Methods
FLU, PCP, INFLUENZA
This study used an experimental design and a survey design. The experimental design evaluated the effect of PCP recommendation on influenza vaccination. A total of 24 CHCs were randomly selected as the intervention (involving 3814 participants) and control (3072 participants) group evenly. The intervention study period was during the 2017–2018 flu season. The 2016–2017 flu season was considered as the baseline comparison. The survey design examined changes in knowledge, attitude, and practice of influenza vaccination among older participants before and after the free influenza vaccination implementation. We randomly invited 1200 participants aged 60 and above during their visits to CHCs in October 2016 and followed them up until October 2017; among them, 958 participants completed the follow-up survey using the same questionnaire.