title: Quantifying the contribution of statins to the decline in population mean cholesterol by socioeconomic group in England 1991 - 2012: a modelling study.
abstract: BACKGROUND
  Serum total cholesterol is one of the major targets for cardiovascular disease prevention. Statins are effective for cholesterol control in individual patients. At the population level, however, their contribution to total cholesterol decline remains unclear. The aim of this study was to quantify the contribution of statins to the observed fall in population mean cholesterol levels in England over the past two decades, and explore any differences between socioeconomic groups.
  
  
  RESULTS
  This is a modelling study based on data from the Health Survey for England. We analysed changes in observed mean total cholesterol levels in the adult England population between 1991-92 (baseline) and 2011-12. We then compared the observed changes with a counterfactual 'no statins' scenario, where the impact of statins on population total cholesterol was estimated and removed. We estimated uncertainty intervals (UI) using Monte Carlo simulation, where confidence intervals (CI) were impractical. In 2011-12, 13.2% (95% CI: 12.5-14.0%) of the English adult population used statins at least once per week, compared with 1991-92 when the proportion was just 0.5% (95% CI: 0.3-1.0%). Between 1991-92 and 2011-12, mean total cholesterol declined from 5.86 mmol/L (95% CI: 5.82-5.90) to 5.17 mmol/L (95% CI: 5.14-5.20). For 2011-12, mean total cholesterol was lower in more deprived groups. In our 'no statins' scenario we predicted a mean total cholesterol of 5.36 mmol/L (95% CI: 5.33-5.40) for 2011-12. Statins were responsible for approximately 33.7% (95% UI: 28.9-38.8%) of the total cholesterol reduction since 1991-92. The statin contribution to cholesterol reduction was greater among the more deprived groups of women, while showing little socio-economic gradient among men.
  
  
  CONCLUSIONS
  Our model suggests that statins explained around a third of the substantial falls in total cholesterol observed in England since 1991. Approximately two thirds of the cholesterol decrease can reasonably be attributed non-pharmacological determinants.
authors: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.
authors: Chris
authors: C
authors: Kypridemos
authors: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom; Department of Hypertension and Diabetology, Medical University of Gdansk, Gdansk, Poland.
authors: Piotr
authors: P
authors: Bandosz
authors: Epidemiology and Population Health Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom.
authors: Graeme L
authors: GL
authors: Hickey
authors: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.
authors: Maria
authors: M
authors: Guzman-Castillo
authors: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom; Lancaster Medical School, Lancaster University, Lancaster, United Kingdom.
authors: Kirk
authors: K
authors: Allen
authors: Centre for Health Informatics, Institute of Population Health, University of Manchester, Manchester, United Kingdom.
authors: Iain
authors: I
authors: Buchan
authors: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.
authors: Simon
authors: S
authors: Capewell
authors: Department of Public Health and Policy, University of Liverpool, Liverpool, United Kingdom.
authors: Martin
authors: M
authors: O'Flaherty
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002318:Cardiovascular Diseases / Q000097:blood* / Q000453:epidemiology / Q000235:genetics; D002784:Cholesterol / Q000097:blood*; D016001:Confidence Intervals; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009010:Monte Carlo Method; D012923:Social Class
chemical_list: D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D002784:Cholesterol