The study was conducted at Tufts Medical Center, an urban tertiary care academic hospital in Boston, USA. It received ethics approval from the Tufts Medical Center/ Tufts University Human Institutional Review Board. A detailed version of the study protocol was reported in 2008 (14 (link)).
Patients with knee OA were recruited from the greater Boston area. To ensure adequate enrollment of underrepresented groups, we placed advertisements in local media. We also used the rheumatology clinic patient database at Tufts Medical Center to identify patients with knee OA. For interested respondents, we determined eligibility through a brief, scripted interview which posed questions whose predictive values for knee OA were known from population-based data. Applicants who screened positive on the telephone interview were scheduled for eligibility visits, when written informed consent was obtained.
The eligibility criteria were: age ≥ 55 years; Body Mass Index (BMI) ≤ 40 kg/m2; WOMAC pain subscale score (visual analog version) > 40 (range 0–500); fulfillment of the American College of Rheumatology criteria for knee OA (15 (link)) with radiographic Kellgren and Lawrence (K/L) knee OA grade ≥ 2 (16 (link)). We excluded individuals who had prior Tai Chi training or similar types of alternative medicine like Qi Gong or yoga; individuals with serious medical conditions, limiting their ability for full participation as determined by primary care physicians; individuals with intra-articular steroid injections in the previous three months, or reconstructive surgery on the affected knee and any intra-articular hyaluronate injections in the previous six months; individuals unable to pass the Mini-Mental examination (score < 24) (17 (link)).
To avoid bias in favor of the Tai Chi intervention, we informed participants that we were studying the effects of two different types of exercise training programs, one of which was combined with nutrition education. Participants were allowed to continue routine medications and maintain their usual visits with their primary care physicians or rheumatologists throughout the study.
Patients with knee OA were recruited from the greater Boston area. To ensure adequate enrollment of underrepresented groups, we placed advertisements in local media. We also used the rheumatology clinic patient database at Tufts Medical Center to identify patients with knee OA. For interested respondents, we determined eligibility through a brief, scripted interview which posed questions whose predictive values for knee OA were known from population-based data. Applicants who screened positive on the telephone interview were scheduled for eligibility visits, when written informed consent was obtained.
The eligibility criteria were: age ≥ 55 years; Body Mass Index (BMI) ≤ 40 kg/m2; WOMAC pain subscale score (visual analog version) > 40 (range 0–500); fulfillment of the American College of Rheumatology criteria for knee OA (15 (link)) with radiographic Kellgren and Lawrence (K/L) knee OA grade ≥ 2 (16 (link)). We excluded individuals who had prior Tai Chi training or similar types of alternative medicine like Qi Gong or yoga; individuals with serious medical conditions, limiting their ability for full participation as determined by primary care physicians; individuals with intra-articular steroid injections in the previous three months, or reconstructive surgery on the affected knee and any intra-articular hyaluronate injections in the previous six months; individuals unable to pass the Mini-Mental examination (score < 24) (17 (link)).
To avoid bias in favor of the Tai Chi intervention, we informed participants that we were studying the effects of two different types of exercise training programs, one of which was combined with nutrition education. Participants were allowed to continue routine medications and maintain their usual visits with their primary care physicians or rheumatologists throughout the study.
