Table 2.

Exploratory Comparisons of Subgroup Differences in SMD of Reduced Anxiety among Studies with Waiting-list Control or Attention Control

Subgroups	# Studies	# Subjects	SMD (95% CI)	p values (grp differences)
Total	32	2,074	−0.53 (−0.62, −0.44)
By Type of Meditation1				P = 0.48
Mindfulness Meditation	11	869	−0.51 (−0.64, −0.37)
Yoga	9	424	−0.63 (−0.88, −0.38
Qigong or Tai Chi	5	288	−0.68 (−1.07, −0.29)
Guided Imagery	5	252	−0.39 (−0.64, −0.14)
By Duration of Study				P = 0.81
4 weeks or shorter	9	453	−0.57 (−0.77, −0.36)
6 to 10 weeks	12	771	−0.56 (−0.71, −0.42)
12 weeks or longer	11	850	−0.50 (−0.66, −0.33)
By Density of meditation training2				P = 0.46
Weekly or less	20	1379	−0.51 (−0.62, −0.40)
2+ a week to daily	10	612	−0.60 (−0.81, −0.39)
By Training/Therapy Delivery method				P = 0.17
Group or Group plus Individual	23	1402	−0.58 (−0.70, −0.46)
Individual	9	672	−0.44 (−0.60, −0.29)
By Homework assignment3				P = 0.83
With Homework	26	1735	−0.52 (−0.61, −0.42)
Without Homework	5	279	−0.56 (−0.98, −0.15)
By Region of studies				P = 0.04
From Western Countries	24	1631	−0.46 (−0.56, −0.27)
From Eastern Countries	8	443	−0.77 (−1.04, −0.50)
By Quality of the Study				P = 0.02
CLEAR-NPT ≥ 0.8	12	981	−0.40 (−0.53, −0.27)
CLEAR-NPT: 0.6—0.8	14	858	−0.61 (−0.75, −0.46)
CLEAR-NPT < 0.6	6	235	−0.83 (−0.15, −0.50)
By Type of Subjects4				P = 0.91
Patients with other health issues	22	1410	−0.53 (−0.65, −0.41)
Healthy subjects (not patient)	6	489	−0.54 (−0.73, −0.35)
Patients with anxiety issue	3	127	0.61 (−0.97, −0.25)

Note:

¹Two studies of TM were not included in subgroup analysis.

²Two studies ran only one session of meditative training and were not included.

³One residential study was not included.

⁴One study with mixed subjects was not included.