Tai Chi for treating cancer-related fatigue: A meta-analysis of randomized controlled trials

Table 1 Search strategy for PubMed

Step	Search strategy
1	Tai Ji[Mesh] OR Tai Chi[Title/Abstract] OR Taijiquan[Title/Abstract] OR Tai Ji Quan[Title/Abstract]
2	Neoplasms[Mesh] OR Cancer[Title/Abstract] OR Tumor[Title/ Abstract] OR malignant[Title/Abstract] OR chemotherapy[Title/Abstract] OR radiotherapy[Title/Abstract] OR immunotherapy [Title/Abstract]
3	fatigue[MeSH] OR cancer-related fatigue[Title/Abstract] OR CRF [Title/Abstract] OR exhaust[Title/Abstract] OR tired[Title/Abstract]
4	randomized controlled trial[Mesh] OR random[Title/Abstract] OR trial[Title/Abstract] OR RCT[Title/Abstract]
5	1 AND 2 AND 3 AND 4

Table 2 Search strategy for EMBASE

Step	Search strategy
1	'tai chi chuan': Ab,ti OR 'tai ji': Ab,ti OR 'taiji quan': Ab,ti OR taijiquan: Ab,ti OR 'tai chi': Ab,ti
2	'neoplasia': Ab,ti OR neoplasms: Ab,ti OR tumor: Ab,ti OR tumour: Ab,ti OR neoplasm: Ab,ti OR cancer: Ab,ti OR 'malignant neoplasm': Ab,ti OR malignancy: Ab,ti OR malignancies: Ab,ti OR chemotherapy: Ab,ti OR radiotherapy: Ab,ti OR immunotherapy: Ab,ti
3	'fatigue': Ab,ti OR 'cancer-related fatigue': Ab,ti OR crf:ab,ti OR lassitude: Ab,ti OR tiredness: Ab,ti OR exhaustion: Ab,ti OR weariness: Ab,ti
4	'randomized controlled trial': Ab,ti OR 'controlled trial, randomized': Ab,ti OR 'randomised controlled study': Ab,ti OR 'randomised controlled trial': Ab,ti OR 'randomized controlled study': Ab,ti OR 'trial, randomized controlled': Ab,ti OR 'randomized controlled trial': Ab,ti
5	1 AND 2 AND 3 AND 4

Table 3 Search strategy for the Cochrane library

Step	Search strategy
1	(Tai Chi): Ti,ab,kw OR (Taiji): Ti,ab,kw OR (T'ai Chi): Ti,ab,kw OR (Chi, Tai): Ti,ab,kw OR (Tai Chi Chuan): Ti,ab,kw
2	(Ji Quan, Tai): Ti,ab,kw OR (Taijiquan): Ti,ab,kw OR (Tai Ji Quan): Ti,ab,kw OR (Tai-ji): Ti,ab,kw OR (Quan, Tai Ji): Ti,ab,kw
3	1 OR 2
4	(Neoplasms): Ti,ab,kw OR (Neoplasm): Ti,ab,kw OR (Tumor): Ti,ab,kw OR (Tumors): Ti,ab,kw OR (Neoplasias): Ti,ab,kw
5	(Neoplasia): Ti,ab,kw OR (Malignancy): Ti,ab,kw OR (Malignant): Ti,ab,kw OR (Malignant Neoplasms): Ti,ab,kw OR (Malignancies): Ti,ab,kw
6	(Malignant Neoplasm): Ti,ab,kw OR (cancer): Ti,ab,kw OR (cancers): Ti,ab, kw
7	4 OR 5 OR 6
8	(fatigue): Ti,ab,kw OR (cancer-related fatigue): Ti,ab,kw OR (CRF): Ti,ab,kw OR (lassitude): Ti,ab,kw OR (tiredness): Ti,ab,kw
9	(exhaustion): Ti,ab,kw OR (weariness): Ti,ab,kw
10	8 OR 9
11	(randomized controlled trial): Ti,ab,kw OR (controlled clinical trial): Ti,ab,kw OR (randomized): Ti,ab,kw OR (placebo): Ti,ab,kw OR (random): Ti,ab,kw
12	(trial): Ti,ab,kw OR (group): Ti,ab,kw
13	11 OR 12
14	3 AND 7 AND 10 AND 13

