Center for Complementary + Integrative Medicine

Overview

The Tufts Center for Complementary and Integrative Medicine (TCIM), within the Division of Rheumatology in the Department of Medicine at Tufts Medical Center/Tufts University School of Medicine, studies the factors of complementary and integrative medicine therapies that affect clinical care and outcomes, including developing and evaluating treatment strategies, decision aids, computer-based systems, and databases for informing practice and policy.

Tai Chi

The primary mission of the TCIM is to improve health outcomes for patients with chronic medical conditions. The TCIM strives to integrate evidence-based, multidisciplinary therapies into conventional care plans for chronic disease prevention and treatment in order to provide the highest quality of clinical care to patients.

The Center has a tripartite area of focus:

  1. To conduct clinical scientific research projects in complementary and integrative medicine therapies.
  2. To provide ongoing professional development and training in the clinical research of integrative medicine for pre-doctoral and post-doctoral candidates.
  3. To provide evidence that can help implement effective integrative medicine practices and improve the clinical care and health of patients with chronic diseases.
Principal investigator

Chenchen Wang, MD, MSc
Director, Center for Complementary and Integrative Medicine

Chenchen Wang, MD, MSc is a Professor at Tufts University School of Medicine and Director of the Center for Complementary and Integrative Medicine in the Division of Rheumatology at Tufts Medical Center in Boston, Massachusetts. She holds strong leadership and mentoring roles in the Tufts Clinical and Translational Science Institute research environment, collaborating actively with multidisciplinary teams in the United States and across the world in Complementary and Integrative Health disciplines. Dr. Wang completed her rheumatology and clinical epidemiology training at McGill University in 1999. 

Her research focuses on clinical and epidemiological studies of Complementary and Integrative Medicine and their applications to treatments in chronic musculoskeletal pain conditions, especially osteoarthritis, rheumatoid arthritis, fibromyalgia, and systemic lupus erythematosus. Currently, Dr. Wang serves as the principal investigator on a number of NIH-funded clinical trials evaluating mind-body therapies on chronic conditions and publishes extensively in this field. She has received the privileged NIH Midcareer Investigator Award in Patient-Oriented Research to protect her time to exclusively train the next generation of integrative medicine scientists in innovative, multi-method, multidisciplinary clinical and translational research programs for chronic diseases. 

In addition, Dr. Wang holds many advisory roles, including serving as a Featured Expert for the New England Journal of Medicine Group Open Forum and membership of the National Advisory Council for Complementary and Integrative Health Approaches at the National Institutes of Health in the United States. She was also elected Vice Chairperson of the World Federation of Chinese Medicine Societies.
Employment opportunities

We are currently seeking candidates for a post-doctoral research fellow and a research assistant/coordinator. These positions will conduct supervised research in the fields of rheumatology and CAM. To learn more about these positions, please visit the Tufts Medical Center Careers website.
Selected publications

Lee AC, Harvey WF, Wong JB, Price LL, Han X, Chung M, Driban JB, Morgan LPK, Morgan NL, Wang C. Effects of Tai Chi versus physical therapy on mindfulness in knee osteoarthritis. Mindfulness 2017. Epub ahead of print. doi: 10.1007/s12671-017-0692-3.

Lee AC, Harvey WF, Price LL, Han X, Driban JB, Chung M, Wong JB, McAlindon TE, Wang C. Mindfulness is associated with treatment response from non-pharmacological exercise interventions in knee osteoarthritis. Arch Phys Med Rehabil 2017. In press.

Chang AH, Lee J, Song J, Price L, Lee AC, Reid KF, Fielding RA, Driban JB, Harvey WF, Wang C. Associations between pre-intervention physical activity levels and treatment response to exercise therapy in persons with knee osteoarthritis. Osteoarthritis Cartilage 2017. In press.

Yuan P, Zhang R, Yang B, Sun X, Kang W, Zhang X, Li J, Dong B, Wang C. Medical bugs in the treatment of osteoarthritis pain: a systematic review.  Osteoarthritis Cartilage 2017. In press.

Zhang R, Han L, Wang C, Yuan P, Xiong Y. Polymorphism of antioxidant selenoprotein genes and Kashin-Beck Disease susceptibility, a systematic review and meta-analysis. Osteoarthritis Cartilage 2017. In press.

