Recommendations for Evaluating Compliance and Persistence With Hypertension Therapy Using Retrospective Data

The epidemiology of atrial fibrillation in adults depends on locale of diagnosis

BACKGROUND

Previous studies on atrial fibrillation (AF) epidemiology have used various case definitions for AF, but the effect of location of diagnosis on the apparent epidemiology of AF is unknown.

METHODS

Population-based study of 46,440 consecutive patients with newly diagnosed AF in Alberta, Canada, from 2000 to 2005.

RESULTS

Of adults newly diagnosed with AF (52.8% men, median 73 years), 51.8% were first diagnosed in hospital, 19.2% in emergency department (ED), and 29.0% in outpatient clinics. Prevalence of AF increased from 613 per 100,000 to 1,148 per 100,000 population over 5 years; however, the age- and sex-standardized incidence of AF remained relatively stable (350 per 100,000 in 2000 and 352 per 100,000 in 2005). The proportion of AF cases diagnosed in hospital declined 21% between 2000 and 2005, whereas the proportion of cases diagnosed in the outpatient setting rose by 50% (P < .0001). Patients diagnosed with AF in the hospital or the ED had more comorbidities and higher CHADS(2) (congestive heart failure, hypertension, age ≥75 years, diabetes mellitus, and prior stroke or transient ischemic attack) scores than those diagnosed in the outpatient setting (all P < .0001). Multivariate adjusted risk of cerebrovascular events or mortality (adjusted odds ratios 4.3, 95% CI 3.9-4.7) was significant for hospital and ED AF diagnosis (adjusted odds ratios 2.4, 95% CI 2.2-2.7) compared with those diagnosed in primary care clinics. New heart failure in the year after diagnosis of AF was 4.5% for inpatients, 3.8% in ED patients, and 2.5% in outpatients.

CONCLUSIONS

Use of hospitalizations alone to define an AF cohort may underestimate incidence while overestimating comorbiditities, thromboembolic risk, and outcomes.

Meta-analysis: impact of drug class on adherence to antihypertensives

BACKGROUND

Observational studies suggest that there are differences in adherence to antihypertensive medications in different classes. Our objective was to quantify the association between antihypertensive drug class and adherence in clinical settings.

METHODS AND RESULTS

Studies were identified through a systematic search of English-language articles published from the inception of computerized databases until February 1, 2009. Studies were included if they measured adherence to antihypertensives using medication refill data and contained sufficient data to calculate a measure of relative risk of adherence and its variance. An inverse-variance-weighted random-effects model was used to pool results. Hazard ratios (HRs) and odds ratios were pooled separately, and HRs were selected as the primary outcome. Seventeen studies met inclusion criteria. The pooled mean adherence by drug class ranged from 28% for β-blockers to 65% for angiotensin II receptor blockers. There was better adherence to angiotensin II receptor blockers compared with angiotensin-converting enzyme inhibitors (HR, 1.33; 95% confidence interval, 1.13 to 1.57), calcium channel blockers (HR, 1.57; 95% confidence interval, 1.38 to 1.79), diuretics (HR, 1.95; 95% confidence interval, 1.73 to 2.20), and β-blockers (HR, 2.09; 95% confidence interval, 1.14 to 3.85). Conversely, there was lower adherence to diuretics compared with the other drug classes. The same pattern was present when studies that used odds ratios were pooled. After publication bias was accounted for, there were no longer significant differences in adherence between angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors or between diuretics and β-blockers.

CONCLUSION

In clinical settings, there are important differences in adherence to antihypertensives in separate classes, with lowest adherence to diuretics and β-blockers and highest adherence to angiotensin II receptor blockers and angiotensin-converting enzyme inhibitors. However, adherence was suboptimal regardless of drug class.

The safety of combining angiotensin-converting-enzyme inhibitors with angiotensin-receptor blockers in elderly patients: a population-based longitudinal analysis

BACKGROUND

The risks associated with using an angiotensin-converting-enzyme (ACE) inhibitor and an angiotensin-receptor blocker together are unclear. This study was designed to determine the safety of combination therapy with these two drugs in clinical practice.

METHODS

We conducted a population-based longitudinal analysis using linked administrative and laboratory data for elderly patients who were new users of an ACE inhibitor, an angiotensin-receptor blocker or a combination of both medications between May 1, 2002, and Dec. 31, 2006. We compared outcomes in patients given combination therapy versus patients given monotherapy using Cox proportional hazards analyses with adjustment for baseline characteristics.

RESULTS

Of the 32,312 new users of either medication (mean age 76.1 years, median creatinine level 92 μmol/L), 1750 (5.4%) received combination therapy. However, 1512 (86.4%) of the patients who were given combination therapy did not have trial-established indications such as heart failure or proteinuria. Renal dysfunction was more common among patients given combination therapy (5.2 [95% confidence interval (CI) 3.4 to 7.9] events per 1000 patients per month) than among patients given monotherapy (2.4 [95% CI 2.2 to 2.7] events per 1000 patients per month) (adjusted hazard ratio [HR] 2.36, 95% CI 1.51 to 3.71). Hyperkalemia was also more common among patients given combination therapy (2.5 [95% CI 1.4 to 4.3] events per 1000 patients per month) than among patients given monotherapy (0.9 [95% CI 0.8 to 1.0] events per 1000 patients per month) (adjusted HR 2.42, 95% CI 1.36 to 4.32). Most patients took combination therapy for only a short time (median three months before at least one agent was stopped).

INTERPRETATION

Combination therapy was frequently prescribed for patients without established indications and was associated with an increased risk of adverse renal outcomes when compared with monotherapy. These results mirrored data from randomized controlled trials.

Diabetes management in an Australian primary care population

WHAT IS KNOWN AND OBJECTIVE

Worldwide studies have shown that significant proportions of patients with type 2 diabetes (T2DM) do not meet targets for glycaemic control, blood pressure (BP) and lipids, putting them at higher risk of developing complications. However, little is known about medicines management in Australian primary care populations with T2DM. The aim of this study was to (i) describe the management of a large group of patients in primary care, (ii) identify areas for improvement in management and (iii) determine any relationship between adherence and glycaemic, BP and lipid control.

