Impact of a structured older persons health assessment on herpes zoster vaccine uptake in Australian primary care.

Vaccine uptake in adult immunisation programs is often suboptimal. We aimed to assess the impact of the structured older persons health assessment (health assessment) on herpes zoster (zoster) vaccine uptake in Australia. We used national general practice electronic medical records (MedicineInsight) of encounters with patients aged 75-79 years because these patients were age-eligible for both free zoster vaccines and health assessments in the two years following the addition of zoster vaccine to the national immunisation program (Nov 2016-Dec 2018). Due to repeated encounters, we used generalized estimating equations with each patient treated as a clustering variable to analyse the comparison of rates of zoster vaccine administration during encounters where a health assessment was provided versus encounters where the health assessment was not provided. In analyses there were 31,876 patients with a total of 266,204 eligible general practice encounters. Of the 5018 encounters where a health assessment was provided, 592 zoster vaccinations also occurred on the same day (118.0/1000 encounters); for the 261,186 encounters where no health assessment was provided, 9226 zoster vaccinations occurred (35.3/1000 encounters). Zoster vaccine was more likely to be administered during a general practice encounter with a health assessment compared to encounters without one (adjusted odds ratio 2.99; 95% CI: 2.76-3.23). In conclusion, the structured older persons health assessment, which acts as both an incentive and a reminder for healthcare providers to recommend vaccinations in adults improves uptake of zoster vaccine in eligible adults. Such interventions may have a role in improving vaccine uptake among older adults.