Antihypertensive persistence, compliance factors identified
MedWire News: Persistence and compliance with antihypertensive therapy have improved since the late 1990s among elderly patients residing in Ontario, Canada, show results of a study that also found the rates of each were highest when patients were initiated on an ACE inhibitor.
Conversely, persistence and compliance were lowest with beta blockers and diuretics, respectively, report Oded Friedman (Mount Sinai Hospital, Toronto, Canada) and team.
Men showed worse persistence/compliance than women, as did patients from urban rather than rural areas and those of low socioeconomic status compared with more affluent patients.
“Awareness of such factors could translate into concerted efforts at optimizing medication-taking behaviors among newly diagnosed elderly hypertensive patients,” explain the authors in the American Journal of Medicine.
The researchers linked four administrative databases and a clinical database to look at trends in antihypertensive use over time among 207,473 patients aged 66 years or older who received a new prescription for an antihypertensive agent between 1997 and 2005.
The patients’ average age was 74.2 years, 58.4% were women, and 41,326 (19.9%) had diabetes. Multivariable analysis showed that persistence with therapy in general and with the initial drug class, as well as medication compliance (Medication Possession Ratio ≥0.8), all increased over the study period, at odds ratios (ORs) per 2-year increment in cohort year of 1.04 (p<0.0001), 1.01 (p=0.013), and 1.07 (p<0.0001), respectively.
Urban residents were less likely to persist with therapy (OR=0.78) or initial drug class (OR=0.79) or to comply (OR=0.82) than rural residents (all p<0.0001).
Persistence was lower in comorbid-free patients, at ORs of 0.76 for therapy and 0.72 for class persistence in patients with a Charlson comorbidity index (CCI) score of 0 versus 2+ patients, but greater in older patients, at corresponding ORs of 1.02 and 1.05 per 5-year increment in age, respectively (all p<0.0001). Conversely, compliance was greater in comorbid-free patients, at an OR of 1.29 for patients with a CCI score of 0 versus 2+, and lower in older patients at an OR of 0.88 per 5-year increment in age (both p<0.0001).
Meanwhile, patients’ income was positively associated with both therapy and class persistence and compliance, at ORs of 1.04, 1.03, and 1.10 per increasing quintile, respectively (all p<0.0001).
Of note, although women were more likely to persist with therapy (OR=1.09), and to comply (OR=1.19), they showed lower class persistence than men (OR=0.95; all p<0.0001).
Finally, regarding drug classes, patients initially prescribed ACE inhibitors were more likely to remain therapy persistent compared with those initiated on all other antihypertensive drug classes (p<0.0001), followed by those receiving an angiotensin receptor blocker initially (p<0.01). Patients initially prescribed diuretics were least likely to persist with the same class (p<0.0001), with those initiating on other drugs showing similar class persistence.
Compliance was greatest with ACE inhibitors and worst with beta blockers.
“Targeted efforts directed towards men, urban residents, and those of low socioeconomic status to increase antihypertensive drug persistence and compliance should be considered,” the authors write.
As different drug classes exert similar cardiovascular benefits, they reason, “any differences between classes in persistence and compliance when used in clinical practice might be expected to translate into difference in real-world effectiveness of each drug class in reducing cardiovascular event rates.”
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By Caroline Price