Randomized controlled trial of a brief dyadic cognitive-behavioral intervention designed to prevent PTSD

Figures & data

Fig. 1 Flow chart of the study participants.

Note. Several randomized participants were lost before baseline, most of them did not return their baseline symptom assessment and/or failed to find a time to meet the therapist in a timely manner. The intent to treat sample completed at least two symptom assessments and received at least one intervention session. Protocol violation in the control group entailed the following exclusion criteria : initiating trauma-related court litigation in one case and a loss of consciousness undiagnosed at the time of recruitment in two cases. Protocol violation in the intervention group entailed coming alone to the dyadic intervention and being diagnosed with a terminal illness during the study.

Table 1 Socio-demographic data: intent-to-treat population

	Group
	Treated (n=37) M (SD)	Untreated (n=37) M (SD)	df	t	p
Age	37.97 (12.58)	34.68 (9.16)	72	1.29	0.20
Peritraumatic distress1	22.70 (8.08)	23.11 (7.40)	72	0.23	0.82
Peritraumatic dissociation2	23.19 (6.87)	21.92 (7.59)	72	−0.75	0.45
Injury severity3	7.62 (6.74)	6.54 (5.00)	72	−0.78	0.44
Negative support4	23.35 (8.27)	24.24 (8.95)	71	0.44	0.66
	n (%)	n (%)	df	χ2	p
Annual household income					0.636
Up to $15,000 CAD	3 (9%)	7 (20%)
$15,001–30,000	8 (22%)	7 (20%)
$30,001–50,000	12 (33%)	11 (31%)
$50,001–70,000	5 (14%)	6 (17%)
$70,001–90,000	4 (11%)	3 (9%)
$90,001 and above	4 (11%)	1 (3%)
Undisclosed5	1	2
Gender			1	1.96	0.16
Female	20 (54%)	14 (38%)
Male	17 (46%)	23 (62%)
Ethnicity			1	0.11	0.74
Caucasian	32 (86%)	31 (84%)
Other	5 (14%)	6 (16%)
Marital status			1	1.26	0.26
Married/living together	25 (69%)	26 (81%)
Other	11 (31%)	6 (19%)
undisclosed5	1	5
Education level			1	2.26	0.13
College graduate or less	24 (65%)	29 (81%)
Some university and more	13 (35%)	7 (19%)
Undisclosed5	N/A	1

1 Peritraumatic Distress Inventory;

2 Peritraumatic Dissociative Experience Questionnaire;

3 Injury Severity Score;

4 Social Constraints Scale;

5 excluded from the statistical test;

6 Fisher's exact test.

Table 2 Brief and early dyadic intervention summary

Protocol component	Description
Orientation	Purpose of the meeting: to share some of their reactions to the traumatic event and to anticipate potential problems and solutions during recovery.
Common reactions	Description and normalization of a wide variety of emotional or physical responses to trauma.
Importance of disclosing	Introduction and reinforcement of the idea that disclosing traumatic event-related thoughts and feelings to the dyadic therapy partner is a pivotal aspect of recovery.
Understanding avoidance	Discussion about the normal tendency to avoid distressing feelings and the negative impact of inhibiting disclosure.
Do's and don'ts	Ways of initiating disclosure, providing support, and responding to social constraints are discussed.
Motivational interview	Pros/cons of discussing traumatic event-related thoughts are examined as an attempt to instill motivation for disclosure and processing.
Discussion	Feedback elicited from the trauma survivor and the dyadic partner about what they have heard, disagreements and concerns they might have.
Referral information	Identify times when professional help should be sought.
	Referral information is given.
Summary	Review of the major points covered during the intervention.
Written material	Handouts reviewing the take-home messages of the meeting are provided.

Fig. 2 Self-reported mean PTSD symptom scores across time for the two study groups according the IES-R.

Table 3 Means and standard deviation of IES-R for every measurement time: intent-to-treat and per-protocol samples

Group	Pre-intervention M (SD)	p 1	Mid-intervention M (SD)	p 1	Post-intervention M (SD)	p 1
Intent-to-treat
Untreated (n=37)	36.01 (19.90)	0.98	35.77 (21.27)	0.15	29.90 (18.38)	0.04
Treated (n=37)	35.64 (20.25)		26.82 (18.33)		21.73 (18.90)
Per-protocol
Untreated (n=32)	35.48 (18.64)	0.94	34.95 (20.47)	0.18	30.32 (17.95)	0.05
Treated (n=34)	35.25 (19.07)		25.99 (16.29)		22.74 (18.94)

Pre-intervention assessment was conducted 10 days post-trauma; the first intervention was conducted 21 days post-trauma; the mid-intervention assessment was conducted immediately before the second session, 35 days post-trauma; the post-intervention assessment was conducted 3 months post-trauma.

1 p-Value resulting from contrasts analysis on the interaction term time*group within the mixed-model ANOVA (repeated-measure) performed on the square root of the IES-R measurement.