Table 2 Participant flow and timetable from screening to follow-up assessment

Week 0

Telephone screen

conducted by one of the investigators

receive patient information statement

verbal consent

complete telephone screening questionnaire to determine eligibility

eligible individuals are invited to attend baseline assessment conducted in groups of 8 individuals

Week 1

Baseline Assessment

administered by blinded assessor

sign patient informed consent

complete demographic data

complete baseline questionnaires

Randomization

generation: using sealed opaque envelopes containing allocation sequence generated by a computer random number function

allocation: the unblinded tai chi instructor will assign participants to one of two groups the tai chi intervention group or the wait-list control group

Week 2 – 11

Intervention

conducted by un-blinded investigator

Tai chi group:

2 × 40 min group sessions/week for 8 weeks

1 × 40 min group session/week for 2 weeks

Wait-list control group:

Continue with pre-established usual health care

After follow-up assessment is complete, participant can join in tai chi program identical to that of intervention

Assessments during intervention

administered via email by blinded assessor

Both groups will receive a bi-weekly questionnaire asking them to list the health care services they have used for their back symptoms

Week 12

Follow-up Assessment

administered by blinded assessor

administered by blinded assessor

complete follow-up questionnaires

after assessment, blinded assessor will leave and tai chi instructor will hand-out certificates of completion to tai chi group and schedule wait-list control group for tai chi program