Zhang Y, Hyon S, Wang C. Acupuncture for pediatric chronic pain relief: a review. Arthritis Rheumatol 2017. In press. 

Lee AC, Desai SA, Knopp HE, Price LL, Han X, Driban JB, Harvey WF, Jang S, Wang C. Determinants of treatment dose-response pattern in physical therapy or tai chi exercise among adults with symptomatic knee osteoarthritis. Am J Phys Med Rehabil 2017;96:a115.

Niles BL, Mori DL, Polizzi CP, Kaiser AP, Ledoux AM, Wang C. Feasibility, qualitative findings, and satisfaction of a brief Tai Chi mind-body program for veterans with posttraumatic stress symptoms. BMJ Open 2016;6:e012464. doi: 10.1136/bmjopen-2016-012464. PMCID: PMC5168527.

Wang C, Schmid CH, Iversen MD, Harvey WF, Fielding RA, Driban JB, Price LL, Wong JB, Reid KF, Rones R, McAlindon T. Comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: a randomized trial. Ann Intern Med 2016;165:77-86. doi:10.7326/M15-2143. PMCID: PMC4960454.

Iversen MD, Price LL, von Heideken J, Harvey WF, Wang C. Physical examination findings and their relationship with performance-based function in adults with knee osteoarthritis. BMC Musculoskelet Disord 2016;17:273. doi: 10.1186/s12891-016-1151-3. PMCID: PMC4941016.

Marszalek J, Price LL, Harvey WF, Driban JB, Wang C. Outcome expectations and osteoarthritis: perceived benefits of exercise are associated with self‐efficacy and depression. Arthritis Care Res (Hoboken) 2016;69:491-498. doi: 10.1002/acr.22969. PMCID: PMC5219866.

Lee AC, Harvey WF, Price LL, Morgan LP, Morgan NL, Wang C. Mindfulness is associated with psychological health and moderates pain in knee osteoarthritis. Osteoarthritis Cartilage 2016. Epub ahead of print. doi: 10.1016/j.joca.2016.06.017. PMCID: PMC5183521.

Chen B, Zhan H, Marszalek J, Chung M, Lin X, Zhang M, Pang J, Wang C. Traditional Chinese medications for knee osteoarthritis pain: a meta-analysis of randomized controlled trials. Am J Chin Med 2016;44:677-703. doi: 10.1142/S0192415X16500373.

AlHeresh R, Lee AC, Price LL, Driban JB, Harvey WF, Wang C. Validity of the PROMIS social role satisfaction short form among adults with osteoarthritis. Gerontologist 2016;56:6-7.

Yu S, Price LL, Driban JB, Harvey WF, Wang C. Fibromyalgia impact is a potential mediator for the associations of self-efficacy and pain catastrophizing with physical functioning in persons with fibromyalgia. Arthritis Rheumatol 2016;68:66-67. doi: 10.1002/art.39977. PMID: 27870508.

Lee AC, Harvey WF, Price LL, Morgan LPK, Morgan NL, Wang C. The role of mindfulness in relation to pain and health in knee osteoarthritis. J Altern Complement Med 2016;22:A80. doi: 10.1089/acm.2016.29003. PMID: 27203472.

Chung M, Lee AC, Wong JB, Han X, Wang C. Cross-sectional and longitudinal construct validity for the improved health assessment questionnaire among adults with knee osteoarthritis. Arthritis Rheumatol 2016;68:586-590. doi: 10.1002/art.39977. PMID: 27870508.

Kong J, Jorgenson K, Wang Z, Wolcott E, Harvey WF, Wang C. Tai Chi significantly modulates resting state functional connectivity of the cognitive control network in fibromyalgia. Arthritis Rheumatol 2016; 68:69-70. doi: 10.1002/art.39977.  PMID: 27870508.

Lee AC, Price LL, Driban JB, Harvey WF, McAlindon TE, Rodday AM, Knopp HE, Wang C. Longitudinal construct validity for four Patient-Reported Outcomes Measurement Information System (PROMIS) short forms: physical function, pain interference, depression, and anxiety among adults with knee osteoarthritis. Arthritis Rheumatol 2016;68:3059-60. doi: 10.1002/art.39977. PMID: 27870508.

