Feasibility of Implementing a Cellphone-Based Reminder/Recall Strategy to Improve Childhood Routine Immunization in a Low-Resource Setting: A Descriptive Report

"Reminder/recall systems are effective ways to improve immunization rates, but their feasibility in primary health care (PHC) settings in Nigeria has not been adequately evaluated."

This is a descriptive report of a cluster randomised controlled trial that evaluated the acceptability and adaptability of an immunisation reminder/recall system in an urban setting in Oyo State in southwest Nigeria. The 2013 Nigeria Demographic and Health Survey showed that only 25.8% of children aged 12-23 months in Oyo State were fully immunised with recommended routine vaccines, leading to outbreaks of vaccine-preventable diseases (VPDs). Effective and novel strategies are therefore being tested to enable the country to meet the World Health Organization (WHO)-recommended 95% level for the sustained control of VPDs and reduce under-five mortality.

For the study, 4 local government areas (LGAs) in Ibadan, Oyo State, Nigeria, were randomly assigned into a cellphone reminder/recall intervention group or a usual care control group. Within each LGA, PHC centres were purposively selected to participate in the study. In each PHC centre, mothers and their infants aged 0-3 months were enrolled into the 2 groups during the infants' first immunisation visit. Mothers (or other contact persons) in the intervention group received cellphone calls reminding them to take their child for scheduled immunisations. Follow-up of all the children lasted until the final scheduled immunisation visit for each child. The trial occurred between August 2012 and September 2013.

A total of 595 mothers/infants pairs (295 in the intervention group and 300 in the control group) participated in the study. Almost all mothers (n = 590, 99.2%) had access to their own cellphone or had access to a cellphone belonging to a significant other. Ninety-eight percent (n = 584) of all mothers were willing to receive immunisation reminder/recall phone calls.

Eighty-seven percent (n = 2,023) of all calls (n = 2,324) for the reminder/recall intervention went through to the recipients, and, of these calls, 1,948 (96.3%) were received. Immunisation compliance rate (the receipt of required number of doses of routine vaccines at the appropriate age at recommended interval) was 79.2% among the children in the intervention group and 46.4% in the control group (p < 0.001).

The researchers note that the majority of the calls made were for reminders about scheduled appointments rather than follow-ups for missed appointments. These results suggest that gentle reminders by health workers can boost immunisation compliance. Furthermore, the fear that the strategy may be costly appeared to be largely unfounded, as calls were relatively inexpensive (about US$.05 per call), and there was often no need to make a recall phone call for missed appointments for majority of the participants.

Although mothers received most calls, the reminder messages seemed to have been conveyed by other contact persons listed during enrollment. This finding suggests the importance of the existing family support system in Nigeria, which the researchers say needs to be strengthened because of the possible contribution of social support to positive child health outcome and health care outcomes in general.

In conclusion: "The use of electronic communication technology in public health interventions can improve clients' adherence and compliance to guidelines related to their treatment, health promotion and diseases prevention."