Clin Rheumatol (2008) 27:211–218 DOI 10.1007/s10067-007-0700-4
ORIGINAL ARTICLE
Tai chi for osteoarthritis: a systematic review Myeong Soo Lee & Max H. Pittler & Edzard Ernst
Received: 7 March 2007 / Revised: 27 June 2007 / Accepted: 29 June 2007 / Published online: 14 September 2007 # Clinical Rheumatology 2007
Abstract The aim of this study was to evaluate data from controlled clinical trials testing the effectiveness of tai chi for treating osteoarthritis. Systematic searches were conducted on MEDLINE, AMED, British Nursing Index, CINAHL, EMBASE, PsycInfo, The Cochrane Library 2007, Issue 2, the UK National Research Register and ClinicalTrials.gov, Korean medical databases, the Qigong and Energy database and Chinese medical databases (until June 2007). Hand searches included conference proceedings and our own files. There were no restrictions regarding the language of publication. All controlled trials of tai chi for patients with osteoarthritis were considered for inclusion. Methodological quality was assessed using the Jadad score. Five randomised clinical trials (RCTs) and seven non-randomised controlled clinical trials (CCTs) met all inclusion criteria. Five RCTs assessed the effectiveness of tai chi on pain of osteoarthritis (OA). Two RCTs suggested significant pain reduction on visual analog scale or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) compared to routine treatment and an attention control program in knee OA. Three RCTs did not report significant pain reduction on multiple sites pain. Four RCTs tested tai chi for physical functions. Two of these RCTs suggested improvement of physical function on activity of daily living or WOMAC compared to routine treatment or wait-list control, whilst two other RCTs failed to do so. In conclusion, there is some encouraging evidence suggesting M. S. Lee (*) : M. H. Pittler : E. Ernst Complementary Medicine, Peninsula Medical School, Universities of Exeter & Plymouth, 25 Victoria Park Road, Exeter EX2 4NT, UK e-mail:
[email protected] e-mail:
[email protected]
that tai chi may be effective for pain control in patients with knee OA. However, the evidence is not convincing for pain reduction or improvement of physical function. Future RCTs should assess larger patient samples for longer treatment periods and use appropriate controls. Keywords Osteoarthritis . Pain . Systematic review . Tai chi
Introduction Osteoarthritis (OA) is the most common joint disease. It is associated with ageing and most often affects the joints of the knees, hips, fingers and lower spine region. It is estimated that about 10% of men and 18% of women aged more than 60 years have symptomatic OA [1]. Eighty percent of those with OA will have limitations in movement, and 25% cannot perform major daily activities of life [1]. Because there is no known cure for OA, the main therapeutic strategy is symptomatic. This includes analgesics, nonsteroidal anti-inflammatory drugs (NSAIDS), COX-2 inhibitor, glucocorticoids, topical analgesics and cartilage protective agents (e.g., diacerin, glucosamin, and chondroitin) as well as exercise and surgery [2, 3]. Exercise is often recommended for management of OA [4–6], and there is some evidence of effectiveness [7, 8]. Tai chi is a form of complementary therapy with similarities to aerobic exercise and includes relaxation, deep and regulated breathing techniques and slow movement. It may offer physiological and psychological benefits for OA sufferers [9]. It is claimed that tai chi is beneficial for arthritis by alleviating joint pain and increasing strength, flexibility and balance in older patients [10–13]. Given these reports, it seems pertinent to evaluate the effectiveness of tai chi as a
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symptomatic treatment of OA. The aim of this paper was to systematically review and critically assess the clinical trial evidence for the effectiveness of tai chi in patients with OA.
Materials and methods
Clin Rheumatol (2008) 27:211–218
ing and withdrawals; the score ranges from a minimum of zero to a maximum of five points. Taking into account that patients and therapists are impossible to blind to tai chi, one point was given for blinding if the outcome assessor was blinded. Discrepancies were resolved by discussion between the two reviewers (MSL, MHP) and if needed, by seeking the opinion of the third reviewer (EE).
Data sources Electronic databases were searched from their respective inceptions through June 2007 using the following databases: MEDLINE, AMED, British Nursing Index, CINAHL, EMBASE, PsycInfo, the ClinicalTrials.gov of National Institute of Health and National Research Register, the Cochrane Library 2007, Issue 2, Korean databases (Korean Studies Information, DBPIA, Korea Institute of Science, Technology Information, Research Information Center for Health Database and Korean Medline, Korea National Assembly Library), the Qigong and Energy Medicine Database (Qigong Institute, Melon Park, version 7.3) and Chinese medical databases (China Academic Journal, Century Journal Project, China Doctor/Master Dissertation Full text DB, China Proceedings Conference Full text DB). The search terms used were taichi or tai adj chi or tai chi chun or Korean or Chinese language terms for tai chi and osteoarthritis, degenerative arthritis, osteoarthritis, joint pain, knee pain, hip pain and arthritis. In addition, our own department files and relevant journals [Focus on Alternative and Complementary Therapies (FACT) up to June 2007] were manually searched. Several tai chi associations (n=10) and experts (n=4) were contacted and asked to contribute any unpublished trials. In addition, the references of all located articles and the proceedings of the 1st International Conference of Tai Chi for Health (December 2006, Seoul, South Korea) were hand-searched for further relevant articles. Study selection All prospective controlled clinical trials of tai chi for OA (not just chronic pain of the knee, hip and back etc.) were included. Trials comparing tai chi with any type of control intervention were included. Any trials with tai chi as a part of a complex intervention were excluded. No language restrictions were imposed. Dissertations and abstracts were also included. Hardcopies of all articles were obtained and read in full.
