Yoga
G2. Waitlist
(control)
PSQI The total score**
improved in G1 vs.
G2.
No
Irwin MR et al.
2008 [37]
112, G1 ¼59, G2 ¼53;
aged 59e85 y; 51
males, 61 females
16 wk,3 times/wk G1. Tai Chi
G2. Health
education (control)
PSQI No significant
difference between
groups.
9wk
The total score**,
subjective sleep
quality*, sleep
efficiency*, sleep
duration** and sleep
disturbance**
improved in sub-G1
(PSQI total score5) vs.
sub-G2 (PSQI total
score 5).
Irwin MR et al.
2014 [26]
123, G1 ¼48, G2 ¼50,
G3 ¼25; aged 55e85 y;
35 males, 88females
4 mo, once/wk G1. Tai chi
G2. Cognitive-
behavioral therapy
(CBT) (control1)
G3. Sleep seminar
education control
(control2)
PSQI, Athens insomnia
scale (AIS), Epworth
sleepiness scale (ESS),
polysomnography
(PSG), sleep diaries
The total score of
PSQI* and score of
AIS* improved in
G1 vs. G3.
12 mo
Effect disappeared.
Jones KD et al.
2012 [35]
101, G1 ¼51, G2 ¼50;
mean age ¼54 y; 7
males, 94 females
12 wk, twice/wk G1. Tai Chi (Yang
style)
G2. Education
(control)
PSQI The total score**
improved in G1 vs.
G2.
No
Larkey LK et al.
2014 [2]
101, G1 ¼49, G2 ¼52;
aged 40e75 y; female
only
12 wk, twice/wk
(first 2 wk), once/wk
(the remainder)
G1. Qi Gong/Tai Chi
Easy
G2. Sham Qi Gong
(control)
PSQI No significant
difference between
groups.
3mo
No significant
difference between
groups.
Li F et al. 2004
[27]
118, G1 ¼62, G2 ¼56;
aged 60e92 y; 22
males, 96 females
24 wk, 3 times/wk G1. Tai Chi (Yang
style, 8-Form Easy
Tai Chi)
G2. Low-impact
exercise (control)
PSQI, ESS The total score**,
subjective sleep
quality**, sleep
latency**, sleep
duration**, sleep
efficiency* and
sleep disturbances*
of PSQI, the score of
ESS** improved in
G1 vs. G2.
No
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e5248
Subjects with co-morbid insomnia. Two studies that investigated
co-morbid insomnia in cancer patients and in patients with type 2
diabetes reported significant improvement in the total score of PSQI
in the MM groups compared to the usual care control [10,28].
Significant improvement in the following sleep domains was re-
ported: subjective sleep quality, daytime dysfunction, sleep dis-
turbances, sleep medication (all as measured by the PSQI), wake
after sleep onset, and sleep efficiency (as measured by actigraphy).
One study targeting people with chronic heart failure reported
significant improvement in stable sleep state measured by the
objective measure of ECG in comparison to waitlist control [9].
Another benefit of MM practice, compared to the usual care
control, was improvement in depression [10]. In addition, signifi-
cant correlations were also seen between improved sleep quality
and improved psychological symptoms as measured by the
symptom checklist-90 depression and anxiety subscales.
Healthy subjects. Out of four studies targeting healthy populations
of older adults, three reported significant improvement in the total
score of the PSQI in comparison to control groups (including
waitlist control, routine daily activities without MM, and usual care
without MM) [22,23,31]. Significant improvement in the following
sleep domains was reported: subjective sleep quality, sleep latency,
sleep duration, sleep efficiency, sleep disturbance, sleep medica-
tions, and daytime dysfunction [22,31]. One study on older adults
reported that PSQI total score, subjective sleep quality, sleep effi-
ciency, sleep duration, and sleep disturbance improved in the
intervention sub-group (PSQI global score 5) at 9 weeks follow-
up, compared to the health education control sub-group [37].
In addition, compared to controls, significant benefits from MM
practice were reported in quality of life [23] as well as health and
mental health status [22].
Studies using sleep quality as a secondary outcome
Subjects with chronic illnesses. One study targeting people with
fibromyalgia symptoms reported significant improvement in
the total score of the PSQI in comparison to education and
Table 3 (continued )
Authors,
reference
number
Sample characteristics
(sample size, age,
gender)
Duration and frequency Intervention style Outcome measures Outcomes Follow-up
Mustian KM
et al. 2013
[28]
410, G1 ¼206,
G2 ¼204; mean
age ¼54 y; 17 males,
393 females
4 wk, twice/wk G1. Yoga for cancer
survivors (YOCAS)
G2. Usual care
(control)
PSQI, Actigraphy The total score**,
daytime
dysfunction**, sleep
medications* and
subjective sleep
quality* of PSQI, the
wake after sleep
onset** and sleep
efficiency*
measured by
actigraphy
improved in G1 vs.
G2.
No
Rao T 2014 [20] 206, G1 ¼G2 ¼103;
aged 16e25 y; both
male and female
12 wk, 5 times/wk G1. Tai Chi (24
style)
G2. Routine daily
activities (control)
PSQI No significant
difference between
groups.
