Outcome of Reminder Text Messages Intervention on Completion of Routine Immunization in Rural Areas, Nigeria

"This study shows that sending one-way reminder text SMS messages to mothers of infants with phone ownership promotes higher full and timely completion of routine childhood immunization."

Completion of routine immunisation for infants has been a challenge in Nigeria, and strategies implemented to promote immunisation coverage, such as National Immunisation Days (NIDS) and Immunisation Plus Days (IPDs) set aside to strengthen the fight against polio, have yielded limited success. One alternative proposed is the use of reminder short message service (SMS), or text, messages to mobilise mothers of infants. This study investigated the effect of reminder SMS sent to mothers in rural communities on full and timely completion of routine childhood immunisation.

The study was conducted in 6 states and the Federal Capital Territory (FCT) between November 2017 and May 2019. Two rural Local Government Areas (LGAs) from each state, including 2 area councils from the FCT, were randomly selected and assigned to the intervention and control groups. Mothers (n=3,500) of infants aged 0-2 months attending immunisation clinics in primary healthcare centres (PHCs) in the 14 LGAs across the 6 states and the FCT and who owned at least 1 mobile phone during the period were randomly enrolled in the study.

The design of the reminder text messages was based on focus group discussions (FGDs) with mothers at PHCs, supplemented with suggestions from questionnaires. First developed in English, the messages were translated to Yoruba, Ijaw, Hausa, and Igbo languages and focused on the following: need to keep the next routine immunisation appointments, benefits of keeping routine immunisation appointments, benefits of timely and full completion of all basic routine immunisations, the consequences of refusal/non-completion of all basic routine immunisations on children's health, and locations of healthcare facilities with routine immunisation services.

The messages were sent 3 times per week to the mobile phones of mothers of infants in the intervention group and their significant others (relatives named by mothers) for 10 months using a bulk SMS account. At the end of the 5th month, research assistants visited the mothers' residence to verify that their house addresses and telephone numbers had not changed.

A mixed-method of data collection was used. Forty-two FGDs were conducted (3 FGD sessions per LGA) among consenting mothers of infants to collect data on their perceptions on immunisation and use of reminder messages. In addition, 28 key informant interviews (KIIs) were conducted among healthcare workers in the PHC facilities where the study was conducted (2 healthcare workers per LGA). A validated semi-structured questionnaire was used to measure immunisation knowledge, attitude, and reported and actual vaccines received. Also, an observational checklist was used to document all childhood routine immunisations from the index child immunisation card.

Adherence to routine immunisation appointment dates and completion of all immunisations was higher in the intervention group (76.0%) compared with the control (73.3%). A significant association between adherence to appointment dates and completeness of routine immunisation vaccine was found. The intervention group had a significantly higher completion rate for measles and yellow fever vaccines (55.3%; 75.9%) compared with the control group (26.8%; 23.9%); a similar pattern was seen for the oral polio vaccine (OPV).

Qualitative findings revealed positive feedback by intervention-group mothers, who said the SMS messages increased their awareness of immunisation dates and influenced their completion of the immunisations; they advocated for the continuation of this programme. Frontline healthcare workers shared similar reactions, with one nurse saying, "One of my expectations...is that people should come out for the immunisation programme, they really came out. They are even happy; they showed us the text messages."

Concluding that interventions using reminder SMS can enhance infant immunisation uptake, the researchers recommend scale-up and integration into the health system to increase national immunisation coverage.