Effectiveness of influenza vaccination for children in Japan: Four-year observational study using a large-scale claims database

Natsumi Shibata, Shinya Kimura, Takahiro Hoshino, Masato Takeuchi, Hisashi Urushihara

Research output: Contribution to journalArticle

4 Citations (Scopus)

Abstract

Background: To date, few large-scale comparative effectiveness studies of influenza vaccination have been conducted in Japan, since marketing authorization for influenza vaccines in Japan has been granted based only on the results of seroconversion and safety in small-sized populations in clinical trial phases not on the vaccine effectiveness. We evaluated the clinical effectiveness of influenza vaccination for children aged 1–15 years in Japan throughout four influenza seasons from 2010 to 2014 in the real world setting. Methods: We conducted a cohort study using a large-scale claims database for employee health care insurance plans covering more than 3 million people, including enrollees and their dependents. Vaccination status was identified using plan records for the influenza vaccination subsidies. The effectiveness of influenza vaccination in preventing influenza and its complications was evaluated. To control confounding related to influenza vaccination, odds ratios (OR) were calculated by applying a doubly robust method using the propensity score for vaccination. Results: Total study population throughout the four consecutive influenza seasons was over 116,000. Vaccination rate was higher in younger children and in the recent influenza seasons. Throughout the four seasons, the estimated ORs for influenza onset were statistically significant and ranged from 0.797 to 0.894 after doubly robust adjustment. On age stratification, significant ORs were observed in younger children. Additionally, ORs for influenza complication outcomes, such as pneumonia, hospitalization with influenza and respiratory tract diseases, were significantly reduced, except for hospitalization with influenza in the 2010/2011 and 2012/2013 seasons. Conclusions: We confirmed the clinical effectiveness of influenza vaccination in children aged 1–15 years from the 2010/2011 to 2013/2014 influenza seasons. Influenza vaccine significantly prevented the onset of influenza and was effective in reducing its secondary complications.

Original languageEnglish
JournalVaccine
DOIs
Publication statusAccepted/In press - 2018 Jan 1

Fingerprint

observational studies
influenza
Human Influenza
Observational Studies
Japan
Vaccination
vaccination
Databases
Influenza Vaccines
vaccines
Hospitalization
Respiratory Tract Diseases
Propensity Score
Occupational Health
Health Insurance
Marketing
insurance
seroconversion
subsidies
Population

Keywords

  • Children
  • Doubly robust method
  • Influenza vaccines
  • Japan
  • Propensity score
  • Vaccine effectiveness

ASJC Scopus subject areas

  • Molecular Medicine
  • Immunology and Microbiology(all)
  • veterinary(all)
  • Public Health, Environmental and Occupational Health
  • Infectious Diseases

Cite this

Effectiveness of influenza vaccination for children in Japan : Four-year observational study using a large-scale claims database. / Shibata, Natsumi; Kimura, Shinya; Hoshino, Takahiro; Takeuchi, Masato; Urushihara, Hisashi.

In: Vaccine, 01.01.2018.

Research output: Contribution to journalArticle

@article{3681d2ed3a27460fbb82729f15d76d68,
title = "Effectiveness of influenza vaccination for children in Japan: Four-year observational study using a large-scale claims database",
abstract = "Background: To date, few large-scale comparative effectiveness studies of influenza vaccination have been conducted in Japan, since marketing authorization for influenza vaccines in Japan has been granted based only on the results of seroconversion and safety in small-sized populations in clinical trial phases not on the vaccine effectiveness. We evaluated the clinical effectiveness of influenza vaccination for children aged 1–15 years in Japan throughout four influenza seasons from 2010 to 2014 in the real world setting. Methods: We conducted a cohort study using a large-scale claims database for employee health care insurance plans covering more than 3 million people, including enrollees and their dependents. Vaccination status was identified using plan records for the influenza vaccination subsidies. The effectiveness of influenza vaccination in preventing influenza and its complications was evaluated. To control confounding related to influenza vaccination, odds ratios (OR) were calculated by applying a doubly robust method using the propensity score for vaccination. Results: Total study population throughout the four consecutive influenza seasons was over 116,000. Vaccination rate was higher in younger children and in the recent influenza seasons. Throughout the four seasons, the estimated ORs for influenza onset were statistically significant and ranged from 0.797 to 0.894 after doubly robust adjustment. On age stratification, significant ORs were observed in younger children. Additionally, ORs for influenza complication outcomes, such as pneumonia, hospitalization with influenza and respiratory tract diseases, were significantly reduced, except for hospitalization with influenza in the 2010/2011 and 2012/2013 seasons. Conclusions: We confirmed the clinical effectiveness of influenza vaccination in children aged 1–15 years from the 2010/2011 to 2013/2014 influenza seasons. Influenza vaccine significantly prevented the onset of influenza and was effective in reducing its secondary complications.",
keywords = "Children, Doubly robust method, Influenza vaccines, Japan, Propensity score, Vaccine effectiveness",
author = "Natsumi Shibata and Shinya Kimura and Takahiro Hoshino and Masato Takeuchi and Hisashi Urushihara",
year = "2018",
month = "1",
day = "1",
doi = "10.1016/j.vaccine.2018.03.082",
language = "English",
journal = "Vaccine",
issn = "0264-410X",
publisher = "Elsevier BV",

