Text message language, all rounds
| Round 1 | Round 2 | Round 3 | |
| Control | No text | No text | No text |
| Intervention Group 1: Text Message Verbiage | Message A: Your child is due for a vaccine (not COVID). It is safe to come in! Call 718-XXX-XXXX tomorrow or schedule online. | Message C: This is a reminder to schedule your child’s routine vaccination appointment. Please call to schedule: 718-XXX-XXXX. | Message D and E: 18:00 Tuesday, 12 September 2022: Your child is due for a vaccine (not COVID). Schedule online (Link) now or call 718-XXX-XXXX tomorrow. 12:00 Thursday, 14 September 2022: We have reserved your child’s next vaccine; Call 718-XXX-XXXX or schedule online (link). |
| Intervention Group 2: Text Message Verbiage | Message B: Your child is due for a vaccine, not COVID. Vaccines prevent your child from getting sick. Call 718-XXX-XXXX or schedule online. | N/A | N/A |
N/A, not applicable.