Trends, core barriers and systematic governance countermeasures of voluntary blood donation decline in the post-COVID-19 era: a mixed-methods longitudinal study in Jiangsu Province, China (2019–2025)

Abstract Introduction Voluntary blood donation is essential for ensuring clinical blood safety and public health security. However, the COVID-19 pandemic has triggered a sustained decline in post-pandemic blood collection, and existing research remains insufficient in systematic analysis and long-term actionable solutions. Method This mixed-methods study integrated quantitative analysis (descriptive statistics, trend analysis, and correlation analysis) and qualitative interviews to investigate the dynamics of voluntary blood donation in Jiangsu Province, China. Data Quantitative data were derived from 81 consecutive months of official records (January 2019–September 2025), and qualitative data were collected from 82 interviewees representing four key stakeholder groups. Results Results demonstrated that whole blood collection decreased by 29.7% in 2025 relative to its 2021 peak; the correlation coefficient for platelet supply and demand was 0.967 (P < 0.001), and that for whole blood–red blood cell was 0.892 (P < 0.001); four core barriers were identified, including health cognition bias, increased life pressure, ineffective incentive policy implementation, and misleading negative public opinion. Conclusion This study clarifies the supply-demand characteristics and underlying determinants of post-pandemic blood donation decline, and proposes a targeted long-term mechanism with global implications to recover blood donation and safeguard public health blood security.