Antihypertensive Medication Adherence in the Department of Veterans Affairs

doi:10.1016/j.amjmed.2006.06.028

The American Journal of Medicine

Volume 120, Issue 1, January 2007, Pages 26-32

https://doi.org/10.1016/j.amjmed.2006.06.028 Get rights and content

Abstract

Purpose

Adherence measures the extent to which patients take medications as prescribed by their health care provider. The control of hypertension is dependent on medication adherence and may vary on the basis of antihypertensive medication class and other factors.

Methods

The Department of Veterans Affairs’ automated pharmacy database captures pharmacy medication use; International Classification of Diseases, 9th Revision, diagnostic codes; and laboratory and patient demographic data on a monthly basis. Hypertensive patients who used thiazide diuretics, beta-blockers, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel antagonists, and alpha-blockers from July 2002 to December 2003 were studied. The first date of prescription filling for each patient within the date range was the index date from which fill and refill dates were collected for up to 18 months to calculate medication posession ratios and days out of medication ratios. Patients were categorized as adherent if the medication posession ratio was 80% or greater. Logistic regression was used to study the association of medication class, age, gender, ethnicity, Veterans Affairs facility, and co-diagnosis with diabetes, schizophrenia/psychosis, depression, and dementia with medication adherence.

Results

We studied 40,492 hypertensive patients taking at least one antihypertensive drug class. The average age per class ranged from 67.4 to 72.9 years; 96% were male; and 51% were white, 8% were African-American, 4% were Asian-American, and 3% were Hispanic. Unadjusted adherence rates based on the medication posession ratio ranged from 78.3% for thiazide diuretics to 83.6% for angiotensin receptor blockers (P <.001). The number of medications (either total or antihypertensive) and age were independent predictors of better adherence. Black ethnicity and depression were associated with worse adherence.

Conclusions

Adherence rates with all antihypertensive medications were high. Although there were statistical differences by drug class, these differences were small. Ethnicity and depression identified groups that might benefit from programs to improve adherence.

Section snippets

Methods

The Veterans Integrated Service Network 21 Pharmacy DataMart and associated databases were used. Veterans Integrated Service Network 21 is a geographic grouping of six VA institutions in Northern California, Northern Nevada, and Hawaii. Automated data extraction routines capture pharmacy, International Classification of Diseases, 9th Revision (ICD-9), laboratory, provider, and patient demographic data on a monthly basis. These data were loaded into an SQL Server database system, and a

Results

We studied 40,492 patients who were taking at least one medication of the 6 antihypertensive drug classes (Table 1). Patients had an average age per group ranging from 67.4 to 72.9 years; 96% were male; and 50.6% were white, 8.2% were African-American, 4.1% were Asian-American, and 3.4% were Hispanic. Ethnicity was not available for analysis for 33.3% of patients. One antihypertensive was taken by 47.9% of patients, 2 antihypertensives were taken by 35% of patients, 3 antihypertensives were

Discussion

For thiazide diuretics, calcium antagonists, beta-blockers, ACE inhibitors, and angiotensin receptor blockers, approximately 80% of medication prescribed appeared to be taken. This is consistent with findings from the Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial in which more than 80% of participants were taking the thiazide diuretic, calcium antagonist, or ACE inhibitor at 1 year.⁴ Unadjusted adherence rates based on medication posession ratio ranged from 78.3%

