Tolerability of antihypertensive drugs in a community-based setting

Time Preference for Immediate Gratification: Associations With Low Medication Adherence and Uncontrolled Blood Pressure

BACKGROUND

In search of innovative approaches to the challenge of uncontrolled hypertension, we assessed the association between preference for immediate gratification (i.e., high discounting rate), low medication adherence, and uncontrolled blood pressure (BP) in adults with hypertension.

METHODS

Using a probability discounting model and the Collier-Williams hypothetical discount rate framework, participants in this cross-sectional study reported their preference for a smaller amount of money available immediately (high discount rate; immediate gratification preference) vs. a larger amount available 1 year later (low discount rate; delayed gratification preference). Multivariable Poisson regression was used to test the association of high discounting rates with low antihypertensive medication adherence using the validated 4-item Krousel-Wood Medication Adherence Scale (K-Wood-MAS-4 score ≥1). Mediation of the association between high discounting rate and uncontrolled BP (systolic/diastolic BP ≥ 130/80 mm Hg) by low adherence was tested using the counterfactual approach.

RESULTS

Among 235 participants (mean age 63.7 ± 6.7 years; 51.1% women; 41.9% Black), 50.6% had a high 1-year discount rate, 51.9% had low K-Wood-MAS-4 adherence, and 59.6% had uncontrolled BP. High discounting rates were associated with low adherence (adjusted prevalence ratio 1.58, 95% confidence interval (CI) 1.18, 2.12). Forty-three percent (95% CI 40.9%, 45.8%) of the total effect of high discount rate on uncontrolled BP was mediated by low adherence.

CONCLUSIONS

Adults with preference for immediate gratification had worse adherence; low adherence partially mediated the association of high discount rate with uncontrolled BP. These results support preference for immediate gratification as an innovative factor underlying low medication adherence and uncontrolled BP.

Medication Adherence: Expanding the Conceptual Framework

Interventions targeting traditional barriers to antihypertensive medication adherence have been developed and evaluated, with evidence of modest improvements in adherence. Translation of these interventions into population-level improvements in adherence and clinical outcomes among older adults remains suboptimal. From the Cohort Study of Medication Adherence among Older adults (CoSMO), we evaluated traditional barriers to antihypertensive medication adherence among older adults with established hypertension (N = 1,544; mean age = 76.2 years, 59.5% women, 27.9% Black, 24.1% and 38.9% low adherence by proportion of days covered (i.e., PDC <0.80) and the 4-item Krousel-Wood Medication Adherence Scale (i.e., K-Wood-MAS-4 ≥1), respectively), finding that they explained 6.4% and 14.8% of variance in pharmacy refill and self-reported adherence, respectively. Persistent low adherence rates, coupled with low explanatory power of traditional barriers, suggest that other factors warrant attention. Prior research has investigated explicit attitudes toward medications as a driver of adherence; the roles of implicit attitudes and time preferences (e.g., immediate vs. delayed gratification) as mechanisms underlying adherence behavior are emerging. Similarly, while associations of individual-level social determinants of health (SDOH) and medication adherence are well reported, there is growing evidence about structural SDOH and specific pathways of effect. Building on published conceptual models and recent evidence, we propose an expanded conceptual framework that incorporates implicit attitudes, time preferences, and structural SDOH, as emerging determinants that may explain additional variation in objectively and subjectively measured adherence. This model provides guidance for design, implementation, and assessment of interventions targeting sustained improvement in implementation medication adherence and clinical outcomes among older women and men with hypertension.

Assessing the clinical impact of CYP2C9 pharmacogenetic variation on phenytoin prescribing practice and patient response in an integrated health system

OBJECTIVE

To assess the impact of CYP2C9 variation on phenytoin patient response and clinician prescribing practice where genotype was unknown during treatment.

METHODS

A retrospective analysis of Resource on Genetic Epidemiology Research on Adult Health and Aging cohort participants who filled a phenytoin prescription between 1996 and 2017. We used laboratory test results, medication dispensing records, and medical notes to identify associations of CYP2C9 genotype with phenytoin blood concentration, neurologic side effects, and medication dispensing patterns reflecting clinician prescribing practice and patient response.

RESULTS

Among 993 participants, we identified 69% extensive, 20% high-intermediate, 10% low-intermediate, and 2% poor metabolizers based on CYP2C9 genotypes. Compared with extensive metabolizer genotype, low-intermediate/poor metabolizer genotype was associated with increased dose-adjusted phenytoin blood concentration [21.3 pg/mL, 95% confidence interval (CI): 13.6-29.0 pg/mL; P < 0.01] and increased risk of neurologic side effects (hazard ratio: 2.40, 95% CI: 1.24-4.64; P < 0.01). Decreased function CYP2C9 genotypes were associated with medication dispensing patterns indicating dose decrease, use of alternative anticonvulsants, and worse adherence, although these associations varied by treatment indication for phenytoin.

CONCLUSION

CYP2C9 variation was associated with clinically meaningful differences in clinician prescribing practice and patient response, with potential implications for healthcare utilization and treatment efficacy.

