Table 4.

Total number of days that the interventions were used (N=128).

Intervention use	Smartphone (n=43)	Diary (n=43)	Website (n=42)	P a
Total number of days intervention usedb
6 weeks (42 days), median (IQR)	36 (21-42)	29 (0-38)	15 (6-33)	.004
Completing every day, n (%)	14 (33)	8 (19)	3 (7)
6 months (184 days), median (IQR)	82 (28-172)	18 (0-37)	15 (7-45)	<.001
Completing every day, n (%)	7 (16 )	0 (0)	0 (0)
Completing 0 days/not returning paper diary, n (%)	1 (2)	31 (78)	3(7)

^a Significant difference between groups assessed by Kruskal-Wallis equality-of-populations rank test because adherence variable not normally distributed and not improved after log transformation; significant difference at P<.05.

^b A usage day is considered to be a day with ≥500 and ≤5000 kcal energy recorded.