Dementia and influenza vaccination: Time trends and predictors of vaccine uptake among older adults

PURPOSE: Older adults with dementia are at an increased risk of hospitalizations with respiratory infections and death, emphasizing the need for a greater focus on preventive measures. In this study, we investigated the uptake of influenza vaccines among older adults with and without dementia.

METHODS: We conducted a cross-sectional study with data from national registries on the entire Danish population aged ≥65 years. We mapped time trends of vaccination for each vaccination season (September to August) from 2002/03 to 2018/19. Using multivariable logistic regression, we estimated the odds of vaccination in 2018/19 in nursing home residents and home-living older adults with and without dementia.

RESULTS: We included 800,387 individuals in 2002/03 and 1,122,319 in 2018/19. After a period of similar and increasing uptake of influenza vaccines among people with and without dementia, the uptake plateaued from 2007/08 to 2018/19 and was consistently higher in those with dementia during this period. The odds of vaccination in 2018/19 were lower for home-living people with dementia compared to home-living people without dementia (OR: 0.76; 95 % CI: 0.74-0.78). The highest odds were among nursing home residents both with (OR: 1.28; 95 % CI:1.24-1.33) and without dementia (1.18; 95 % CI: 1.14-1.22).

CONCLUSION: Between 2002/03 and 2018/19 vaccine coverage among older adults in Denmark was <60 %, regardless of dementia status, not reaching the WHO target of 75 %. Home-living older adults with dementia were 24 % less likely to receive an influenza vaccine, representing an important target group for future vaccination programs.