Table 3.

Process measures and self-reported influenza vaccinations for portal message recipients.

Action	Portal users, n (%)
Randomized	19,506
Message senta	19,479 (100)
Logged in to patient portal	13,862 (71.2)
Opened message	10,112 (51.9)
Responded to “Have you received a flu vaccination on or after August 1, 2015?”	2570 (13.2)
Reported receiving a flu vaccination	386 (2.0)
Responded to “Do you plan to get a flu vaccination this flu season?”	2176 (11.2)
Reported that they planned to get a flu vaccination	1814 (9.3)

^a27 patients were no longer portal users by the time we sent the messages (due to change in medical record numbers, invalid patient portal IDs, etc).