Further evidence for bias in observational studies of influenza vaccine effectiveness: The 2009 influenza a(H1N1) pandemic

American Journal of Epidemiology

Volumn 178, Issue 8, 2013, Pages 1327-1336

  Jackson, Michael L ^a   Yu, Onchee ^a   Nelson, Jennifer C ^a   Naleway, Allison ^a   Belongia, Edward A ^a   Baxter, Roger ^a   Narwaney, Komal ^a   Jacobsen, Steven J ^a   Shay, David K ^a   Jackson, Lisa A ^a  

^a CENTER FOR HEALTH STUDIES   (United States)

Author keywords

confounding factors (epidemiology); epidemiologic methods; influenza; influenza, pandemic; vaccine effectiveness; vaccines

Indexed keywords

INFLUENZA VACCINE;

ESTIMATION METHOD; HEALTH CARE; HEALTH SERVICES; INFLUENZA; MORTALITY; PROJECT MANAGEMENT; QUALITATIVE ANALYSIS; SEASONAL VARIATION; VACCINATION; VACCINE; WINTER;

ARTICLE; AUTUMN; DRUG EFFICACY; HUMAN; INFLUENZA A (H1N1); INFLUENZA VACCINATION; MANAGED CARE ORGANIZATION; OBSERVATIONAL STUDY; PANDEMIC; SEASONAL INFLUENZA; SUMMER; UNITED STATES; WINTER;

CONFOUNDING FACTORS (EPIDEMIOLOGY); EPIDEMIOLOGIC METHODS; INFLUENZA; INFLUENZA, PANDEMIC; VACCINE EFFECTIVENESS; VACCINES;

AGED; BIAS (EPIDEMIOLOGY); CONFOUNDING FACTORS (EPIDEMIOLOGY); EPIDEMIOLOGIC METHODS; FEMALE; HUMANS; INFLUENZA A VIRUS, H1N1 SUBTYPE; INFLUENZA VACCINES; INFLUENZA, HUMAN; MALE; MORTALITY; OBSERVATION; PANDEMICS; PROPORTIONAL HAZARDS MODELS; RETROSPECTIVE STUDIES; SEASONS; UNITED STATES;

UNITED STATES;

EID: 84885790098     PISSN: 00029262     EISSN: 14766256     Source Type: Journal    
DOI: 10.1093/aje/kwt124     Document Type: Article

References (24)

