VANCOUVER, B.C. – Text message reminders are an effective strategy for increasing receipt and timeliness of influenza vaccination in children, and they work even better when they contain brief educational information, a randomized trial showed.
Historically, only about half of children needing a second dose actually get it, according to first author Dr. Melissa Stockwell of the department of pediatrics at Columbia University Medical Center, New York.
The average time at which that dose is received is twice the recommended 28 days. "So we clearly have a problem," she said at the annual meeting of the Pediatric Academic Societies.
Common reasons for failing to return for the second vaccine doses include forgetting to do so, and lack of knowledge that a second dose is needed or why.
The trial, called Flu2Text, was conducted among 660 low-income, urban children aged 6 months to 8 years who received the first of two doses of flu vaccine at community clinics affiliated with an academic medical center and whose parents had a cell phone that could receive text messages. In the groups randomized to messages, the messages were sent three times before the second dose was due, once on the due date, and once 2 weeks thereafter.
The results showed that the rate of receipt of the second dose of vaccine was 57% among children whose parents were given only usual care, consisting of a written reminder of the due date for the second dose. But it was 67% in a group sent conventional text messages, which reminded them to bring their child on the due date and gave clinic walk-in hours, and 73% in a group sent educational text messages, which included the same reminder, brief information, and the option to ask for more information about why timing was important, why two doses are needed, and the nature of adverse effects (P = .003).
The rate of timely receipt (defined in the trial as receipt of the second dose within 42 days of the first dose) was 27% with usual care, compared with 34% with conventional text messages and 44% with educational text messages (P = .001).
"Among young, low-income urban children, the addition of text message reminders was associated with increased receipt and timeliness of a second dose of flu vaccine," Dr. Stockwell said. "Embedding educational information did seem to impact its effectiveness, particularly in getting vaccines in a more timely fashion."
A session attendee wondered, "Did you ask in the postsurvey why some parents did not get the second dose despite the reminders?"
"Yes," Dr. Stockwell replied. "Some of it was a reaction. A lot of our population is convinced that the flu shot causes the flu. So some said, ‘My kid was really sick after the first dose, so I decided not to come back.’ That was the most common."
Another attendee commented, "The dose response is really quite striking. But even with the conventional texting, it looks like it is a little more effective than in past studies. ...The whole thing just seems to be a little better. What’s going on?"
"I think it’s because our previous studies looked at first dose, and this was looking at second dose. So these are families who have gotten past the sort of vaccine hesitancy and misperceptions about the flu vaccine – not everybody, but most of them. So you sort of take that whole part out, so now you are just sort of dealing more with not knowing they need a second dose or the effectiveness. That’s my guess as to why."
In additional study findings, none of the text messages was undeliverable, and only 0.5% of parents randomized to text messages opted to stop receiving them. In the educational text message group, 16% of parents responded to the interactive messages to get more information.
Overall, 98% of parents in the text message groups were very satisfied. The aspects they most commonly liked were the inclusion of a reminder, the provision of information, the quick nature of texting, and the perception that the messages demonstrated that the clinic cared about them.
Also, the majority credited the text message with having an impact on their child getting the second dose of vaccine (61%) and getting it sooner than they would have without the reminder (70%).
Study limitations included the inability to enroll 12% of otherwise eligible children whose families did not have a cell phone and the potential lack of generalizability to other settings, said Dr. Stockwell.
He disclosed an affiliation with the Pfizer Medical Education Group.