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FractureNCT07231016

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

An observational study of Fracture and Influenza Vaccination, run by Taipei Medical University Hospital at 1 site in Taiwan.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial 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. Read more about this study

Who is it for?
Ages 20 days and olderHealthy volunteers can take part
Conditions the study is for
Fracture, Influenza Vaccination
How many people
561,566 participants
Where
1 siteTaiwan
Study dates
1 Nov 2019to 1 Jan 2025
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 20 days and older
  • All sexes
  • Healthy volunteers accepted
  • Child, Adult, Older adult

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.

Who may be able to join

  • Patients with fracture hospitalization who aged more than 65 years

Who cannot join

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

Trial locations and contacts

1 site in 1 country.

Taiwan1 site
  • Taipei Medical University Hospital

    Taipei, 110

Other trials in Taiwan

About this study

Official title: The Protective Effect of Influenza Vaccine for Vulnerable Population

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.

Read the detailed description

A nested retrospective cohort design was adopted to evaluate the influence of IVs on clinical outcomes following fracture-related hospitalizations. The analysis drew upon a nationwide, dynamic cohort comprising more than 23 million insured individuals. From this population, we identified 561,566 patients aged 65 years and older who were admitted for fracture treatment between 2009 and 2020. Among them, 213,381 individuals had received an IV within the 12 months prior to admission, whereas 348,185 had not.

To mitigate potential confounding, we applied 1:1 propensity score matching, pairing each vaccinated patient with a nonvaccinated counterpart. The matching criteria included demographic characteristics (age, sex), socioeconomic status (low-income designation), fracture type, comorbidities (documented within the previous 24 months), emergency department visits, and hospital admissions during the 12 months preceding the fracture event.

The primary outcomes were assessed within 30 days postadmission and included the occurrence of pneumonia, septicemia, urinary tract infections, intensive care, hospital length of stay, total medical expenditure, and 30-day mortality. Postfracture infectious complications were identified through physician-coded diagnoses during the index hospitalization or in subsequent inpatient and outpatient claims within 30 days. To avoid confounding due to preexisting infections, individuals with documented cases of pneumonia or septicemia within the six months before fractures were excluded from the analysis.

Keywords
Influenza vaccination, infectious diseases, mortality, fracture
Medical subject headings
Fractures, Bone, Influenza, Human, Communicable Diseases

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

Study groups in NCT07231016
Study groupRoleWhat they receive
Patients with fracture hospitalizationA 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.

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. post-fracture 30-day mortality

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

    Measured: 30-day period after fracture hospitalization

  2. mortality after fracture

    30-day mortality after fracture hospitalization

    Measured: 30-day period after fracture hospitalization

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted17 Nov 2025
  2. Study start1 Nov 2019
  3. Primary completion1 Jan 2025
  4. Study completion1 Jan 2025

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Observational model
Cohort
Time perspective
Retrospective
Enrolment
561,566 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07231016
Sponsor's protocol ID
TMU-JIRB-201910032
Other IDs
TMU-Joint Institutional Review
Status last verified
Oct 2019
First submitted
13 Nov 2025
Last updated
17 Nov 2025
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No

Questions about this trial

What is this clinical trial studying?

An observational study of Fracture and Influenza Vaccination, run by Taipei Medical University Hospital at 1 site in Taiwan.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 1 inclusion and 1 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 17 Nov 2025. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in Taiwan. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

post-fracture 30-day mortality (time frame: 30-day period after fracture hospitalization). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 17 Nov 2025.

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