Self-reported Morisky Eight-item Medication Adherence Scale for Statins Concords with the Pill Count Method and Correlates with Serum Lipid Profile Parameters and Serum HMGCoA Reductase Levels

Background It is imperative that non-compliance with statins be identified and addressed to maximize their clinical benefits. Patient self-reporting methods are convenient to apply in clinical practice but need to be validated. Objective We studied the concordance of a patient self-report method, Morisky eight-item medication adherence scale (MMAS)), with the pill count method in measuring adherence with statins and their correlation with extended lipid profile parameters and serum hydroxyl-methylglutaryl coenzyme A reductase (HMGCoA-R) enzyme levels. Methods MMAS and the pill count method were used to measure the adherence with statins in patients on statins for any duration. Patients were subjected to an estimation of extended lipid profile and serum HMGCoA-R levels at the end of three months follow-up. Results Out of a total of 200 patients included in the study, 117 patients had a low adherence (score less than 6 on MMAS) whereas 65 and 18 patients had medium (score 6 or 7) and high adherence (score of 8), respectively. The majority of patients who had low adherence to statins by MMAS were nonadherent by the pill count method yielding a concordance of 96.5%. Medium or high adherence to statins by the MMAS method had a concordance of 89.1% with the pill count method. The levels of total cholesterol, low-density lipoprotein-cholesterol, apolipoprotein B, and HMGCoA-R were negatively correlated with compliance measured by pill count and MMAS in a statistically significant way and with similar correlation coefficients. HMGCoA-R levels demonstrated a plateau phenomenon, with levels being 9-10 ng/ml when compliance with statin therapy was greater than 60% by pill count and greater than 6 on the Morisky scale. Conclusion In conclusion, MMAS and the pill count method showed concordance in measuring adherence to statins. These methods need to be explored further for their interchangeability as surrogates for biomarker levels.

Adherence to Antihypertensive Therapy

Adherence to antihypertensive medication remains a key modifiable factor in the management of hypertension. The multidimensional nature of adherence and blood pressure (BP) control call for multicomponent, patient-centered interventions to improve adherence. Promising strategies to improve antihypertensive medication adherence and BP control include regimen simplification, reduction of out-of-pocket costs, use of allied health professionals for intervention delivery, and self-monitoring of BP. Research to understand the effects of technology-mediated interventions, mechanisms underlying adherence behavior, and sex-race differences in determinants of low adherence and intervention effectiveness may enhance patient-specific approaches to improve adherence and disease control.

Somatosensory Amplification Is a Predictor of Self-Reported Side Effects in the Treatment of Primary Hypertension: a Pilot Study

PURPOSE

Side effects consist of drug-specific and non-specific symptoms. Both components are based on bodily sensations that a person perceives after taking a drug and subsequently attributes to the drug. We suggest that somatosensory amplification (SSA) may explain a proportion of inter-individual differences in reports of side effects that cannot be accounted for by drug-specific safety profiles. This hypothesis was investigated in hypertensive patients starting a new pharmacotherapy.

METHOD

This longitudinal study included 50 patients (66 % women, aged 55 ± 14 years) with a diagnosis of primary hypertension. Patients completed the Somatosensory Amplification Scale (SSAS), started to take their new medication, and recorded side effects on a daily basis for 4 weeks.

RESULTS

After controlling for age, gender, number of pills taken, and previous personal and family experiences with medication side effects in the regression analyses, SSAS scores remained a significant predictor of reported side effects over the entire study period (weeks 1 and 2: β = .621, p < .001; weeks 3 and 4: β = .493, p = .003). In a subsample comprising patients taking the four most commonly used drug regimes, SSAS was a significant predictor of side effects, even when controlling for type of medication.

CONCLUSION

In this sample of patients undergoing anti-hypertensive pharmacotherapy, higher SSA scores predicted increased reports of medication side effects. To account for this tendency and to improve compliance with medication regimes, this group may require special education about the nocebo phenomenon.

The influence of illness acceptance on the adherence to pharmacological and non-pharmacological therapy in patients with hypertension

BACKGROUND

The available publications show that 50% of patients with hypertension discontinue their medications within the first 12 months after the beginning of treatment.

AIM

The aim of the study was to analyse the relationship between the acceptance of illness and the adherence to pharmacological and non-pharmacological therapy in patients with hypertension.

METHODS

The study included 102 patients with hypertension examined with validated instruments: Acceptance of Illness Scale (AIS), Health Behavior Inventory (HBI) and Morisky Medication Adherence Scale (MMAS-8).

RESULTS

High (>30 points) and moderate (19-29 points) levels of AIS were presented respectively by 59 and 43 patients. In a univariate analysis, the level of AIS had a statistically significant, independent, positive influence on all domains of the HBI questionnaire: HBI (Spearman's coefficient of rank correlation (r_S) =+0.3997), healthy eating habits (r_S=+ 0.376), preventive behaviours (r_S=+0.242), positive mental attitude (r_S=+0.504), health practices (r_S=+0.264). In univariate analysis the level of MMAS-8 was influenced by female gender (r_S=+0.325; p=0.001), higher education level (r_S=+0.241; p=0.015), employment (r_S=+0.217; p=0.029) and short duration of illness (r_S=+0.229; p=0.022). Multiple regression analysis showed that female gender was an independent predictor of pharmacological adherence (β=+0.325; p=0.001). Illness acceptance was an independent predictor in two domains of the HBI: positive mental attitude HBI domain (β=+0.468; p<0.001) and healthy eating habits (β=+0.321; p=0.001).

