Perfectionism as a predictor of change in digital self-guided interventions for public speaking anxiety in adolescents: A secondary analysis of a four-armed randomized controlled trial

Figures & data

Table 1. Observed means and standard deviations for PSAS, SIAS, SPS and EDI-P.

		Waitlist + Online PE			VR only			Online PE + EXP			VR + online EXP
		N	Mean	SD	N	Mean	SD	N	Mean	SD	N	Mean	SD
PSAS	Pre	20	65.00	6.24	20	65.00	8.25	39	67.51	7.12	20	63.90	7.26
	Post	15	60.27	9.76	16	55.00	10.39	26	61.04	11.03	16	55.44	11.07
	Follow-up	11	56.09	12.54	16	52.50	11.08	18	61.17	10.95	12	53.50	12.30
SIAS	Pre	20	11.40	5.60	20	10.60	5.44	39	10.56	5.22	20	10.45	5.85
	Post	15	10.27	6.60	16	8.88	6.25	26	9.73	6.19	16	9.31	5.99
	Follow-up	11	9.00	6.31	16	7.94	5.09	18	10.06	5.88	12	11.58	4.62
SPS	Pre	20	11.40	6.35	20	9.85	5.24	39	12.54	7.26	20	11.45	6.82
	Post	15	9.60	7.16	16	6.50	5.70	26	9.73	7.02	16	8.31	6.03
	Follow-up	11	9.55	7.26	16	5.44	4.60	18	9.94	6.55	12	9.92	5.33
EDI-P	Pre	20	6.90	3.91	20	7.05	4.24	39	7.31	3.53	20	6.55	4.61
	Post	15	7.20	3.99	16	6.75	4.25	26	6.77	3.12	15	6.67	3.92
	Follow-up	11	7.18	3.71	16	6.63	4.92	18	6.61	3.93	12	6.58	3.82

Note: PSAS = Public Speaking Anxiety Scale, SIAS = Social Interaction Anxiety Scale, SPS = Social Phobia Scale, EDI-P = Eating Disorder Inventory—Perfectionism, SD = Standard deviation, EXP = Exposure, PE = Psychoeducation.

Table 2. Results from two-piece growth curve level and change models for the three outcome variables PSAS, SIAS and SPSS. Change is estimated per week.

	Pre			Change Pre—Post^a				Change Post—FU^b				Total change^c
	M	SD	p	M	P	SD	P^I	M	P	SD	P^I	M	P
PSAS	65.43	6.76	<.001	−1.14	<.001	1.15	<.001	−0.21	.009	0.44	.005	−24.23	<.001
SIAS	10.76	4.82	<.001	−0.17	.084	0.70	.001	−0.05	.200	0.18	.183	−4.10	.008
SPS	11.59	6.21	<.001	−0.48	<.001	0.65	.009	−0.01	.824	0.24	.094	−8.91	<.001

Note: FU = Follow-up, PSAS = Public Speaking Anxiety Scale, SIAS = Social Interaction Anxiety Scale, SPS = Social Phobia Scale, M = Mean, SD = Standard deviation, p = significance at group level, p^I = significance at individual level.

^aChange Pre—Post equivalent to change 0–6 weeks

^bChange Post—Follow-up equivalent to change 6–18 weeks

^cTotal change for the total study period from pre to follow up was estimated based on change per week in each interval multiplied with 18 weeks.

Table 3. Changes in PSAS, SPS-6, and SIAS-6 in the intervals Pre – Post and Post – Follow-up predicted by treatment groups and changes in EDI-P, in addition to the interaction terms between pre-treatment levels in EDI-P and treatment groups.

	Change Pre—Post		Change Post—Follow-up
	b	p	b	p
PSAS
Waitlist + Online PE^a	−0.50	.139	−0.53	.002
VR only	−1.60	.026	0.25	.448
Online PE+EXP	0.04	.950	0.34	.345
VR + Online EXP	−0.91	.177	0.05	.901
EDI-P change^b	0.49	.205	0.85	.013
EDI-P Pre*VR only	0.13	.109	0.02	.675
EDI-P Pre*Online PE+EXP	−0.09	.203	0.02	.706
EDI-P Pre*VR+Online EXP	−0.02	.814	0.04	.372
SIAS-6
Waitlist + Online PE^a	−0.11	.532	−0.16	.043
VR only	−0.58	.146	0.14	.363
Online PE+EXP	0.64	.078	−0.34	.041
VR + Online EXP	0.53	.179	−0.04	.833
EDI-P change^b	0.26	.200	0.46	.002
EDI-P Pre*VR only	0.07	.154	−0.01	.743
EDI-P Pre*Online PE+EXP	−0.07	.067	0.05	.006
EDI-P Pre*VR+Online EXP	−0.11	.009	0.05	.014
SPS-6
Waitlist + Online PE^a	−0.29	.117	−0.15	.108
VR only	−0.86	.035	0.32	.080
Online PE+EXP	0.85	.023	−0.29	.142
VR + Online EXP	0.38	.344	−0.04	.871
EDI-P change^b	0.26	.209	0.57	.002
EDI-P Pre*VR only	0.10	.034	−0.02	.306
EDI-P Pre*Online PE+EXP	−0.14	.000	0.06	.008
EDI-P Pre*VR+Online EXP	−0.11	.014	0.04	.105

Note: FU: Follow-up, PE = Psychoeducation, EXP = Exposure, PSAS = Public Speaking Anxiety Scale, SIAS − 6 = Social Interaction Anxiety Scale − 6, SPS = Social Phobia Scale − 6, EDI—P = Eating Disorder Inventory—Perfectionism, b = unstandardized regression coefficient.

^aThe reference group with intercept value.

^bChanges in EDI-P predicting the outcome changes within the Pre—Post and Post—Follow-up intervals.