Statins are a family of cholesterol-lowering drugs widely used to prevent heart attack and stroke. Randomised clinical trials (RCTs) have shown that statins are safe and effective in younger (<75yrs) and generally healthier older people. Unfortunately, results of available studies are not generalisable to the entire older population since older and sicker patients have not been adequately represented in RCTs.
Therefore, we plan to investigate the effect of statins for the prevention of heart attack and stroke and selected adverse events in a representative sample of older primary care patients using routinely collected GP data. The use of GP data will allow investigating real world effects in groups of older and sicker patients who are under-represented in RCTs. We also aim to estimate whether the healthcare cost of providing statins is justified by their effects in these groups of elderly patients.
As part of the NIHR School for Public Health Research ‘Ageing Well’ programme, this research will increase the evidence base on the use of statins in later life, helping doctors and policy-makers to make decisions and scientists to inform new experimental research, overall benefiting the care of older people.
The primary objective is to assess the effectiveness of statins for prevention of myocardial infarction (MI). Secondarily, we aim to explore selected potential adverse reactions, the effect of age and burden of disease on statins effectiveness, and the cost-effectiveness of statins.
To do this, a retrospective parallel cohorts study will be constructed in a sample of 60+ CPRD patients. Statins (class) receipt will be the exposure and MI and IS the primary endpoints. Selected adverse reactions (i.e. falls/fractures, Parkinson’s disease, Alzheimer’s disease, ischemic stroke and death), and costs (derived by extracting health-care utilisation measures from CPRD and deriving Healthcare Resource Group categories from Hospital Episode Statistics) and QALYs (based on observed outcomes and data from the literature) will also be investigated as secondary endpoints.
Main hypotheses will be tested by using Cox regressions; effect of age and disease burden by interaction terms; confounding will be addressed by propensity score and difference in difference methods (when applicable). Missing-at-random will be assumed and data will be explored to investigate this assumption. Decision modelling will be used to synthesise the results of CPRD-HES data analysis, existing evidence from the literature and expert opinion for cost-effectiveness analysis.
David Melzer - Chief Investigator - University of Exeter
Alessandro Ble - Corresponding Applicant - University of Exeter
Adam Streeter - Collaborator - University of Exeter
Jane Masoli - Collaborator - University of Exeter
Joao Delgado - Collaborator - University of Exeter
Jose M Valderas - Collaborator - University of Exeter
Kirsty Bowman - Collaborator - University of Exeter
Peter Hughes - Collaborator - University of Exeter
Ruben Mujica Mota - Collaborator - University of Exeter
William Henley - Collaborator - University of Exeter
HES Admitted Patient Care;ONS Death Registration Data;Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation