Treatment optimisation in older primary care patients – a focus on antihypertensive medication reduction

Thesis

Background: Antihypertensive treatments are widely used among older adults to effectively reduce morbidity from cardiovascular disease. However, these treatments are also associated with potential harms, and the evolving risk-benefit balance in ageing patients has raised questions about the necessity of indefinite treatment. Recent guidelines have suggested discontinuing antihypertensive therapy for some older patients. However, robust evidence to support this approach is still lacking. Therefore, this thesis aims to address this gap by examining the association between reducing antihypertensive treatment and long-term outcomes in older patients.

Methods: This thesis comprises four empirical chapters. The first is a systematic review that identifies and synthesises outcomes following the cessation of cardiovascular medications. The second chapter develops a method to detect sustained changes in complex pharmacotherapeutic regimens using routinely collected primary care data from the Clinical Practice Research Datalink (CPRD) GOLD dataset. The third chapter investigates patient characteristics associated with the continuation or discontinuation of treatment. Finally, the fourth chapter examines long-term outcomes following the reduction of antihypertensive treatment.

Results: The systematic review found no evidence of a short-term association between antihypertensive treatment discontinuation and all-cause hospitalisation. Using a representative English primary care cohort treated with antihypertensives, a novel algorithm was developed to detect sustained changes in longitudinal data, resulting in the successful identification of treatment reduction. Over time, one-third of patients on antihypertensive treatment reduced their medication. Patients who were older, experienced polypharmacy, or had lower blood pressure were more likely to reduce treatment, whereas those with additional cardiovascular risk factors were more likely to continue. Treatment reduction was associated with a decrease in all-cause hospitalisation; however, it was also associated with increases in all-cause mortality and cause-specific hospitalisation.

Conclusion: This work established that antihypertensive treatment is routinely reduced in primary care and that this intervention is potentially associated with a reduction in all-cause hospitalisation but increased cause-specific harm in a generalisable older population. These findings suggest that discontinuation of antihypertensive treatment should potentially be avoided in patients who tolerate the therapy well. Future research should focus on identifying specific patient populations, specific drug classes, clinical conditions, and strategies for managing long-term preventive pharmacological interventions to better guide treatment decisions.

Authors: van der Veen, RS

• DOI: 10.5287/ora-7rnn1qr88
• Type of award: DPhil
• Level of award: Doctoral
• Awarding institution: University of Oxford
• Language: English
• Keywords: observational research; pharmacoepidemiology; medication reduction
• Subjects: Medication management; Primary care (Medicine)