12 wk
No significant
difference between
groups.
Taylor-Piliae RE
et al. 2014
[25]
145, G1 ¼53, G2 ¼44,
G3 ¼48; mean age ¼70
y; 77 males, 68 females
12 wk, 3 times/wk G1. Tai Chi (Yang
style)
G2. Group-based
Exercise (control1)
G3. Written
materials,
resources and
weekly phone call
(control2)
PSQI No significant
difference between
groups.
No
Wang C et al.
2010 [7]
66, G1 ¼G2 ¼33; mean
age ¼50 y; 9 males, 57
females
12 wk, twice/wk G1. Tai Chi (Yang
style)
G2. Wellness
education and
stretching (control)
PSQI The total score**
improved in G1 vs.
G2.
12 wk
Effect sustained.
Wang F 2008
[10]
90, G1 ¼G2 ¼G3 ¼30;
aged 36e70 y; 31males,
59females
4 mo, twice/wk G1. Baduanjin þ
relaxation Qi
Gong (Qi Gong)
G2. Liuzijue þ
relaxation Qi
Gong (Qi
Gong)
G3. Usual care
(control)
PSQI The total score*,
subjective sleep
quality* and sleep
disturbance*
improved in G1 vs.
G3.
The subjective
sleep quality**
improved in G2 vs.
G3.
No
Yeh GY et al.
2008 [9]
18,G1 ¼8,G2 ¼10;
mean age ¼59 y; 9
males, 9 females
12 wk, twice/wk G1. Tai Chi (Yang
style)
G2. Waitlist
(control)
Electrocardiogram
(ECG)
Stable sleep state*
improved in G1 vs.
G2.
No
Note: * indicates p<.05, ** indicates p<.01.
Abbreviations: AIS, Athens insomnia scale; CBT, cognitive-behavioral therapy; ECG, electrocardiogram; ESS, Epworth sleepiness scale; G1, group 1; G2, group 2; G3, group 3;
GSDS, general sleep disturbance scale; PSG, polysomnography; PSQI, Pittsburgh sleep quality index; SE, sleep efficiency; Sl, sleep latency; WASO, wakefulness after sleep onset;
YOCAS, yoga for cancer survivors.
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e52 49
stretching control [7]. This effect was sustained at 12-week
follow-up.
In this study, compared to the control group, the overall severity
of fibromyalgia, global pain status, physical performance, quality of
life, and depression was also improved.
Two studies targeting cancer patients did not find any signifi-
cant differences between intervention and control groups
(including sham MM and education) in terms of sleep quality
[2,32]. One of these two studies reported the same result at 3-
month follow-up [2].
Studies which did not clearly mention sleep quality as a primary or a
secondary outcome
Subjects with chronic illnesses. Two studies targeting people with
lymphoma and fibromyalgia reported significant improvement in
the total score of the PSQI in comparison to control groups
(including waitlist and education control) [21,35]. Significant im-
provements in the following five PSQI domains were also reported:
subjective sleep quality, sleep latency, sleep duration, daytime
dysfunction, and sleep medication [21]. The significant improve-
ment in the total score of PSQI and the five PSQI domains
mentioned above, compared to waitlist control, was sustained in a
3-month follow-up [21].
Other benefits of MM practice, compared to the control,
included the improvement of common fibromyalgia symptoms,
such as pain and physical function (including mobility) [35].
Two studies targeting people with cancer and stroke did not find
any significant differences between intervention and waitlist con-
trol groups in terms of sleep quality [25,34].
Healthy subjects. One study targeting healthy populations of col-
lege students did not find any significant differences between
intervention and routine daily activities control in terms of sleep
quality at post-treatment and at 12-week follow-up [20].
Discussion
Primary findings
This systematic review revealed that RCT efficacy studies of MM
on sleep quality have been increasing in recent years. The 17 high
quality studies reviewed suggest that MM may have the potential to
improve sleep quality in a variety of patient populations. Even
though evidence is limited, this systematic review, which includes
studies published between 2004 and 2014, provides evidence that
MM may be useful for the treatment of both uncomplicated
insomnia as well as insomnia comorbid with medical and psychi-
atric conditions. These findings are consistent with previous meta-
analyses of the efficacy of psychological and behavioral in-
terventions for insomnia [12,13,40,41].
All of the high quality studies reviewed that showed no effect
on sleep outcomes did not specifically target sleep problems.
Some of these studies used sleep as a secondary outcome; others
used it as an additional outcome. In these studies, diagnostic
criteria of insomnia were not mentioned. Sleep quality evalua-
tion was not considered in the primary inclusion or exclusion
criteria.
In addition, in terms of different populations, all the MM
studies targeting individuals either with uncomplicated insomnia
or co-morbid insomnia showed significant effects on sleep out-
comes. No effect on sleep outcomes was shown in studies
targeting individuals either with various health conditions or
from specific demographic groups, such as older adults and
college students. Further well-designed studies specifically
investigating the effect of MM on sleep problems or insomnia are
needed.
