Individual-Level Prediction of Exposure Therapy Outcome Using Structural and Functional MRI Data in Spider Phobia: A Machine-Learning Study

Table 1

Pretreatment sample description of posttreatment responders and nonresponders.

Variables	Posttreatment responders	Posttreatment non-responders	value
	Demographic characteristics at pretreatment
Gender (m/f)	13/90	12/75	n.s.
Site distribution	WÜ:54	WÜ:29	1.3-2
	MS:49	MS: 58
Age (SD)	26.6 (7.5)	30.4 (9.9)	3.6-3
Years of education (SD)	14.6 (3.0)	14.5 (3.0)	n.s.
Clinical characteristics at pretreatment
Age of onset spider phobia (SD)	7.2 (4.6)	6.4 (4.6)	n.s.
Comorbid depression, n (%)	3 (2.9)	3 (3.4)	n.s.
SPQ (SD)	20.8 (3.5)	19.9 (4.2)	n.s.
LSAS (SD)	22.4 (16.0)	26.1 (18.6)	n.s.
ASI-3 (SD)	14.6 (7.0)	16.2 (8.1)	n.s.
STAI trait (SD)	34.7 (8.4)	35.8 (8.2)	n.s.
BDI-II total (SD)	3.0 (3.6)	3.3 (3.9)	n.s.
UI-18 (SD)	37.5 (12.4)	39.9 (13.3)	n.s.
Promis-specific phobia (SD)	11.3 (8.4)	11.0 (8.9)	n.s.
FEAS anxiety (SD)	102.3 (13.5)	100.6 (10.8)	n.s.
FAS (SD)	83.6 (12.7)	83.3 (11.7)	n.s.
Final BAT distance (cm) (SD)	175.7 (61.4)	158.1 (69.2)	n.s.
Posttreatment
SPQ (SD)	13.2 (2.4)	17.8 (2.0)	<2.2-16
Follow-up
SPQ (SD)	12.2 (2.8)	15.3 (3.2)	1.5-10

Statistical tests were two-sided -test for continuous variables and chi-squared tests for categorical variables. WÜ: Würzburg; MS: Münster; SPQ: spider fear questionnaire; LSAS: Liebowitz Social Anxiety Scale; ASI-3: Anxiety Sensitivity Scale 3; STAI: State-Trait Anxiety Inventory; BDI-II: Beck Depression Inventory II; UI-18: Unsicherheitsintoleranz (intolerance of uncertainty) 18 scale; PROMIS: Patient-Reported Outcomes Measurement Information System (PROMISPHO: specific phobia); FEAS: Fragebogen zur Ekel und Angst vor Spinnen (questionnaire regarding disgust and fear of spiders); FAS: Fragebogen zur Angst von Spinnen (questionnaire regarding the fear of spiders); BAT: behavioural avoidance test.