Table 2.
Characteristics of included systematic reviews
| Author, year | Country | Disease/condition | Studies included (no. and study design) | Sample sizea | Tai Chi intervention | Comparisons | Outcome and measurement |
|---|---|---|---|---|---|---|---|
| Farhang et al. (2019) [14] | Chile | Mild cognitive impairment | 4 about Tai Chi (3 RCTs, 1 PNRCT) | 529 | 2–3 × 30–90 min/week for 4–24 weeks | Stretching and relaxation exercise, no intervention, no TC practice, psychoeducation |
1) Cognitive function: CDR, ADAS-cog 2) Executive function: DSF and DSB, TMT 3) Memory: The Logical Memory—delayed recall, HVLT, RBMT, RBMT-II, TEA 4) Visuospatial ability: Block Design Test |
| Zhang et al. (2020) [16] | China | Mild cognitive impairment | 7 RCTs | 1068 | 3 × 30–50 min/week for 12–52 weeks | Stretching, daily activity, health education |
1) Global cognitive function: MMSE 2) Memory: Logical Memory Delayed Recall Test 3) Executive function: Digit Span Test (DST) Forward & Backward 4) Verbal fluency: CVFT 5) Visual span: Visual Span Test Forward and Backward or Block Design Test 6) Depressive symptoms: CSDD or GDS |
| Lim et al. (2019) [22] | Canada | Early-stage dementia | 9 (6 RCTs, 2 NRCTs, 1 PNCT) | 11–238 | 1–4 × 20–60 min/week for 8–52 weeks | Health talk group, handicraft, adapted physical group activity and education on health, no intervention, stretching and relaxation exercises, education group on cognitive impairment, health and cultural information class |
1) Global cognition: MMSE, ADAS-Cog, CDR 2) Working memory and executive function: DSB, DSC, DSF, 15-Word immediate recall and/or TMT-B 3) Attention and concentration: Stroop Colour and Word, DSB 4) Verbal learning and memory: HVLT-R, 15-Word 30-Min Delayed Recall, RBMT 5) Self-perception of memory: MIC, SMC 6) Semantic memory: CVF 7) Visuospatial ability: Block Design Test |
| Wang et al. (2018) [23] | China | Cognitive impairment, mild cognitive impairment or dementia | 7 about Tai Chi (2 RCTs, 2 CCS, 3 CCT) | 808 | 2–3 × 30–90 min/week for 8–48 weeks | Health talk, handicraft, memory intervention program, muscle-stretching and toning exercise, usual lifestyle, usual care |
1) Global cognition: MMSE, ADAS-cog, MoCA 2) Memory: MIC, immediate verbal recall, delayed verbal recall, HVLT, RBMT 3) Executive function: CVF, DSF, forward digit sequence, DSB, backward digit sequence, TMT-A and B |
| Wei et al. (2020) [2] | China | Mild cognitive impairment | 12 (4 RCTs, 7 quasi-experimental studies, 1 nonrandomized control group pretest–posttest design) | 981 | 2–5 × 30–60 min/week for 12–52 weeks | Maintain usual daily physical activities, related health education, stretching and toning exercise |
1) Global cognitive ability: MMSE, MoCA, ADAS-Cog, CDR 2) Memory: AVLT-long-term delayed recall 3) Attention: DSB, DSF 4) Executive ability: TMT 5) Language domain of cognition: CVF 6) Visual-spatial cognition: block design test, visual span test 7) IADL: Lawton’s instrumental activities of daily living and functional activities questionnaire (FAQ) 8) Quality of life: SF-12, PD-39 |
| Yang et al. (2020) [4] | China | Mild cognitive impairment | 11 RCTs | 1061 | 1–6 × 30–120 min/week for 10–48 weeks | Stretching and toning exercise, escitalopram plus health education, maintain routine daily activities, no intervention, nonathletic activities, educational information related to cognition, memory training |
