Quantitative Definition of Low-Health-Interest Populations by Using Regression Trees: A Nationwide Internet Survey in Japan.

BACKGROUND: Reducing health disparities is a public health issue. Identification of low-health-interest populations is important, but a definition of people with low health interest has not yet been established. We aimed to quantitatively define low-health-interest populations. METHODS: A nationwide cross-sectional internet survey was conducted in 2022. We compiled regression tree (RT) analyses with/without adjustment for age, sex, and socioeconomic status with the 12-item Interest in Health Scale (IHS, score range 12-48) as an explanatory variable and the 10 composite health behaviors as a dependent variable. We defined the first IHS branching condition from the root node as a lower-health-interest group and the terminal node with the lowest health behaviors as the lowest-health-interest group. RESULTS: The mean IHS value of 22,263 analyzed participants was 32.1 ± 5.6; it was higher in females and in those who were aged over 45 years, had a high education, a high income, or a spouse. The first branching condition was IHS 31.5, and the terminal node branched at 24.5, before/after adjustment for covariates. CONCLUSIONS: We determined the cutoff values of the IHS as <32 for a lower-health-interest group and <25 for the lowest-health-interest group. Using these cutoffs might enable us to reveal the characteristics of low-health-interest populations.

Health information and COVID-19 vaccination: Beliefs and attitudes among Japanese university students.

Coronavirus disease 2019 (COVID-19) vaccination of adolescent and young adults is important for infection control. Factors influencing vaccination behavior in this age group include the source of information about the vaccine and social norms. However, there are few studies on factors influencing vaccination behavior among Japanese university students. This study aimed to assess beliefs, attitudes, and sources of information about the COVID-19 vaccine among university students in Japan. A cross-sectional online questionnaire survey was conducted among students in Teikyo University, Japan in September, 2021. The survey was designed to collect demographic information, vaccination status, attitudes, beliefs, and anxiety about the vaccine, sources of information, and whether or not the participant watched an educational movie. The factors associated with beliefs and attitudes were analyzed using logistic and linear regression. A total of 4,062 valid questionnaires were retrieved. The positive vaccine behavior group included 3,725 students (91.7%). The most common source of information on the COVID-19 vaccine was TV/radio (75.0%), and the most common Social networking service (SNS) for COVID-19 information was Twitter (31.1%). Approximately 85% students believed in the efficacy of vaccination. Positive attitude was associated with female sex and watching an educational movie by the university. Concern about the vaccine was positively associated with information from acquaintances or Instagram, and negatively associated with information from Twitter, and watching the educational movie. The majority of students had positive beliefs and attitudes toward COVID-19 vaccination, and social media and educational movies produced by the university had a large influence on their attitude toward vaccination behavior. On the contrary, some students were anxious about vaccination. Promotion of educational movies on social media by the universities is an effective way to encourage vaccination among young people.