Social contact patterns and associated factors survey of Shangrao City.

Objective: This study aimed to quantitatively analyze social contact patterns among residents of Shangrao City, Jiangxi Province, and to examine their variations across different demographic groups. The findings are intended to provide empirical data for developing localized transmission dynamic models of respiratory infectious diseases and for formulating targeted prevention and control strategies. Methods: A cross-sectional online survey was conducted among Shangrao residents from April to September 2025, and 2,101 valid questionnaires were analyzed. Daily total, household, and non-household contacts were described by demographic groups. Factors associated with daily total contacts were examined using negative binomial regression, with results reported as incidence rate ratios (IRRs) and 95% confidence intervals. Post-stratification weighting based on the 2020 Seventh National Population Census of Shangrao was performed as a sensitivity analysis. Results: The mean daily number of contacts was 7.91, including 2.73 household and 5.19 non-household contacts. Adolescents aged 5-19 years had the highest mean daily total contacts (9.99). In the negative binomial regression, the 5-19 years group had more contacts than the 20-29 years reference group (IRR 1.74, Conclusion: Social contact patterns in Shangrao City are dominated by age, with adolescents (5-19 years) and highly mobile populations exhibiting the highest contact frequencies. These conclusions were robust to post-stratification weighting against the 2020 Seventh National Population Census of Shangrao. The study addresses the absence of empirical social contact data in a Chinese prefecture-level city and provides directly applicable evidence for localized epidemic risk assessment and early-warning modelling of respiratory infectious diseases.