Description of the condition
Idiopathic Parkinson's disease (PD) is one of the most prevalent neurodegenerative diseases. Its clinical manifestations include a combination of hypokinesia, bradykinesia, rigidity, and rest tremor (Clarke 2007). The pathologic feature of idiopathic PD is progressive loss of dopamine production cells in the substantia nigra of the brain stem (Clarke 2007). The overall age-adjusted prevalence of PD is 1% globally, and the average age at onset is around 65 years (Clarke 2007). Prevalence increases with age: 0.5% to 1.0% among people aged 65 to 69 years; and 1% to 3% among those aged 80 years and over (Nussbaum 2003). A recent cost evaluation study revealed that the mean annual cost was GBP5993 (Findley 2003) in United Kingdom and $13,543 in United States (Kaltenboeck 2012). It accounted for approximately 38% of the costs per PD patient among the National Health Service costs in the United Kingdom (Findley 2003). Because the cost of PD increases with age and with disease severity, more money will be required to care for PD patients in the future aging society (Findley 2003; Kaltenboeck 2012).
Description of the intervention
Conventional treatment of Parkinson’s disease
Levodopa is the primary treatment for PD; however, its long-term use is limited by motor complications and drug-induced dyskinesia. Dopamine agonists are options for initial treatment and have been shown to delay the onset of motor complications (Goetz 2005; Rao 2006; Suchowersky 2006; Volker 2006).
Mind-body movement therapies
Mind-body therapies are one of the common alternative and complementary medicinal treatment modalities, which are based on the concepts of the interaction between the mind and body. The aim of these techniques mainly focuses on reducing tension or stress and enhancing individual well-being. Mind-body therapies can be classified according to their characteristic features: motionless in sitting meditation; passive movement in massage or therapeutic touch; a guided set of sequential movements in yoga, tai chi, or qigong; and highly independent individual movement in dance/movement therapy (Goodill 2005). Among these, mind-body movement therapies are relatively non-strenuous and thus do not require high physical capacity. However, these techniques might improve patients' physical functions and emotional health (Yeh 2004). In this sense, these techniques may be appropriate for PD patients with reduced balance control, flexibility, muscular strength, quality of life, and social well-being (Lee 2008).
How the intervention might work
Possible mechanisms for the effects of mind-body movement therapies include normalising neurotransmitter levels such as dopamine, muscle-strengthening and balancing, or neuro-physiological regulation through promotion of cerebral output (Keteyian 1999).
Why it is important to do this review
Considering the increase in the prevalence of PD and the interest in non-pharmacological treatments for PD, a well-organised and up-to-date systematic review is necessary to evaluate the efficacy and safety of mind-body movement therapies for PD.
The aim of this review is to comprehensively and critically evaluate the effects of mind-body movement therapies (yoga, tai chi and qigong) for patients with Parkinson's disease (PD) comparing any type of control treatments.
Criteria for considering studies for this review
Types of studies
We will include p rospective, randomised controlled trials (RCTs) in this systematic review.Trials that collected outcomes without reporting them will be included, while trials that did not collect clinical outcomes will be excluded. Studies comparing two different forms of mind-body movement therapies will be excluded.
Types of participants
We will include p atients with Parkinson's disease (PD), irrespective of severity and pathologic basis, if they were diagnosed by a clinician using radiologic or definite clinical criteria. We will include studies of PD patients who have any duration of disease regardless of their age and sex and studies of participants with severe mental disorders, dementia, pulmonary, or cutaneous infection. Trials testing any atypical parkinsonism (i.e. neurodegenerative parkinsonism other than PD) will be excluded. We will also exclude s tudies involving participants who had fluctuations or any secondary cause of parkinsonism, such as drug-induced parkinsonism or structural lesion.
Types of interventions
Three types of mind-body movement therapies (yoga, tai chi, and qigong) will be included.
Comparison: mind-body movement therapies versus conventional treatments (pharmacological, non-pharmacological, or surgical), no treatment, exercise therapies, or waiting-list controls. Intervention for mind-body movement therapies can be used as the single treatment or together with other 'conventional' treatments including pharmacological treatment such as dopaminergic compounds, as long as the same standard treatment is provided to both groups.
Types of outcome measures
- Parkinsonian rating scales (Unified Parkinson's Disease Rating Scale (UPDRS); Webster scale)
- Global improvement of symptoms.
- Impairment scales (Colombia University Rating Scale (CURS), Parkinson’s Disease Impairment Scale, Hoehn and Yahr Stage Scale (H-Y scale), etc).
- Disability scales (Northwestern University Disability Scale (NUDS), Activity of Daily Living Scale (ADL), etc).
- Quality of life (the modified Parkinson’s Disease Quality of Life questionnaire (PDQL), etc).
- The occurrence of adverse events related to the prolonged use of dopaminergic agents.
- The occurrence of falls.
- Adverse events related to the intervention used (type, frequency and severity).
