Empowering Older People's Preventive Care Utilization Through Mental Model Approach and Patient Activation Approach: a Randomized Control Trial for Promoting Vaccination Uptake

1. Introduction:

The global population aged above 60 years is projected to reach 2.1 billion by 2050. Hong Kong also has a rapid aging population. In 2018, there were around 1.27 million people aged 65 years or above, accounting for 17.9% of the total population in Hong Kong, which was estimated to increase to 2.44 million and 31.9% of the total population by 2038. Age increases with a sharp rise in multimorbidity. In Hong Kong, it was estimated that around 70% of the population aged 60 years or above had at least one chronic disease and 40% had multimorbidity. This will cause substantial burden to the health care systems.

Underutilization of preventive care in older people Encouraging older people's utilization of preventive care is crucial for reducing the pressure of population aging placed on the health care systems and promoting healthy aging. In England, it was estimated that regular health check-up can prevent 390 premature deaths and gain an additional 1,370 people being free of disease per million people before age of 80 years. A meta-analysis estimated that influenza vaccination in older people reduced hospital admission due to influenza or pneumonia by 27% and all-cause mortality by 47%. Adding pneumococcal vaccination to influenza vaccination can additionally prevent pneumonia and death by 15% and 19%, respectively. However, underutilization of preventive care was widespread. For instance, it was reported that only 40% of the Hong Kong older people had regular medical check-ups to screen for chronic diseases. In Hong Kong, free or subsidized influenza vaccination and pneumococcal vaccinations are provided for older people aged 50 years or above and those aged 65 years or above, respectively. However, only 45% of the target age group received seasonal influenza vaccines in 2020/2021 and 46% had received pneumococcal vaccines as of February 2021. In addition, older people were found to be much more hesitant about taking COVID-19 vaccination, with less than 20% of persons aged 60 or older being vaccinated 6 months after the COVID-19 vaccination programme launched in Hong Kong.

Linking to older people's decision-making preference Preventive care utilization involves a decision-making process of identifying available preventive care options, evaluating these options based on available information or by engagement with information seeking and finally choosing the favourable options. This is a cognitively demanding process. However, age increases with decline in cognitive function. Attributing to their declined cognitive function, older people tend to seek less information, favour fewer options and simpler information in decision making, and have poorer decision-making competence. However, older people were suggested to have better emotional and experiential skills which sometimes compensate their declined cognitive function in decision making. Older people's decision making tend to be gain-oriented and they were better at making use of positive information than negative information in decision making. Older people had greater cognitive engagement in decisions that were more emotionally relevant, and better performance in recognizing social norms-related cues in decision making. Older people's better performance in affective decision making may be explained using the Socioemotional Selectivity Theory (SST). According to SST, older people naturally perceive that they have limited time for future and hence they selectively pay more attention to the emotional contents of the decisions, put more effort to decisions that are more emotionally meaningful for them, and value more for optimizing emotional experience and maintaining emotional connectivity with others in decision making. Most existing studies to examine older people's decision making preference focused on the financial domain and few studies linked older people's decision-making preference to preventive care utilization.

Thus, older people should need support to facilitate preventive care utilization. First, due to decline in cognitive function, older people may need support for identifying available preventive care services suitable for their age groups and recognizing personal need for preventive care. The investigators' previous study found that older people generally had insufficient understanding about what preventive care was. For instance, healthy lifestyle was the most frequently mentioned preventive care while other preventive care services were not recognized. Some had misperceptions about preventive care. The investigators' recent qualitative study found that older people misinterpreted pneumococcal vaccination as a curative care rather than preventive care (unpublished data). Inability to distinguish preventive care from curative care shaped a misperception that need for preventive care depended on somatic symptoms. Second, information should be presented in a way of being emotionally relevant for older people, emphasizing the benefits of behaviours rather than prevention of loss, to eventually facilitate the achievement of emotional positivity, stability, and connectivity. However, current advocacy for preventive care in older people remains primarily based on the conventional three-level disease prevention model emphasizing prevention of loss. This may reduce older people's motivation to cognitively engage in understanding and making use of the information for preventive care utilization. Third, preventive care utilization requires older people to be more future-oriented, actively planning and striving for a better future. However, it was found that older people particularly those who were 70 years or above had a more negative view of and feeling helpless about the present-the present fatalistic perspective which impaired their decision making competence. This suggests the importance of promoting a positive future time perspective particularly in those who are 70 years or older for promoting their preventive health behaviours. Review of literature suggested that older people in general had lower self-efficacy in decision making. Meanwhile healthcare professional and family tend to leave the medical decisions to older people themselves to avoid feeling of regret once wrong decision is made, which is a case in Hong Kong regarding older people's COVID-19 vaccination.