CONCLUSIONS

(1) Correlation analysis shows that illness acceptance is an important factor contributing to a higher level of adherence to non-pharmacological therapy of hypertension (total index of health behaviours: healthy eating habits, preventive behaviours, positive mental attitude, health practice) but has no influence on adherence to pharmacological treatment. (2) Female gender, higher levels of education, and the short duration of the disease significantly improve patients' adherence to the prescribed pharmacological and non-pharmacological therapy of hypertension.

Cost–Benefit Analysis of Home Blood Pressure Monitoring in Hypertension Diagnosis and Treatment

Home blood pressure (BP) monitoring has been shown to be more effective than clinic BP monitoring for diagnosing and treating hypertension. However, reimbursement of home BP monitoring is uncommon in the United States because of a lack of evidence that it is cost beneficial for insurers. We develop a decision-analytic model, which we use to conduct a cost–benefit analysis from the perspective of the insurer. Model inputs are derived from the 2008 to 2011 claims data of a private health insurer in the United States, from 2009 to 2010 National Health and the Nutrition Examination Survey data, and from published meta-analyses. The model simulates the transitions among health states from initial physician visit to hypertension diagnosis, to treatment, to hypertension-related cardiovascular diseases, and patient death or resignation from the plan. We use the model to estimate cost–benefit ratios and both short- and long-run return on investment for home BP monitoring compared with clinic BP monitoring. Our results suggest that reimbursement of home BP monitoring is cost beneficial from an insurer’s perspective for diagnosing and treating hypertension. Depending on the insurance plan and age group categories considered, estimated net savings associated with the use of home BP monitoring range from $33 to $166 per member in the first year and from $415 to $1364 in the long run (10 years). Return on investment ranges from $0.85 to $3.75 per dollar invested in the first year and from $7.50 to $19.34 per dollar invested in the long run.

Exercise as medicine: Role in the management of primary hypertension

Primary hypertension affects ∼1 in 5 Canadians and significantly increases the risk of myocardial infarction, stroke, heart failure, and early mortality. Guidelines for the management of hypertension recommend lifestyle modifications (e.g., increased physical activity, smoking cessation, moderate alcohol consumption, improved dietary choices) as the frontline strategy to prevent and manage high blood pressure (BP). In particular, acute and chronic aerobic exercise has consistently been shown to reduce resting and ambulatory BP, with the largest effects in hypertensive patients. Current guidelines recommend 30–60 min of moderate- to vigorous-intensity aerobic exercise 4–7 days per week, in addition to activities of daily living. The role of resistance training in the management of hypertension is less clear, although available data suggests resistance exercise can be performed safely without risk of increasing BP or adverse events. Presently, resistance exercise (8–10 exercises, 1–2 set(s) of 10–15 repetitions, 2–3 days/week) is advocated only as an adjunct exercise modality. Patients desiring to begin an exercise program should complete the Physical Activity Readiness Questionnaire (PAR-Q or PAR-Q+) or as required, the Electronic Physical Activity Readiness Medical Examination (ePARmed-X) or Physician Clearance Form in consultation with their clinician and (or) trained exercise professional. A greater emphasis on utilizing exercise as medicine will produce positive nonpharmacologic benefits for hypertensive patients and improve overall cardiovascular risk profiles.

Antihypertensive drug treatment changes in the general population: the CoLaus study

Background

Changes in antihypertensive drug treatment are paramount in the adequate management of patients with hypertension, still, there is little information regarding changes in antihypertensive drug treatment in Switzerland. Our aim was to assess those changes and associated factors in a population-based, prospective study.

Methods

Data from the population-based, CoLaus study, conducted among subjects initially aged 35–75 years and living in Lausanne, Switzerland. 772 hypertensive subjects (371 women) were followed for a median of 5.4 years. Data Subjects were defined as continuers (no change), switchers (one antihypertensive class replaced by another), combiners (one antihypertensive class added) and discontinuers (stopped treatment). The distribution and the factors associated with changes in antihypertensive drug treatment were assessed.

Results

During the study period, the prescription of diuretics decreased and of ARBs increased: at baseline, diuretics were taken by 46.9% of patients; angiotensin receptor blockers (ARB) by 44.7%, angiotensin converting enzyme inhibitors (ACEI) by 28.8%, beta-blockers (BB) by 28.0%, calcium channel blockers (CCB) by 18.9% and other antihypertensive drugs by 0.3%. At follow-up (approximately 5 years later), their corresponding percentages were 42.8%, 51.7%, 25.5%, 33.0% 20.7% and 1.0%. Among all participants, 54.4% (95% confidence interval: 50.8-58.0) were continuers, 26.9% (23.8-30.2) combiners, 12.7% (10.4-15.3) switchers and 6.0% (4.4-7.9) discontinuers. Combiners had higher systolic blood pressure values at baseline than the other groups (p < 0.05). Almost one third (30.6%) of switchers and 29.3% of combiners improved their blood pressure status at follow-up, versus 18.8% of continuers and 8.7% of discontinuers (p < 0.001). Conversely, almost one third (28.3%) of discontinuers became hypertensive (systolic ≥140 mm Hg or diastolic ≥90 mm Hg), vs. 22.1% of continuers, 16.3% of switchers and 11.5% of combiners (p < 0.001). Multivariate analysis showed baseline uncontrolled hypertension, ARBs, drug regimen (monotherapy/polytherapy) and overweight/obesity to be associated with changes in antihypertensive therapy.

