Influenza Vaccine Text Message Reminders for Urban, Low-Income Pregnant Women: A Randomized Controlled Trial

摘要

Objectives. We evaluated the impact of influenza vaccine text message reminders in a low-income obstetric population. Methods. We conducted a randomized controlled trial that enrolled 1187 obstetric patients from 5 community-based clinics in New York City. The intervention group received 5 weekly text messages regarding influenza vaccination starting mid-September 2011 and 2 text message appointment reminders. Both groups received standard automated telephone appointment reminders. The prespecified endpoints were receipt of either pre- or postpartum influenza vaccination calculated cumulatively at the end of each month (September–December 2011). Results. After adjusting for gestational age and number of clinic visits, women who received the intervention were 30% more likely to be vaccinated as of December 2011 (adjusted odds ratio [AOR]?=?1.30; 95% confidence interval [CI]?=?1.003, 1.69 end of September: AOR?=?1.34; 95% CI?=?0.98, 1.85; October: AOR?=?1.35; 95% CI?=?1.05, 1.75; November: AOR?=?1.27; 95% CI?=?0.98, 1.65). The subgroup of women early in the third trimester at randomization showed the greatest intervention effect (December 31: 61.9% intervention vs 49.0% control; AOR?=?1.88; 95% CI?=?1.12, 3.15). Conclusions. In this low-income obstetric population, text messaging was associated with increased influenza vaccination, especially in those who received messages early in their third trimester. There are an estimated 226?000 hospitalizations annually in the United States caused by influenza, with 3000 to 49?000 deaths annually over the past 3 decades. 1,2 Pregnant women are at increased risk for influenza morbidity and mortality. 3 Although pregnant women represent only 1% of the US population, in the 2009 H1N1 pandemic, they had a disproportionately higher mortality risk. 4,5 Infants are also more likely than other age groups to experience influenza-related morbidity and mortality, but infants younger than 6 months of age are too young to be vaccinated. Vaccination during pregnancy helps to protect newborns both through passive transfer of immunity 6 and by “cocooning” the newborn from influenza exposure by vaccinating those in close proximity. 7 It is, therefore, strongly recommended that women receive influenza vaccination during pregnancy; those who are not vaccinated during pregnancy should be vaccinated in the postpartum period. 2,3 Women should be vaccinated early in the fall, as soon as the vaccine becomes available, to achieve protection before influenza begins circulating in the community. 3 Despite these recommendations, only 47% of pregnant women in the United States received the influenza vaccine in the 2011–2012 season. 8 Protection against influenza is especially important in low-income communities where the risk of influenza transmission is higher. 9 Text messaging has been successfully used to increase vaccination coverage in general pediatric and adolescent populations, as well as in an adult travel clinic. 10–14 Although pregnant women have demonstrated interest in text messages, 15,16 vaccine text message reminder-recalls have been limited in this population. Text messages can be used to remind women to be vaccinated against influenza, remind those who remain unvaccinated, and provide educational information regarding influenza and the vaccine. 15,17–19 Most adults in the United States have a cell phone, 20 and cell phone use is higher in lower income populations. 21 We assessed the impact of influenza vaccine-related text messages in low-income urban obstetric patients. We hypothesized that text messages would be more efficacious compared with usual care.