TABLE 3

Impact of Intervention Based on Enrollment Date: Receipt of Second Dose Influenza Vaccine by April 30, 2013, and by Day 42 Post Vaccination

% Receipt Second DoseDifference Versus Written Text Message ReminderDifference Versus Conventional Text Message Reminder
Absolute Difference, % (95% CI)RR (95% CI)Absolute Difference, % (95% CI)RR (95% CI)
Receipt by April 30
 Receipt of first dose before November 15
  Educational text message (n = 111)89.2% (99)P = .03412.6% (11.7–13.5)1.17 (1.03–1.32)10.6% (9.7–11.4)1.13 (1.01–1.27)
  Conventional text message (n = 117)78.6% (92)2.1% (1.2–2.9)1.03 (0.89–1.18)
  Written reminder only (n = 111)76.6% (85)
 Receipt of first dose after or on November 15
  Educational text message (n = 105)55.2% (58)P = .01318.2% (17.3–19.1)1.49 (1.11–2.01)1.5% (0.6%–2.5%)1.03 (0.81–1.32)
  Conventional text message (n = 108)53.7% (58)16.7% (15.7–17.6)1.45 (1.07–1.96)
  Written reminder only (n = 108)37.0% (40)
Receipt by day 42 post vaccination
 Receipt of first dose before November 15
  Educational text message (n = 111)49.5% (55)P = .00420.7% (19.8–21.6)1.72 (1.21–2.43)15.1% (14.2–15.9)1.44 (1.05–1.97)
  Conventional text message (n = 116)34.5% (40)5.7% (4.8–6.5)1.20 (0.81–1.76)
  Written reminder only (n = 111)28.8% (32)
 Receipt of first dose after or on November 15
  Educational text message (n = 105)37.1% (39)P = .04914.9% (14.0–15.9)1.67 (1.09–2.57)3.8% (2.9–4.7)1.11 (0.77–1.61)
  Conventional text message (n = 108)33.3% (36)11.1% (10.2–12.0)1.50 (0.96–2.33)
  Written reminder only (n = 108)22.2% (24)
  • Receipt by day 42 does not include participant who received the second dose too early and was not revaccinated. CI, 95% confidence interval; RR, relative rate.