METHODS

This was a retrospective, epidemiological study of primary care patients with T2DM diabetes, with HbA(1c) of >7%, recruited in 90 Australian community pharmacies. Data collected included demographic details, diabetes history, current medication regimen, height, weight, BP, physical activity and smoking status.

RESULTS AND DISCUSSION

Of the 430 patients, 98% used antidiabetics, 80% antihypertensives, 73% lipid lowering drugs and 38% aspirin. BP and all lipid targets were met by only 21% and 14% of the treated patients and 21% and 12% of the untreated patients respectively. Medication adherence was related to better glycaemic control (P = 0.04).

WHAT IS NEW AND CONCLUSIONS

An evidence-base prescribing practice gap was seen in this Australian primary care population of T2DM patients. Patients were undertreated with antihypertensive and lipid lowering medication, and several subgroups with co-morbidities were not receiving the recommended pharmacotherapy. Interventions are required to redress the current evidence-base prescribing practice gap in disease management in primary care.

Adherence to antihypertensive therapy affects Ambulatory Arterial Stiffness Index

BACKGROUND

A major contributor to poor blood pressure (BP) control is nonadherence to therapy, which remains poorly recognized by physicians. The prevention of hypertension-induced changes in arterial wall, namely increased arterial stiffness and peripheral vascular resistance, is a reasoned adequate end-point of hypertension treatment. Indirect measurement of these arterial factors can be derived from the analysis of 24-hour Ambulatory BP Monitoring (24 h-ABPM). This pilot study evaluated the association between antihypertensive therapy adherence and 24 h-ABPM-derived parameters in hypertensive patients.

METHODS

We studied 42 hypertensive patients (70±10 years) in chronic antihypertensive therapy. Patients were divided according to the Morisky Medication Adherence Scale (MMAS) in Low-Adher (MMAS <6) and High-Adher (MMAS 6-8) groups. The Ambulatory Arterial Stiffness Index (AASI) and its symmetric calculation (Sym_AASI) were derived from 24 h-ABPM. A bivariate logistic regression analysis was performed to evaluate the predictive value of MMAS for increased AASIs (i.e. above the median).

RESULTS

Low-Adher group (n=17) showed higher AASIs compared to High-Adher group (n=25). The two groups were similar in terms of BP burden at the 24 h-ABPM. AASIs were inversely related to MMAS. MMAS resulted a predictor for both increased AASI (O.R. 0.49, 95% CI 0.31-0.76, P<0.01) and increased Sym_AASI (O.R. 0.67, 95% CI 0.47-0.95, P=0.026). After adjustment for PP, age and nocturnal diastolic BP reduction, MMAS persisted as an inverse predictor only of increased AASI. MMAS was also related to the diastolic vs systolic BP correlation coefficient r.

CONCLUSIONS

Low adherence to antihypertensive therapy seems to be associated with increased standard AASI. In this setting, AASI could represent an additional information derived from the 24 h-ABPM in hypertensive patient evaluation.

A competing risks prescription refill model of compliance and persistence

OBJECTIVES

There is evidence to suggest that noncompliant and nonpersistent behaviors have differing risk factors, clinical consequences, and responses to intervention. This has led to calls for these behaviors to be defined and measured separately to characterize medication-taking behavior comprehensively. Current prescription refill models of compliance are, however, unable to appropriately distinguish between noncompliant and nonpersistent behaviors. To address this limitation, a prescription refill model of medication-taking behavior in which noncompliance and nonpersistence are treated as competing risks is presented.

METHODS

The proposed competing risks model of compliance and persistence is compared with a selection of widely applied prescription refill models of compliance and persistence using a common cohort of patients prescribed statin therapy.

RESULTS

The competing risks model allows the simultaneous measurement of noncompliance and nonpersistence, the partitioning of their individual contributions to medication-taking behavior, and the estimation of noncompliance risk for patients with varying treatment persistence. The results from this model provide information about the relative and overall contributions of noncompliant and nonpersistent behaviors to medication-taking behavior. The methodology also allows an assessment of the differential influence of various risk factors on these behaviors.

CONCLUSIONS

The proposed competing risks model differentiates between noncompliant and nonpersistent behaviors using prescription refill data. Results from the model provide insights into the dynamics of noncompliant and nonpersistent behaviors that have not been possible with current prescription refill methodologies.

Efficacy and safety of a single-pill combination of amlodipine/valsartan in Asian hypertensive patients inadequately controlled with amlodipine monotherapy

OBJECTIVE

The antihypertensive efficacy of amlodipine/valsartan combination has not been evaluated in Asian patients as previous large-scale studies enrolled very few patients. This multicentre, randomised, double-blind study assessed the efficacy and safety of a single-pill combination of amlodipine/valsartan versus amlodipine in Asian hypertensive patients.

METHODS

After a 1-4-week washout period, patients (mean sitting diastolic BP [msDBP]: >or=95-<110 mmHg) were treated with amlodipine 5 mg for 4 weeks. Patients inadequately controlled on amlodipine (msDBP >or=90 and <110 mmHg) were randomised to receive amlodipine/valsartan 5/80 mg (n = 349) or amlodipine 5 mg (n = 349) for 8 weeks. Efficacy variables were change in msDBP, mean sitting systolic BP (msSBP) from baseline (at randomisation) to week 8 endpoint, and BP control rate (<140/90 mmHg) at week 8 endpoint. Safety assessments included monitoring and recording of adverse events (AEs).