1. Jackson LA, Jackson ML, Nelson JC, et al. Evidence of bias in estimates of influenza vaccine effectiveness in seniors. Int J Epidemiol. 2006;35(2):337-344.
2. Jackson ML,Weiss NS, Nelson JC, et al. To rule out confounding, observational studies of influenza vaccine need to include analyses during the "preinfluenza period" [letter]. Arch Intern Med. 2007;167(14):1553- 1554. (Pubitemid 47124191)
3. Nichol KL. Challenges in evaluating influenza vaccine effectiveness and the mortality benefits controversy. Vaccine. 2009;27(45):6305-6311.
4. Nichol KL, Nordin JD, Nelson DB, et al. Effectiveness of influenza vaccine in the community-dwelling elderly. N Engl J Med. 2007;357(14):1373-1381. (Pubitemid 47535592)
5. Simonsen L, Taylor RJ, Viboud C, et al. Mortality benefits of influenza vaccination in elderly people: an ongoing controversy. Lancet Infect Dis. 2007;7(10):658-666. (Pubitemid 47444564)
6. Fedson DS,Wajda A, Nicol JP, et al. Clinical effectiveness of influenza vaccination in Manitoba. JAMA. 1993;270(16): 1956-1961. (Pubitemid 23312612)
7. Nichol KL, Nordin J, Mullooly J, et al. Influenza vaccination and reduction in hospitalizations for cardiac disease and stroke among the elderly. N Engl J Med. 2003;348(14): 1322-1332. (Pubitemid 36384099)
8. Shapiro Y, Shemer J, Heymann A, et al. Influenza vaccination: reduction in hospitalizations and death rates among members of "Maccabi Healthcare Services" during the 2000-2001 influenza season. Isr Med Assoc J. 2003;5(10):706-708. (Pubitemid 37369034)
9. Simonsen L, Reichert TA, Viboud C, et al. Impact of influenza vaccination on seasonal mortality in the US elderly population. Arch Intern Med. 2005;165(3):265-272. (Pubitemid 40216277)
10. Jackson LA, Nelson JC, Benson P, et al. Functional status is a confounder of the association of influenza vaccine and risk of all cause mortality in seniors. Int J Epidemiol. 2006;35(2): 345-352.
11. Campitelli MA, Rosella LC, Stukel TA, et al. Influenza vaccination and all-cause mortality in community-dwelling elderly in Ontario, Canada, a cohort study. Vaccine. 2010; 29(2):240-246.
12. Fireman B, Lee J, Lewis N, et al. Influenza vaccination and mortality: differentiating vaccine effects from bias. Am J Epidemiol. 2009;170(5):650-656.
13. Ortqvist A, Granath F, Askling J, et al. Influenza vaccination and mortality: prospective cohort study of the elderly in a large geographical area. Eur Respir J. 2007;30(3): 414-422. (Pubitemid 351182062)
14. Hottes TS, Skowronski DM, Hiebert B, et al. Influenza vaccine effectiveness in the elderly based on administrative databases: change in immunization habit as a marker for bias. PLoS One. 2011;6(7):e22618.
15. Hak E, Hoes AW, Nordin J, et al. Benefits of influenza vaccine in US elderly-appreciating issues of confounding bias and precision [letter]. Int J Epidemiol. 2006;35(3): 800-802. (Pubitemid 43985583)
16. Centers for Disease Control and Prevention. Update: influenza activity-United States, August 30, 2009-March 27, 2010, and composition of the 2010-11 influenza vaccine. MMWR Morb Mortal Wkly Rep. 2010;59(14):423-430.
17. Baggs J, Gee J, Lewis E, et al. The Vaccine Safety Datalink: a model for monitoring immunization safety. Pediatrics. 2011;127(suppl 1):S45-S53.
18. Nordin J, Mullooly J, Poblete S, et al. Influenza vaccine effectiveness in preventing hospitalizations and deaths in persons 65 years or older in Minnesota, New York, and Oregon: data from 3 health plans. J Infect Dis. 2001; 184(6):665-670. (Pubitemid 32826416)
19. Jackson ML, Nelson JC,Weiss NS, et al. Influenza vaccination and risk of community-acquired pneumonia in immunocompetent elderly people: a population-based, nested casecontrol study. Lancet. 2008;372(9636):398-405.
20. Centers for Disease Control and Prevention, US Department of Health and Human Services. United States Influenza Surveillance Data: 1997-1998 Through 2007-2008 Seasons. Atlanta, GA: Centers for Disease Control and Prevention; 2011. (http://www.cdc.gov/flu/weekly/ussurvdata.htm). (Accessed May 20, 2011).
21. Jackson ML, Nelson JC, Jackson LA. Why do covariates defined by International Classification of Diseases codes fail to remove confounding in pharmacoepidemiologic studies among seniors? Pharmacoepidemiol Drug Saf. 2011; 20(8):858-865.
22. Hak E, Verheij TJ, Grobbee DE, et al. Confounding by indication in non-experimental evaluation of vaccine effectiveness: the example of prevention of influenza complications. J Epidemiol Community Health. 2002; 56(12):951-955. (Pubitemid 35440661)
23. Hancock K, Veguilla V, Lu X, et al. Cross-reactive antibody responses to the 2009 pandemic H1N1 influenza virus. N Engl J Med. 2009;361(20):1945-1952.
24. Baxter R, Lee J, Fireman B. Evidence of bias in studies of influenza vaccine effectiveness in elderly patients. J Infect Dis. 2010;201(2):186-189.