Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2021 May:25:20.154.
doi: 10.7812/TPP/20.154.

Trends in Influenza Vaccine Uptake and Severe Influenza-Related Outcomes at Kaiser Permanente Southern California, 2007-2017

In-Lu Amy Liu  1 , Hilary C Tanenbaum  1 , Lei Qian  1 , Lina S Sy  1 , Wansu Chen  1 , Steven J Jacobsen  1
Affiliations

Trends in Influenza Vaccine Uptake and Severe Influenza-Related Outcomes at Kaiser Permanente Southern California, 2007-2017

In-Lu Amy Liu et al. Perm J. 2021 May.

Abstract

Introduction: Major efforts to increase influenza vaccine uptake among Kaiser Permanente Southern California (KPSC) members have been undertaken in recent years. However, whether these improvements translate to a decline in severe influenza-related outcomes has not been examined. We aimed to understand the impact of the influenza vaccination program at KPSC by examining influenza vaccine uptake and 3 severe influenza-related outcomes.

Methods: We conducted an ecologic trend analysis to understand influenza vaccine uptake and influenza-related hospitalization, intensive care unit (ICU) admission, and mortality for each influenza season (2007-2017). The same cohort was followed from the influenza season to the noninfluenza season immediately afterward while using the noninfluenza season as the comparison group. We also assessed the within-season correlation between influenza vaccine uptake and influenza-related outcomes.

Results: Influenza vaccine uptake rose from 23.9% to 45.5%, and all 3 influenza-related outcome rates declined (hospitalization: 35.4-26.8/10,000 patients; ICU: 5.9-5.2/10,000 patients; and mortality: 3.4-2.3/10,000 patients). Influenza vaccine uptake was negatively correlated with hospitalization (-0.32, p < 0.001) and mortality (-0.29, p = 0.001). However, once we adjusted for the noninfluenza season, the results of the correlation analysis were no longer statistically significant.

Conclusion: Although we could not establish a statistically significant inverse relationship between influenza vaccination and severe influenza-related outcomes over the study period, our findings indicate an overall decline in influenza-related outcomes over the study period, suggesting improvements in both preventive and acute care quality at KPSC.

PubMed Disclaimer

Conflict of interest statement

Disclosure Statement: In-Lu Amy Liu, MS, reports no conflicts of interest. Hilary C Tanenbaum, PhD, MS, MPH, received research contract grants from companies of GlaxoSmithKline and Modulated Imaging. Lei Qian, PhD, received a research contract grant from GlaxoSmithKline. Lina S Sy, MPH, received research contract grants from companies of GlaxoSmithKline, Dynavax, and Novavax. Wansu Chen, PhD, MS, reports no conflicts of interest. Steven J Jacobsen, MD, PhD, reports no conflicts of interest xist.

Figures

Figure 1.
Figure 1.
Influenza vaccine uptake, 2007-2017§, Kaiser Permanente Southern California. § Influenza vaccination period defined as September-April.*Overall rates were standardized for age, sex, and race/ethnicity using data from the last season (2016-17).
Figure 2.
Figure 2.
Rates of influenza-related outcomes per 10,000 patients, 2007-2017, Kaiser Permanente Southern California.
See this image and copyright information in PMC

Similar articles

See all similar articles

Cited by

References

    1. Grohskopf LA, Sokolow LZ, Broder KR, et al. . Prevention and control of seasonal influenza with vaccines. MMWR Recomm Rep 2016 Aug;65(5):1-54. DOI: 10.15585/mmwr.rr6505a1 - DOI - PubMed
    1. Lin MH, Wood JR, Mittelman SD, Freyer DR. Institutional adherence to cardiovascular risk factor screening guidelines for young survivors of acute lymphoblastic leukemia. J Pediatr Hematol Oncol 2015 May;37(4):e253-7. DOI: 10.1097/MPH.0000000000000320, PMID:25757021 - DOI - PubMed
    1. Fukushima W, Hirota Y. Basic principles of test-negative design in evaluating influenza vaccine effectiveness. Vaccine 2017 Aug;35(36):4796-800. DOI: 10.1016/j.vaccine.2017.07.003, PMID:28818471 - DOI - PubMed
    1. World Health Organization . Evaluation of influenza vaccine effectiveness: A guide to the design and interpretation of observational studies. Geneva: World Health Organization; 2017. Report No.: 9241512121.
    1. Fireman B, Lee J, Lewis N, Bembom O, van der Laan M, Baxter R. Influenza vaccination and mortality: Differentiating vaccine effects from bias. Am J Epidemiol 2009 Sep;170(5):650-6. DOI: 10.1093/aje/kwp173, PMID:19625341 - DOI - PMC - PubMed

Substances