Lee AC, Price LL, Driban JB, Harvey WF, McAlindon TE, Rodday A, Wang C. Minimally Important Differences (MID) for four Patient Reported Outcome Measurement Information System (PROMIS) short forms: physical function, pain interference, depression, and anxiety among adults with knee osteoarthritis. Arthritis Rheumatol 2016;68: 377-8. doi: 10.1002/art.39977. PMID: 27870508.

Lee AC, Price LL, Han X, Chung M, Harvey WF, Driban J, McAlindon TE, Wang C. Mindfulness predicts treatment response from non-pharmacological therapy in knee osteoarthritis. Arthritis Rheumatol 2016;68:378-80. doi: 10.1002/art.39977. PMID: 27870508.

Liu W, Lee AC, Harvey WF, Price LL, Driban JB, Wang C. Postural stability is associated with lower pain, lower stiffness, and higher muscle power among adults with symptomatic knee osteoarthritis. Arthritis Rheumatol 2016;68:402-3. doi: 10.1002/art.39977. PMID: 27870508.

Wang C, Schmid C, Fielding RA, Harvey WF, Price LL, Driban JB, Reid K, Kalish RA, Rones R, McAlindon TE. Tai Chi is more effective than aerobic exercise in treating fibromyalgia: a randomized controlled trial. Arthritis Rheumatol 2016;68:2874-2876. doi: 10.1002/art.39977.  PMID: 27870508.

Lee AC, Harvey WF, Price LL, Morgan LPK, Morgan NL, Wang C. The role of mindfulness in relation to chronic pain and psychological health in knee osteoarthritis. Med Sci Sports Exerc 2016;48:S1056-7. doi: 10.1249/01.mss.0000488180.57091.86.

Reid KF, Price L, Harvey WF, Driban JB, Fielding RA, Wang C. Changes in leg muscle strength and power after tai chi exercise in patients with symptomatic knee osteoarthritis. Osteoarthritis Cartilage 2016;24:S430. doi: 10.1016/j.joca.2016.01.776.

Chung M, Zhao N, Wong JB, Wang C. Prospective economic evaluation of the costs for medications and nutraceuticals in knee osteoarthritis. Osteoarthritis Cartilage 2016;24:S349-50. doi: 10.1016/j.joca.2016.01.629.

Wang C, Price L, Schmid C, Harvey W, Driban J, McAlindon T. A positive response to nonpharmaceutical interventions in adults with knee osteoarthritis. Osteoarthritis Cartilage 2016;24:S490-1. doi: 10.1016/j.joca.2016.01.899.

Wang C, Ramel R. “Tai Chi/Qi Gong.” Integrative Pain Management: Massage, Movement, and Mindfulness Based Approaches. Ed. Diana L. Thompson and Marissa Brooks. N.p.: Handspring Limited, 2016. 203-17.

Reid KF, Price LL, Harvey WF, Driban JB, Hau C, Fielding RA, Wang C. Muscle power is an independent determinant of pain and quality of life in knee osteoarthritis. Arthritis Rheumatol 2015;67:3166-73. doi: 10.1002/art.39336. PMCID: PMC4661064.

Chen B, Zhan H, Chung M, Lin X, Zhang M, Pang J, Wang C. Chinese herbal bath therapy for the treatment of knee osteoarthritis: meta-analysis of randomized controlled trials. Evid Based Complement Alternat Med 2015;2015:949172. doi: 10.1155/2015/949172. PMCID: PMC4592903.

Driban JB, Morgan N, Price LL, Cook KF, Wang C. Patient-Reported Outcomes Measurement Information System (PROMIS) instruments among individuals with symptomatic knee osteoarthritis: a cross-sectional study of floor/ceiling effects and construct validity. BMC Musculoskelet Disord 2015;16:253. doi: 10.1186/s12891-015-0715-y. PMCID: PMC4570513.

Wang C, McAlindon T, Fielding RA, Harvey WF, Driban JB, Price LL, Kalish R, Schmid A, Scott TM, Schmid CH. A novel comparative effectiveness study of Tai Chi versus aerobic exercise for fibromyalgia: study protocol for a randomized controlled trial. Trials 2015;16:34. doi:10.1186/s13063-015-0548-x. PMCID: PMC4323027.