Conclusion

In Switzerland, ARBs have replaced diuretics as the most commonly prescribed antihypertensive drug. Uncontrolled hypertension, ARBs, drug regimen (monotherapy or polytherapy) and overweight/obesity are associated with changes in antihypertensive treatment.

Relationship of treatment satisfaction to medication adherence: findings from a cross-sectional survey among hypertensive patients in Palestine

BACKGROUND

The concepts of medication adherence and Treatment satisfactions are commonly used in clinical research for assessing pharmaceutical care and improving treatment outcomes. Generally, one would expect a positive relationship between the two concepts. The objectives of this study were to investigate the factors associated with adherence to antihypertensive therapy among hypertensive patients and to assess the relationship between antihypertensive medication adherence and treatment satisfaction.

METHODS

A cross-sectional study was conducted, adopting the Morisky eight-item Medication Adherence Scale (MMAS) for the assessment of medication adherence and using the Treatment Satisfaction Questionnaire for Medication (TSQM 1.4) for the assessment of treatment satisfaction. Descriptive and comparative statistics were used to describe socio-demographic and disease-related characteristics of the patients. All analyses were performed using SPSS v 15.0.

RESULTS

Four hundred and ten hypertensive patients were enrolled in the study. The mean age of participants was 58.38 ± 10.65 years; 52% were female and 36.8% had low antihypertensive medication adherence. There was a significant difference in the mean scores in the Effectiveness (p < 0.001), Convenience (p < 0.001), and Global Satisfaction (p < 0.001) domains, but not in the Side Effects (p = 0.466) domain among patients with different levels of adherence. After adjustment for covariates using multiple linear regression, global treatment satisfaction was still statistically significantly (p = 0.001) associated with medication adherence.

CONCLUSIONS

Low treatment satisfaction may be an important barrier for achieving high rates of adherence to treatment. These study findings could be helpful in clinical practice, mainly in the early treatment of hypertensive patients, at a point where improving treatment satisfaction is still possible.

Acupuncture, a promising adjunctive therapy for essential hypertension: a double-blind, randomized, controlled trial

BACKGROUND

This study assessed effects of acupuncture as an add-on to conventional antihypertensive managements such as medication or lifestyle modification for hypertensive or pre-hypertensive subjects.

METHODS

A randomized, double-blind, placebo-controlled trial was conducted at Kyung Hee University Hospital. Forty-one hypertensive or pre-hypertensive (systolic BP> or =120 mmHg or diastolic BP> or =80 mmHg) volunteers were recruited and randomly assigned into real or sham acupuncture groups. The hypertensive subjects on antihypertensive medication continued their medication. Acupuncture point prescriptions were partially individualized, based on the Saam acupuncture theory. Park's sham needle method was adopted for the sham procedure. Measurements were performed at baseline, weeks 4 and 8. BP, scales of overall health and pain, and anticipation or satisfaction for the treatments, were recorded.

RESULTS

Thirty subjects completed the intervention, all of whom were on antihypertensive medication. The sham acupuncture group showed no significant change in mean BP, while the real acupuncture group showed a significant (p<0.01) decrease in mean BP after 8 weeks of intervention from 136.8/83.7 to 122.1/76.8 mmHg. Other factors showed no difference between the groups throughout the study.

CONCLUSION

Acupuncture seems to offer an additional benefit to the treatment of hypertensive patients.

Updated report on comparative effectiveness of ACE inhibitors, ARBs, and direct renin inhibitors for patients with essential hypertension: much more data, little new information

OBJECTIVES

A 2007 systematic review compared angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor blockers (ARBs) in patients with hypertension. Direct renin inhibitors (DRIs) have since been introduced, and significant new research has been published. We sought to update and expand the 2007 review.

DATA SOURCES

We searched MEDLINE and EMBASE (through December 2010) and selected other sources for relevant English-language trials.

STUDY ELIGIBILITY CRITERIA, PARTICIPANTS, AND INTERVENTIONS

We included studies that directly compared ACE inhibitors, ARBs, and/or DRIs in at least 20 total adults with essential hypertension; had at least 12 weeks of follow-up; and reported at least one outcome of interest. Ninety-seven (97) studies (36 new since 2007) directly comparing ACE inhibitors versus ARBs and three studies directly comparing DRIs to ACE inhibitor inhibitors or ARBs were included.

STUDY APPRAISAL AND SYNTHESIS METHODS

A standard protocol was used to extract data on study design, interventions, population characteristics, and outcomes; evaluate study quality; and summarize the evidence.

RESULTS

In spite of substantial new evidence, none of the conclusions from the 2007 review changed. The level of evidence remains high for equivalence between ACE inhibitors and ARBs for blood pressure lowering and use as single antihypertensive agents, as well as for superiority of ARBs for short-term adverse events (primarily cough). However, the new evidence was insufficient on long-term cardiovascular outcomes, quality of life, progression of renal disease, medication adherence or persistence, rates of angioedema, and differences in key patient subgroups.

LIMITATIONS

Included studies were limited by follow-up duration, protocol heterogeneity, and infrequent reporting on patient subgroups.

