Table 1 Summary of the quality of studies

 Recall bias

Low risk

Prospective data collection

-

-

Some risk

Retrospective data collection within previous 12 months

33.3 (6)

[7, 26,27,28, 31, 42]

High risk

Retrospective data collection not within previous 12 months

66.7 (12)

[29, 30, 32,33,34,35,36,37,38,39,40,41]

Any pilot, feasibility, pretest, or previous use of study materials

61.1 (11)

[28, 30,31,32, 34, 35, 37, 38, 40,41,42]

Report efforts to address nonresponsive bias or information bias

16.7 (3)

[28, 30, 35]

Any adjustment of confounders in analyses of variables associated with TM use

27.8 (5)

[28, 31, 32, 37, 40]

Where response rate = (number of participants in the study/number of people invited to take part) × 100

44.4 (8)

[7, 26, 29,30,31,32, 36, 40]

Any attempt to achieve a sample of participants that represents the larger population from which they were drawn (but cannot be a single center sample)

16.7 (3)

[30, 35, 42]

Report participants’ diagnoses

22.2 (4)

[26, 29, 31, 39]

Report participants’ socioeconomic status

83.3 (15)

[7, 26,27,28,29,30, 32,33,34,35,36,37,38, 40, 41]

Report participants’ ages

88.9 (16)

[7, 26,27,28,29,30,31,32,33,34,35,36,37,38, 41, 42]

Report participants’ ethnicity

27.8 (5)

[26,27,28, 35, 42]

Report participants’ gender

100 (18)

[7, 26,27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42]

Information about the definition of TM/a list of TM modalities provided to participants

27.8 (5)

[7, 30, 34, 35, 41]

Report the prevalence of use of specific TM modalities

88.9 (16)

[7, 27,28,29,30,31,32,33,34,35,36,37,38,39, 41, 42]

Report how often or for what duration the TM were/are used by study participants

11.1 (3)

[35, 36, 42]

Report the reasons for the use of TM by study participants

61.1 (11)

[27, 29,30,31, 33, 34, 36,37,38,39, 42]