Table 4 Basic characteristics of the included literatures

Ref.	Research object	Sample size		Intervention measure		Intervention cycle	Intervener	Outcome measures
		Treatment	Control	Treatment	Control
Chen[18] (2021)	Breast cancer patients after chemotherapy	26	26	Simplified 24-form Tai Chi	Treatment and routine. Training and exercise	16 weeks, 3 times a week, 60 minutes each time	Professional teachers	CFS body composition, blood lipids
Ge and Shentu[19] (2019)	Lung cancer patients undergoing chemotherapy	39	39	Simplified 24-form Tai Chi	Treatment and routine training	6 weeks, twice a day, 30 minutes each time	Full-time nurses	RPFS, FACT-G, T lymphocyte subset
Han et al[20] (2019)	Breast cancer patients undergoing chemotherapy	20	21	Eight forms of Tai chi	Treatment and routine training	12 weeks, twice a day, 5 days a week	Researchers	RPFS-CV
Jiang et al[21] (2013)	Lung cancer patients	30	30	Simplified 24-form Tai Chi	Treatment and routine training	30 days, twice a day, 30 minutes each time	Full-time nurses	BFI, SRSS
Wang[22] (2017)	Breast cancer patients who underwent modified radical mastectomy and chemotherapy	45	41	Tai Chi	Treatment and routine Training and exercise	Starting from 10 days after the operation, 6 months, twice a day, 20 minutes each time	Researchers	CFS, PSQI, WHOQOL-BREF, SAS, SDS
Yang et al[23] (2022)	Breast cancer patients who underwent modified radical mastectomy and chemotherapy	38	41	SimplifiedTai Chi	Treatment and routine. Training and exercise	12 weeks, twice a day, 5 times a week, 20 minutes each time	Researchers	RPFS-CV, FACT-B, Inflammatory factors
Zhang et al[24] (2016)	Lung cancer patients undergoing chemotherapy	38	36	Eight forms of Tai Chi	Treatment and routine training	12 weeks, 3-4 times a week, 60 minutes each time	Professional teachers	MFSI-SF
Zheng et al[25] (2022)	Postoperative patients with gastric cancer	53	53	Simplified 24-form Tai Chi	Treatment and routine training	12 weeks, 7 days after discharge, 3 times a week, 60 minutes each time	Full-time nurses	RPFS, PSQI
Zhou et al[26] (2018)	Patients with nasopharyngeal carcinoma undergoing chemoradiotherapy	42	41	Simplified 24-form Tai Chi	Treatment and routine training	During chemotherapy, 5 times a week, 60 minutes each time	Researchers	MFSI-SF, Heart rate variability parameters

CFS: Cancer fatigue scale; BFI: Brief fatigue inventory; RPFS: Revised piper fatigue scale; RPFS-CV: Revised piper fatigue scale-Chinese version; MFSI-SF: Multidimensional fatigue symptom inventory-short form; PSQI: Pittsburgh sleep quality index; SRSS: Self-rating scale of sleep; FACT-G: Functional assessment of cancer therapy-general; FACT-B: FACT-breast; WHOQOL-BREF: WHO quality of life-BREF.

Table 5 Psychometric properties and applicability of multidimensional fatigue Scales in cancer-related fatigue assessment

Scale	Items	Score range	Domains assessed	Reliability (α)	Characteristics
CFS[27-31]	15	0-60	Physical, affective, and cognitive	0.88	Describes the fatigue of current situation
BFI[27-31]	9	0-10 per subscale	Fatigue intensity	0.96	Examines fatigue in the previous 24 hours
RPFS[27-31]	22	0-10 per subscale	Behavioural/intensity, cognitive, affective and sensory	0.97	Multidimensional quantitative assessment reflects the complexity of patient fatigue and its impact on life. Addresses CRF's dual physical-cognitive pathology
RPFS-CV[27-31]	22	0-10 per subscale		0.91
MFSI-SF[27-31]	30	0-4 per subscale	General, physical, Emotional, mental and Vigor	0.87-0.96	Ease of use and scoring are of a moderate level

CRF: Cancer-related fatigue; CFS: Cancer fatigue scale; BFI: Brief fatigue inventory; RPFS: Revised piper fatigue scale; RPFS-CV: Revised piper fatigue scale-Chinese version; MFSI-SF: Multidimensional fatigue symptom inventory-short form.

Table 6 A narrative assessment of the efficacy of Tai Chi for cancer-related fatigue: Analysis of sources of heterogeneity