RESULTS

Baseline characteristics were comparable between the groups. Most patients were Chinese (86.4%), men (65.1%), with a baseline BP 139.5/94.5 mmHg. At week 8 endpoint, the least square mean reduction in BP was significantly greater with amlodipine/valsartan combination than amlodipine monotherapy (-11.4/-9.7 vs. -7.4/-7.1 mmHg; p < 0.0001) with a higher BP control rate (69.2 vs. 57.6%; p = 0.0013). Ambulatory BP monitoring in a subgroup of patients (n = 82), showed a significant 24-h mean BP reduction from baseline with amlodipine/valsartan (-7.3/-6.3 mmHg; p < 0.0001), whereas the reduction was not significant with amlodipine (-0.2/+0.3 mmHg; p > 0.05). The overall incidence of AEs was similar in both groups. Peripheral oedema occurred only in the amlodipine group n = 4 (1.1%) and not in the amlodipine/valsartan combination. Hypotension was reported in only one patient in the amlodipine/valsartan combination. Six patients (0.9%) experienced serious AEs, of which only one SAE, i.e. gastric ulcer, was reported to be related to amlodipine treatment.

CONCLUSION

The single-pill combination of amlodipine/valsartan was efficacious and well-tolerated in Asian hypertensive patients who were inadequately controlled on amlodipine alone. As with all clinical trials, the entry criteria may limit the extrapolation of these results to a broader population. ClinicalTrials.gov Identifier: NCT00413049.

Patient and physician beliefs about control over health: association of symmetrical beliefs with medication regimen adherence

BACKGROUND

Past work suggests that the degree of similarity between patient and physician attitudes may be an important predictor of patient-centered outcomes.

OBJECTIVE

To examine the extent to which patient and provider symmetry in health locus of control (HLOC) beliefs was associated with objectively derived medication refill adherence in patients with co-morbid diabetes mellitus (DM) and hypertension (HTN).

PARTICIPANTS

Eighteen primary care physicians at the VA Iowa City Medical Center and affiliated clinics; 246 patients of consented providers with co-morbid DM and HTN.

DESIGN

Established patient-physician dyads were classified into three groups according to the similarity of their HLOC scores (assessed in parallel). Data analysis utilized hierarchical linear modeling (HLM) to account for clustering of patients within physicians.

MAIN MEASURES

Objectively derived medication refill adherence was computed using data from the VA electronic pharmacy record; blood pressure and HgA1c values were considered as secondary outcomes.

KEY RESULTS

Physician-patient dyads holding highly similar beliefs regarding the degree of personal control that individual patients have over health outcomes showed significantly higher overall and cardiovascular medication regimen adherence (p = 0.03) and lower diastolic blood pressure (p = 0.02) than in dyads in which the patient held a stronger belief in their own personal control than did their treating physician. Dyads in which patients held a weaker belief in their own personal control than did their treating physician did not differ significantly from symmetrical dyads. The same pattern was observed after adjustment for age, physician sex, and physician years of practice.

CONCLUSIONS

These data are the first to demonstrate the importance of attitudinal symmetry on an objective measure of medication adherence and suggest that a brief assessment of patient HLOC may be useful for tailoring the provider's approach in the clinical encounter or for matching patients to physicians with similar attitudes towards care.

Antihypertensive drug persistence and compliance among newly treated elderly hypertensives in ontario

BACKGROUND

Poor medication-taking behaviors are important considerations in the management of hypertension.

METHODS

We conducted a retrospective cohort study addressing antihypertensive drug persistence and compliance by linking 4 administrative databases and a province-wide clinical database in Ontario, Canada, to derive a cohort of elderly hypertensive patients, aged 66 years or more, who had received a new prescription for an antihypertensive agent between 1997 and 2005 to determine trends across years and associations with drug class and sociodemographic and other factors.

RESULTS

Our cohort consisted of 207,473 patients (58.4% were women, mean age 74.2 years, 73.1% were comorbid-free), 41,236 of whom had diabetes. Persistence and compliance increased between 1997 and 2005 (all P<.02) and were greater in those of higher socioeconomic status but lesser in urban residents (all P<.0001). Persistence was lower in comorbid-free patients and greater in older patients, whereas compliance was lower in older patients and greater in women and comorbid-free patients (all P<.0001). Significant differences between the drug classes emerged with initial prescriptions for all drug classes showing greater therapy and class persistence compared with diuretics (all P<.0001). Angiotensin-converting enzyme inhibitors showed the best therapy persistence and compliance, and beta-blockers showed the worst compliance (all P<.0001).

CONCLUSION

Our data provide evidence of an overall improvement in antihypertensive drug compliance and persistence across years, as well as significant differences across drug classes and other patient-level factors. Awareness of such factors could translate into concerted efforts at optimizing medication-taking behaviors among newly diagnosed elderly hypertensive patients.

A clinician's guide to the assessment and management of nonadherence in glaucoma

PURPOSE

To apply lessons learned in the treatment of systemic hypertension to the problem of nonadherence in glaucoma medical therapy.

CLINICAL RELEVANCE

Although physicians recognize that nonadherence with glaucoma medication is a problem, most lack the skill set to identify nonadherent patients, to identify the causes of nonadherence, and to provide solutions to address nonadherence.

METHODS

A PubMed search was conducted using the terms "adherence" OR "compliance" AND "hypertension," with the following limitations: title, English language, humans, from 2000 through 2009. Other studies identified outside of the PubMed search were included if relevant.

RESULTS

Studies from the systemic hypertension literature suggest that simplifying medication regimens, lowering costs, and patient education about the disease and the importance of taking medications are successful strategies for improving adherence. In addition, good family or social support, frequent physician visits, and pairing medication administration with specific activities (such as meals or brushing one's teeth) can help improve adherence.

CONCLUSIONS

The body of literature on adherence interventions in chronic diseases such as systemic hypertension shows that although many interventions have been tested and evaluated, only some are successful. Paradigms derived from behavioral medicine and nursing offer valuable lessons on how to motivate patients to change behavior, but these activities require skill sets not traditionally taught in medical school. Just as there are myriad causes of nonadherence, the interventions most likely will need to be multifaceted and tailored to the individual patient.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

Factors associated with compliance, discontinuation and switching of calcium channel blockers in 20,156 Chinese patients

BACKGROUND

Noncompliance and nonpersistence to antihypertensive drugs is a recognized worldwide problem. Calcium channel blockers (CCBs) are commonly prescribed among Chinese patients yet few studies have been conducted to study the factors associated with their compliance, discontinuation, and switching profiles.

