Digital interventions for influenza vaccine uptake in older adults: systematic review, meta-analysis

Background

Seasonal influenza causes substantial morbidity and mortality among older adults, while vaccination coverage often remains below WHO targets. Digital interventions may improve influenza vaccine uptake, but their effectiveness remains unclear.

Methods

This systematic review assessed digital interventions to increase influenza vaccination uptake among adults aged ≥60 years. We searched MEDLINE, CENTRAL, CINAHL, Web of Science and ERIC from December 2017, following a previous review, to identify randomized and cluster-randomized controlled trials. Two reviewers independently screened studies, extracted data, assessed risk of bias (RoB) using Cochrane criteria. Random-effects meta-analyses evaluated the association between digital interventions and influenza vaccine uptake.

Results

Of 9211 records, 18 studies were included. 16 interventions targeted patients, including SMS reminders, patient portals, and electronic prompts; 2 focused on providers. Patient automated reminders versus usual care or no reminder showed a small, non-significant increase in uptake (12 RCTs; 3307338 participants; RR 1.003, 95% CI 1.000-1.005; I²=45%). Patient non-automated reminders showed a larger exploratory effect (4 RCTs; 2147 participants; RR 1.743, 95% CI 1.148-2.646), but heterogeneity was substantial (I²=90.7%). Simple reminders (8 RCTs; RR 1.004, 95% CI 1.003-1.006; I²=0%) and reminders with behavioural nudges (7 RCTs; RR 1.003, 95% CI 1.001-1.005; I²=24.9%) were associated with higher uptake. Egger test did not suggest small-study effects for automated reminders (P = 0.535). RoB was: 13 low, 3 some concerns, 2 high.

Conclusions

Digital interventions were associated with a modest increase in influenza vaccination uptake. Given their low cost and scalability, these strategies may help improve vaccination coverage in older populations. Further research should clarify whether reminder-based strategies are sufficient or if other digital approaches may be more effective.

Key messages

• Digital reminder interventions were associated with a modest increase in influenza vaccination uptake and may help improve coverage in older populations.

• Reminders are promising, but further research is needed to assess whether other digital strategies may be more effective.