1) Global cognitive function: MMSE, MoCA, ADAS-Cog, MDRS, CDR-SOB 2) Memory and learning: delayed recall, DSF, DSB, California Verbal Learning Test, Rey Auditory Verbal Learning Test (immediate and delayed recall), Mattis memory score, logical memory-delayed recall score, and Wechsler Memory Scale 3) Mental speed and attention: visual span (forward), visual span (backward), Stroop Colour and Word Test, Mattis attention score, FAB, Chinese Trail A (seconds), Chinese Trail B (seconds), Trail Making Test A (errors), Stroop Colour and Word Test, Trails A Time (seconds), Trails B Time (seconds), TMT Part A, TMT Part B 4) Ideas, Abstraction, Figural Creations, and Mental Flexibility: CVF, Mattis conceptualization score, Mattis initiation score, category verbal fluency (animals), WAIS, and Trail-Making Test Part B-A score 5) Visuospatial perception: Rey Figure Test (recall), block design score, clock drawing test, bell cancellation test, Mattis construction score, and Rey Figure Test (copying) |
| Zheng et al. (2017) [3] | China | Mild cognitive impairment | 3 RCTs | 455 | 2–3 × 30–90 min/week for 20–48 weeks | Usual daily activities; stretching and relaxation exercises, memory intervention program | WAIS, RBMT, SMC, ADAS-cog, BBS, CSDD, CDR, CVF, DAD, DR, NPI, MMSE, VS, DTC, HVLT, RAPA, RBMT, SF-36, TEA, UG |
| Zou et al. (2019) [24] | China | Mild cognitive impairment | 6 about Tai Chi (3 RCTs, 3 NRCTs) | 789 | 2–4 × 30–90 min/week for 12–52 weeks | Stretching exercise, memory training, unaltered lifestyle, educational class |
1) Global cognition: MMSE, CDR, MoCA 2) Executive function: TMT-B, DST-FB 3) Short-term memory: Delayed Recall Test, RBMT, RBMT-delayed 4) Cognitive processing speed: DST-F, DSST 5) Visuospatial ability: block design test |
Abbreviations: RCT randomised controlled trial, PNRCT pilot non-randomised controlled trial, NRCT non-randomised controlled trial, PNCT prospective non controlled trial, CCS cluster controlled studies, CCT controlled clinical trials, CDR Clinical Dementia Rating, CVFT Category Verbal Fluency Test, ADAS-cog Alzheimer Disease Assessment Scale—Cognitive Subscale, DSF Digit Span forward, DSB Digit Span backward, TMT Trial-Making Test, TMT-A Trial-Making Test-Part A, TMT-B Trial-Making Test-Part B, HVLT Hopkins Verbal Learning Test, HVLT-R Hopkins Verbal Learning test–Revised, RMBT Rivermead Behavioural Memory Test, TEA Test of Everyday Attention, MMSE Mini-Mental Status Exam, DSC Digit Symbol Coding, MIC Memory Inventory for Chinese Questionnaire, SMC Subjective Memory Complaints Scale, MoCA Montreal Cognitive Assessment, AVLT Auditory Verbal Learning Test, IADL Instrumental Activities of Daily Living, PD-39 Parkinson’s Disease Questionnaire-39, MDRS Mattis Dementia Rating Scale, CDR-SOB Clinical Dementia Rating Sum of Boxes, FAB Frontal Assessment Battery, WAIS Wechsler Adult Intelligence Scale, BBS Berg Balance Scale, CSDD Cornell Scale for Depression in Dementia, CVF category verbal fluency, DAD, Disability Assessment for Dementia, DR delayed recall, NPI Neuropsychiatric Inventory; VS visual span, DTC dual-task cost, RAPA Rapid Assessment of Physical Activity Scale, SF-36 RAND 36-Item Short-Form Health Survey-Medical Outcomes Study, UG usual gait, DST-FB Digit Span Test Forward–Backward, DSST Digit Symbol Substitution Test, GDS Geriatric Depression Scale
aSample size of the included Tai Chi studies