Ye Y, Chen B, Kalish RA, Wang C. Tripterygium Wilfordii for the treatment of systemic lupus systematosus: meta-analysis of randomized controlled trials. Arthritis & Rheumatol 2015;67:2211-2. doi: 10.1002/art.39448.

Chung M, Liu S, Fu Z, Price LL, Wong JB, Wang C. Content validity of the improved health assessment questionnaire in knee osteoarthritis patients. Arthritis Rheumatol 2015;67:3078-9. doi: 10.1002/art.39448.

Chen B, Lo C, Zhan H, Lin X, Wang C. Traditional Chinese medicine for osteoarthritis pain: a meta-analysis. Osteoarthritis Cartilage 2015;23:A356-7. doi: 10.1016/j.joca.2015.02.658.

Zhao N, Chung M, Wong JB, Wang C. Economic burden of medications and nutraceuticals in knee osteoarthritis. Osteoarthritis Cartilage 2015;23:A198-9. doi: 10.1016/j.joca.2015.02.992.

Wang C, Iversen MD, McAlindon T, Harvey WF, Wong JB, Fielding RA, Driban JB, Price LL, Rones R, Gamache T, Schmid CH. Assessing the comparative effectiveness of Tai Chi versus physical therapy for knee osteoarthritis: design and rationale for a randomized trial. BMC Complement Altern Med 2014;14:333. doi: 10.1186/1472-6882-14-333. PMCID: PMC4171546.

Morgan N, Irwin MR, Chung M, Wang C. The effects of mind-body therapies on the immune system: meta-analysis. PLoS One 2014;9:e100903. doi:10.1371/journal.pone.0100903. PMCID: PMC4079606.

Wang C. Challenges for the future of complementary and integrative care. Health Care Curr Rev 2014;2:e102. doi: 10.4172/hccr.1000e102.

Gamache T, Price LL, Driban JB, Harvey WF, Wang C. Education effects on outcome expectations for exercise in adults with knee osteoarthritis. Arthritis Rheumatol 2014;66:S1249. doi: 10.1002/art.38914.

Goldsmith JV, Price LL, Driban JB, Harvey WF, Wang C. The cost and effectiveness of various recruitment strategies in a mind body clinical trial among older adults with knee osteoarthritis. Arthritis Rheumatol 2014;66:S1019. doi: 10.1002/art.38914.

Schmid A, Harvey WF, Price LL, Wang C. Cost-effectiveness and yield of different recruitment strategies utilized in an exercise trial of fibromyalgia patients. Arthritis Rheumatol 2014;66:S1019-20. doi: 10.1002/art.38914.

Wolcott E, Harvey WF, Price LL, Driban JB, Morgan N, Lucas M, Wang C. Mindfulness is associated with symptom severity and pain impact in patients with fibromyalgia. Arthritis Rheumatol 2014;66:S587-8. doi: 10.1002/art.38914.

Zhang Y, Price LL, Morgan N, Morgan L, Wang C. Mindfulness is associated with sleep quality among patients with fibromyalgia. Arthritis Rheumatol 2014;66:S490. doi: 10.1002/art.38914.

Chang S, Price LL, Driban J, Harvey WF, Wang C. Associations of physical and mental factors with outcome expectations for exercise in a clinical trial. Arthritis Rheumatol 2014;66:S587. doi: 10.1002/art.38914.

Chen V, Harvey WF, Driban JB, Chung M, Price LL, Wang C. A cross-sectional analysis of psychological symptoms, sleep quality, and functional balance in fibromyalgia. Arthritis Rheumatol 2014;66:S906-7. doi: 10.1002/art.38914.

Chung M, Wong JB, Chang S, Wang C. Nutraceutical products and pain or non-pain medications use in patients with knee osteoarthritis. Arthritis Rheumatol 2014;66:S110. doi: 10.1002/art.38914.

Raman G, Zhang Y, Minichiello V, D'Ambrosio C, Wang C. Tai Chi and sleep quality in adults: a systematic review and meta-analysis. J Altern Complement Med 2014;20:66. doi:10.1089/acm.2014.5173.

Raman G, Mudedla S, Wang C. How effective is Tai Chi mind-body therapy for fibromyalgia: a systematic review and meta-analysis. J Altern Complement Med 2014;20:66. doi:10.1089/acm.2014.5172.