CONCLUSIONS AND IMPLICATIONS OF KEY FINDINGS

Evidence does not support a meaningful difference between ACE inhibitors and ARBs for any outcome except medication side effects. Few, if any, of the questions that were not answered in the 2007 report have been addressed by the 36 new studies. Future research in this area should consider areas of uncertainty and be prioritized accordingly.

Safety and tolerability of the direct renin inhibitor aliskiren: a pooled analysis of clinical experience in more than 12,000 patients with hypertension

While the safety of renin-angiotensin system (RAS)-blocking drugs such as angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers is well known, less is known about the new direct renin inhibitor aliskiren. The authors pooled data from 12 randomized controlled trials of aliskiren in patients with hypertension and analyzed the incidence and types of adverse events (AEs) and laboratory abnormalities. Studies were characterized as short-term (≤2 months) placebo-controlled or long-term (>2 months) active-controlled. Relative risks for AEs of particular interest for RAS blockers were calculated. In short-term studies, AEs occurred in similar proportions of aliskiren 150 mg and 300 mg (33.6% and 31.6%, respectively) and placebo treatment groups (36.8%). In long-term studies, a lower proportion of patients treated with aliskiren 150 mg and 300 mg had AEs (33.7% and 43.2%, respectively) than those treated with ACE inhibitors (60.1%), angiotensin receptor blockers (53.9%), and thiazide diuretics (48.9%). Events of special interest, including angioedema, hyperkalemia, and diarrhea occurred in similar proportions of patients taking aliskiren, placebo, and comparator agents. In studies of up to 36 weeks, patients treated with aliskiren were significantly less likely to develop cough than those treated with ACE inhibitors. At the registered doses of 150 mg and 300 mg daily, aliskiren has safety and tolerability profiles similar to placebo, other RAS blockers, and diuretics. Cough rates are lower with aliskiren compared with ACE inhibitors.

Impact of prolonged antihypertensive duration of action on predicted clinical outcomes in imperfectly adherent patients: comparison of aliskiren, irbesartan and ramipril

BACKGROUND

Most patients miss occasional doses of antihypertensives. The use of 'forgiving' drugs (i.e. drugs with duration of action longer than the 24-h dosing interval) may allow an adequate blood pressure (BP) reduction to be maintained despite missed doses.

AIM

To quantify the effects of adherence level and duration of action on estimated mean systolic BP (SBP) reduction and cardiovascular disease (CVD) risk.

METHOD

For 1250 patients, we simulated 256-day dosing histories with realistically distributed drug holidays based on a study of electronically monitored dosing records. Adherence was set to the desired level by altering the proportion of doses missed. Mean office SBP-lowering effect (aliskiren 300 mg, -14.1 mmHg; irbesartan 300 mg, -13.3; ramipril 10 mg, -10.1 mmHg) and the rate of SBP increase after stopping treatment (off-rate; aliskiren, 1.0 mmHg/day; irbesartan, 3.6 mmHg/day; ramipril, 4.0 mmHg/day) were taken from the results of a randomised, double-blind trial. SBP was averaged over time and patient to estimate mean reductions in SBP and 10-year CVD risk (Framingham risk equation, baseline absolute 10-year CVD risk: 27%).

RESULTS

Predicted reductions in SBP and CVD risk with aliskiren were larger and less affected by imperfect adherence than the reductions with irbesartan or ramipril. For aliskiren, reducing adherence from 90% to 60% led to a predicted rise in SBP of 1.0 mmHg and three additional CVD events per 1000 treated patients; larger predicted differences were observed for irbesartan (2.5 mmHg; 7.5 events/1000 treated patients) and ramipril (2.2 mmHg; 6.7 events/1000 treated patients).

CONCLUSION

To offset the effects of imperfect adherence, a common challenge with antihypertensives, for better BP management it may be prudent to prescribe 'forgiving' drugs.

Barriers to and determinants of medication adherence in hypertension management: perspective of the cohort study of medication adherence among older adults

Low adherence to antihypertensive medication remains a public health challenge. Understanding barriers to, and determinants of, adherence to antihypertensive medication may help identify interventions to increase adherence and improve outcomes. The Cohort Study of Medication Adherence in Older Adults is designed to assess risk factors for low antihypertensive medication adherence, explore differences across age, gender, and race subgroups, and determine the relationship of adherence with blood pressure control and cardiovascular outcomes over time. This article discusses the relevance of this study in addressing the issue of barriers to anithypertensive medication adherence.

Women tolerate drug therapy for coronary artery disease as well as men do, but are treated less frequently with aspirin, beta-blockers, or statins

BACKGROUND

Women have worse morbidity, mortality, and health-related quality-of-life outcomes associated with coronary artery disease (CAD) compared with men. This may be related to underutilization of drug therapies, such as aspirin, beta-blockers, angiotensin-converting enzyme (ACE) inhibitors, or statins. No studies have sought to describe the relationship of gender with adverse reactions to drug therapy (ADRs) for CAD in clinical practice.

OBJECTIVE

The aim of this study was to determine the prevalence of ADRs associated with common CAD drug therapies in women and men in clinical practice.

METHODS

In a cohort of consecutive outpatients with CAD, detailed chart abstraction was performed to determine the use of aspirin, beta-blocker, ACE inhibitor, and statin therapy, as well as the ADRs reported for these treatments. Baseline clinical characteristics were also determined to identify the independent association of gender with use of standard drug treatments for CAD.