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Higher blood pressure levels in patients with depression may be associated with lower adherence to antihypertensive medications (AHMs). Here, we use electronic health record (EHR) data from the Estonian Biobank (EstBB) to investigate the role of lifetime depression in AHM adherence and persistence. We also explore the relationship between antidepressant initiation and intraindividual change in AHM adherence among hypertension (HTN) patients with newly diagnosed depression. Diagnosis and pharmacy refill data were obtained from the National Health Insurance database. Adherence and persistence to AHMs were determined for hypertension (HTN) patients initiating treatment between 2009 and 2017 with a three-year follow-up period. Multivariable regression was used to explore the associations between depression and AHM adherence or persistence, adjusting for sociodemographic, genetic, and health-related factors. A linear mixed-effects model was used to estimate the effect of antidepressant treatment initiation on antihypertensive medication adherence, adjusting for age and sex. We identified 20,724 individuals with newly diagnosed HTN (6294 depression cases and 14,430 controls). Depression was associated with 6% lower probability of AHM adherence (OR = 0.943, 95%CI = 0.909–0.979) and 12% lower odds of AHM persistence (OR = 0.876, 95%CI = 0.821–0.936). Adjusting for sociodemographic, genetic, and health-related factors did not significantly influence these associations. AHM adherence increased 8% six months after initiating antidepressant therapy (N = 132; β = 0.078; 95%CI = 0.025–0.131). Based on the EHR data on EstBB participants, depression is associated with lower AHM adherence and persistence. Additionally, antidepressant therapy may help improve AHM adherence in patients with depression.
Electronic alerts to initiate anticoagulation dialogue in patients with atrial fibrillation
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The benefit of an electronic support system for the prescription and adherence to oral anticoagulation therapy among patients with atrial fibrillation (AF) and atrial flutter at heightened risk for of stroke and systemic thromboembolism is unclear.
To evaluate the effect of a combined alert intervention and shared decision-making tool to improve prescription rates of oral anticoagulation therapy and adherence.
A prospective single arm study of 939 consecutive patients treated at a large tertiary healthcare system.
An electronic support system comprising 1) an electronic alert to identify patients with AF or atrial flutter, a CHA₂DS₂-VASc score ≥ 2, and not on oral anticoagulation and 2) electronic shared decision-making tool to promote discussions between providers and patients regarding therapy.
The primary endpoint was prescription rate of anticoagulation therapy. The secondary endpoint was adherence to anticoagulation therapy defined as medication possession ratio ≥ 80% during the 12 months of follow-up.
Between June 13, 2018 and August 31, 2018, the automated intervention identified and triggered a unique alert for 939 consecutive patients with AF or atrial flutter, a CHA₂DS₂-VASc score ≥2 who were not on oral anticoagulation. The median CHA₂DS₂-VASc score among all patients identified by the alert was 2 and the median untreated duration prior to the alert was 495 days (interquartile range 123 – 1,831 days). Of the patients identified by the alert, 345 (36.7%) initiated anticoagulation therapy and 594 (63.3%) did not: 68.7% were treated with a non-Vitamin K antagonist oral anticoagulant (NOAC), 22.0% with warfarin, and 9.3 % combination of NOAC and warfarin. Compared with historical anticoagulation rates, the electronic alert was associated with a 23.6% increase in anticoagulation prescriptions. The overall 1-year rate of adherence to anticoagulant therapy was 75.4% (260/345).
An electronic automated alert can successfully identify patients with AF and atrial flutter at high risk for stroke, increase oral anticoagulation prescription, and support high rates of adherence.
Risk factor control across the spectrum of cardiovascular risk: Findings from the Hispanic Community Health Study/Study of Latinos (HCHS/SOL)
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Presence of cardiovascular disease (CVD) risk factors (RFs) should prompt patients and their providers to work aggressively towards controlling those that are modifiable. The extent to which a greater CVD RF burden is related to CVD RF control in a contemporary and diverse Hispanic/Latino population is not well-understood.
Using multicenter community-based data from the Hispanic Community Health Study/Study of Latinos, we assessed the self-reported prevalence of hypertension, hypercholesterolemia, diabetes, and prevalent CVD (ischemic heart disease or stroke). We used contemporaneous guidelines to define RF control. Multivariable logistic regression for complex survey sampling was used to examine whether having more CVD RFs was associated with CVD RF control (adjusting for age, sex, Hispanic background group, education, and health insurance).
Our sample included 8521 participants with at least one CVD RF or prevalent CVD. The mean age in HCHS/SOL target population was 49 (SE 0.3) years and 56% were women. Frequency of one, two, or three self-reported CVD RFs was 57%, 26%, 8%, respectively, and overall 9% of participants had prevalent CVD. After adjusting for sociodemographic factors, compared to those reporting one CVD RF, individuals with three CVD RFs were the least likely to have blood pressure, cholesterol, and glucose optimally controlled (odds ratio [OR]: 0.56; 95% confidence interval [CI]: 0.40–0.80). However, those with prevalent CVD were more likely to have all three risk factors controlled, (OR: 1.43; 95% CI: 1.01–2.01).
Hispanic/Latino adults with three major CVD RFs represent a group with poor overall CVD RF control. Secondary CVD prevention fares better. The potential contributors to inadequate CVD RF control in this highly vulnerable group warrants further investigation.
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Citation Excerpt :
Because the maintenance of optimal medication adherence is difficult, approximately half of patients are taking <80% of their prescribed medications [16]. Inadequate adherence including failure to fill new prescriptions, incomplete use, premature discontinuation is common [17–22] and is linked to greater morbidity and mortality across a range of chronic conditions [23–25]. Individuals with limited health literacy and English proficiency are at particularly high risk for inadequate adherence over time [26–29].
Individuals with type 2 diabetes manage complex multi-drug regimens, but nearly half of all patients do not consistently take the dose prescribed for them, and therefore may not receive the full potential therapeutic benefit. Both patient and health system factors contribute to achieving and maintaining medication adherence. To determine if patients with type 2 diabetes who are concurrently managing other chronic conditions could improve their adherence, we devised and are testing a multifaceted, primary care-based strategy to provide health literacy-appropriate and language concordant regimen information, guidance and reminders.
We are testing the effectiveness of an electronic health record (EHR) based strategy and short message service (SMS) text reminders to help patients with type 2 diabetes adhere to their medications.
We are conducting a 3-arm, multi-site trial to test and compare the effectiveness of the EHR, and EHR + SMS text reminder strategies compared to usual care on medication adherence. Our goal is to enroll a total of 900 English or Spanish-speaking patients with type 2 diabetes and hemoglobin A1C value ≥7.5%. Enrolled participants will complete interviews at baseline and 3 and 6 months following their baseline interview.
Our trial is evaluating practical, clinic-based, scalable, evidence-based solutions for patients with type 2 diabetes managing complex medication regimens. Our findings will evaluate strategies that can be implemented broadly in primary care practices, and programmed as defaults within EHRs to support appropriate medication adherence to allow the widespread implementation of those strategies.
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: The views expressed in the article do not necessarily represent the views of the Department of Veterans Affairs or of the United States Government.

