TABLE 1.

Descriptive statistics for pre-test variables with Mann-Whitney tests for differences between participants who did and did not complete the full study.

Pre-test variable	Completed full study (N = 355)	Did not complete full study (N = 1260)	Mann–Whitney test
	M (SD)	M (SD)	Z	p	r
P Age	35.3 (12.4)	34.5 (12.1)	1.00	0.318	0.03
P DRF	42.8%(28.5%)	38.4%(28.0%)	2.34	0.019	0.06
P DC Lucid per month	1.1 (2.4)	1.5 (3.7)	0.53	0.593	0.01
P Lucid tech freq	0.4 (1.1)	0.3 (1.0)	2.17	0.030	0.05

P, pre-test variable.