Subjects: 192 patients were enrolled and recruited from four General Out-patient clinics in Yau Tsim Mong and Wong Tai Sin districts.
Study Design: Prospective single blind randomized controlled trial
Subjects were randomized into Pulmonary rehabilitation program (PRP) group (n = 98) and Pulmonary rehabilitation program with Tai chi group (TC)(n=94). Details of PRP and PRP + Tai Chi will be discussed below.
Both groups will be given booklet on COPD information and management.
Randomization:
Computer generated pre-assigned randomization of subjects to group allocation is made after baseline assessment. At each stage, assessors for outcome measures and data collection are blinded to the patient's grouping. Patients, investigator and physiotherapist are open to the group allocation.
Standardized medical treatment:
All COPD patients are managed according to practical guidelines recommended by the Hospital Authority. Medical treatment is reviewed and changed if clinically appropriate. In response to an exacerbation, antibiotic is added if a respiratory infection is the cause and oral steroid may be prescribed if clinically indicated.
Measurement and Evaluation
Baseline assessment:
1. Medical aspect: GOLD staging of COPD; Baseline spirometry test including bronchodilator reversibility test.
2. Self-Efficacy: COPD Self Efficacy Scale (CSES); Self-Efficacy for Managing Shortness of Breath (SEMSOB)
3. Quality of life related measures: St. George Respiratory Questionnaire ( SGRQ)
4. Exercise Capacity: 6 Minutes Walking Distance Test (6MWT)
Reassessment done at 2 months and 6 months using:
1. Primary Outcome measures and Secondary measures outcome mentioned in outcome measures
2. Spirometry exclusive of bronchodilator reversibility test
Statistical methods
Descriptive statistics including mean, standard deviation, frequency and percentages were used to describe the demographic characteristics and summarize the baseline characteristics of the variables. Independent T-test was used to examine the difference in demographic characteristics and baseline outcome measures between the PRP and TC group. Paired T-test was performed to examine the differences of outcome measures, including spirometry, 6 MWT, SGRQ-HKC, CSES, SEMSOB before and after intervention program within group. Analysis of covariance(ANCOVA) were used to examine the differences of outcome variables between PRP and TC group adjusted for age, sex, body mass index BMI, smoking and education, with the corresponding baseline value as a covariate. A p-value of 0.05 ws used as the level of statistical significance. Confidence intervals ( 95%) of the mean differences between baseline and 6 months post intervention values were calculated to compare the effects with the minimum clinically important difference (MCID) for the SGRQ-HKC. All analyses were conducted using Statistical package for the Social Sciences SPSS version 16.0.
Pulmonary Rehabilitation Programme (PRP) Details :
The revised PRP consisted of 12 sessions (twice per week for 6 weeks) with 6-10 subjects per session. The standard content consists of physical training including warm up \& cool down exercise and aerobic exercises.
For the PRP group, patients performed 5 minutes warm up exercises. Then 2 aerobic activities including treadmill exercise and lower limb ergometry exercise lasting 20 minutes each,were prescribed. 15 minutes rest were given between each exercise. After the aerobic exercises, 5 minutes cool down exercises, followed by 15 minutes of relaxation exercise was conducted before patients completed that session. Each session lasted for about 1 hour and 20 minutes.They were instructed to continue unsupervised home exercises consisting of 5 minutes of warm-up, 5 minutes of Thera-Band strengthening exercises, 30 minutes of aerobic exercises, 5 minutes cool down and 15 minutes of relaxation exercise for at least one hour 5-7 days/week.
For the PRP + Tai Chi group, the exercise content is totally identical to the PRP group except 15 minutes of Tai Chi exercises was substituted to the 15 minutes of relaxation exercise. Each session also lasted for about 1 hour and 20 minutes. The 5 forms of Suen Style of Tai Chi are chosen because it will encourage larger limbs movement as well as chest wall movement incorporated with diaphragmatic breathing and breathing control.
Details of the 5 forms of Sun Style Tai Chi chosen are:
1. commencing form
2. single whip : left and right
3. turn with slanted flying: left and right
4. wave hands like clouds: left and right
5. moving as if shutting a door
The exercise intensity level of the aerobic activities will be set at a target heart rate of 60-70 % of their maximum heart rate and rate of perceived dyspnea(RPD) level of not more than 7. Vital signs will be monitored before, during \& after exercise to ensure that the exercise heart rate does not exceed the target level. Also, any time when patient feels discomfort with RPD level reaching 7, the exercise will be stopped and patient is allowed to rest.
