Validation of a clinician-administered diagnostic measure of ICD-11 PTSD and Complex PTSD: the International Trauma Interview in a Swedish sample

Figures & data

Figure 1. Alternative models of the latent structure of ICD-11 PTSD and CPTSD symptoms.

PTSD, Posttraumatic stress disorder; DSO, Disturbances in self-organization; Re, Re-experiencing; Av, Avoidance; Th, Sense of current threat; AD, Affective dysregulation; NSC, Negative self-concept; DR, Disturbances in relationships.

Table 1. Descriptive statistics of the International Trauma Interview (ITI) and external variables.

	Full sample		No disorder		PTSD		CPTSD
	(N = 184)		(N = 144)		(N = 29)		(N = 11)
	Mean	SD	Mean	SD	Mean	SD	Mean	SD
ITI total	9.6	8.0	7.0	6.1	14.9	4.3	28.3	5.5
PTSD total	5.2	4.4	3.6	3.1	10.2	2.4	13.2	3.7
Reexperiencing	1.4	1.6	0.8	1.3	3.1	1.0	3.7	1.8
Avoidance	2.3	2.0	1.8	1.8	3.7	1.3	5.1	1.4
Sense of Threat	1.6	1.8	1.0	1.4	3.4	1.3	4.4	2.2
DSO total	4.3	4.9	3.4	4.2	4.7	3.6	15.1	3.2
Affect dysregulation	1.5	1.7	1.3	1.5	1.7	1.7	4.3	1.9
Negative self-concept	1.6	2.3	1.2	1.9	1.7	2.1	6.6	1.6
Disturbances in relationships	1.3	1.8	1.0	1.6	1.3	1.6	4.3	1.7
IES-R
Total	30.9	21.3	25.2	18.9	48.9	16.8	56.2	15.2
Intrusion	11.8	8.1	9.8	7.3	18.1	6.4	21.6	6.2
Avoidance	11.8	8.7	10.0	8.3	18.1	6.7	18.6	6.5
Hyperarousal	7.2	6.4	5.4	5.4	12.6	5.6	16.0	4.9
SCL-27
Depression	5.5	3.7	4.8	3.5	7.2	3.9	8.9	3.2
Dysthymia	8.3	4.6	7.6	4.6	10.1	4.2	12.0	3.3
Vegetative	6.0	5.7	4.6	4.9	10.8	5.4	11.9	5.7
Agoraphobic	4.0	4.3	2.8	3.4	6.7	4.3	11.4	3.7
Social	8.3	3.8	7.5	3.5	9.8	3.9	13.0	3.3
Mistrust	4.1	4.0	3.3	3.6	6.6	4.3	8.3	3.6
ISI	15.4	7.1	14.1	6.7	18.6	6.9	23.2	3.7
AUDIT	6.2	5.9	6.0	6.1	6.3	5.7	8.1	2.8
DES	9.2	12.9	7.8	11.9	11.5	11.9	19.3	21.4
WHODAS	18.1	17.3	15.1	15.9	24.9	17.6	39.8	15.2
BBQ	49.7	22.1	52.3	22.3	47.3	17.4	23.5	8.2

PTSD, Posttraumatic stress disorder; DSO, Disturbances in self-organization; IES-R, Impact of Event Scale-Revised; SCL-27, Symptom Checklist-27; ISI, Insomnia Severity Index; AUDIT, Alcohol Use Disorder identification test; DES, Dissociative Experience Scale-taxon; WHODAS, WHO Disability Assessment Schedule 2.0; BBQ, Brunnsviken Brief Quality of Life Scale.

Table 2. Model fit statistics for the alternative models of the International Trauma Interview.

Models	χ^2	df	P	CFI	TLI	RMSEA	(90% CI)
1	199	54	.000	.903	.881	.121	(.103–.139)
2	51	39	.099	.992	.987	.040	(.000–.069)
3	133	48	.000	.943	.922	.098	(.078–.118)
4	64	47	.049	.989	.984	.044	(.003–.070)
5	73	50	.018	.985	.980	.050	(.021–.074)
6	83	50	.002	.978	.971	.060	(.036–.082)
7	92	53	.001	.974	.968	.063	(.040–.084)

Estimator = WLSMV; n = 182; χ², Chi-Square Goodness of Fit statistics; df, degrees of freedom; P = Statistical significance; CFI, Comparative Fit Index; TLI, Tucker Lewis Index; RMSEA (90% CI), Root Mean Square Error of Approximation with 90% confidence intervals; Best fitting model in bold.

Table 3. Standardized factor loadings (standard errors) for model 4.

First order	Re	Av	Th	AD	NSC	DR
Nightmares	.71 (.08)
Flashbacks	.60 (.07)
Internal avoidance		.73 (.07)
External Avoidance		.72 (.07)
Hypervigilance			.73 (.07)
Startle reactions			.80 (.07)
Long time to calm down				.45 (.10)
Feeling numb				.47 (.10)
Failure					.91 (.04)
Worthless					.96 (.03)
Cut-off from others						.90 (.04)
Difficult to stay close						.78 (.06)
Second order			PTSD			DSO
Re-experiencing (Re)			.95 (.11)
Avoidance (Av)			1.03 (.07)
Sense of current threat (Th)			.80 (.07)
Affective dysregulation (AD)						1.37 (.24)
Negative self-concept (NSC)						.86 (.05)
Disturbances in relationships (DR)						.94 (.06)

All factor loadings were statistically significant at P < .001.

Re, Re-experiencing; Av, Avoidance; Th, Sense of current threat; AD, Affective dysregulation; NSC, Negative self-concept; DR, Disturbances in relationships; PTSD = Posttraumatic stress disorder, DSO = Disturbances in self-organization.

Table 4. Standardized regression coefficients between PTSD and DSO and each external variable.

	Impact of Event Scale-Revised			Symptom Checklist-27
	Int	Avo	Hyper	Dep	Dys	Veg	Agora	Mis	Soc	ISI	AUDIT	DES	WHODAS	BBQ
Latent PTSD	.88***	.69***	.81***	.07	.16	.49***	.59***	.36**	.19*	.40**	.00	−.02	.25**	.08
Latent DSO	−.03	.06	.06	.65***	.58***	.28**	.17	.29**	.55***	.28**	.06	.53***	.43***	−.75***
Female	.09	.15*	.02	−.05	.04	.07	.08	.06	.06	−.02	−.08	.05	−.02	.02
Age	.21**	.05	.15*	.16*	.04	.10	.04	.01	−.09	.23	−.06	−.03	.04	−.04
Interpersonal event	−.22**	−.09	−.14*	−.04	−.10	−.07	−.04	.00	−.04	−.16	.21	−.50*	.00	.08
R^2	.62***	.52***	.61***	.42***	.44***	.43***	.49***	.40***	.59***	.39***	.07	.27***	.37***	.44***

The associations were adjusted for gender, age and event type.

PTSD, Posttraumatic Stress Disorder; DSO, Disturbances in Self-Organization; Int, Intrusion; Avo, Avoidance; Hyper, Hyperarousal; Dep, Depression; Dys, Dysthymic; Veg, Vegetative; Agora, Agoraphobic; Mis, Mistrust; Soc, Social phobia; ISI, Insomnia Severity Index; AUDIT, Alcohol Use Disorder Identification Test; DES, Dissociative Experience Scale-taxon; WHODAS, World Health Organization Disability Schedule 2.0; BBQ, Brunnsviken Brief Quality of Life Scale.

* P < .05, ** P < .01, *** P < .001.