Effect of mobile text message reminders on routine childhood vaccination: a systematic review and meta-analysis

Abstract

Background: The World Health Organization estimates that 29% of under-five mortality could be prevented with existing vaccines. However, non-consistent attendance for immunization appointments remains a global challenge to healthcare providers. Thus, innovative strategies are required to reach the last mile where technology could be effectively utilized to achieve better compliance with children immunization schedules. Therefore, the aim of the review was to systematically collect and summarize the available evidence on the effectiveness of text message reminders on childhood vaccination.

Methods: This review was conducted according to a priori published protocol on PROSPERO. A systematic literature search of databases (PubMed/MEDLINE, EMBASE, Cochrane/Wiley library, and Science direct) was conducted. Eligibility and risk of bias assessments were performed independently by two reviewers. PRISMA flow diagrams were used to summarize the study selection process. Taking into account the level of heterogeneity, a random effects model was used and risk ratios with their 95% CI were used to present the pooled estimates. To investigate the sources of heterogeneity, subgroup analysis and meta-regression analysis were also considered. In this review, publication bias was assessed statistically using Harbord test.

Results: A total of 1771 articles were searched. Out of those 1771 articles, 558 duplicated articles were removed. About 1213 articles were further screened, and finally, ten articles met the inclusion criteria. The meta-analysis showed that there is a significant effect of text message reminders on childhood vaccination coverage (RR = 1.11; 95% CI 1.05-1.17) with a moderate level of heterogeneity (I² = 64.3%, P = 0.003). The results from the Harbord test suggested that there is no evidence for publication bias (P = 0.340).

Conclusion: This review highlights the potential benefits of incorporating mobile text message reminders into the standard management of childhood immunizations, especially in low- and middle-income countries. The frequency and timing of the text message reminders are also crucial in determining the effectiveness of text message reminders. Hence, mHealth interventions deserve more attention as a potential innovation to improve healthcare programs.

Systematic review registration: PROSPERO CRD42017074230.

Keywords: Immunization; Text message; Vaccination; mHealth.

Fig. 1

PRISMA flow diagram representing the study selection process [21]

Fig. 2

Forest plot showing the pooled estimate and level of heterogeneity

Fig. 3

Risk of bias assessment for the included studies

Fig. 4

Subgroup analysis by countries’ income status

Fig. 5

Subgroup analysis by timing of the last text message reminder

Fig. 6

Subgroup analysis by number of messages for a single schedule

Fig. 7

Outputs of meta-regression analysis

Fig. 8

Funnel plot to assess publication bias

Fig. 9

Outputs of the Harbord test to assess publication bias

Fig. 10

Assessment of certainty of evidence using GRADEpro software