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AJM Theme Issue: CardiologyClinical research studyAntihypertensive Medication Adherence in the Department of Veterans Affairs

Abstract

Purpose

Methods

Results

Conclusions

Section snippets

Methods

Results

Discussion

Clin Ther

Clin Ther

Clin Ther

Am J Med

Value Health

Am J Med

Control Clin Trials

JAMA

The burden of adult hypertension in the United States 1999 to 2000: a rising tide

Hypertension

Prevention of stroke by antihypertensive drug treatment in older persons with isolated systolic hypertensionFinal results of the Systolic Hypertension in the Elderly Program

JAMA

The antihypertensive and lipid-lowering treatment to prevent heart attack trail

JAMA

Effects of different blood-pressure-lowering regimens on major cardiovascular events: results of prospectively-designed overview of randomized trials

Lancet

Effect of treatment on morbidity in hypertensionII. Results in patients with diastolic blood pressure averaging 90 through 114 mm Hg

JAMA

Prevalence of hypertension in the US adult population: results from the Third National Health and Nutrition Examination Survey, 1988-1991

Hypertension

Controlling blood pressure in 50% of all hypertensive patients: an achievable goal in the healthy people 2010 report?

J Invest Med

Trends in antihypertensive drug therapy of ambulatory patients by US office-based physicians

Hypertension

Adherence to medication

N Engl J Med

Long-term persistence in use of statin therapy in elderly patients

JAMA

AJM Theme Issue: Cardiology
Clinical research study
Antihypertensive Medication Adherence in the Department of Veterans Affairs