Literature	Critical Appraisal Skills Program Checklist (Section C)
Literature	10. How valuable is the research?
Teo et al., 2019	Highlight that Singaporean elders were misled that the flu vaccine is a travel precaution only. Active vaccine promotion by healthcare professionals also plays a vital role in influenza vaccination, as the absence of advice or promotion may interpret as influenza vaccination not necessary.
Cummings, Kong, & Orminski, 2020	Highlights that Singaporean elders were making confusion about the term’s “influenza”, “flu”, and “common cold”, leading to underweighting the severity of influenza disease and the need for the vaccine. There are many misconceptions about the influenza vaccine such as ingredients, usage, cost of the vaccine and so on also contribute to a lower vaccination ratio.
Siu, 2018	Cultural factors affect older adults’ discussion of vaccination in Hong Kong, as the elders think the injection location like hospitals and clinics in the area for the sick person, made them not want to go. It also points out that lacking promotion from healthcare professionals leads to low vaccine acceptance.
McIntyre, Zecevic, & Diachun, 2014	Doctors’ advice for vaccination and vaccination experience from others was important for elders to vaccinate. Even if the elders know the effectiveness of the influenza vaccine, they may still refuse the vaccine due to the recognition that they are healthy enough against influenza.
Rikin et al., 2018	Side effects, and adverse vaccine reactions have become a major concern for US elderly getting the flu vaccine. Negative experiences from their social network and themselves also affect their vaccination status, such as lost productivity experience, pain in the injection site for a period, or getting the flu despite being vaccinated.
Kaljee et al., 2017	Insufficient vaccine information from healthcare professionals may contribute to lower vaccination in the USA. Elder perceptions of health also lead to their vaccination status, they think they can prevent flu except for vaccines, or manage flu themselves effectively. On the other hand, US elders’ vaccine and flu experience affect whether they continue with the vaccine or not.
Briggs et al., 2019	Healthcare practitioners' suggestions once again influence older adults' decisions about flu vaccination. Anti-vaccination influence also affects their choice of vaccination. The research also indicated rural and remote areas of older Australians found it difficult to access flu vaccination centers for vaccination, making them refuse vaccination.
Sun et al., 2020	Perceived limited benefits of influenza vaccination, fear of side effects of vaccination, and beliefs in their immune system were the comment barriers for Hong Kong elders to being vaccinated.