Influenza Vaccination Against Infectious Complications and Mortality in Older Adults With Fractures: a Large-scale Retrospective Cohort Study

NCT07231016 | Completed

• 2 other identifiers: TMU-JIRB-201910032TMU-Joint Institutional Review
• Study Type: observational
• Target: 561,566
• Locations: 1 country
• Sites: 1

Brief Summary

Background: Both influenza and bone fractures are significant contributors to morbidity and mortality among older adults. This study evaluated the associations between influenza vaccination (IV) and adverse outcomes following fracture-related hospitalizations in elderly individuals. Methods: A retrospective cohort study was conducted utilizing data from a health insurance database in Taiwan. The study included 561,566 individuals aged 65 years and older who were hospitalized for fractures between 2009 and 2020. Patients were stratified according to whether they had received an IV within the 12 months preceding their fracture event. Propensity score matching was employed between the vaccinated and unvaccinated groups. Multivariate logistic regression models were used to estimate adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for postfracture infectious complications and 30-day mortality associated with prior IV.

Conditions

Fracture; Influenza Vaccination

Keywords

Influenza vaccination; infectious diseases; mortality; fracture

Outcome Measures

Primary Outcomes (2)

• post-fracture 30-day mortality

  We calculated the mortality after fracture hospitalization within 30-day period.

  30-day period after fracture hospitalization

• mortality after fracture

  30-day mortality after fracture hospitalization

  30-day period after fracture hospitalization

Study Arms (1)

Patients with fracture hospitalization

A retrospective cohort study was conducted utilizing data from a health insurance database in Taiwan. The study included 561,566 individuals aged 65 years and older who were hospitalized for fractures between 2009 and 2020.

Eligibility Criteria

• Age: 20 Days+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

This study utilized a nationwide, population-based cohort encompassing over twenty million insured individuals. From this cohort, we identified older adults admitted for fracture treatment between 2009 and 2020. Among them, approximately two in five had received an influenza vaccination within the year before hospitalization. To minimize confounding, we performed one-to-one propensity score matching, pairing each vaccinated patient with an unvaccinated counterpart based on demographic, socioeconomic, and clinical characteristics, including age, sex, income status, fracture type, comorbidities, and prior healthcare utilization.

You may qualify if:

• Patients with fracture hospitalization who aged more than 65 years

You may not qualify if:

• People had no fracture hospitalization and people aged lower than 65 years

Sponsors & Collaborators

• Taipei Medical University Hospital: lead

Study Sites (1)

Taipei Medical University Hospital

Taipei, 110, Taiwan

Location

MeSH Terms

Conditions

Fractures, Bone; Influenza, Human; Communicable Diseases

Condition Hierarchy (Ancestors)

Wounds and Injuries; Respiratory Tract Infections; Infections; Orthomyxoviridae Infections; RNA Virus Infections; Virus Diseases; Respiratory Tract Diseases; Disease Attributes; Pathologic Processes; Pathological Conditions, Signs and Symptoms

Study Officials

• Chien-Chang Liao, PhD, MPH

  Taipei Medical University Hospital

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: RETROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: November 13, 2025
• First Posted: November 17, 2025
• Study Start: November 1, 2019
• Primary Completion: January 1, 2025
• Study Completion: January 1, 2025
• Last Updated: November 17, 2025

Record last verified: 2019-10

Data Sharing

• IPD Sharing: Will not share

Locations

TW (1)