Analysis dimensions	Number of studies	Ref.	SMD (effect size)	I2	Effect direction and consistency	Notes
Grouped by cancer type
Breast cancer	4	Chen[18] (2021)	-1.70 (-2.51, -0.89)	87%	Negative and consistent	Statistically significant negative effect
		Han et al[20] (2019)
		Wang[22] (2017)
		Yang et al[23] (2022)
Lung cancer	3	Ge and Shentu[19] (2019)	-0.98 (-1.44, -0.53)	79%	Negative and consistent	Statistically significant negative effect
		Jiang et al[21] (2013)
		Zhang et al[24] (2016)
Gastric cancer	1	Zheng et al[25] (2022)				Single-study estimate
Nasopharyngeal carcinoma	1	Zhou et al[26] (2018)				Single-study estimate
Grouped by treatment methods
Undergoing chemotherapy	6	Chen[18] (2021)	-1.51 (-2.15, -0.87)	88%	Negative and consistent	Statistically significant negative effect
		Ge and Shentu[19] (2019)
		Han et al[20] (2019)
		Wang[22] (2017)
		Yang et al[23] (2022)
		Zhang et al[24] (2016)
Undergoing chemoradiotherapy	1	Zhou et al[26] (2018)				Single-study estimate
Routine treatment	2	Jiang et al[21] (2013)	-0.73 (-1.28, -0.19)	64%	Negative and consistent	Statistically significant negative effect
		Zheng et al[25] (2022)
Grouped by intervention time
≤ 4 weeks	2	Jiang et al[21] (2013)	-0.48 (-0.81, -0.15)	0%	Negative and consistent	Statistically significant negative effect
		Wang[22] (2017)
4 < weeks ≤ 8	4	Ge and Shentu[19] (2019)	-0.95 (-1.61, -0.28)	86%	Negative and consistent	Statistically significant negative effect
		Han et al[20] (2019)
		Yang et al[23] (2022)
		Zhou et al[26] (2018)
8 < weeks ≤ 12	5	Han et al[20] (2019)	-1.30 (-1.97, -0.62)	89%	Negative and consistent	Statistically significant negative effect
		Wang[22] (2017)
		Yang et al[23] (2022)
		Zhang et al[24] (2016)
		Zheng et al[25] (2022)
> 12 weeks	2	Chen[18] (2021)	-1.27 (-2.12, -0.42)	79%	Negative and consistent	Statistically significant negative effect
		Wang[22] (2017)
Grouped by comparative measures
The control group receiving conventional rehabilitation training	3	Chen[18] (2021)	-1.76 (-2.85, -0.67)	91%	Negative and consistent	Statistically significant negative effect
		Yang et al[23] (2022)
		Wang[22] (2017)
The control group without conventional rehabilitation training	6	Ge and Shentu[19] (2019)	-1.06 (-1.48, -0.64)	76%	Negative and consistent	Statistically significant negative effect
		Han et al[20] (2019)
		Jiang et al[21] (2013)
		Zhang et al[24] (2016)
		Zheng et al[25] (2022)
		Zhou et al[26] (2018)
Grouped by assessment scales
CFS	2	Chen[18] (2021)	-3.53 (-4.45, -2.62)	0%	Negative and consistent	Statistically significant negative effect
		Wang[22] (2017)
RPFS/RPFS-CV	4	Ge and Shentu[19] (2019)	-1.26 (-1.52, -1.00)	56%	Negative and consistent	Statistically significant negative effect
		Han et al[20] (2019)
		Yang et al[23] (2022)
		Zheng et al[25] (2022)
MFSI-SF	2	Zhang et al[24] (2016)	-9.42 (-15.63, -3.22)	69%	Negative and consistent	Statistically significant negative effect
		Zhou et al[26] (2018)

CRF: Cancer-related fatigue; CFS: Cancer fatigue scale; BFI: Brief fatigue inventory; RPFS: Revised piper fatigue scale; RPFS-CV: Revised piper fatigue scale-Chinese version; MFSI-SF: Multidimensional fatigue symptom inventory-short form.

Table 7 GRADE evidence quality rating results

Quality assessment							No. of patients		Effect	Quality
Number of studies	Study design	Risk of bias	Inconsistency	Indirectness	Imprecision	Other considerations	Tai Chi intervention	Control	Std. mean difference (95%CI)
Cancer-related fatigue
9	Randomized trials	Not serious	Serious1	Not serious	Not serious	None	331	328	SMD -1.29; (-1.72, -0.85)	Moderate
Sleep quality
2	Randomized trials	Not serious	Not serious	Not serious	Serious2	None	75	71	SMD -0.45; (-0.78, -0.12)	Moderate
Quality of life
3	Randomized trials	Not serious	Serious3	Not serious	Serious2	None	122	121	SMD 0.70; (0.23, 1.16)	Low

¹Due to significant heterogeneity among studies (I² = 84%, P < 0.00001), the evidence grade was downgraded by one level owing to serious inconsistency.

²Given the small sample size and limited data, we downgraded the evidence for imprecision by one level.

³Due to significant heterogeneity among studies (I² = 68%, P = 0.003), the evidence grade was downgraded by one level owing to serious inconsistency.

SMD: Standardised mean difference.