Table 2.

Participant Demographic Characteristics in Each Experimental Condition and the Statistical Significance of Cross-Condition Comparisons

	Experimental condition
	Neutral (n=15)	DT (n=15)	DT-reduced (n=15)	p
Age (in years)
M	22.00	26.73	23.53	0.060
SD	3.00	7.04	5.11
Gender
Male	33.3%	40.0%	40.0%	0.910
Female	66.7%	60.0%	60.0%
Time since mTBI (in years)
M	2.52	3.76	5.88	0.079
SD	2.83	3.24	5.21
Years of Education (Completed)
Secondary School	73.3%	46.7%	60.0%	0.331
Bachelor Degree	13.3%	20.0%	20.0%
Diploma	13.3%	26.7%	6.7%
Masters	0.00%	0.00%	13.3%
PhD	0.00%	6.7%	0.00%
Injury cause
Sport-related	66.7	66.7	40.0	0.161
Non sport-related	33.3	33.3	60.0
Pre-threat (IPQ-R subscales)
Consequences
M	2.03	1.78	1.72	0.373
SD	0.57	0.73	0.62
Recovery timeline
M	2.09	2.10	1.74	0.276
SD	0.63	0.83	0.55
Effort (TOMM) Trial 2 score
M	50.00	50.00	49.93	0.165
SD	0.00	0.00	0.26
Understood test instructions (% passing)	-	46.67%	66.67%	0.269

N=45.

Cross-condition comparisons were performed using ANOVA tests for continuous variables and Chi-square tests for categorical tests. Significance evaluated at p=0.05 (2-tailed). Pre-induced threat (or participants understanding of the injury they had experienced) was assessed using the Illness Perception Questionnaire-Revised, IPQ-R⁴⁹, timeline and consequences subscales. The 6-item subscales are rated on a 5 point Likert scale, ranging from 1 (strongly disagree) to 5 (strongly agree); higher scores indicate more negative illness perceptions. Effort was assessed using the Test of Memory and Malingering (TOMM⁵⁰) and comprehension of instructions was assessed by determining whether the participants had read and understood the experimental instructions (i.e., summarize the instructions (qualitative; plus did you respond as per the instructions (yes/no).

DT, diagnosis threat; DT-reduced, diagnosis threat reduced; M, mean; SD, standard deviation; mTBI, mild traumatic brain injury; IPQ-R, Illness Perception Questionnaire-Revised.