Table 2. Change in engagement rate by Facebook post characteristic, 2014–2016.

Post characteristic	Change in engagement rate (% points)	95% CI	P value*
Post campaign vs. non
Campaign—Bring Your Brave	−0.25	(−0.69, 0.19)	0.27
Campaign—Know:BRCA	0.37	(−0.41, 1.15)	0.35
Not campaign	Referent	Referent	Referent
Post type
Photo	0.90	(0.47, 1.33)	<0.0001
Video (including YouTube links)	−0.36	(−1.15, 0.42)	0.37
Status or link	Referent	Referent	Referent
Time of day posted
12:00–7:59 am	−0.07	(−0.88, 0.75)	0.87
8:00–9:59 am	−0.73	(−1.56, 0.09)	0.080
10:00–11:59am	−0.64	(−1.44, 0.16)	0.12
12:00–1:59 pm	−0.65	(−1.52, 0.22)	0.14
2:00–5:59 pm	Referent	Referent	Referent
6:00–9:59 pm	−0.81	(−2.91, 1.29)	0.45
10:00–11:59 pm	N/A	N/A	N/A
Year posted
2014	Referent	Referent	Referent
2015	−1.43	(−1.86, −1.00)	< 0.0001
2016	−2.46	(−3.10, −1.83)	< 0.0001

*, Wald Chi-square. N/A, not applicable.