Table 3.

Model summary of the hierarchical stepwise regression analysis on predictors of the acceptance of stress management apps (N=141).

Model 1a	R	R 2	Adjusted R2	SE	Change in R2	Change in F (df1,df2)	P value
Step 1b	.32a	.10	.10	.98	.10	16.18 (1,139)	<.001
Step 2c	.38b	.14	.13	.96	.04	6.23 (1,138)	.01
Step 3d	.78c	.61	.60	.65	.46	161.04 (1,137)	<.001
Step 4e	.79d	.62	.61	.64	.02	6.26 (1,136)	.01

^aDependent variable: acceptance of mobile health (mHealth; behavioral use intention). Model 1 refers to the main model according to the statistical plan in distinction to post hoc analyses. (Models 2 and 3 as presented in Multimedia Appendix 2).

^bPredictors: (constant), mHealth app use (entered in block 1).

^cPredictors: (constant), mHealth app use, stress symptoms (block 1).

^dPredictors: (constant), mHealth app use, stress symptoms (block 1), attitude toward using mHealth (block 2).

^ePredictors: (constant), mHealth app use, stress symptoms (block 1), attitude toward using mHealth, skepticism/perceived risks (block 2). The UTAUT determinants (entered as block 3) added no further significant predictive contribution and were thus excluded.