METHODS

From clinical databases we studied 20,156 patients prescribed a CCB as their antihypertensive monotherapy from January 2004 to June 2007 in a large Territory of Hong Kong. We evaluated their compliance by medication possession ratios (MPRs), cumulative incidences of discontinuation and switching within 180 days after the prescription; and evaluated their associated factors using multivariable logistic regression analyses.

RESULTS

The crude compliance level, discontinuation and switching rates at 180 days were 85.0, 3.1, and 5.0%, respectively. Older patients (aged > or =50 years; adjusted odds ratio (aOR) 1.21-1.34, P < 0.001), female gender (aOR 0.89, 95% confidence interval (CI) 0.82-0.96 for males, P = 0.004), fee payers (aOR 1.09, 95% CI 1.00-1.20, P = 0.050), service settings in family medicine specialist clinic (FMSC) (aOR 1.64, 95% CI 1.33-2.01, P < 0.001), and follow-up visits (aOR 3.24, 95% CI 2.93-3.58, P < 0.001) were positively associated with good compliance. Younger age and new visits were significantly associated with drug discontinuation or switching.

CONCLUSIONS

Younger patients, male subjects, and new visitors were more likely to be noncompliant to CCB among ethnic Chinese. They represent the target subjects where primary care physicians should spend more effort on patient education to improve drug compliance.

Medication adherence: its importance in cardiovascular outcomes

Medication adherence usually refers to whether patients take their medications as prescribed (eg, twice daily), as well as whether they continue to take a prescribed medication. Medication nonadherence is a growing concern to clinicians, healthcare systems, and other stakeholders (eg, payers) because of mounting evidence that it is prevalent and associated with adverse outcomes and higher costs of care. To date, measurement of patient medication adherence and use of interventions to improve adherence are rare in routine clinical practice. The goals of the present report are to address (1) different methods of measuring adherence, (2) the prevalence of medication nonadherence, (3) the association between nonadherence and outcomes, (4) the reasons for nonadherence, and finally, (5) interventions to improve medication adherence.

Improving outcomes in hypertensive patients: focus on adherence and persistence with antihypertensive therapy

Although effective control of blood pressure (BP) reduces the risk of cardiovascular events in patients with hypertension, BP control rates among treated patients in actual clinical practice are less than optimal. Although the costs of medicines and medical care (which are difficult to estimate both in clinical trials and general clinical practice) are important, medication-taking behavior--adherence and persistence with antihypertensive regimens--influences BP control rates. Many factors affect adherence and persistence with medications, including efficacy and tolerability of drugs prescribed, such that rates vary greatly among antihypertensive classes. In general, medications with fewer adverse effects (in registration trials or large outcomes studies) are associated with increased adherence and lower discontinuation rates. More widespread use of such agents, particularly those available in generic formulations or in low-cost formularies, may lead to better long-term BP control and fewer cardiovascular events.

Practical aspects of treatment discontinuation and adherence

Hypertension control in populations, although improving, remains far from satisfactory, even though effective and inexpensive therapies are available. Among many factors responsible for this situation, poor adherence to treatment appears to be particularly important. Unfortunately, even if its causes have been quite well defined, this problem is still far from being solved in clinical practice. The present paper discusses the key issues related to treatment adherence, and discontinuation in hypertension, in the light of recent evidence coming from the ONgoing Telmisartan Alone and in combination with Ramipril Global Endpoint Trial (ONTARGET) and Telmisartan Randomized AssessmeNt Study in ACE iNtolerant subjects with cardiovascular Disease trial (TRANSCEND).

Does synchronizing initiation of therapy affect adherence to concomitant use of antihypertensive and lipid-lowering therapy?

Although efficacious medications are available to treat hypertension and dyslipidemia, treatment adherence is often poor. This retrospective study evaluated adherence in patients newly initiating antihypertensive (AH) and lipid-lowering (LL) therapies simultaneously versus within 180 days of one another. Data were analyzed for US managed care plan enrollees initiating AH before LL (cohort 1;n = 7099), LL before AH (cohort 2; n = 3229), or AH/LL simultaneously (cohort 3; n = 5072). A multivariate model evaluated potential predictors of adherence (medication possession ratio >or= 0.80 over a bimonthly period). Percentages of patients adherent to AH/LL at 2, 6, and 12 months were as follows: 59.4%, 32.7%, and 31.3% in cohort 1; 45.0%, 30.8%, and 31.0% in cohort 2; and 75.2%, 34.4%, and 34.0% in cohort 3, respectively. After adjustment for potential confounders, patients initiating AH before LL therapy, or LL before AH therapy, were less likely to be adherent than patients prescribed both agents simultaneously (odds ratios = 0.838 and 0.691, respectively; P , 0.0001). Synchronous initiation of AH and LL therapies is an important predictor of adherence.

Can improved prescription medication labeling influence adherence to chronic medications? An evaluation of the Target pharmacy label

BACKGROUND

Prescription medication labels contain valuable health information, and better labels may enhance patient adherence to chronic medications. A new prescription medication labeling system was implemented by Target pharmacies in May 2005 and aimed to improve readability and understanding.

OBJECTIVE

We evaluated whether the new Target label influenced patient medication adherence.

DESIGN AND PATIENTS

Using claims from two large health plans, we identified patients with one of nine chronic diseases who filled prescriptions at Target pharmacies and a matched sample who filled prescriptions at other community pharmacies.

MEASUREMENTS

We stratified our cohort into new and prevalent medication users and evaluated the impact of the Target label on medication adherence. We used linear regression and segmented linear regression to evaluate the new-user and prevalent-user analyses, respectively.

RESULTS

Our sample included 23,745 Target users and 162,368 matched non-Target pharmacy users. We found no significant change in adherence between new users of medications at Target or other community pharmacies (p = 0.644) after implementing the new label. In prevalent users, we found a 0.0069 percent reduction in level of adherence (95% CI -0.0138-0.0; p < 0.001) and a 0.0007 percent increase in the slope in Target users (the monthly rate of change of adherence) after implementation of the new label (95% CI 0.0001-0.0013; p = 0.001).

