Table 3.

Summary of Unconditional and Moderated Intervention Effects in Studies Using the Spielberger State-Trait Anxiety Inventory

	STAI – State Anxiety					STAI – Trait Anxiety
	k	F	τ2	ES	95% CI	k	F	τ2	ES	95% CI
Overall intervention effect	34		39.93	−5.72	−8.17/−3.27	12		11.11	−3.75	−6.20/−1.30
Moderated intervention effects
Pre-intervention STAI scores		16.06***	22.73				13.10***	2.53
Slope (increment per scale-point)	34			−0.58	−0.84/−0.32	12			−0.33	−0.51/−0.15
Targeted at distressed patients		5.25*	32.68				0.14	10.64
Targeted intervention	4			−13.07	−19.60/−6.58	3			−4.50	−8.96/−0.03
Not targeted	30			−4.80	−7.12/−2.49	9			−3.53	−5.98/−1.08
Type of intervention		1.39	37.42				2.49	8.07
CBT	14			−7.86	−11.52/−4.20	4			−6.24	−9.90/−2.59
Non-CBT	20			−4.31	−7.28/−1.34	8			−2.78	−5.07/−0.48
Mode of delivery (setting)		1.90	37.66				15.50***	0.00
Individual	16			−6.30	−9.65/−2.94	6			−3.34	−4.86/−1.82
Group	4			−9.00	−15.94/−2.94	2			−9.95	−12.46/−7.44
Self-administered	14			−4.19	−7.78/−0.61	4			−1.42	−3.12/+0.29
Number of sessions (dose)		3.01*	33.52				1.09	9.10
<4 sessions	12			−5.20	−8.86/−1.53	6			−2.90	−5.70/−0.11
4–6 sessions	11			−2.97	−6.90/+0.97	3			−6.49	−10.65/−2.33
>6 sessions	11			−9.00	−12.88/−5.14	3			−2.90	−7.08/+1.27

Note. STAI = State-Trait Anxiety Inventory; CBT = Cognitive Behavioral Treatment; ES = Raw effect size; CI = Confidence interval; Values were derived from unconditional random effects models and conditional mixed-effects models, τ² is the between-study variance in each model;

^*p < .05;

^**p < .01;

^***p < .001.