tetano
Editor, Senior Moderator
Vaccine. 2013 Jul 9. pii: S0264-410X(13)00913-4. doi: 10.1016/j.vaccine.2013.06.103. [Epub ahead of print]
Variable definitions of the influenza season and their impact on vaccine effectiveness estimates.
Sullivan SG, Tay EL, Kelly H.
Source
WHO Collaborating Centre for Reference and Research on Influenza, Melbourne, Australia. Electronic address: sheena.sullivan@influenzacentre.org.
Abstract
Vaccine effectiveness (VE) studies are often made for a "season" which may refer to different analysis periods in different systems. We examined whether the use of four different definitions of season would materially affect estimates of influenza VE using data from the Victorian general practice (GP) sentinel surveillance network for 2007-2012. In general, the choice of analysis period had little effect on VE estimates (≤five percentage points) when there was a statistically significant protective effect of vaccination (2007, 2010 and 2012). In contrast, for years when the analysis period varied widely depending on the method used and when VE estimates were imprecise, the change in VE estimate was as much as 43 percentage points (2008). Studies of influenza VE should clearly define the analysis period used and, where possible, provide sensitivity analyses to align this definition with other VE studies.
Copyright ? 2013. Published by Elsevier Ltd.
KEYWORDS:
Influenza, Influenza season, Influenza vaccine, Influenza-like illness, Vaccine effectiveness
PMID:
23850417
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23850417
Variable definitions of the influenza season and their impact on vaccine effectiveness estimates.
Sullivan SG, Tay EL, Kelly H.
Source
WHO Collaborating Centre for Reference and Research on Influenza, Melbourne, Australia. Electronic address: sheena.sullivan@influenzacentre.org.
Abstract
Vaccine effectiveness (VE) studies are often made for a "season" which may refer to different analysis periods in different systems. We examined whether the use of four different definitions of season would materially affect estimates of influenza VE using data from the Victorian general practice (GP) sentinel surveillance network for 2007-2012. In general, the choice of analysis period had little effect on VE estimates (≤five percentage points) when there was a statistically significant protective effect of vaccination (2007, 2010 and 2012). In contrast, for years when the analysis period varied widely depending on the method used and when VE estimates were imprecise, the change in VE estimate was as much as 43 percentage points (2008). Studies of influenza VE should clearly define the analysis period used and, where possible, provide sensitivity analyses to align this definition with other VE studies.
Copyright ? 2013. Published by Elsevier Ltd.
KEYWORDS:
Influenza, Influenza season, Influenza vaccine, Influenza-like illness, Vaccine effectiveness
PMID:
23850417
[PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/23850417