Does the fear avoidance model explain persistent symptoms after traumatic brain injury?

Figures & data

Table 1. Patient characteristics.

	TBI (n = 48)			mTBI (n = 31)			Moderate to severe TBI (n = 17)
Variables	n	Value	Data range	n	Value	Data range	n	Value	Data range
Gender, % male		47.9			35.5			70.9*
Age in years, mean (SD)		45.5 (15.6)	[16–78]		46.3 (14.1)	[16–78]		44.2	[20–76]
Education level, mean (SD)	46	5.4 (1.0)	[3,4,5,6,7]	30	5.5 (0.9)	[4,5,6,7]	16	5.1 (1.0)	[3,4,5,6,7]
Premorbid work status	37			28			9
% > 24h paid work		59.4			67.9			33.3
% ≤ 24h paid work		10.8			10.7			11.1
% no paid work		29.7			21.4			55.6
Current work status	37			28			9
% > 24h paid work		24.3			28.6			11.1
% ≤ 24 paid work		32.4			32.2			33.3
% no paid work		43.2			39.3			55.6
Time since injury in months, median (IQR)		34.0 (53)	[2–373]		30.0 (45)	[2–126]		52.0 (56)	[4–373]
Cause of injury
Traffic accidents, %		45.8			45.2			47.2
Sport, %		14.7			16.2			11.8
Violence, %		10.4			6.5			17.6
Falls, %		29.2			32.3			23.5
Cognitive disorders % yes	31	80.6		17	76.5		14	85.7
Duration multidisciplinary treatment in months, mean (SD) or median (IQR) in case of skewness		5.0 (10)	[0–32]		5.0 (9)	[0–32]		8.5 (8.2)	[0–26]

Notes. IQR Interquartile Range. The mTBI group forms a subgroup of the TBI group. The TBI group consists of 48 patients, of which 31 are considered mild. If applicable, sample size deviations due to missing data are mentioned separately. Significant differences between ‘mild’ and ‘moderate to severe’ TBI group are marked. * p < 0.05.

Table 2. Prevalence of post-concussion symptoms (%).

Post-concussion symptom (RPQ)	TBI (n = 48)	mTBI (n = 31)	Moderate to severe TBI (n = 17)
Headaches	64.6	77.4	41.2*
Dizziness	58.3	61.3	52.9
Nausea	25.0	38.7	0.0**
Increased sensitivity to noise	70.8	80.6^5	52.9*
Sleep disturbances	54.2	54.8	52.9
Fatigue	85.4^2	93.5^1,2,3	70.6^4,5*
Irritability	77.1^5	77.4	76.5^2,3
Feeling depressed/teary-eyed	62.5	64.5	58.8
Feeling impatient or frustrated	75.0	74.2	76.5^2,3
Forgetfulness	83.3^3	93.5^1,2,3	64.7*
Reduced ability to concentrate	91.7^1	93.5^1,2,3	88.2^1
Slowing of thought processes	81.3^4	87.1^4	70.6^4,5
Blurred vision	29.2	29.0	29.4
Increased sensitivity to light	39.6	51.6	17.6*
Double vision	18.8	19.4	17.6
Feeling agitated/restless	58.3	61.3	52.9

Notes. RPQ Rivermead Post-Concussion Symptoms questionnaire. Top 5 ranking of most reported symptoms is provided in superscript. Significant differences in proportion between patients with ‘mild’ and ‘moderate to severe’ TBI are marked. * p < 0.05, ** p < 0.01.

Table 3. Correlations among and descriptive statistics of all measures.

	TBI (n = 48)			mTBI (n = 31)			TBI (n = 48)				mTBI (n = 31)
Variables	M (SD)	Data range	%I	M (SD)	Data range	%I	RPQ	PCS-CS	FMA	HADS	RPQ	PCS-CS	FMA	HADS
Post-concussion symptoms (RPQ)	30.58 (14.69)	0–60	92	33.32 (15.16)	0–60	90	-	0.63**	0.54**	0.63**	-	0.69**	0.59**	0.65**
Catastrophizing (PCS-CS)	15.96 (11.82)	0–44	10	17.39 (12.82)	0–44	16	-	-	0.34*	0.63**	-	-	0.37*	0.63**
Fear avoidance (FMA)	35.46 (8.87)	18–61	35	34.13 (8.05)	18–61	29	-	-	-	0.45**	-	-	-	0.44**
Depression (HADS-D)	6.45 (4.29)	0–17	42	6.90 (4.38)	0–17	45	-	-	-	-	-	-	-	-

Notes. RPQ Rivermead Post-Concussion Symptoms questionnaire, PCS-CS Post-Concussion Symptoms Catastrophizing Scale, FMA Fear of Mental Activities scale, HADS-D depression subscale of the Hospital Anxiety and Depression Scale, %I Percentage of participants with an impairment as defined by cut-off scores according the scoring manual (see method section). * p < 0.05, ** p < 0.01.

Figure 1. Fear avoidance model in patients with TBI (n = 48).

Notes. Values shown are Pearson correlations and based on cross-sectional data. * p < 0.05, ** p < 0.01.

Figure 2. Fear avoidance model in patients with mTBI, a sub-group (n = 31).

Notes. Values shown are Pearson correlations and based on cross-sectional data. ** p < 0.01.