CONCLUSIONS

We found no changes in adherence of chronic medication in new users, and small and likely clinically unimportant changes in prevalent users after implementation of the new label. While adherence may not be improved with better labeling, evaluation of the effect of labeling on safety and adverse effects is needed.

Profiles of mortality among Chinese hypertensive patients in Hong Kong: a cohort study

We studied the profiles of all-cause and cardiovascular (CVS) mortality among users of different antihypertensive classes in a Chinese population. From electronic patient records, a cohort study was conducted among 18,338 patients who ever newly prescribed an alpha-blocker, thiazide diuretic, beta-blocker, calcium channel blocker (CCB) or agents acting on the renin-angiotensin system (RAS) without drug discontinuation or switching in the public primary-care sector in a large Territory of Hong Kong during January 2004-June 2007. The odds ratios of mortality (all-cause and CVS) were evaluated according to the prescribed antihypertensive drug classes by Cox proportional hazards regression analyses. A total of 823 deaths (4.5%) were reported during the study period. The crude proportions of all-cause mortality were highest in alpha-blockers (6.2%) and CCB (5.7%), but lowest in beta-blockers (2.8%). Compared with CCB, patients on thiazide diuretics were shown to have statistically significantly lower all-cause (adjusted hazard ratios (aHRs) 0.75, 95% CI 0.60, 0.93, P=0.010) and CVS mortality (aHR 0.40, 95% CI 0.21, 0.78, P=0.007), but the 95% CI of the odds ratios of the major drug classes overlapped. When each drug class was used as a reference group, or when patients with only uncomplicated hypertension were included, their respective 95% CI similarly overlapped. Antihypertensive drug classes were associated with statistically comparable odds of all-cause and CVS mortality. This finding from real-life clinical practice further supports the position statements from international guidelines, which recommend that the major antihypertensive drug classes are suitable for initiating pharmacotherapy for the management of hypertension.

Blood pressure reduction, persistence and costs in the evaluation of antihypertensive drug treatment--a review

Background

Blood pressure lowering drugs are usually evaluated in short term trials determining the absolute blood pressure reduction during trough and the duration of the antihypertensive effect after single or multiple dosing. A lack of persistence with treatment has however been shown to be linked to a worse cardiovascular prognosis. This review explores the blood pressure reduction and persistence with treatment of antihypertensive drugs and the cost consequences of poor persistence with pharmaceutical interventions in arterial hypertension.

Methods

We have searched the literature for data on blood pressure lowering effects of different antihypertensive drug classes and agents, on persistence with treatment, and on related costs. Persistence was measured as patients' medication possession rate. Results are presented in the form of a systematic review.

Results

Angiotensin II receptor blocker (ARBs) have a competitive blood pressure lowering efficacy compared with ACE-inhibitors (ACEi) and calcium channel blockers (CCBs), beta-blockers (BBs) and diuretics. 8 studies describing the persistence with treatment were identified. Patients were more persistent on ARBs than on ACEi and CCBs, BBs and diuretics. Thus the product of blood pressure lowering and persistence was higher on ARBs than on any other drug class. Although the price per tablet of more recently developed drugs (ACEi, ARBs) is higher than that of older ones (diuretics and BBs), the newer drugs result in a more favourable cost to effect ratio when direct drug costs and indirect costs are also considered.

Conclusion

To evaluate drugs for the treatment of hypertension several key variables including the blood pressure lowering effect, side effects, compliance/persistence with treatment, as well as drug costs and direct and indirect costs of medical care have to be considered. ARBs, while nominally more expensive when drug costs are considered only, provide substantial cost savings and may prevent cardiovascular morbidity and mortality based on the more complete antihypertensive coverage. This makes ARBs an attractive choice for long term treatment of hypertension.

Association of antihypertensive monotherapy with serum sodium and potassium levels in Chinese patients

BACKGROUND

International guidelines on management of hypertension recommend any major classes of antihypertensive drugs. However, the low prescribing rate of thiazides has been attributed to concerns about electrolyte disturbances and studies between antihypertensive drug classes and hyponatremia/hypokalemia among Chinese patients were scarce.

METHODS

From clinical databases we included 2,759 patients who received their first-ever antihypertensive monotherapy from January 2004 to June 2007 in a large territory of Hong Kong. We studied the plasma sodium and potassium levels 8 weeks after prescriptions and factors associated with hyponatremia and hypokalemia by multivariable regression analyses.

RESULTS

Among major antihypertensive drug classes, thiazide users had the lowest sodium level (139.6 mEq/l, 95% confidence interval (CI) 139.3, 140.0, P < 0.001) and patients-prescribed calcium channel blockers (CCBs; 3.92 mEq/l, 95% CI 3.89, 3.95) or thiazide diuretics (3.99 mEq/l, 95% CI 3.93, 4.04) had the lowest potassium levels (P < 0.001). Multivariate analysis reported that advanced age (> or =70 years, odds ratio (OR) 7.49, 95% CI 2.84, 19.8, P < 0.001), male gender (OR 2.38, 95% CI 1.45, 3.91, P < 0.001), and thiazide users (OR 2.42, 95% CI 1.29, 4.56, P = 0.006) were significantly associated with hyponatremia, while renin-angiotensin system (RAS) (OR 0.31, 95% CI 0.13, 0.73, P = 0.008) and beta-blockers (BBs) (OR 0.35, 95% CI 0.23, 0.54, P < 0.001) users were less likely to present with hypokalemia. However, the proportions having normonatremic (95.1%) and normokalemic (89.4%) levels were high.

CONCLUSIONS

In view of the low prevalence of hyponatremia and hypokalemia associated with thiazides, physicians should not be deterred from prescribing thiazide diuretics as first-line antihypertensive agents as recommended by most international guidelines.

The combination of amlodipine/valsartan 5/160 mg produces less peripheral oedema than amlodipine 10 mg in hypertensive patients not adequately controlled with amlodipine 5 mg

AIMS

To demonstrate the benefit of the combination amlodipine/valsartan 5/160 mg over amlodipine 10 mg, in producing a lower incidence of peripheral oedema for a comparable mean sitting systolic blood pressure (MSSBP) reduction.