Secondary findings
Sleep quality was assessed in patients with a variety of health
conditions. The improvement of sleep quality was accompanied
with the improvement of various outcomes, including physical
performance in patients with fibromyalgia and depression and
quality of life in a number of chronic health conditions. However,
because the association between sleep quality and health condi-
tions has not been clearly demonstrated, the mechanism by which
MM improves sleep quality and other outcomes in the context of
these different health conditions needs to be further studied. For
example, future studies could address specific changes in patients
with hypothalamic-pituitary-adrenal axis disorders, circadian dis-
orders, or immune dysregulation, and could investigate MM-
induced changes in gene expression as a way of further pinpoint-
ing the mechanism of improved sleep quality in different
populations.
As shown in the high-quality studies reviewed here, the com-
ponents of MM interventions can improve psychological and
behavioral factors associated with poor sleep quality, such as anx-
iety, depression, and chronic pain. Such evidence suggests there is
value in exploring these MM interventions as potential crossover
treatments for sleep disturbance, depression, and chronic pain.
Because older adults and patients with cancer may suffer from
these symptoms, which can worsen sleep disturbance [28,37],
further research on MM interventions in hypnotic users becomes
very relevant.
Strengths
All studies reviewed here were RCTs, suggesting the highest
level of evidence for the interventions tested. The specific content
of MM interventions was fairly consistent and relevant. A
particular strength of this review was the inclusion of studies
from a broad search of the literature. Inclusion of studies pub-
lished in Chinese language journals greatly expanded the evi-
dence available to assess the efficacy of MM on sleep quality and
helped overcome the inherent language bias that was present in
systematic reviews that only included articles published in
English.
Limitations
A meta-analysis of the studies in this field could not be per-
formed due to the high level of clinical and methodological het-
erogeneity. Because sleep problems are likely to have diverse
pathophysiologic origins across different chronic illness conditions,
the inclusion of multiple populations and disease groups is a major
limitation in assessing this literature. The effect of MM on sleep
quality in any given health condition or population, along with
related mechanisms, will ultimately need to be individually and
comprehensively studied.
Although it is hypothesized that MM has a positive impact on
sleep outcomes, most studies reviewed here were feasibility
studies or pilot studies. More than one-third of the studies were
considered low-quality studies that received a Jadad score of 2.
More than one-third of the studies did not describe the
randomization process. Double blind studies were rare (only one
of the 27 studies reviewed here was double blind), although
blinding is admittedly challenging in complex interventions such
as MM [42]. Sample sizes used in most of the high quality trials
reviewed here were small to medium (n <100in10of17trials).
F. Wang et al. / Sleep Medicine Reviews 30 (2016) 43e5250
The specifics of each MM intervention (e.g., duration, frequency,
style of practice) varied across studies, making direct comparison
of individual studies difficult. Although some studies used
attention control or active control, most did not. Of those that did
not, waitlist control, treatment as usual, or routine daily activities
appeared as the most frequent control conditions. As a result,
while MM appears to be a promising modality, the lack of active
controls in these studies does limit the conclusions that can be
drawn. In addition, few studies compared different forms of MM,
such as yoga and tai chi, or dynamic qi gong and static qi gong,
which may involve different physiological demand-energy
expenditure. So the underlying mechanisms that might govern
improvements in sleep related to the varying energy
expenditures in different MM practices remain to be
investigated.
Furthermore, most studies used self-report questionnaires to
evaluate outcomes of therapeutic interventions instead of relying
on more objective measurements such as actigraphy or PSG. A
follow-up assessment was used in only seven trials and typically for
a maximum of twelve months, which may be too short for those
with chronic insomnia or co-morbid insomnia. As in any review of
this type, readers may disagree with the decisions made by the
bilingual authors to identify criteria used to categorize the mind-
body interventions. Finally, it is certainly possible that other com-
plementary and alternative medicine strategies not addressed in
this review may offer equally or more beneficial effects in treating
insomnia symptoms.
Conclusions
This systematic review demonstrates that MM interventions
may have beneficial effects for various populations on a range of
sleep measures. However, due to the clinical heterogeneity and
methodological limitations, clinically relevant conclusions
cannot be drawn. More RCTs with rigorous research design,
including more consistent use of attention controls and more
specific aims, are needed to clearly establish the efficacy of MM
in improving sleep quality, as well as the potential of MM to be
used in interventions for populations with a variety of health
conditions or specific demographic groups. Ultimately, the bio-
logical mechanism by which MM improves sleep quality and
other outcomes in the context of these different health condi-
tions will have to be studied to provide a complete under-
standing of how techniques such as tai chi, qi gong, and yoga
influence sleep.
Conflicts of interest
The authors declare that they have no competing interests and
gain no financial benefits from this study.
Acknowledgments
Research was funded by the following project: Exploration
Project of China Academy of Chinese Medical Sciences (grant
number ZZ0708078 grant name Clinical Observation on the Effect
of Traditional Chinese Medicine Psychotherapy to Insomnia with
Estazolam).
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