A new study led by researchers from Maccabi Healthcare Services in Isreal suggests that flu vaccination rates among older adults are strongly associated with prior-year vaccination status, frequent primary care visits, and a spouse’s vaccination status, while dementia was identified as a significant barrier to receiving the vaccine.
In the retrospective cross-sectional study, published last week in BMC Public Health, researchers analyzed electronic health record data from nearly 303,000 adults aged 65 and older during the 2022-23 flu season. Overall, 53.2% received a flu vaccine, which is well below the 75% coverage target for this age-group recommended by the World Health Organization and European health agencies.
Prior-year vaccination boosted uptake 30-fold
The strongest predictor of receiving a flu vaccine was having received a flu shot the previous year. Older adults vaccinated in 2021-22 were 30 times more likely to be vaccinated again in 2022-23 than those who skipped vaccination the year before (odds ratio [OR], 30.1), “suggesting that health behaviors are often maintained over time and that past behavior strongly influences future actions,” write the researchers.
The findings also highlight the importance of identifying first-time vaccine recipients and making the flu vaccine part of routine care for older adults.
Regular engagement with a primary care physician (PCP) also appeared to play a major role. Compared with older adults who had no primary care visits, those with one to three visits were almost twice as likely to receive a flu shot than those with no visits (OR, 1.86). Older adults with four or more PCP visits were nearly three times as likely to receive a flu shot as those with fewer visits (OR, 2.82).
In a subgroup analysis of nearly 192,000 participants, having a vaccinated spouse was strongly associated with vaccination uptake, increasing the odds more than eightfold (OR, 8.33). The finding underscores how household decision-making patterns may play a significant role in vaccine uptake, note the authors.
Dementia a barrier to vaccination
In contrast, dementia was linked to lower vaccination rates. Older adults with dementia were 22% less likely to receive flu vaccines than those without that diagnosis (OR, 0.78). “Several factors may contribute to this disparity, including reduced patient autonomy, fragmented care, caregiver burden, competing clinical priorities, and assumptions about limited benefit in advanced disease,” write the authors.
The researchers also observed several spikes in vaccination uptake during the season that coincided with text-message reminder campaigns and electronic alerts sent to healthcare providers to promote the flu vaccine. This finding suggests that digital outreach and clinical prompts may improve vaccine coverage.
“By implementing coordinated approaches across clinical, community, and caregiving settings, public health systems can make meaningful progress toward achieving international vaccination targets and reducing influenza-related morbidity in aging populations,” they write.