METHODS

After a 4-week amlodipine 5 mg run-in phase, inadequately controlled hypertension patients (aged > or = 55 years, MSSBP > or = 130 and < or = 160 mmHg) were randomised to receive amlodipine/valsartan 5/160 mg or amlodipine 10 mg for 8 weeks, followed by amlodipine/valsartan 5/160 mg for 4 weeks for all patients. Primary variables were MSSBP change from baseline to week 8 and incidence of peripheral oedema reported as an AE. Resolution of peripheral oedema was assessed 4 weeks after switching patients from amlodipine 10 mg to amlodipine/ valsartan 5/160 mg.

RESULTS

At week 8, MSSBP showed greater reduction with amlodipine/valsartan 5/160 mg than amlodipine 10 mg (least square mean: -8.01 vs.-5.95 mmHg, p < 0.001 for non-inferiority and p = 0.002 for superiority). Systolic control, overall BP control and systolic response rate at week 8 were significantly higher with combination than amlodipine 10 mg (34 vs. 26%; 57 vs. 50%; 36.57 vs. 27.77%, respectively). Incidence of peripheral oedema was significantly lower with the combination than amlodipine 10 mg (6.6 vs. 31.1%, p < 0.001). Peripheral oedema resolved in 56% patients who switched from amlodipine 10 mg to the combination, without the loss of effect on BP reduction.

CONCLUSION

In non-responders to amlodipine 5 mg, treatment with amlodipine/valsartan 5/160 mg induced significantly less peripheral oedema than amlodipine 10 mg for similar BP reduction. Peripheral oedema resolved in > 50% patients switching from amlodipine 10 mg to the combination.

Long-term tolerability and efficacy of the combination of amlodipine/valsartan in hypertensive patients: a 54-week, open-label extension study

OBJECTIVE

To evaluate the long-term tolerability and efficacy of the amlodipine/valsartan 5/320 mg once daily (o.d.) combination in hypertensive patients.

METHODS

This was a 54-week, multicenter, open-label extension study in patients with mild-to-moderate essential hypertension selected after successfully completing a core study during which they received either placebo, amlodipine, valsartan or combination therapy. Eligible patients (mean sitting diastolic blood pressure [MSDBP] < or = 95 mmHg and mean sitting systolic blood pressure [MSSBP] < or = 150 mmHg; n = 403) were started with amlodipine/valsartan 2.5/160 mg o.d. Following the initial 2-week treatment period, patients were force titrated to amlodipine/valsartan 5/320 mg o.d. for the remainder of the trial. Only the first 150 patients who successfully completed 28 weeks of the extension study were eligible to continue further treatment for 12 months. Efficacy variables were change from core study baseline in MSDBP and MSSBP at study (extension) endpoint. Safety assessments consisted of monitoring and recording all adverse events and serious adverse events.

RESULTS

Reductions in MSDBP and MSSBP were achieved at each extension visit. At endpoint, the reductions in MSDBP and MSSBP were 17.0 and 24.2 mmHg. Summary statistics by subgroup indicate that the combination of amlodipine/valsartan 5/320 mg was effective regardless of age, gender, or stage of hypertension. Peripheral edema occurred in 1.2% of the patients. No case of edema was classified as serious or severe, and no patient was discontinued due to edema. No deaths or clinically significant laboratory findings were observed during this extension study.

CONCLUSIONS

Long-term treatment with the amlodipine/valsartan 5/320 mg combination was well-tolerated. Clinically significant and persistent reductions in blood pressure were achieved. Limitations included an open-label design and inclusion of only those patients at or near goal blood pressure after the preceding core trial.

Impact of electronic monitoring of drug adherence on blood pressure control in primary care: a cluster 12-month randomised controlled study

BACKGROUND

Poor long-term adherence is an important cause of uncontrolled hypertension. We examined whether monitoring drug adherence with an electronic system improves long-term blood pressure (BP) control in hypertensive patients followed by general practitioners (GPs).

METHODS

A pragmatic cluster randomised controlled study was conducted over one year in community pharmacists/GPs' networks randomly assigned either to usual care (UC) where drugs were dispensed as usual, or to intervention (INT) group where drug adherence could be monitored with an electronic system (Medication Event Monitoring System). No therapy change was allowed during the first 2 months in both groups. Thereafter, GPs could modify therapy and use electronic monitors freely in the INT group. The primary outcome was a target office BP<140/90 mmHg.

RESULTS

Sixty-eight treated uncontrolled hypertensive patients (UC: 34; INT: 34) were enrolled. Over the 12-month period, the likelihood of reaching the target BP was higher in the INT group compared to the UC group (p<0.05). At 4 months, 38% in the INT group reached the target BP vs. 12% in the UC group (p<0.05), and 21% vs. 9% at 12 months (p: ns). Multivariate analyses, taking account of baseline characteristics, therapy modification during follow-up, and clustering effects by network, indicate that being allocated to the INT group was associated with a greater odds of reaching the target BP at 4 months (p<0.01) and at 12 months (p=0.051).

CONCLUSION

GPs monitoring drug adherence in collaboration with pharmacists achieved a better BP control in hypertensive patients, although the impact of monitoring decreased with time.

The design of an observational study of hypertension management, adherence and pressure control in Blood Pressure Success Zone Program participants

AIMS

The Blood Pressure Success Zone (BPSZ) Program, a nationwide initiative, provides education in addition to a complimentary trial of one of three antihypertensive medications. The BPSZ Longitudinal Observational Study of Success (BPSZ-BLISS) aims to evaluate blood pressure (BP) control, adherence, persistence and patient satisfaction in a representative subset of BPSZ Program participants. The BPSZ-BLISS study design is described here.

