Mobile Phone Text Message Reminders to Improve Vaccination Uptake: A Systematic Review and Meta-Analysis
University of Cape Town (Louw, Kalan, Engel); South African Medical Research Council (Hohlfeld, Engel)
"The findings of this systematic review highlight the simplicity and effectiveness of mobile phone text message reminders (MPTMRs) in improving vaccination uptake....MPTMRs are a universally effective strategy across various contexts, populations, and interventions."
Various studies have shown the efficacy of mobile phone text message reminders (MPTMRs), either alone or in combination with interventions such as postcards, auto dialer calls, and letters, in improving vaccination coverage in defined populations for various diseases and in different clinical and country settings. These studies indicate that text message reminders and recall have the potential to facilitate behaviour changes, leading to adherence to vaccination schedules by reminding caregivers of infants, adolescents, and adults of scheduled vaccination appointments and providing the required encouragement to ensure timely attendance to improve vaccination uptake. This systematic review sought to assess scientific evidence evaluating the efficacy of MPTMRs as an intervention to improve vaccination uptake.
The researchers included randomised controlled trials (RCTs) of caregivers of children, adolescents, or adults who received MPTMRs for improving vaccine uptake and recall visits. They searched the Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, and Scopus to identify relevant studies published up to January 24 2024. They then used Cochrane's Risk of Bias tool to assess the included studies and reported the results as risk ratios with 95% confidence intervals (CIs), using a random effects model.
Twenty-five studies (n = 64,536 participants) were considered for quantitative synthesis of evidence regarding vaccination recall. The studies were conducted in the United States, Africa, Australia, Pakistan, Guatemala, and India. Pooled data favoured MPTMRs for vaccination recall compared to usual care (risk ratio (RR) = 1.09 [95% CI: 1.06, 1.13]; I2 = 76%). Subanalysis by intervention characteristics, country setting, country economic status, and vaccination type did not change the effectiveness of the intervention. More specifically:
- Intervention characteristics (whether MPTMRs were used alone or combined with other components) showed no significant modification of the intervention's effectiveness. This finding indicates that the core element - reminding individuals about upcoming vaccination appointments through text messaging - remains effective, regardless of additional components, such as educational content or supplementary communication methods. The simplicity of MPTMRs likely plays a key role in their wide applicability and success, as they directly address one of the most common barriers to vaccination: missed appointments due to forgetfulness.
- A country setting subgroup analysis (urban vs. rural) also revealed no substantial differences in the effectiveness of MPTMRs, challenging the notion that urban areas, which often have better infrastructure and access to health services, would show a greater benefit from text message reminders. Instead, the results suggest that the intervention is equally effective in rural or semi-urban settings, where health service access is more challenging.
- The review did not find significant differences in effectiveness when stratifying by country economic status (low- and middle-income countries [LMICs] vs. high-income countries [HICs]). This finding indicates that MPTMRs have the potential to be just as effective in resource-limited settings as in more affluent ones.
- The type of vaccination (early childhood vaccines, human papillomavirus (HPV), or seasonal influenza) did not significantly impact the effectiveness of MPTMRs. These results reflect the adaptability of MPTMRs in reminding individuals of vaccinations across different stages of life, from infancy to adulthood, and for both routine and seasonal vaccinations.
Among the implications for future research: A 2022 paper demonstrated that language could have a positive influence on vaccine hesitancy. Tailoring MPTMRs to include language specific to the population could thus influence vaccine hesitancy, which may have a positive effect on appointment adherence and subsequently vaccination recall. More studies are needed to assess tailored MPTMRs on vaccination recall, irrespective of the population.
As of this writing, an estimated 7.41 billion people were mobile phone owners, with an increase to 7.49 billion people expected in 2025. Since mobile phone use has also become more widespread, and MPTMRs were shown to be cost-effective in distributing health information in LMICs, MPTMRs could be used as a tool to penetrate areas that are hard to reach, fuel adoption of health interventions, and expand the reach of vaccination programmes in LMICs.
In conclusion: "MPTMRs may be a useful tool to supplement existing standard practice within the health care system to facilitate behavior changes that may promote vaccination uptake. These findings could enable evidence-based decision making and enable evaluation of critical factors that influence achieving and sustaining immunization coverage globally, irrespective of the target population, country setting, and vaccination type."
Vaccines 2024, 12, 1151. https://doi.org/10.3390/vaccines12101151. Image credit: Freepik
- Log in to post comments