Chen B, Chung M, Zhan H, Cao Y, Wang C. Traditional Chinese herbal medicated bath therapies for osteoarthritis. Osteoarthritis Cartilage 2014;22:423-4. doi: 10.1016/j.joca.2014.02.798.

Chung M, Wang C. Can alcohol consumption be an alternative treatment for fibromyalgia? Arthritis Res Ther 2013;15:126. doi: 10.1186/ar4394. PMCID: PMC3979099.

Schmid A, Mcalindon T, Schmid CH, Wang C. The influence of Tai Chi exercise on proprioception in patients with knee osteoarthritis: results from a pilot randomized controlled trial. Int J Integr Med 2013;1:1-9. doi: 10.5772/57137.

Raman G, Zhang Y, Minichiello VJ, D’Ambrosio C, Wang C. Tai Chi improves sleep quality in healthy adults and patients with chronic conditions: a systematic review and meta-analysis. J Sleep Disorders Ther 2013;2:141. doi:10.4172/2167-0277.1000141.

Reid K, Price LL, Harvey WF, Driban JB, Fielding RA, Wang, C. Higher leg extensor muscle power output is associated with reduced pain and better quality of life in patients with symptomatic knee osteoarthritis. Arthritis Rheum 2013;65:S104. doi: 10.1002/art.38216.

Erickson EM, Driban JB, Price LL, Wang C, McAlindon TE, Harvey WF. Classification of alignment by self report versus radiograph results in unexpected and discrepant pain and functional outcomes. Arthritis Rheum 2013;65:S105. doi: 10.1002/art.38216.

Wang C.  Complementary and alternative medicine and osteoarthritis. Int J Integr Med 2013;1:69-73.

Wang C. Role of Tai Chi in the treatment of rheumatologic diseases. Curr Rheumatol Rep 2012;14:598-603. doi: 10.1007/s11926-012-0294-y. PMCID: 23055009.

Wang C. Complementary and alternative medicine in the treatment of rheumatoid arthritis. Rheumatoid Arthritis - Treatment. January 2012. http://www.intechopen.com/articles/show/title/complementary-and-alternative-medicine-in-the-treatment-of-rheumatoid-arthritis

Wong J, Wang C. Cost-effectiveness of Tai Chi mind-body exercise for the treatment of fibromyalgia. Arthritis Rheum 2012;64:S1121. doi: 10.1002/art.37735.

Iversen, MD, Sylvester K, Grader A, Boneparth M, Whitmore M, Shahzad, F, Driban J, Wang, C. A rich description of clinical exam features in patients with knee osteoarthritis and their correlation with functional outcomes. Arthritis Rheum 2012;64:S347. doi: 10.1002/art.37735.

Bannuru, RR, Samuel A, Wang C. How effective is Tai Chi mind-body therapy for knee osteoarthritis (KOA)? A systematic review and meta-analysis. Osteoarthritis Cartilage 2012;20:281-282. doi: 10.1016/j.joca.2012.02.483.

Yuan W, Bannuru RR, Kong L, Cheng Y, McAlindon T, Fang M, Wang C.  A massage therapy on pain relief for knee osteoarthritis: A systematic review and meta-analysis. Osteoarthritis Cartilage 2012;20:281. doi: 10.1016/j.joca.2012.02.482.

Abariga SA, Wang C. Tai Chi and health related quality of life in patients with chronic conditions: a systematic review and meta-analysis of randomized controlled trials. BMC Complement Altern Med 2012;12:299. doi: 10.1186/1472-6882-12-S1-P299.

Wang C. Tai Chi and rheumatic diseases. Rheum Dis Clin North Am 2011;37:19-32. doi: 10.1016/j.rdc.2010.11.002. PMCID: 21220083.

Wong J, Griffith M, Wang C, Economic burden of fibromyalgia: a systematic review and meta-analysis. Arthritis Rheum 2011;63:902. doi: 10.1002/art.33310.

Kong L, Bannuru RR, Yuan W, Cheng, YW, McAlindon T, and Wang C. Therapeutic massage on pain relief for fibromyalgia: a systematic review and meta-analysis. Arthritis Rheum 2011;63:747. doi: 10.1002/art.33310.

