Letters sent to Medicare beneficiaries increased uptake of the flu vaccine.

What was the challenge?

The flu results in more than 200,000 hospitalizations and up to 48,000 deaths annually. The flu vaccine reduces the likelihood of infection by more than 60% and is fully covered by Medicare, yet only 6 in 10 Americans 65 and over actually receive the vaccination.

What was the program change?

CMS, NVPO, and OES co-designed behaviorally-informed letters to encourage flu vaccination uptake. All letters emphasized the risks of flu, encouraged the recipient to get vaccinated, and included the sender’s signature and picture.

How did the evaluation work?

We randomly sampled 228,000 Medicare fee-for-service beneficiaries 66 and older in the fall of 2014. One half of the sample served as the control group and received no letter. The remaining participants were randomly assigned to receive one of four letters.

What was the impact?

Receiving any of the four letters increased flu vaccination uptake by 0.59 percentage points, from 25.9% in the control group to 26.5% in the treatment group. The increase is equivalent to 673 additional Medicare beneficiaries receiving their flu vaccination.

Related Publication
David Yokum, Julie C. Lauffenburger, Roya Ghazinouri, and Niteesh K. Choudhry. Letters designed with behavioural science increase influenza vaccination in Medicare beneficiaries. Nature Human Behaviour 2 (2018): 743–749.





Project Type

Program Change and Evaluation


Health and Human Services



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