Results The searches identified 181 potentially relevant studies, of which, 169 studies were excluded (Fig. 1). Among these, two randomised clinical trials (RCTs) were excluded because they did not clarify the type of arthritis [15], whilst the other reported different outcome measures for an already published trial [16]. Twelve trials, five RCTs and seven non-randomised controlled clinical trials (CCTs) met the inclusion criteria and were reviewed (Table 1). One ongoing RCT which is conducted at Turfs New England Medical Center, USA funded by NCCAM was located from ClinicalTrials.gov at (http://clinicaltrials.gov). This is a three-armed, single-blind RCT over a 12-week treatment period assessing the effectiveness of tai chi for knee pain, stiffness and physical function and health related quality of life in patients with knee osteoarthritis compared with a stretching and wellness education program. Study quality All included RCTs described the methods of randomisation [17–21]. Three of the five RCTs reported details on allocation concealment [17, 18, 21]. Sufficient details of dropouts and withdrawals were described in 10 of the 12 included trials [17–26], except two studies which were published as an abstracts only [27, 28]. Two of three RCTs [18, 19, 21] that analysed a sample size of ≥40 reported intergroup differences of pain on visual analog scale (VAS) or Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) in favour of tai chi compared with routine treatment and attention control [18, 21]. The three CCTs with analysed sample sizes of ≥40 reported the superiority of tai chi on pain reduction compared with no treatment, self-help management and aquatic exercise [22, 25, 26]. Outcomes
Data extraction and quality assessment Pain All articles were read by two independent reviewers (MSL, MHP), and data from the articles were extracted according to pre-defined criteria. The Jadad score [14] was calculated by assessing three criteria: description of randomisation, blind-
Five RCTs [17–21] assessed the effectiveness of tai chi on pain of OA compared with usual physical activity [20], routine treatment [21], attention control program [18],
Clin Rheumatol (2008) 27:211–218 Fig. 1 Flowchart of trial selection process. RCT Randomised clinical trial
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Papers identified (n=181)
Excluded after scanning titles / abstract • Not relevant (n=129) • Not concerned with OA (n=23)
Papers retrieved for further evaluation (n= 29)
Excluded after full assessment (n=17) • Not controlled trial (n=4) •Duplicate publication in conference proceeding (n=9) • Not relevant (n=2) •RCT not concerned with OA (n=1) •RCT duplicate publication with difference main outcome measures (n=1)
Clinical trials included (n=12) • RCTs (n=5) • Non RCTs (n=7)
hydrotherapy and wait-list control [19] or Bingo recreation [17]. Two RCTs suggested significant pain reduction on VAS [18] or WOMAC [21] compared to an attention control program or routine treatment in knee OA, respectively. Three RCTs did not report significant pain reduction on the pain subscale of the arthritis impact measurement scale (AIMS), WOMAC compared with usual physical activity [20], hydrotherapy and waiting list [19] or Bingo recreation [17] in multiple sites pain. The extent of heterogeneity of control treatment and OA sites prevented a meaningful meta-analysis across these trials. Compared with no treatment, three CCTs reported intergroup differences [22, 26, 27]. Three CCTs tested tai chi for treating pain on WOMAC or VAS compared with a self-help management program [23–25]. Two CCTs
reported positive effects of tai chi for pain on WOMAC [23, 25], whilst one CCT failed to do so on VAS [24]. One CCT also compared tai chi with aquatic exercise [25], which showed intergroup differences for pain on WOMAC in favour of tai chi compared with aquatic exercise. Function Four RCTs tested tai chi for physical function on WOMAC or activity of daily living (ADL) [17–19, 21]. Two suggested improvement of physical function on ADL or WOMAC scales compared to routine treatment [21] or waiting list control [19]. Compared to attention control [18] or Bingo recreation [17], there were no such effects on WOMAC physical function or ADL, respectively. The
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Table 1 Summary of controlled clinical studies of tai chi for osteoarthritis First author (year) [ref]
Design, quality scorea, allocation concealment OA site Sample size (allocated / analysed)
Experimental intervention (regimen)
Control intervention (regimen)
Main Outcomes
Intergroup differences
Author’s conclusion
Hartman (2000) [20]
RCT, 3, n.r. Multiple joint (hip, knee, ankles, foot) 35/33
Tai Chi (60 min, 2 times weekly for 12 weeks, n=19)
Usual physical activity (n=16), routine care, total 3 times group meeting, and telephone discussion (every 2 weeks)
Pain (AIMS) Arthritis selfefficacy Quality of life (AIMS)
NS P
