Half of all cancer patients are now expected to survive from their cancer for 10 years. The risk of developing cardiovascular disease (i.e. having a heart attack or stroke) is recognised as a key potential life-long consequence of cancer treatment. Cardiovascular disease is the second leading cause of long-term complications and death among cancer survivors, after secondary cancers. Guidelines recommend people aged 40-74 years should have their blood pressure, cholesterol, and other risk factors measured every 5 years, and their risk of developing cardiovascular disease in the next 10 years should be estimated. Those patients considered at high risk should be offered advice to lower their risk and should typically be offered cholesterol lowering therapy (a statin) and a medicine to lower blood pressure. It is not clear whether these cardiovascular risk prevention guidelines are being followed.
With this study using UK primary care data (2005-2013) we aim to understand whether recommended risk factor monitoring and medicines to prevent CVD are optimally implemented among cancer survivors compared to the general population. We will also investigate whether cancer survivors are more or less likely to continue or stop taking medicines for CVD risk versus the general population.
This retrospective cohort study in Clinical Practice Research Datalink (2005-2013) aims to understand whether recommended risk factor monitoring (blood pressure, cholesterol, cardiovascular disease risk scores) and pharmacological interventions (statins and antihypertensives) to prevent cardiovascular disease are optimally implemented among cancer survivors versus the general population; and whether persistence on preventive therapies is different in cancer survivors.
The study population will be drawn from all research quality patients in CPRD who were 40 years or older between 2005 and 2013. Follow-up time will be categorised as non-cancer, first year since cancer diagnosis, and ≥1 year since cancer diagnosis (i.e. cancer survivors). Only patients with a cardiovascular risk score recorded will be included in the statin uptake analysis and those who initiate a statin the persistence analysis.
Descriptive statistics will be used to describe baseline demographics and cardiovascular risk distribution of the cancer survivors cross-tabulated with controls. Logistic regression modelling will be used to produce unadjusted and adjusted ORs, to estimate the association between cancer survivorship and initiation of therapy among those with high recorded cardiovascular risk, adjusted for confounders. We will measure time-to-discontinuation of therapy using Kaplein Meier curves. Hazard ratios for persistence will be estimated using Cox proportional hazards model.
Health Outcomes to be Measured:
Blood pressure, lipids, CVD risk score recorded in the past 1,3 and 5 years according to age, gender and year since cancer diagnosis Markers of cardiovascular risk including serum cholesterol, systolic and diastolic blood pressure First prescription of statin therapy recorded within 1 month (and 3 months in sensitivity analysis) of first high CV risk record First prescription of antihypertensives (AHT) recorded within 1 month (and 3 months in sensitivity analysis) of first high CV risk record Time from eligibility to first initiation of a statin/AHT Time from statin initiation to first cessation of therapy Time from AHT initiation to first cessation of therapy
Patient Level Index of Multiple Deprivation;Practice Level Index of Multiple Deprivation