Wang C, Schmid CH, Rones R, Kalish R, Yinh J, Goldenberg D, Lee Y, McAlindon T. A randomized trial of Tai Chi for fibromyalgia. N Engl J Med 2010;363:743-54. doi: 10.1056/NEJMoa0912611. PMCID: PMC3023168.

Wang C, Bannuru R, Ramel J, Kupelnick B, Scott, T, Schmid CH. Tai Chi on psychological well-being: systematic review and meta-analysis. BMC Complement Altern Med 2010;10;23. doi: 10.1186/1472-6882-10-23. PMCID: 2893078.

Wang C, Schmid C, Lee Y, McAlindon T.  Does obesity in patients with fibromyalgia modify response to tai chi therapy: analysis of a randomized controlled trial. Arthritis Rheum 2010; 62:95. doi: 10.1002/art.30166.

Wang C, Schmid C, McAlindon T.  Influence of Tai Chi exercise on proprioception in patients with knee osteoarthritis:  results from a pilot randomized controlled trial. Osteoarthritis Cartilage 2010;18:145-146.

Jacobson E, Yangga T, McAlindon T. Wang C. Effect of Tibetan medicated-bath therapy on rheumatoid arthritis: a systematic review. Proceedings of The 2010 International Congress on Complementary Medicine Research, the Online Supplement.

Ramel J, Bannuru R, Griffith M, Wang C. Exercise for fibromyalgia pain: a meta-analysis of randomized controlled trials. Curr Rheum Rev 2009;5:188-193. doi: 10.2174/157339709790192459.

Wang C, Schmid C, Hibberd P, Roubenoff  R, Kalish R, Rones R, McAlindon T. Tai Chi is effective in treating knee osteoarthritis: a randomized controlled trial. Arthritis Rheum 2009;61:1545-53. doi: 10.1002/art.24832. PMCID: 19877092.

Yeh GY, Wang C, Wayne P, Phillips R. Tai Chi exercise for patients with cardiovascular conditions and risk factors: a systematic review. J Cardiopulm Rehabil Prev 2009;29:152-60. doi: 10.1097/HCR.0b013e3181a33379. PMCID: PMC2755083.

Wang C, DePablo P, Chen XY, Schmid C, McAlindon T. Acupuncture for pain relief in patients with rheumatoid arthritis: a systematic review. Arthritis Rheum 2008;59:1249-56. doi: 10.1002/art.24009. PMCID: 18759255

Wang C. Tai Chi improves pain and functional status in adults with rheumatoid arthritis: results of a pilot single-blinded randomized controlled trial. Med Sport Sci 2008;52;218-29. doi: 10.1159/000134302.

Wang C, Schmid C, Hibberd P, Kalish R, Roubenoff R, Rones R, Okparavero A, McAlindon T. Tai Chi for treating knee osteoarthritis: designing a long-term follow up randomized controlled trial. BMC Musculoskelet Disord 2008;9:108. doi: 10.1186/1471-2474-9-10. PMCID: PMC2529300.

Yeh GY, Wang C, Wayne PM, Phillips RS.  The effect of Tai Chi exercise on blood pressure: a systematic review. Prev Cardiol 2008;11:82-89.
Other selected publications

Wang C, Harris WS, Chung M, Lichtenstein AH, Balk EM, Kupelnick B, Jordan HS, Lau J. n-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review. Am J Clin Nutr 2006;84:5-17.

Wang C, Collet JP, Lau J. The effect of Tai Chi on health outcomes in patients with chronic conditions: a systematic review. Arch Intern Med 2004;164:493-501. doi: 10.1001/archinte.164.5.493.

Wang C, Schwaitzberg S, Berliner E, Zarin DA, Lau J. Hyperbaric oxygen for treating wounds: a systematic review of the literature. Arch Surg 2003;138:272-9. doi:10.1001/archsurg.138.3.272.

Balk EM, Bonis PA, Moskowitz H, Schmid CH, Ioannidis JP, Wang C, Lau J. Correlation of quality measures with estimates of treatment effect in meta-analyses of randomized controlled trials. JAMA 2002;287:2973-82. doi:10.1001/jama.287.22.2973.

Wang C, Mayo NE, Fortin PR. The relationship between health related quality of life and disease activity and damage in systemic lupus erythematosus. J Rheumatol 2001;28:525-32.