RESULTS

Consecutive patients with CAD (153 men, 151 women) were included in the study. Women and men were observed to have a similar prevalence of cardiac risk factors and comorbidities, except that men had significantly higher prevalence of atrial fibrillation (30 [19.6%] men vs 15 [9.9%] women; P = 0.03) and significantly lower mean (SD) high-density lipoprotein cholesterol concentrations (45 [16] mg/dL for men vs 55 [19] mg/dL for women; P < 0.001). No significant differences were observed between the sexes in the prevalence of ADRs; however, significantly fewer women than men were treated with statins (118 [78.1%] vs 139 [90.8%], respectively; P = 0.003). After adjusting for clinical characteristics, women were also found to be less likely than men to receive aspirin (odds ratio [OR] = 0.164; 95% CI, 0.083-0.322; P = 0.001) and beta-blockers (OR = 0.184; 95% CI, 0.096-0.351; P = 0.001).

CONCLUSIONS

Women and men experienced a similar prevalence of ADRs in the treatment of CAD; however, women were significantly less likely to be treated with aspirin, beta-blockers, and statins than were their male counterparts. To optimize care for women with CAD, further study is needed to identify the cause of this gender disparity in therapeutic drug use.

Predictive validity of a medication adherence measure in an outpatient setting

This study examines the psychometric properties and tests the concurrent and predictive validity of a structured, self-reported medication adherence measure in patients with hypertension. The authors also assessed various psychosocial determinants of adherence, such as knowledge, social support, satisfaction with care, and complexity of the medical regimen. A total of 1367 patients participated in the study; mean age was 52.5 years, 40.8% were male, 76.5% were black, 50.8% graduated from high school, 26% were married, and 54.1% had income <$5,000. The 8-item medication adherence scale was reliable (alpha=.83) and significantly associated with blood pressure control (P<.05). Using a cutpoint of <6, the sensitivity of the measure to identify patients with poor blood pressure control was estimated to be 93%, and the specificity was 53%. The medication adherence measure proved to be reliable, with good concurrent and predictive validity in primarily low-income, minority patients with hypertension and might function as a screening tool in outpatient settings with other patient groups.

Predictive validity of a medication adherence measure in an outpatient setting

This study examines the psychometric properties and tests the concurrent and predictive validity of a structured, self-reported medication adherence measure in patients with hypertension. The authors also assessed various psychosocial determinants of adherence, such as knowledge, social support, satisfaction with care, and complexity of the medical regimen. A total of 1367 patients participated in the study; mean age was 52.5 years, 40.8% were male, 76.5% were black, 50.8% graduated from high school, 26% were married, and 54.1% had income <$5,000. The 8-item medication adherence scale was reliable (alpha=.83) and significantly associated with blood pressure control (P<.05). Using a cutpoint of <6, the sensitivity of the measure to identify patients with poor blood pressure control was estimated to be 93%, and the specificity was 53%. The medication adherence measure proved to be reliable, with good concurrent and predictive validity in primarily low-income, minority patients with hypertension and might function as a screening tool in outpatient settings with other patient groups.

The significance of compliance and persistence in the treatment of diabetes, hypertension and dyslipidaemia: a review

OBJECTIVES

To review studies of patient compliance/persistence with cardiovascular or antidiabetic medication published since the year 2000; to compare the methods used to measure compliance/persistence across studies; to compare reported compliance/persistence rates across therapeutic classes and to assess whether compliance/persistence correlates with clinical outcomes.

METHODS

English language papers published between January 2000 and November 2005 investigating patient compliance/persistence with cardiovascular or antidiabetic medication were identified through searches of the MEDLINE and EMBASE databases. Definitions and measurements of compliance/persistence were compared across therapeutic areas using contingency tables.

RESULTS

Of the 139 studies analysed, 32% focused on hypertension, 27% on diabetes and 13% on dyslipidaemia. The remainder covered coronary heart disease and cardiovascular disease (CVD) in general. The most frequently reported measure of compliance was the 12-month medication possession ratio (MPR). The overall mean MPR was 72%, and the MPR did not differ significantly between treatment classes (range: 67-76%). The average proportion of patients with an MPR of >80% was 59% overall, 64% for antihypertensives, 58% for oral antidiabetics, 51% for lipid-lowering agents and 69% in studies of multiple treatments, again with no significant difference between treatment classes. The average 12-month persistence rate was 63% and was similar across therapeutic classes. Good compliance had a positive effect on outcome in 73% of the studies examining clinical outcomes.

CONCLUSIONS

Non-compliance with cardiovascular and antidiabetic medication is a significant problem, with around 30% of days 'on therapy' not covered by medication and only 59% of patients taking medication for more than 80% of their days 'on therapy' in a year. Good compliance has a positive effect on clinical outcome, suggesting that the management of CVD may be improved by improving patient compliance.

