Text Message Reminders Could Improve Vaccination Rates, Study Suggests

Text messaging has the potential to improve vaccination rates in low-income urban settings, says a study recently published in JAMA: The Journal of the American Medical Association (JAMA).

In a randomized, controlled trial involving more than 9,000 children and adolescents ages 6 months to 18 years, parents of children randomized to the intervention group received as many as five weekly immunization registry-linked text messages that provided educational information and instructions regarding Saturday immunization clinics. Participants in the study, which was conducted during the 2010-11 influenza season, were primarily minorities, 88 percent were publicly insured, and 58 percent were from Spanish-speaking families.

The authors predicated their research, in large part, on data from a number of studies that examined the prevalence of mobile device use among various patient populations, including one that suggests a significant proportion -- 92 percent -- of low-income families have mobile phones. Of that proportion, 96 percent are able to receive text messages.

Although the overall influenza immunization rate in the JAMA study population remained relatively low, the authors acknowledge, "a text messaging intervention, compared with usual care, was associated with an increased rate of influenza vaccination."

"The intervention effect was greater in the subgroup analysis accounting for delivery of text messages, lending support to the inference that text messaging was effective in promoting the behavioral changes leading to increased vaccination," they say. "Using text messaging (especially when linked with EHRs [electronic health records] or registries) to identify and notify large patient populations in need of vaccination could be an efficient means for improving influenza vaccination rates in adults, as well as children and adolescents."

The study points out that text messaging to increase vaccination coverage has many strengths, including the ability to reach large populations at a relatively low cost.

"Once the system is set up, the only variable cost is the sending of the text messages, which, even using commercial platforms, usually cost pennies per message," the authors say. "Therefore, depending on the size of the population, even amortizing upfront and monitoring costs, text messaging is inexpensive on a per-individual basis."

The technology also can be linked to EHRs easily using common software packages, thus, greatly expanding the ability to direct each message at a carefully specified group.

"By using such linkages, patients needing vaccination can be rapidly identified and automatically notified," say the authors. "Text messages also may be targeted to selected populations, as well as tailored based on age or risk factors such as asthma. In addition, text messaging may be particularly useful for notifications that are more urgent because unlike postal mailings, they are received immediately after being sent."

It's conceivable that the use of text messaging could readily be expanded to include widespread transmission of other types of health messages, as well, research has suggested. In part, that's because early release data from the CDC's National Health Interview Survey (page 11 of 14-page PDF; About PDFs) indicate that the percentage of adults and children living in wireless-only households increased at a steady rate between 2004 and 2007 (the time period covered by the survey).