摘要：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. Immunization reminder–recalls are widely recommended as a way to increase immunization uptake. 1–5 They may be particularly effective at providing cues to action when parents are unfamiliar with changes in vaccine recommendations. New additions to routine vaccine schedules (such as pertussis and meningococcal vaccines for adolescents 6 ) and interruptions in vaccine supply (such as those that occur during shortages 7 ) may leave parents unaware that their child is not fully immunized, making them ideal candidates for reminder–recalls. Low-income families, who are at high risk for limited health literacy, 8 may be at particular risk for not having needed immunizations. 9,10 Unfortunately, among low-income urban populations and adolescents, traditional mail or telephone reminder–recall interventions have had limited impact on immunization outcomes. 11–13 Cellular telephone technology provides a novel method for implementing reminder–recalls. Wireless telephone networks have penetrated 96% of the total US population. 14 In hard-to-reach low-income communities, wireless market penetration is especially high; thus, text messaging may be a particularly effective mechanism for delivering reminder–recalls in this population. 15–19 Families and patients seem interested in vaccine-related text messages, but the efficacy of reminder–recalls for pediatric or adolescent immunizations remains underexamined. 18,20–22 We conducted 2 independent, randomized studies to assess the feasibility and efficacy of text message reminder–recalls in an urban, low-income population. In the first study, Text4Health–Adolescents, we assessed the impact of text message reminder–recalls on young patients' return to their medical home for a needed routine vaccination. In the second study, Text4Health–Peds, we assessed the impact of using text messages to mobilize parents of children underimmunized for Haemophilus influenzae B (Hib) to attend special immunization sessions.
