Patients are stopping and starting blood pressure medications, especially in the first year of treatment, suggesting the need for more effective interventions to improve adherence.
An Australian study of more than 31,000 older patients newly initiated on blood pressure lowering therapy between 2008 and 2016 found that 40-70% discontinued treatment during follow-up.
Time to discontinuation was typically between 159 to 373 days however re-initiation of therapy was also common (31-49% of patients depending on the particular agent) and was usually within 177 to 302 days.
Patients on fixed dose combination (FDC) therapy were the most likely to stick with their prescribed therapy followed by those on angiotensin II receptor blockers, beta‐blockers, ACE inhibitors, calcium channel blockers, diuretics then other anti-hypertensives.
Overall, 50-60% of patients maintained good adherence to the majority of blood pressure lowering (BPL) agents at six months.
“At 12 months, increasing variance in adherence occurred across different BPL categories, with good adherence ranging from 34% among patients receiving other anti‐hypertensives to 51% among patients receiving fixed dose combinations (FDCs). Beyond 12 months, adherence steadily decreased across all BPL categories. At 3 years, 21% to 42% of users remained good adherence to BPL agents.”
Discontinuation of treatment was higher among older patients, those whose treatment was initiated by GPs, and those with co-morbid diabetes, gastrointestinal disease, autoimmune disease or chronic pain.
The researchers said the high re‐initiation rate after discontinuing treatment suggested adverse events or other medical reasons did not explain the lack of adherence.
“Therefore, it is crucial to reinforce adherence and persistence to BPL agents, especially in the first year since initiation. A number of studies have proposed promising interventions to improve medical adherence in older populations, including providing feedback and reminders, reducing the pill burden, improving health literacy, motivational interviewing, and multi‐facet interventions.”
They added that while FDCs have been proven to improve persistence and adherence by reducing pill burden, their use in this study was at a relatively low level (21%).
“This is consistent with the recommendation of conservative use of FDC in older patients due to increased risks of BPL‐induced adverse events.”