[Source: PLoS ONE, full page: (LINK). Abstract, edited.]
The Impact of Influenza Vaccinations on the Adverse Effects and Hospitalization Rate in the Elderly: A National Based Study in an Asian Country
Tsung-Yu Ho1#, Kuang-Yung Huang3,4,9#, Tza-Ta Huang9,10, Yung-Sung Huang2, Hsu-Chueh Ho1,4, Pesus Chou5, Chun-Hung Lin6, Chang-Kao Wei6, Wei-Chang Lian7, Ting-Chang Chen7, Hsien-Bin Huang9, Ching-Chih Lee1,4,5,8*
1 Department of Otolaryngology, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, 2 Divsion of Neurology, Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, 3 Division of Allergy, Immunology, and Rheumatology, Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, 4 School of Medicine, Tzu Chi University, Hualian, Taiwan, 5 Community Medicine Research Center and Institute of Public Health, National Yang-Ming University, Taipei, Taiwan, 6 Department of Surgery, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, 7 Division of Metabolism and Endocrinology, Department of Internal Medicine, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, 8 Cancer Center, Buddhist Dalin Tzu Chi General Hospital, Chiayi, Taiwan, 9 Department of Life Science and Institute of Molecular Biology, National Chung Cheung University, Chiayi, Taiwan, 10 Department of Oral and Maxillofacial Surgery, Changhua Christian Hospital, You-Lin Branch, You-Lin, Taiwan
To examine the risk of adverse effects of special interest in persons vaccinated against seasonal influenza compared with unvaccinated persons aged 65 and above.
We retrospectively observed 41,986 vaccinated elderly persons and 50,973 unvaccinated elderly persons in Taiwan from October 1, 2008, through September 30, 2009, using the National Health Insurance database. Neurological and autoimmune disorders and one-year hospitalization rates and in-hospital mortality rates were analyzed according to the vaccination status. Propensity score analysis was used to assess the relationship between adverse outcomes, hospitalization rates, and vaccination status.
45% of the elderly received influenza vaccination. Multiple logistic regression showed that the probability of being vaccinated was related to more patients visiting for URI symptoms (odds ratio (OR), 1.03; 95% CI, 1.02–1.03), men (OR, 1.15; 95% CI, 1.12–1.17), increased age (OR, 1.02; 95% CI, 1.02–1.03), and more comorbidities (OR, 1.2; 95% CI, 1.17–1.23). There were no statistical differences in neurological and autoimmune diseases between the vaccinated and unvaccinated individuals using propensity score analysis, but vaccinated persons had a reduced hospitalization rate of 19% (odds ratio [OR], 0.81; 95% CI, 0.77–0.84) for the first six-months and 13% for one-year of follow-up (OR, 0.87; 95% CI, 0.85–0.9).
Based on data from the one-year follow-ups among 93,049 elderly persons in Taiwan, reassuring results for selected neurological and autoimmune diseases were found among the vaccinated individuals after adjusting other factors. Influenza vaccination decreased the risk for hospitalization. Public health strategies must continue to improve the influenza vaccination rate among the elderly with information based upon tangible evidence.
Citation: Ho T-Y, Huang K-Y, Huang T-T, Huang Y-S, Ho H-C, et al. (2012) The Impact of Influenza Vaccinations on the Adverse Effects and Hospitalization Rate in the Elderly: A National Based Study in an Asian Country. PLoS ONE 7(11): e50337. doi:10.1371/journal.pone.0050337
Editor: Jianqing Xu, Fudan University, China
Received: June 24, 2012; Accepted: October 18, 2012; Published: November 28, 2012
Copyright: © 2012 Ho et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Funding: The authors have no support or funding to report.
Competing interests: The authors have declared that no competing interests exist.
* E-mail: firstname.lastname@example.org
# These authors contributed equally to this work.