Implementing SMS Reminders for Routine Immunization in Northern Nigeria: A Qualitative Evaluation Using the RE-AIM Framework

"...SMS reminders in local languages could improve vaccination demand and uptake in resource-constrained settings due to their perceived importance and impact."

Evidence has shown that reminder and recall systems can improve health-seeking behaviour in vaccination. Mobile phone text messaging, also known as short message service (SMS), is a cost-effective method of disseminating health information and reminders. Using the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework, this study qualitatively assessed the impact of a SMS reminder intervention implemented in Kebbi State, Northwest Nigeria. The findings may guide and inform future SMS reminder interventions to improve childhood immunisation uptake in low- and middle-income countries (LMICs).

The Immunization Reminder and Information SMS System (IRISS), also known as Tunatar da ni (meaning "Remind me" in the Hausa language), is a cloud-hosted customised registration and message scheduling application that provides automated registration and delivers one-way immunisation information via SMS. The application houses four databases: contact information, child data, health facility information, and a message library.

The researchers designed the project as a 2-arm cluster randomised controlled trial (RCT) to assess the IRISS intervention's impact on improving demand for and uptake of immunisation. Fourteen local government areas (LGAs) received the SMS intervention for one year between May 20 2019 and May 31 2020, while the remaining 7 LGAs did not receive the intervention. IRISS delivered immunisation information to the public and parents/caregivers in the 14 intervention LGAs in 3 ways:

1. General broadcasts: IRISS sent general broadcasts to 190,000 active subscribers every quarter to improve positive norms about vaccination. The broadcasts contained informative messages about immunisation, prompting the recipient to opt-in to the IRISS e-registry for more information. Individuals who responded to general broadcasts were called "leads" and scheduled for the weekly targeted broadcasts.
2. Targeted broadcasts: IRISS sent two targeted broadcasts every week. Every Thursday, IRISS sent messages on immunisation benefits to 3,924 leads, 1,010 community gatekeepers (district heads, village heads, Mai-ungwas, imams), and 406 health workers. Every Sunday, details about immunisation days at the nearest health centre are sent to 1,010 community gatekeepers to pass on to their communities and congregations using existing structures. Within the intervention period, IRISS sent 160,428 and 15,150 targeted broadcasts on the benefits of immunisation and health facility schedules, respectively.
3. Individualised/personalised reminders: 21,906 vaccine-age children (approximately 61% of the intended population) were registered into the IRISS application. During the intervention period, IRISS sent 36,722 individualised reminders to parents/caregivers a day before their child's immunisation due dates.

IRISS disseminated all messages in the local Hausa language.

In June 2020, the researchers conducted 14 focus group discussions, 13 in-depth interviews, and 20 key informant interviews among 144 purposively selected participants from 5 LGAs of Kebbi State. Most (124, or 86%) were community members, and 99 (69%) were males. Their ages ranged from 19 to 77 years. For analysis, the researchers used a deductive approach to develop preliminary codes based on the RE-AIM framework and an inductive approach to generate themes that emerged from the interviews.

The results are shared in line with the RE-AIM framework. In brief:

• Reach: Most participants from the intervention LGAs received IRISS messages such as (i) a reminder of their child's vaccine due dates on their mobile phones or via proxy, (ii) a message on the immunisation schedule of the nearest facility, (iii) a message on the importance of vaccination, and (iv) a message on COVID-19. (Although the SMS reminder dissemination on immunisation ended in May 2020, the Nigerian Center for Disease Control (NCDC) used the IRISS application to send messages on COVID-19 preventive measures in the Hausa language across the 21 LGAs between June 5 and July 31 2020.) The key facilitators of involvement in the IRISS intervention were its perceived importance in reminding and educating community members on the importance of immunisation and satisfaction with the message content, especially the health facility day and operation time accuracy. Despite low phone ownership and literacy levels, involving trusted stakeholders in the community, such as the health workers who served as proxies for receiving the SMS for both community gatekeepers and parents, encouraged participation.
• Effectiveness: Many participants noted that personalised messages reminded caregivers, especially those who were busy, and prompted them to go for vaccination. Receiving IRISS messages also increased awareness and knowledge about vaccination and triggered discussions about immunisation in the community. The IRISS intervention appealed to health workers and programme managers because it reduced their workload and served as a performance monitoring tool to track immunisation and intervention defaulters.
• Adoption: Policymakers adopted the intervention because it aligns with the state's priority to improve immunisation coverage. In fact, decision-makers expressed willingness to scale up IRISS to the remaining 7 LGAs, given the perceived impact.
• Implementation: The most frequently cited implementation barriers were low mobile phone ownership, especially among rural dwellers, and the inability to read text messages due to low literacy. Community members agreed to have educated ones receive the SMS reminder and the uneducated get the messages via phone calls or town announcers. (For example, when informed by the health workers, the community gatekeepers used town announcers to convey messages on scheduled immunisation services in the nearest health facility.) Incorporating phone calls or Robocalls in SMS reminder applications could be a simpler alternative for those who cannot read and do not know how to open text messages.
• Maintenance: State decision-makers noted that support for the intervention's sustainability depends on the available data to show its impact on improving coverage and affordability by the state government.

In short, this study found that the IRISS intervention served as a reminder, prompted vaccination visits, increased awareness and knowledge about vaccination, and sparked immunisation discussions among community members. Among the key factors that encouraged participation at the community level were health workers' involvement in supporting IRISS registration and sensitisation. These individuals are trusted stakeholders who influenced the acceptability of a vaccination reminder intervention in Kebbi State. Community members' desire to participate in the IRISS intervention due to its perceived impact aligns with the state decision-makers and service providers.

The researchers conclude that "the IRISS automated one-way reminders in local languages could improve vaccination demand and uptake in resource-constrained settings due to its perceived importance and impact....Targeted interventions are required for the uneducated and those without access to mobile phones to benefit from the intervention."