Evaluating the impact of influenza vaccine on preventing stroke hospitalization and death in Chinese elderly hypertensive patients: A retrospective cohort study

BACKGROUND: The effect of influenza vaccination on stroke remains controversial, particularly given the paucity of studies conducted in mainland China. METHODS: Using a comprehensive database obtained from the Regional Health Information Platform, we conducted a 7-month retrospective cohort analysis of 457,887 elderly individuals residing in an eastern Chinese city. Using multivariate competing risks regression analysis, we derived subdistribution hazard ratios (sHRs) along with the corresponding 95 % confidence intervals (CIs). RESULTS: There was no significant difference in the proportion of hospitalizations for stroke between those who received the influenza vaccine and those who did not (7.50 per 1000 vs. 8.12 per 1000; adjusted sHR: 0.96, 95 % CI: 0.90-1.02). However, a pronounced reduction in stroke-related mortality was observed among vaccinated individuals, with a rate of 0.18 ‰ compared with 0.54 ‰ among the unvaccinated (adjusted sHR: 0.47, 95 % CI: 0.33-0.69). CONCLUSION: This study highlights the substantial role of influenza vaccination in reducing the risk of stroke-related mortality in elderly hypertensive patients. Therefore, efforts to increase influenza vaccination rates in this population are strongly encouraged.