Tai Chi Versus Conventional Exercise to Improve Cognitive Performance in Older Adults With Mild Cognitive Impairment

Change in the score of the Montreal Cognitive Assessment. The score ranged from 0 to 30. Higher score indicates a better cognitive function.

Participants scoring equal or below the 7th percentile of the age- and education-corrected normative data will be considered as having MCI.

Change in the score of the Montreal Cognitive Assessment. The score ranged from 0 to 30. Higher score indicates a better cognitive function.

Participants scoring equal or below the 7th percentile of the age- and education-corrected normative data will be considered as having MCI.

The Clinical Dementia Rating (CDR) is a numeric scale of 0-3 points based on clinician/ certified rater ratings of cognition and daily function in the domains of memory, orientation, judgment and problem solving, community affairs, home and hobbies, and personal care. Rating from 0, 0.5, 1, 2 and 3 indicated subjects' cognitive function having healthy, very mild impairment, mild impairment, moderate impairment and severe impairment respectively.

The NIH Toolbox Cognitive Function Battery (CFB) will be used to objectively evaluate the various cognitive domains. CFB assesses cognitive abilities in different cognitive domains, including memory, executive function and attention. CFB will be delivered on a tablet computer.

The Cognitive Self-Report Questionnaire (CSRQ) will be used to examine the subjective cognitive performance. The CSRQ is validated in Hong Kong and comprises 25 questions with an overall score ranging from 0-100. A higher score indicates worse self-perception on cognitive performance.

The memory inventory for the Chinese - a questionnaire exploring subjective memory complaints and the effects on daily activities - will be performed to examine the subjective memory complaints.

The Pittsburgh Sleep Quality Index (PSQI) will be used to assess sleep quantity and the perceived restfulness and disturbance of sleep by gathering information on usual bed time, wake time, time to fall asleep, time of actual sleep, and quality of sleep. Each item is rated on a "0-3" Likert scale, with a higher score indicating poorer sleep quality.

The Hospital Anxiety and Depression Scale assesses the severity of depression and anxiety. This 14-item questionnaire has subscales for both depression and anxiety and the overall score ranges from 0-21, with a higher score indicating more severe depressive/anxious symptoms.

The 12-Item Short Form Survey measures health-related quality of life. It has 12 items assessing physical functioning, emotional and mental health, bodily pain, general health, vitality, and social functioning, with higher overall scores indicating a better quality of life.

Subjects' use of medications, unrelated to dementia and psychiatric conditions (e.g., sleep, dyslipidemic and hypertensive pills) will be recorded along with detailed usage information. Data on medication dose and weekly frequency will be presented as the total number of lowest recommended dose in 7 days for the analysis.

Physical function and balancing performance will be assessed using the Short Physical Performance Battery (SPPB). The SPPB involves repeated timed chair stands, timed standing balance (with feet in parallel in semi-tandem and tandem positions), and a 4-meter walk to measure the usual gait speed.

Actigraph/IPAQ method to monitor and record habitual physical activity. Actigraph activity monitor (wGT3X-BT or GT9X, Actigraph, USA), a 3-axis accelerometer, will be used to objectively determine the habitual daily physical movement/activities.