title: Pre-admission statin use and in-hospital severity of 2009 pandemic influenza A(H1N1) disease.
abstract: BACKGROUND
  Statins are drugs that are used to lower plasma cholesterol levels. Recently, contradictory claims have been made about possible additional effects of statins on progression of a variety of inflammatory disorders, including infections. We therefore examined the clinical course of patients admitted to hospital with 2009 pandemic influenza A(H1N1), who were or weren't taking statins at time of admission.
  
  
  METHODS
  A retrospective case-control study was performed using the United Kingdom Influenza Clinical Information Network (FLU-CIN) database, containing detailed information on 1,520 patients admitted to participating hospitals with confirmed 2009 pandemic influenza A(H1N1) infection between April 2009 and January 2010. We confined our analysis to those aged over 34 years. Univariate analysis was used to calculate unadjusted odds ratios (OR) and 95 percent confidence intervals (95%CI) for factors affecting progression to severe outcome (high dependency or intensive care unit level support) or death (cases); two multivariable logistic regression models were then established for age and sex, and for age, sex, obesity and "indication for statin" (e.g., heart disease or hypercholesterolaemia).
  
  
  RESULTS
  We found no statistically significant association between pre-admission statin use and severity of outcome after adjustment for age and sex [adjusted OR: 0.81 (95% CI: 0.46-1.38); n = 571]. After adjustment for age, sex, obesity and indication for statin, the association between pre-admission statin use and severe outcome was not statistically significant; point estimates are compatible with a small but clinically significant protective effect of statin use [adjusted OR: 0.72 (95% CI: 0.38-1.33)].
  
  
  CONCLUSIONS
  In this group of patients hospitalized with pandemic influenza, a significant beneficial effect of pre-admission statin use on the in-hospital course of illness was not identified. Although the database from which these observations are derived represents the largest available suitable UK hospital cohort, a larger study would be needed to confirm whether there is any benefit in this setting.
authors.affiliation: Centre for Peri-operative Medicine and Critical Care Research, Imperial College Healthcare NHS Trust, London, United Kingdom. stephen.brett@imperial.ac.uk
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Brett
authors.forename: Puja
authors.initials: P
authors.lastname: Myles
authors.forename: Wei Shen
authors.initials: WS
authors.lastname: Lim
authors.forename: Joanne E
authors.initials: JE
authors.lastname: Enstone
authors.forename: Barbara
authors.initials: B
authors.lastname: Bannister
authors.forename: Malcolm G
authors.initials: MG
authors.lastname: Semple
authors.forename: Robert C
authors.initials: RC
authors.lastname: Read
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Taylor
authors.forename: Jim
authors.initials: J
authors.lastname: McMenamin
authors.forename: Karl G
authors.initials: KG
authors.lastname: Nicholson
authors.forename: Jonathan S
authors.initials: JS
authors.lastname: Nguyen-Van-Tam
authors.forename: Peter J M
authors.initials: PJ
authors.lastname: Openshaw
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006760:Hospitalization; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D053118:Influenza A Virus, H1N1 Subtype / Q000502:physiology*; D007251:Influenza, Human / Q000453:epidemiology* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D058873:Pandemics; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors