Table 1.

Inter-item correlations, item-total correlations and Cronbach’s alphas for the new scales (Study 2).

	Polonium 210 version (n = 506)			Carbon monoxide version (n = 507)			Anthrax version (n = 506)
Scale (number of items)	Cronbach’s alpha	Mean corrected item-total correlation (minimum, maximum)	Mean inter-item correlation (minimum, maximum)	Cronbach’s alpha	Mean corrected item-total correlation (minimum, maximum)	Mean inter-item correlation (minimum, maximum)	Cronbach’s alpha	Mean corrected item-total correlation (minimum, maximum)	Mean inter-item correlation (minimum, maximum)
Mystery (4)	0.85	0.69 (0.57, 0.72)	0.58 (0.47, 0.70)	0.83	0.67 (0.57, 0.71)	0.55 (0.43, 0.68)	0.80	0.61 (0.48, 0.68)	0.50 (0.40, 0.61)
Serious health effects (6)	0.84	0.63 (0.59, 0.70)	0.48 (0.39, 0.59)	0.84	0.62 (0.58, 0.67)	0.47 (0.37, 0.58)	0.82	0.59 (0.56, 0.62)	0.43 (0.36, 0.51)
Hidden health effects (5)	0.70	0.47 (0.41, 0.55)	0.33 (0.19, 0.43)	0.85	0.66 (0.57, 0.69)	0.53 (0.45, 0.62)	0.80	0.58 (0.55, 0.66)	0.44 (0.34, 0.50)
Difficult to spot exposure (3)	0.72	0.54 (0.50, 0.59)	0.46 (0.39, 0.52)	0.65	0.47 (0.43, 0.52)	0.40 (0.34, 0.46)	0.67	0.49 (0.43, 0.56)	0.40 (0.31, 0.48)
Difficult to discriminate symptoms (3)	0.70	0.52 (0.43, 0.58)	0.45 (0.36, 0.57)	0.71	0.54 (0.47, 0.60)	0.47 (0.39, 0.57)	0.66	0.48 (0.32, 0.53)	0.40 (0.32, 0.53)
At-risk groups (4)	0.94	0.86 (0.82, 0.90)	0.80 (0.75, 0.88	0.92	0.81 (0.71, 0.88)	0.74 (0.65, 0.87)	0.94	0.86 (0.80, 0.90)	0.80 (0.73, 0.87)