}

TY - JOUR

T1 - Effectiveness of influenza vaccination for children in Japan

T2 - Four-year observational study using a large-scale claims database

AU - Shibata, Natsumi

AU - Kimura, Shinya

AU - Hoshino, Takahiro

AU - Takeuchi, Masato

AU - Urushihara, Hisashi

PY - 2018/1/1

Y1 - 2018/1/1

N2 - Background: To date, few large-scale comparative effectiveness studies of influenza vaccination have been conducted in Japan, since marketing authorization for influenza vaccines in Japan has been granted based only on the results of seroconversion and safety in small-sized populations in clinical trial phases not on the vaccine effectiveness. We evaluated the clinical effectiveness of influenza vaccination for children aged 1–15 years in Japan throughout four influenza seasons from 2010 to 2014 in the real world setting. Methods: We conducted a cohort study using a large-scale claims database for employee health care insurance plans covering more than 3 million people, including enrollees and their dependents. Vaccination status was identified using plan records for the influenza vaccination subsidies. The effectiveness of influenza vaccination in preventing influenza and its complications was evaluated. To control confounding related to influenza vaccination, odds ratios (OR) were calculated by applying a doubly robust method using the propensity score for vaccination. Results: Total study population throughout the four consecutive influenza seasons was over 116,000. Vaccination rate was higher in younger children and in the recent influenza seasons. Throughout the four seasons, the estimated ORs for influenza onset were statistically significant and ranged from 0.797 to 0.894 after doubly robust adjustment. On age stratification, significant ORs were observed in younger children. Additionally, ORs for influenza complication outcomes, such as pneumonia, hospitalization with influenza and respiratory tract diseases, were significantly reduced, except for hospitalization with influenza in the 2010/2011 and 2012/2013 seasons. Conclusions: We confirmed the clinical effectiveness of influenza vaccination in children aged 1–15 years from the 2010/2011 to 2013/2014 influenza seasons. Influenza vaccine significantly prevented the onset of influenza and was effective in reducing its secondary complications.

AB - Background: To date, few large-scale comparative effectiveness studies of influenza vaccination have been conducted in Japan, since marketing authorization for influenza vaccines in Japan has been granted based only on the results of seroconversion and safety in small-sized populations in clinical trial phases not on the vaccine effectiveness. We evaluated the clinical effectiveness of influenza vaccination for children aged 1–15 years in Japan throughout four influenza seasons from 2010 to 2014 in the real world setting. Methods: We conducted a cohort study using a large-scale claims database for employee health care insurance plans covering more than 3 million people, including enrollees and their dependents. Vaccination status was identified using plan records for the influenza vaccination subsidies. The effectiveness of influenza vaccination in preventing influenza and its complications was evaluated. To control confounding related to influenza vaccination, odds ratios (OR) were calculated by applying a doubly robust method using the propensity score for vaccination. Results: Total study population throughout the four consecutive influenza seasons was over 116,000. Vaccination rate was higher in younger children and in the recent influenza seasons. Throughout the four seasons, the estimated ORs for influenza onset were statistically significant and ranged from 0.797 to 0.894 after doubly robust adjustment. On age stratification, significant ORs were observed in younger children. Additionally, ORs for influenza complication outcomes, such as pneumonia, hospitalization with influenza and respiratory tract diseases, were significantly reduced, except for hospitalization with influenza in the 2010/2011 and 2012/2013 seasons. Conclusions: We confirmed the clinical effectiveness of influenza vaccination in children aged 1–15 years from the 2010/2011 to 2013/2014 influenza seasons. Influenza vaccine significantly prevented the onset of influenza and was effective in reducing its secondary complications.

KW - Children

KW - Doubly robust method

KW - Influenza vaccines

KW - Japan

KW - Propensity score

KW - Vaccine effectiveness

UR - http://www.scopus.com/inward/record.url?scp=85045575132&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85045575132&partnerID=8YFLogxK

U2 - 10.1016/j.vaccine.2018.03.082

DO - 10.1016/j.vaccine.2018.03.082

M3 - Article

C2 - 29661585

AN - SCOPUS:85045575132

JO - Vaccine

JF - Vaccine

SN - 0264-410X

ER -