Search methods for identification of studies
We will search the following electronic databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library); P roquest Dialog for MEDLINE; Proquest Dialog for EMBASE; EbscoHOST for the Cumulative Index to Nursing and Allied Health Literature (CINAHL); Proquest Dialog for the Allied and Complementary Medicine Database (AMED); the Chinese Medical Database (CNKI); Science Links Japan (J-East); the Korean Medical Databases (KoreaMed, KMbase, the National Digital Science Links (NDSL), the Korea Institute of Science and Technology Information (KISTI), the Korean Studies Information Service System (KISS), and Oriental Medicine Advanced Searching Integrated System (OASIS)).
We will search fo r relevant literature regardless of language or publication status. We will search for ongoing studies by accessing the following databases: the World Health Organization's (WHO) International Clinical Trials Registry Platform (ICTRP) (www.apps.who.int/trialsearch/); the Chinese Clinical Trial Registry (www.chictr.org); ISRCTN (www.controlledtrials.com/isrctn/); the National Institutes of Health Clinical Trials Database (www.clinicaltrials.gov); and the Clinical Research Information Service (CRiS) of the Republic of Korea.
We will contact the authors of included studies, and researchers in the field for ongoing and unpublished studies, if necessary. The search strategies for MEDLINE, EMBASE and CENTRAL are shown in Appendix 1, Appendix 2 and Appendix 3 The other database search strategies will be based on the MEDLINE search strategy presented in Appendix 1.
Searching other resources
We will review the bibliographic references of all included trials to identify other relevant studies. In addition, we will review unpublished conference proceedings relevant to the present review, if available.
Data collection and analysis
Selection of studies
MSL and THK will review all of the titles and abstracts of studies retrieved from the electronic searches, and both will select relevant articles by title and abstract. Potentially relevant articles will be obtained in full text. Two independent review authors will review hard copies of each publication to determine their inclusion based on the inclusion criteria (see Criteria for considering studies for this review). Two review authors (MSL and THK) and an arbiter (EE) will resolve any disagreements through discussion. We will contact the authors of the included studies for clarification if necessary.
Data extraction and management
Two review authors (MSL and BCS) will extract data from the selected reports or studies independently. We will enter data using a predefined collection form. We will resolve any disagreement by discussion or where necessary, by arbitration by a third review author (EE). We will extract the following characteristics of the reports or studies: study design, duration of the study, trial setting, ethical approval, demographic data for participants (age, sex, country, and ethnic group), total number of subjects randomised to the intervention and control groups, causes of PD, severity of PD, the number of drop-out participants, details of interventions (types of interventions, such as yoga, tai chi, or qigong), control interventions and all of the relevant outcomes. We will contact the corresponding authors of the included trial reports for missing data. We will review the outcomes associated with rehabilitation and include those that are clinically relevant. We will not include outcomes from laboratory tests so as to reduce misinterpretation of the results (as explained in the Cochrane Handbook for Systematic Reviews of Interventions) (section 5.4.1) (O’Connor 2011).
Assessment of risk of bias in included studies
According to the guidelines of the Cochrane Handbook for Systematic Reviews of Interventions, we will assess the risk of bias to evaluate the methodological quality of the included studies (Higgins 2011). We will evaluate the following domains for methodological quality: sequence generation; allocation concealment; blinding of participants, personnel and outcome assessors; incomplete outcome data; and selective outcome reporting. We will judge the evaluated domains as 'low risk of bias', 'high risk of bias', or 'uncertain risk of bias' according to the criteria (Appendix 4).
- Sequence generation: 'Low' (random number table, computer-generated random numbers, coin toss, drawing lots, throwing dice or shuffling cards), 'High' (sequence generation by date of admission, clinical record number and odd) or 'Uncertain'
- Allocation concealment: 'Low' (through telephone or web-based central allocation or with opaque, sealed envelopes with sequential numbers), 'High' (predictable methods such as an open allocation schedule or the use of non-opaque, non-sealed or non-sequentially numbered envelopes) or 'Uncertain'
- Blinding of participants and personnel: 'Low' ( blinding of participants), 'High' (no blinding or incomplete description of randomisation process) or 'Uncertain'
- Blinding of outcome assessors: 'Low' (assessors are blinding to allocation of participants), 'High' (no blinding or incomplete description of randomisation process) or 'Uncertain'
- Incomplete outcome data: 'Low' (detailed description of missing data or imputation of data), 'High' (improper description of missing data) or 'Uncertain'
- Selective outcome reporting: 'Low' (complete description of outcomes in a predefined way or published protocol or complete inclusion of all expected outcomes in case of no available protocol), 'High' (incomplete description of predefined outcomes or reports of newly added outcomes) or 'Uncertain' (insufficient information)
Any disagreements will be resolved through discussion. A third party (Lee MS or Kim T-H) will resolve any unresolved disagreements. The results will be presented in 'Risk of Bias' tables for each study.
