Table 2.

PROMIS Sleep Disturbance 6-item Scale Internal Consistency Data

Scale Cronbach’s α: .86
Inter-item correlation:.50
	Item Mean [SD]	Corrected Item-Total Correlation	Cronbach’s Alpha if Item Deleted
Quality Sleep	2.2 [.869]	.67	.83
Refreshing	2.2 [.844]	.57	.84
Problem with sleep	2.1[1.02]	.71	.82
Difficulty falling asleep	1.9 [1.11]	.65	.83
Restless	2.0 [1.10]	.65	.83
Tried hard to get to sleep	1.9 [1.13]	.63	.83