Longitudinal Analyses of Blood Lipids and Future Risk of Dementia in CPRD (Lipids and dementia)

Study type

• Study type:
  Non-interventional study
• Scope of the study:
  Assessment of risk minimisation measure implementation or effectiveness

  Disease epidemiology

Non-interventional study

• Non-interventional study design:
  Cohort

Study drug and medical condition

• Medical condition to be studied:
  Lipids

  Dementia Alzheimer's type

  Vascular dementia

  Hyperlipidaemia

  Hypercholesterolaemia

Population studied

• Age groups:
  • Adults (46 to < 65 years)
  • Adults (65 to < 75 years)
  • Adults (75 to < 85 years)
  • Adults (85 years and over)
• Estimated number of subjects:
  1800000

Study design details

• Main study objective:
  The primary objectives of the analysis is to estimate the age-specific association between lipids - total cholesterol, low density lipoprotein (LDL) and high density cholesterol (HDL) and future risk of Alzheimer´disease, vascular dementia and all dementia.
• Outcomes:
  Alzheimer´s disease, Vascular dementia, All dementia, All-cause death
• Data analysis plan:
  To relate lipids (total choleterol, LDL and HDL) to risk of dementia, Poisson regression models will be used to estimate incidence rates and rate ratios. Adjustment for age (in 5-year bands), sex, and baseline date (at index). To update age at risk as people move through the age categories. Adjustment of rate ratios for additional baseline cardiovascular covariates. To fit separate Poisson regression models in each category for follow intervals and age-at-risk. Correction for regression dilution bias using serial lipid measurements. To assess selective mortality bias, a simulation study to investigate the size of competing risk of mortality, with ´joint frailty´ models. To confirm well-established association of lipids with all cause mortality