Measures of treatment effect
We will calculate the summary statistics for the treatment effects for each study after all of the treatment effects of mind-body movement therapies are compared with those of the matched control interventions. For dichotomous data, we will present treatment effects as risk ratios (RRs) with 95% confidence intervals (CIs). For continuous data, we will use mean differences (MDs) for the measurement of the treatment effect with 95% CIs. Where there are different scales of outcome variables, we will use standardised mean differences (SMDs) with 95% CIs.
Unit of analysis issues
Data from the parallel-group studies will be included for meta-analysis. If there are cross-over trials, we will adopt the first phase of the data for analysis. If there are any studies that have multiple observation of outcome variables, the time frame of included studies will be classified as short-term (within 4 weeks) and long-term (over 4 weeks) follow-up, and meta-analysis will be conducted accordingly.
Dealing with missing data
The intention-to-treat (ITT) principle will be applied for the statistical analysis. The corresponding authors of the included studies will be contacted and asked to provide any missing or insufficient data. If there a re missing data which cannot be provided by the original authors, we will make the assumption that these outcomes are classified as treatment failures, and perform the ITT analyses with the imputed data. We will perform a sensitivity analysis comparing ITT analyses with an analyses of available data (no imputation of missing data), and will discuss the potential impact on the findings.
Assessment of heterogeneity
We will conduct statistical analysis using the I
Assessment of reporting biases
To detect reporting biases, we will draw funnel plots using Egger's method if more than 10 studies are included in an individual analysis (Egger 1997). We will consider whether asymmetry indicates a possible reporting bias.
If a significant number of studies are identified, a meta-analysis will be conducted according to the random-effects model, which may be a reasonable method for analysis of the variety of included mind-body movement therapies.
The data will be synthesised separately according to modalities as follows, if these data are available:
- Yoga, tai chi, or qigong versus conventional treatments (e.g. pharmacological, non-pharmacological, or surgical)
- Yoga, tai chi, or qigong versus no treatment or waiting-list controls.
- Yoga, tai chi, or qigong versus exercise therapies
- (Yoga, tai chi, or qigong) plus conventional treatment versus conventional treatments (as long as the same standard treatment is provided to both groups)
Subgroup analysis and investigation of heterogeneity
If data are available, we will conduct a subgroup analysis according to the severity of PD such as H-Y grade and the types of mind-body movement therapies (for example, yoga, tai chi, and qigong).
We will conduct a sensitivity analysis as follows:
- risk of bias (sequence generation, allocation concealment, or blinding of participants or assessors);
- sample size (small sample size studies, for example, below 40 in each group, and large sample size studies, for example, over 40 in each group);
- analysing data as available, with no imputation of missing data.
Lee MS was supported by the Korea Institute of Oriental Medicine (KIOM) (K14281 and K14400 ).
Appendix 1. Search strategy for MEDLINE in OVID interface (1950-2013)
2 exp Parkinsonian Disorders/
3 1 or 2
4 tai chi/
6 tai chi chuan/
8 t’ai chi chuan/
9 4 or 5 or 6 or 7 or 8
14 10 or 11 or 12 or 13
16 chi gong/
17 chi kung/
18 qi gong/
19 15 or 16 or 17 or 18
20 9 or 14 or 19
21 3 and 20
Appendix 2. Search strategy for EMBASE (2009-2013)
2 exp Parkinsonian Disorders/
3 or/ 1 - 2
4 exp tai chi/
6 tai chi chuan/
8 t’ai chi chuan/
14 or / 10 -13
16 chi gong/
17 chi kung/
18 qi gong/
19 or / 15 -18
20 or /9,14,19
21 and /3, 20
Appendix 3. Search strategy for CENTRAL (1995-2013)
1 MeSH descriptor Parkinson
2 MeSH descriptor (Parkinsonian Disorders)
4 #1 or #2 or #3
5 MeSH descriptor (tai chi)
7 (tai chi chuan).kw
9 (t’ai chi chuan).kw
10 #5 or #6 or #7 or #8 or #9
11 MeSH descriptor Yoga
15 #11 or #12 or #13 or #14
16 MeSH descriptor qigong
17 (chi gong).kw
18 (chi kung).kw
19 (qi gong).kw
20 #16 or #17 or #18 or #19
21 #10 or #15 or #20
21 #4 and #21
Contributions of authors
The protocol was drafted by MSL, THK, BCS, and EE.
The search strategy was developed and will be performed by MSL and THK.
Copies of studies will be obtained by BCS.
Selection of the studies to include will be conducted by MSL and THK, and EE will act as an arbiter at the study selection stage.
Extraction of data from studies will be conducted by MSL and BCS, and EE will act as an arbiter at the data extraction stage.
Data entry into Review Manager 5 will be performed by MSL and BCS.
The analysis will be conducted by MSL, THK, and BCS.
Interpretation of the analysis will be conducted by MSL, THK, BCS, and EE.
The final review will be drafted by MSL, THK, BCS, and EE.
The review will be updated by MSL and BCS.
Declarations of interest
There are no conflicts of interest.
Sources of support
- Korea Institute of Oriental Medicine , Korea, South.Lee MS was supported by KIOM (K14281 and K14400).
- No sources of support supplied