Table 2.

Comparison of app usage outcomes from Google Analytics for participants and nonparticipants. Total: Aggregate count. Mean: Average per user. RR: rate ratio (exact Poisson test), with test for equal rates. Counts of audio files started and completed include both repeated usages of the same files and usages of different files by an individual.

Usage outcome	Participants (n=151)	Nonparticipants (n=96)	RRa (95% CI)	P value
	Total (mean)	Total (mean)
Opening the app	2912 (19.3)	1895 (19.7)	0.98 (0.92-1.04)	.43
Updated a quit date	29 (0.19)	18 (0.19)	1.02 (0.55-1.96)	>.99
Audio files started	2725 (18.0)	1625 (16.9)	1.07 (1.00-1.13)	.04
Audio files completed	2288 (15.2)	1315 (13.7)	1.11 (1.03-1.18)	.003

^aRR: rate ratio.