Study Shows Tailored Online Interventions Improve Seasonal Influenza Vaccination in Older Adults

In a recent study published in JAMA Network Open, researchers evaluated the efficacy of tailored online interventions in improving seasonal influenza vaccination (SIV) uptake among older adults.

Background

SIV can effectively prevent influenza and mortality among older adults. The Center for Health Protection in Hong Kong recommends that adults aged 65 or older receive SIV yearly.

• Although SIV is free for this age group in Hong Kong, its coverage is inadequate and was 40.4% in 2021-22.
• Fewer trials have compared the efficacy of mailing reminders to no intervention but had small effect sizes.
• Home visits and telephone sessions appear effective, but they are more resource-intensive.
• Standard verbal education by medical students was effective in increasing SIV uptake, but tailored interventions for SIV are lacking among older adults.

About the Study

In the present study, researchers assessed the efficacy of chatbot-delivered stage of change (SOC)-tailored interventions in improving SIV uptake among older adults in Hong Kong. This non-blinded randomized controlled trial (RCT) was performed between December 2021 and July 2022.

• Eligible subjects were community-dwelling, Cantonese- or Mandarin-speaking smartphone users aged 65 or older who did not take SIV during the 2021-22 influenza season.
• Individuals with contraindications to SIV, cognitive impairment, deafness, blindness, or the inability to communicate were excluded.
• Random telephone sampling was implemented for recruitment. Participants were offered supermarket coupons after the baseline survey and six months post-intervention.

Findings

Overall, 396 participants completed the baseline survey; they were aged, on average, 70.2. Most subjects (62.9%) were females. Approximately 60% of participants had ever been vaccinated for influenza.

• About 37.4%, 22%, and 40.6% of participants were at the pre-contemplation, contemplation, and preparation stages, respectively.
• At six months, 100 and 70 participants in the intervention and control groups were at the action stage.
• The SIV uptake rate and the average SOC score were significantly higher among intervention subjects than controls.
• Among the intervention participants completing at least two sessions, 55.6% progressed to a higher SOC, with a statistically significant increase in their mean SOC score from the first to the (most) recent session.

Conclusions

The study revealed a higher efficacy of SOC-tailored intervention in improving SIV uptake than the standard, non-SOC-tailored intervention, with about ten percentage points higher SIV uptake rate in the intervention group than the overall SIV coverage among older adults in Hong Kong.

The intervention system was viable to provide tailored health promotional messages according to participants’ SOC and required fewer resources, given that it can automatically evaluate SOC and select appropriate interventions.

Overall, the findings suggest that SOC-tailored interventions may be (more) sustainable in increasing SIV uptake.