Effects of initial antihypertensive drug class on patient persistence and compliance in a usual-care setting in the United States

Antihypertensive treatment regimen persistence and compliance were measured using a retrospective cohort study of pharmacy claims data. Newly treated patients receiving monotherapy with angiotensin II receptor blockers (ARBs), angiotensin-converting enzyme inhibitors (ACEIs), calcium channel blockers (CCBs), beta-blockers (BBs), or diuretics were followed for 1 year (N=242,882). A higher proportion of ARB patients (51.9%) were persistent in taking prescribed medication compared with those in the ACEI (48.0%), BB (40.3%), CCB (38.3%), and diuretic groups (29.9%). Compared with patients receiving diuretics, those receiving ARBs (hazard ratio [HR], 0.593; P<.0001), ACEIs (HR, 0.640; P<.0001), CCBs (HR, 0.859; P<.0001), and BBs (HR, 0.819; P<.0001) were all less likely to discontinue therapy. Compliance was similar in ACEI and ARB patients, but patients receiving ARBs and ACEIs had better compliance than those receiving BBs, CCBs, or diuretics. The lesser degree of compliance and persistence observed in patients receiving diuretics compared with other antihypertensive medications may have public health as well as cost implications.

Predictors of self-reported noncompliance with antihypertensive drug treatment: a prospective cohort study

BACKGROUND

Persistence and compliance are different aspects of the broader concept of adherence to drug treatment. In a prior study, determinants of nonpersistence in a group of patients newly prescribed antihypertensive medications were examined.

OBJECTIVE

To determine noncompliance among those who were persistent with therapy.

METHODS

A prospective cohort study was conducted, in which individuals prescribed a new antihypertensive monotherapy were identified through a network of 173 pharmacies. Participants were interviewed by telephone twice during a three-month period. At the end of this period, individuals who reported still taking the medication initially prescribed were included in the analysis. Self-reported noncompliance was measured at three months. Data were analyzed using a multivariate logistic regression model.

RESULTS

Of 509 eligible participants, 118 (23.2%) reported noncompliance with their drug treatment. Noncompliance was significantly associated with the use of angiotensin-converting enzyme inhibitors (adjusted OR [AOR] 3.0; 95% CI 1.17 to 7.92) compared with the angiotensin II receptor blocker losartan, and with the belief that hypertension is not a risk factor for cardiovascular diseases (AOR 2.0; 95% CI 1.21 to 3.33). On the other hand, noncompliance was inversely associated with the use of more than four pills of medication per day (AOR 0.3; 95% CI 0.15 to 0.64).

CONCLUSIONS

Compliance with drug treatment could be improved by proper selection of medication, and by attempts to correct the false perceptions patients may have about hypertension. Further research is needed to better understand the clinical significance of a higher number of pills as a predictor of good compliance. Further research is also needed using different means of measuring noncompliance.

Persistence and discontinuation patterns of antihypertensive therapy among newly treated patients: a population-based study

The objective was to assess persistence with antihypertensive therapy (AHT) and discontinuation patterns in patients newly dispensed different antihypertensive drug classes in a natural Canadian population-based setting. Hypertensive patients initiating AHT monotherapy were included in this 3-year retrospective cohort study (N=21 326) using the Saskatchewan health-care databases. Persistence was defined as consistently refilling a new prescription for AHT within 90 days of a previous dispensing. New courses of AHT were also documented in nonpersistent patients. Kaplan-Meier and Cox regression analyses were used to compare persistence and new courses of therapy across initial drugs. Compared to the newer angiotensin II antagonists (AIIAs), the likelihood of discontinuing therapy over the 39-month study period was significantly higher for angiotensin-converting enzymes inhibitors (HR=1.29; 95% CI=1.16-1.43), calcium channel blockers (HR=1.42; 95% CI=1.27-1.60), beta blockers (HR=1.62; 95% CI=1.45-1.80) and diuretics (HR=1.92; 95% CI=1.73-2.14). In the year following treatment discontinuation, between 54 and 75% of patients initiated a second course of treatment. Patients initiated on an AIIA had a significantly higher likelihood of starting a new course of therapy after a first treatment discontinuation, compared to all other agents. In conclusion, hypertensive patients initiated on an AIIA not only had greater persistence to AHT but were also more likely to initiate a new course of AHT after discontinuation than those initiating treatment with other agents. Further studies are required that relate intermittent treatment behaviours to health outcomes and costs in hypertension.

Uptake of angiotensin II receptor blockers in the treatment of hypertension

OBJECTIVE

To examine trends in prescribing of angiotensin II receptor blockers (ARBs) as initial and second-line treatment of hypertension.

METHODS

We performed a cohort study in the Integrated Primary Care Information database, a general practice research database in The Netherlands. We included hypertensive patients who were newly treated with antihypertensive drugs between 1996 and 1999. Initial treatment was defined as the first prescribed antihypertensive drug after diagnosis of hypertension. As second-line treatment, we considered prescriptions of a second antihypertensive drug class, either as switch or addition. We used logistic regression and Cox proportional hazard analysis to estimate time trends in use of ARBs as initial or second-line treatment.

RESULTS

In total, 8% of the 3,102 newly treated hypertensive patients received ARBs as initial treatment. Initial ARB use increased significantly from 4% to 10% during the period 1996-1999, whereas calcium channel blocker and angiotensin-converting enzyme inhibitor (ACE-I) use decreased. ARBs were used as second-line treatment in less than 4% of 2,544 patients who were initially treated with an antihypertensive drug other than an ARB: 2% switched to an ARB (mostly from ACE-Is) and 1% received ARBs as add-on treatment. Diuretics and beta-blockers were used five to ten times more often as add-on treatment than ARBs.

CONCLUSION

ARBs achieved a position in the treatment of hypertension as initial rather than second-line therapy.