METHODS

A total of 20,000 physicians were invited to participate in the study. Using a call centre supported Interactive Voice Response System (IVRS), physicians report BP and other data at enrolment and every usual care visit up to 12 +/- 2 months; subjects self-report BPs, persistence, adherence and treatment satisfaction at 3, 6 and 12 months post-BPSZ Program enrolment. In addition to BPSZ Program enrolment medications, physicians prescribe antihypertensive medications and schedule visits as per usual care. The General Electric Healthcare database will be used as an external reference.

RESULTS

After 18 months, over 700 IRB approved physicians consented and enrolled 10,067 eligible subjects (48% male; mean age 56 years; 27% newly diagnosed); 97% of physicians and 78% of subjects successfully entered IVRS enrolment data. Automated IVRS validations have maintained data quality (< 5% error on key variables). Enrolment was closed 30 April 2007; study completion is scheduled for June 2008.

CONCLUSIONS

The evaluation of large-scale health education programmes requires innovative methodologies and data management and quality control processes. The BPSZ-BLISS design can provide insights into the conceptualisation and planning of similar studies.

Assessment of adherence, persistence, and costs among valsartan and hydrochlorothiazide retrospective cohorts in free-and fixed-dose combinations

OBJECTIVES

To assess medication adherence, persistence, and costs between cohorts of patients in managed care settings using a fixed-dose combination (FDC) or individual components (IC) of valsartan and hydrochlorothiazide in an insurance claims database.

METHODS

Medical and prescription claims for hypertensive patients using a combination of valsartan and HCTZ were identified from the IHCIS National Managed Care Benchmark Database via a retrospective cohort analysis. Study subjects had at least 110 days prior to start of study medications during which no other antihypertensive medications were prescribed, and were followed for 12 months. Claims for 8711 adult patients were analyzed for adherence, persistence and costs. General linear regression was conducted to detect differences in adherence among groups. Covariates included age, gender, persistence, number on concomitant cardiovascular drugs, and number of cardiovascular diagnoses.

RESULTS

Most subjects used an FDC product (N=8150, 93.6%) vs. the IC (N=561, 6.4%). The FDC group had a larger portion of males and less concomitant cardiovascular medications or disease. A random sample of 1628 of the FDC subjects had improved values for medication adherence compared to the IC group (62.1 vs. 53.0%, p<0.001) and persistence values were improved at both 180 days (73 vs. 28%, p<0.001) and 365 days (54 vs. 19%, p<0.001). Both prescription drug costs ($1587 vs. $2050, p<0.001) and medical costs ($3343 vs. $3817, p<0.001) were lower in the FDC cohorts.

CONCLUSIONS

The use of fixed-dose therapy in hypertension may lead to increased adherence and persistence with a positive financial impact on both prescription and total medical costs. As with any retrospective claims database analysis, unobserved systematic differences between the two medication groups may exist.

Adherence to prescribed antihypertensive drug treatments: longitudinal study of electronically compiled dosing histories

OBJECTIVE

To describe characteristics of dosing history in patients prescribed a once a day antihypertensive medication.

DESIGN

Longitudinal database study.

SETTING

Clinical studies archived in database for 1989-2006.

PARTICIPANTS

Patients who participated in the studies whose dosing histories were available through electronic monitoring.

MAIN OUTCOME MEASURES

Persistence with prescribed antihypertensive treatment and execution of their once a day drug dosing regimens.

RESULTS

The database contained dosing histories of 4783 patients with hypertension. The data came from 21 phase IV clinical studies, with lengths ranging from 30 to 330 days and involving 43 different antihypertensive drugs, including angiotensin II receptor blockers (n=2088), calcium channel blockers (n=937), angiotensin converting enzyme inhibitors (n=665), beta blockers (n=195), and diuretics (n=155). About half of the patients who were prescribed an antihypertensive drug had stopped taking it within one year. On any day, patients who were still engaged with the drug dosing regimen omitted about 10% of the scheduled doses: 42% of these omissions were of a single day's dose, whereas 43% were part of a sequence of several days (three or more days-that is, drug "holidays"). Almost half of the patients had at least one drug holiday a year. The likelihood that a patient would discontinue treatment early was inversely related to the quality of his or her daily execution of the dosing regimen.

CONCLUSIONS

Early discontinuation of treatment and suboptimal daily execution of the prescribed regimens are the most common facets of poor adherence with once a day antihypertensive drug treatments. The shortfalls in drug exposure that these dosing errors create might be a common cause of low rates of blood pressure control and high variability in responses to prescribed antihypertensive drugs.

The economic consequences of noncompliance in cardiovascular disease and related conditions: a literature review

OBJECTIVES

To review studies on the cost consequences of compliance and/or persistence in cardiovascular disease (CVD) and related conditions (hypertension, dyslipidaemia, diabetes and heart failure) published since 1995, and to evaluate the effects of noncompliance on healthcare expenditure and the cost-effectiveness of pharmaceutical interventions.

METHODS

English language papers published between January 1995 and February 2007 that examined compliance/persistence with medication for CVD or related conditions, provided an economic evaluation of pharmacological interventions or cost analysis, and quantified the cost consequences of noncompliance, were identified through database searches. The cost consequences of noncompliance were compared across studies descriptively.

RESULTS

Of the 23 studies identified, 10 focused on hypertension, seven on diabetes, one on dyslipidaemia, one on coronary heart disease, one on heart failure and three covered multiple diseases. In studies assessing drug costs only, increased compliance/persistence led to increased drug costs. However, increased compliance/persistence increased the effectiveness of treatment, leading to a decrease in medical events and non-drug costs. This offset the higher drug costs, leading to savings in overall treatment costs. In studies evaluating the effect of compliance/persistence on the cost-effectiveness of pharmacological interventions, increased compliance/persistence appeared to reduce cost-effectiveness ratios, but the extent of this effect was not quantified.

CONCLUSIONS

Noncompliance with cardiovascular and antidiabetic medication is a significant problem. Increased compliance/persistence leads to increased drug costs, but these are offset by reduced non-drug costs, leading to overall cost savings. The effect of noncompliance on the cost-effectiveness of pharmacological interventions is inconclusive and further research is needed to resolve the issue.

