Objectives. We conducted 2 studies to determine the impact of text message immunization reminder–recalls in an urban, low-income population.
Methods. In 1 study, text message immunization reminders were sent to a random sample of parents (n = 195) whose children aged 11 to 18 years needed either or both meningococcal (MCV4) and tetanus–diphtheria–acellular pertussis (Tdap) immunizations. We compared receipt of MCV4 or Tdap at 4, 12, and 24 weeks with age- and gender-matched controls. In the other study, we compared attendance at a postshortage Haemophilus influenzae B (Hib) immunization recall session between parents who received text message and paper-mailed reminders (n = 87) and those who only received paper-mailed reminders (n = 87).
Results. Significantly more adolescents with intervention parents received either or both MCV4 and Tdap at weeks 4 (15.4% vs 4.2%; P < .001), 12 (26.7% vs 13.9%; P < .005), and 24 (36.4% vs 18.1%; P < .001). Significantly more parents who received both Hib reminders attended a recall session compared with parents who only received a mailed reminder (21.8% vs 9.2%; P < .05). After controlling for age, gender, race/ethnicity, insurance status, and language, text messaging was still significantly associated with both studies’ outcomes.
Conclusions. Text messaging for reminder–recalls improved immunization coverage in a low-income, urban population.