Table 2.

Results of reliability analyses.

		TBI sample				General population sample				Original English version1
Scale	Item	Cronbach’s ɑ	McDonald’s ɷ	Cronbach’s ɑ if item omitted	CITC	Cronbach’s ɑ	McDonald’s ɷ	Cronbach’s ɑ if item omitted	CITC	Cronbach’s ɑ
Physical	Headache	0.79	0.83	0.78	0.45	0.85	0.86	0.84	0.51	0.81
	Nausea			0.75	0.65			0.83	0.58
	Balance problems			0.76	0.61			0.82	0.66
	Dizziness			0.76	0.62			0.82	0.65
	Blurred vision			0.75	0.65			0.83	0.57
	Feeling slowed down			0.76	0.56			0.83	0.57
	Sensitivity to light			0.79	0.42			0.83	0.58
	Sensitivity to noise			0.77	0.55			0.84	0.52
Emotional	Irritability	0.69	0.73	0.66	0.55	0.66	0.68	0.64	0.42	0.62
	Sadness			0.66	0.56			0.48	0.53
	Nervousness			0.44	0.74			0.56	0.47
Cognitive	Difficulty thinking clearly	0.73	0.80	0.65	0.66	0.79	0.84	0.70	0.66	0.84
	Difficulty concentrating			0.70	0.57			0.74	0.57
	Difficulty remembering			0.69	0.57			0.77	0.52
	Thinking more slowly			0.65	0.67			0.72	0.61
Fatigue	Fatigue	0.74	0.74	-	-	0.76	0.76	-	-	0.79
	Drowsiness			-	-			-	-
Total		0.90	0.91	-	-	0.89	0.90	-	-	0.90

¹Values obtained from the original validation study by Sady et al. (11). CITC, corrected item-total correlations. The values printed in bold are within the permissible cut-off values (Cronbach’s ɑ and McDonald’s ɷ: ≥ 0.70, Cronbach’s ɑ if item omitted does not exceed Cronbach’s ɑ; CITC: ≥ 0.30). Cronbach’s ɑ if item omitted and CITC are reported for scales with k > 2 items.