Abstract
Introduction Vaccination is essential for preventing infectious diseases such as pneumonia and seasonal viral infections. The COVID-19 pandemic has underscored the critical role of vaccination in public health. However, vaccination uptake can be influenced by biopsychosocial conditions. Immunocompromised individuals, for instance, face restrictions with live vaccines, and psychosocial factors like loneliness can negatively impact attitudes towards vaccination. This study aims to clarify the association between loneliness and pneumococcal vaccination rate among regular patients in a rural Japanese community. Method A cross-sectional study was conducted at Unnan City Hospital in Unnan City, a rural area in southeastern Shimane Prefecture, Japan. Participants included patients over 40 who regularly visited the general medicine department between September 1, 2023, and November 31, 2023. Data on vaccination rates for pneumococcal pneumonia and loneliness levels assessed using the Japanese version of the three-item University of California, Los Angeles (UCLA) Loneliness Scale were collected. Additional data on demographics, BMI, renal function, and comorbidities were extracted from electronic medical records. Statistical analyses were performed to identify factors associated with vaccination rates, including univariate and multivariate logistic regression. Results Out of 1,024 eligible patients, 647 participated in the study. Participants with higher loneliness had significantly lower vaccination rates for pneumococcal pneumonia (22.3% vs. 34.2%, p = 0.001). The multivariate logistic regression model showed that higher loneliness was significantly associated with lower vaccination likelihood (odds ratio (OR) = 0.54, 95% CI = 0.37-0.78, p = 0.0011). Age was positively associated with vaccination (OR = 1.08, 95% CI = 1.06-1.11, p < 0.001), whereas higher comorbidity scores (Charlson Comorbidity Index (CCI) ≥ 5) and frequent healthy eating practices were associated with lower vaccination rates. Conclusion This study demonstrates a significant association between higher loneliness levels and lower pneumococcal vaccination rates among patients in a rural Japanese community. Addressing psychosocial barriers such as loneliness could enhance vaccination uptake. Public health interventions focused on reducing loneliness and enhancing social support are essential to improving vaccination rates and preventing infectious diseases. Further research should explore the causal mechanisms and develop targeted strategies to mitigate the impact of loneliness on health behaviors.