Evidence map›Paper›PMID 40082958›Full record

Observational studyBMC medicine2025

Reduced risks of influenza-associated hospitalization and complications following vaccination among over 2 million older individuals: a nationwide study using target trial emulation framework.

Zi-Yang Peng, Yun-Ting Hua, Wan-Ting Huang, Jin-Shang Wu, Huang-Tz Ou

Abstract readObservational Study
In one paragraph

Observational study in BMC medicine, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 7 papers.

0numbers the graph read from it
0cells of the map it votes in
7citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

7 citing papers in PubMed.

  1. Article
  2. Article
  3. Vaccination status as a determinant of hospitalization in influenza: Insights from emergency department data.European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology · 2026
    Observational
  4. Article
  5. Review
  6. Article
  7. Review
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Zi-Yang PengInstitute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Yun-Ting HuaInstitute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan.
Wan-Ting HuangGlobal Health Program, College of Public Health, National Taiwan University, Taipei, Taiwan.
Jin-Shang WuDepartment of Family Medicine, National Cheng Kung University Hospital, College of Medicine, National Cheng Kung University Hospital, National Cheng Kung University National Cheng Kung University, Tainan, Taiwan.
Huang-Tz OuInstitute of Clinical Pharmacy and Pharmaceutical Sciences, College of Medicine, National Cheng Kung University, Tainan, Taiwan. huangtz@mail.ncku.edu.tw.

Funding

National Science and Technology Council NSTC 112-2628-B-006-008-MY3
6 · The paper itself

Abstract

backgroundCurrent evidence on influenza vaccine effectiveness (VE), which is predominately derived from small high-risk older populations and focuses on specific influenza-related complications, might not be generalizable to real-world older populations with diverse characteristics in Taiwan. Therefore, this observational study with a target trial emulation framework aimed to evaluate the clinical effectiveness of an influenza vaccine on influenza infection, complications, and associated healthcare utilization and costs.

methods1,214,392 propensity-score-matched pairs of vaccinated and unvaccinated older populations from the influenza season of 2018/2019 were identified from Taiwan's National Health Insurance Research Database. VE (estimated as 1 minus hazard ratio [HR]*100%) and the HRs were used for influenza events and associated complications, respectively.

resultsPrimary analyses show 14% (10-18%) of VE against influenza-associated hospitalization, irrespective of age, frailty status, and underlying influenza risk. Notably, a decline in VE for influenza-associated hospitalization was observed when the observational period following vaccination was extended (25% [19-30%], 23% [18-28%], and 14% [10-18%] for the intervals October 2018-March 2019, October 2018-May 2019, and October 2018-September 2019, respectively). Compared with non-vaccination, having an influenza vaccination significantly reduced risks of influenza-associated death by 30%, various respiratory by 12-26%, cardiovascular complications by 39-47%, and acute kidney injury by 23%. Approximately savings of USD 3,000,000 in total from averting influenza-associated hospitalization following vaccination were found. The non-significant effects of the influenza vaccine on negative control outcomes support the validity of the study procedures.

conclusionsVE for severe influenza events (i.e., those requiring hospitalization) and related complications among the real-world older population was corroborated. To avoid severe influenza episodes and complications and minimize associated economic consequences, continuous influenza vaccine uptake over different influenza seasons is recommended for this population.

Indexed as

HospitalizationInfluenza, HumanInfluenza VaccinesVaccinationVaccine EfficacyAgedAged, 80 and overFemaleHumansMaleTaiwanInfluenza VaccinesCardiovascular diseasesInfectious/pulmonary diseasesInfluenza-associated deathsInfluenza-associated hospitalizationsInfluenza vaccinationKidney diseasesTarget trial emulation

Identifiers

PMID40082958
PMCPMC11907999

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.