Correction

Figures & data

Table 3. Descriptive statistics (M, SD) and Internal consistency (Cronbach’s α) for the standard scores and symptom validity indicators on two postconcussion symptom questionnaires (RPQ, NSI).

	Experimental condition
Variable	Control n = 103	MS n = 92	BMS n = 103	Total N = 298	Cronbach’s α
mRPQ, total	18.77 (12.29)	32.89 (20.82)	61.32 (29.47)	37.84 (28.42)	.98
95% CI	16.40-21.14	28.64- 37.14	55.63 − 67.01
Standard Symptoms Subscale (SS)
Average score	1.05 (0.63)	1.64 (0.87)	2.64 (1.05)	1.78 (1.10)
Total score	16.78 (10.07)	26.18 (13.99)	42.24 (16.85)	28.48 (17.53)	.97
95% CI	14.84 − 18.72	23.32 − 29.04	38.99 − 45.49
Atypical Symptoms Subscale (AS)
Average score	0.13 (0.20)	0.45 (0.53)	1.27 (1.00)	0.62 (0.83)
Total score	1.99 (3.04)	6.71 (7.99)	19.08 (15.03)	9.35 (12.41)	.96
95% CI	1.40 − 2.58	5.08 − 8.34	16.18 − 21.98
Symptom Domain Scores (SDS), totals
Somatic	0.38 (0.88)	2.12 (2.77)	6.10 (5.27)	2.89 (4.25)	.89
Cognitive	0.39 (0.82)	1.91 (2.78)	6.32 (5.23)	2.91 (4.30)	.92
Affective	1.22 (1.90)	2.67 (3.17)	6.66 (5.30)	3.55 (4.41)	.86
mNSI
NSI, total	15.23 (10.53)	25.45 (17.16)	45.37 (24.01)	28.80 (22.11)	.98
Validity-10, total	4.46 (3.92)	10.02 (8.11)	18.99 (10.95)	11.20 (10.19)	.96
mBIAS, total	5.39 (1.11)	6.26 (2.69)	8.69 (4.45)	6.80 (3.39)	.91
Distractor Items, total	1.38 (1.57)	2.23 (3.05)	4.84 (4.18)	2.84 (3.46)	.85

Notes: N = 298. Control = honest responder; MS = mild TBI simulator; BMS = biased mild TBI simulator; RPQ = Rivermead Post-concussion Symptoms Questionnaire; mRPQ = modified Rivermead Post-concussion Symptoms Questionnaire; mRPQ Standard Symptoms Subscale (SS) scores are derived from standard (unmodified) RPQ items; mNSI = modified NSI (with embedded SVI items); NSI = Neurobehavioral Symptoms Inventory; Validity-10 = A SVI that is derived from the NSI items (Vanderploeg et al., 2014); mBIAS = mild brain injury atypical symptoms scale (Cooper et al., 2011); Distractor Items from the [Concussion] Risk Perception Questionnaire (Fedor & Gunstad, 2015).

Table 4. Intercorrelations between selected scores from the mRPQ and mNSI (Spearman’s Rho).

	ρ	p
mRPQ Standard Subscale (SS) and NSI	.93	<.001
mRPQ Atypical Subscale (AS) and
NSI Val-10	.84	<.001
mBIAS	.75	<.001
“distractor” items	.69	<.001
mBIAS and
mRPQ atypical somatic symptoms	.74	<.001
mRPQ atypical cognitive symptoms	.69	<.001
mRPQ atypical affective symptoms	.71	<.001

Notes: N = 298; mRPQ = modified Rivermead Post-concussion Symptoms Questionnaire (Windle & Sullivan, 2019); mNSI = modified Neurobehavioral Symptoms Inventory, with the modification comprising the addition of: a) mild brain injury atypical symptoms scale (mBIAS) items; (Cooper et al., 2011), and; b) “distractor” items from the [Concussion] Risk Perception Questionnaire (Fedor & Gunstad, 2015). NSI = Neurobeahavioral Symptom Inventory. Spearman’s Rho used because of breaches of normality. All correlations significant (Bonferroni-adjusted α of .007).