Medication adherence: a key factor in achieving blood pressure control and good clinical outcomes in hypertensive patients

PURPOSE OF REVIEW

Patients' adherence to antihypertensive drug regimens is a complex but important factor in achieving blood pressure control and reducing adverse cardiovascular outcomes. Approximately one half of patients with hypertension adhere to prescribed medications, and fewer than one in three patients have controlled blood pressure.

RECENT FINDINGS

Several recent studies have highlighted the importance of patient medication adherence and have outlined factors that affect patient compliance with prescribed therapy.

SUMMARY

On the basis of published studies, a conceptual framework of factors that affect patient adherence is presented. Recognizing patient nonadherence to medical therapy as a factor leading to poor blood pressure control and adverse outcomes remains a key challenge for clinicians caring for patients with hypertension.

Antihypertensive utility of perindopril in a large, general practice-based clinical trial

The authors evaluated, in a community-based open-label trial, the effectiveness and safety of perindopril in 13,220 US hypertensive patients and studied how physicians adhere to hypertension treatment guidelines. Patients received perindopril 4 mg q.d. for 6 weeks. Based on physicians perception of blood pressure response, the patient was either maintained on 4 mg or the dose was increased to 8 mg for an additional 6 weeks. From baseline to week 12, the mean sitting blood pressure significantly declined from 156.9/94.5 mm Hg to 139.2/84.0 mm Hg. Further dose titration resulted in a clinically significant reduction in blood pressure in all patients with inadequate response on 4 mg at week 6. Blood pressure control (<140/<90 mm Hg) was achieved at 12 weeks in 48.8% patients. The subpopulation analyses demonstrated that perindopril monotherapy was effective in both men and women, in patients of all ethnicities, and in patients <65 and > or =65 years of age. Perindopril was safe and well tolerated in all hypertensive subgroups including high-risk patients. Physicians were more attuned to controlling diastolic than systolic blood pressure, and their adherence to the treatment guidelines was found to be not optimal.

A randomized, double-blind, active-controlled, parallel-group comparison of valsartan and amlodipine in the treatment of isolated systolic hypertension in elderly patients: the Val-Syst study

BACKGROUND

Some antihypertensive therapies are limited by dose-dependent adverse effects (AEs). The angiotensin II receptor blocker valsartan has been shown to reduce blood pressure (BP) in a dose-related manner with minimal dose-limiting AEs. Amlodipine besylate is a potent dihydropyridine calcium channel blocker also with dose-related antihypertensive efficacy, but with possible dose-limiting AEs, particularly peripheral edema.

OBJECTIVES

This study compared the risk/benefit profiles of valsartan and amlodipine in elderly patients who have isolated systolic hypertension (ISH).

METHODS

This 24-week, randomized, double-blind, active-controlled, titration-to-effect, parallel-group study was conducted at 35 outpatient centers in Italy. Elderly (aged 60-80 years) patients with ISH received oral treatment with valsartan 80-mg capsules or amlodipine 5-mg capsules once daily. After 8 weeks of treatment, the dose of the patients with poorly controlled systolic BP (SBP) was titrated to 160 mg (valsartan) or 10 mg (amlodipine) once daily. At week 16, if trough SBP was still not adequately controlled, a low-dose diuretic (hydrochlorothiazide [HCTZ] 12.5 mg) was added to the treatment regimen for an additional 8 weeks. Tolerability was assessed at all study visits using physical examination and patient interview.

RESULTS

Of 421 randomized patients (231 women, 190 men; mean [SD] age, 69 [6] years), 208 were included in the valsartan group, and 213 in the amlodipine group. The efficacy of valsartan-based treatment. in reducing SBP was similar to that of amlodipine-based treatment. With doubled doses, efficacy (change in SBP) increased significantly from baseline (both P < 0.01). The frequency of AEs doubled with amlodipine 10 mg but was not clinically relevant with valsartan 160 mg. Overall, AEs were observed in 31.9% of those receiving amlodipine versus 20.2% of the patients receiving valsartan (P < 0.003), with peripheral edema rates of 26.8% and 4.8%, respectively (P < 0.001).

CONCLUSIONS

In this study population of elderly patients with ISH, valsartan-given alone or in combination with HCTZ 12.5 mg-showed similar efficacy but better tolerability than amlodipine-based treatment.

Compliance and persistence with newer antihypertensive agents

Individuals with hypertension need to stay on therapy with antihypertensive medication to obtain the full benefits of blood pressure reduction. There are important differences in tolerability across antihypertensive drug classes, and these differences influence the extent to which patients are willing to continue taking their drugs. Three separate sources of evidence--postmarket surveillance studies, medical/prescription database studies, and discontinuation of study medication in long-term endpoint clinical trials--support the proposition that angiotensin II antagonists, the newest class of antihypertensives, are well tolerated, and that patients whose initial treatment is an angiotensin II antagonist are more likely to persist with therapy than patients who use other classes of antihypertensives. Recent landmark trials with losartan in hypertensive patients with left ventricular hypertrophy (Losartan Intervention For Endpoint reduction [LIFE]) and in diabetes (Reduction of Endpoints in NIDDM with the Angiotensin II Antagonist Losartan [RENAAL]) demonstrated excellent tolerability, a high level of persistence, and clinical benefits exceeding those provided by blood pressure control alone for the prototype angiotensin II antagonist in clinical settings.