Cost-effectiveness analysis of different systolic blood pressure targets for people with a history of stroke or transient ischaemic attack: economic analysis of the PAST-BP (Prevention After Stroke – Blood Pressure) Study

Background: The PAST-BP trial found that using a lower systolic blood pressure (SBP) target (<130 mmHg or lower versus < 140mmHg) in a primary care population with prevalent cerebrovascular disease was associated with a small additional reduction in blood pressure (2.9 mmHg). Objectives: To determine the cost effectiveness of an intensive systolic blood pressure target (<130mmHg or lower) compared with a standard target (<140mmHg) in people with a history of stroke or transient ischaemic attack Perspective: UK National Health Service (NHS) and Personal Social Services (PSS) Setting: People with a history of stroke or transient ischaemic attack (TIA) on general practice stroke/TIA registers in England. Methods: A Markov model with a one year time cycle and a 30 year time horizon was used to estimate the cost per quality adjusted life year (QALY) of an intensive target versus a standard target. Individual patient level data were used from the PAST BP trial with regard to change in blood pressure and numbers of primary care consultations over a 12 month period. Published sources were used to estimate life expectancy, and risks of cardiovascular events and their associated costs and utilities. Results: In the base-case results, aiming for an intensive blood pressure target was dominant, with the incremental lifetime costs being £169 lower per patient than for the standard blood pressure target with a 0.08 QALY gain. This was robust to sensitivity analyses, unless intensive blood pressure lowering reduced quality of life by 2% or more. Conclusion: Aiming for a systolic blood pressure target of < 130mmHg or lower is cost effective in people who have had a stroke/TIA in the community, but it is difficult to separate out the impact of the lower target from the impact of more active management of blood pressure.