Predictors of persistence with antihypertensive therapy: results from the NHANES

BACKGROUND

More than 40% of treated hypertensives in the United States do not have their blood pressure under control. This is partly owing to non-persistence with prescribed medication, which occurs within 1 year in 32-53% of newly treated patients. Knowledge of factors related to non-persistence is limited, partly because previous studies have being conducted mostly in elderly patients enrolled in a single health insurance.

METHODS

Weighted logistic regression was used to identify factors associated with non-persistence in hypertensive patients from National Health and Nutrition Examination Surveys III (NHANES III) and NHANES 1999-2002 who had been prescribed antihypertensive medication.

RESULTS

Of 6100 participants, 903 were non-persistent (sampling weighted national prevalence of 12.5%), even though they had elevated blood pressure. Non-persistence was 12 times higher in patients <30 years than in those > or =50 years old (P < 0.001), 31% higher in men than in women (P = 0.01), and 43% higher in Hispanics, as compare to other racial groups (P = 0.03). Patients with low income were almost two times more likely to be non-persistent (P < 0.001). Having no health insurance increased non-persistence by 88% (P = 0.002), and patients who did not visit their doctor during the last year were 10 times more likely to be non-persistent than those who made at least one medical visit (P < 0.001).

CONCLUSIONS

In addition to young age, factors related to access to health care and medications (low income, health insurance, and visits to the doctor) were the main predictors of non-persistence. Policies that improve access to health care and patient follow-up may be of great impact in maintaining persistence.

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.

Initial and sustained cardiovascular risk reduction in a pharmacist-led diabetes cardiovascular risk clinic

Background

The atherogenic milieu of hypertension, hyperglycaemia and dyslipidaemia results in an excess of cardiovascular deaths in the diabetic population.

Objective

To determine the efficacy and long-term success of a pharmacist-delivered cardiovascular risk reduction clinic.

Methods

Patients with diabetes not achieving blood pressure (BP) and lipid targets at a standard diabetes clinic had a mean of four visits to the pharmacist-delivered clinic.

Results

BP was significantly reduced by attending the clinic (mean reduction in clinic BP 23/10 mmHg). Ambulatory BP monitoring demonstrated a mean reduction of 13/9 mmHg from clinic entry to discharge and this effect was sustained six months post-discharge .

Total cholesterol was reduced by 0.4 mmol/L (p=0.002) during clinic attendances and remained unchanged post discharge.

Conclusion

Patients previously thought to be `resistant' to treatment can have significant reductions in cardiovascular risk factors when enrolled in a short-lived, intense clinic set-up. This is maintained

What factors contribute to the inadequate control of elevated blood pressure?

Inadequate control of blood pressure may be attributed to both provider-related and patient-related factors. Health care provider-related factors may include an excessive reliance on monotherapy and reluctance to increase drug doses or add additional antihypertensive agents to the treatment regimen. The primary patient-related factor is nonadherence with the prescribed antihypertensive medication. Although the high cost of therapy is sometimes a reason for poor adherence, drug side effects or dosing considerations may be more important factors. Better adherence with antihypertensive medication is associated with a significantly greater likelihood of achieving blood pressure control and, consequently, with lower costs and reduced utilization of health care resources. Therefore, strategies that improve long-term adherence should be adopted. Single-pill, or fixed-dose, combination therapy is one approach that improves adherence, while also providing the antihypertensive efficacy needed to help patients achieve their blood pressure goals.

Patient, physician, pharmacy, and pharmacy benefit design factors related to generic medication use

BACKGROUND

Increased use of generic medications conserves insurer and patient financial resources and may increase patient adherence.

OBJECTIVE

The objective of the study is to evaluate whether physician, patient, pharmacy benefit design, or pharmacy characteristics influence the likelihood that patients will use generic drugs

DESIGN, SETTING, AND PARTICIPANTS

Observational analysis of 2001-2003 pharmacy claims from a large health plan in the Western United States. We evaluated claims for 5,399 patients who filled a new prescription in at least 1 of 5 classes of chronic medications with generic alternatives. We identified patients initiated on generic drugs and those started on branded medications who switched to generic drugs in the subsequent year. We used generalized estimating equations to perform separate analyses assessing the relationship between independent variables and the probability that patients were initiated on or switched to generic drugs.

RESULTS

Of the 5,399 new prescriptions filled, 1,262 (23.4%) were generics. Of those initiated on branded medications, 606 (14.9%) switched to a generic drug in the same class in the subsequent year. After regression adjustment, patients residing in high-income zip codes were more likely to initiate treatment with a generic than patients in low-income regions (RR = 1.29; 95% C.I. 1.04-1.60); medical subspecialists (RR = 0.82; 0.69-0.95) and obstetrician/gynecologists (RR = 0.81; 0.69-0.98) were less likely than generalist physicians to initiate generics. Pharmacy benefit design and pharmacy type were not associated with initiation of generic medications. However, patients were over 2.5 times more likely to switch from branded to generic medications if they were enrolled in 3-tier pharmacy plans (95% C.I. 1.12-6.09), and patients who used mail-order pharmacies were 60% more likely to switch to a generic (95% C.I. 1.18-2.30) after initiating treatment with a branded drug.

CONCLUSIONS

Physician and patient factors have an important influence on generic drug initiation, with the patients who live in the poorest zip codes paradoxically receiving generic drugs least often. While tiered pharmacy benefit designs and mail-order pharmacies helped steer patients towards generic medications once the first prescription has been filled, they had little effect on initial prescriptions. Providing patients and physicians with information about generic alternatives may reduce costs and lead to more equitable care.

Compliance with refilling prescriptions for atypical antipsychotic agents and its association with the risks for hospitalization, suicide, and death in patients with schizophrenia in Quebec and Saskatchewan: a retrospective database study

OBJECTIVE

The objective of this analysis was to describe the patterns of compliance with atypical antipsychotics among patients with schizophrenia in actual practice in 2 Canadian provinces and to examine the relation between degrees of compliance and the risks of hospitalization, suicide, and death.

METHODS

Adults with a diagnosis of schizophrenia who filled at least 1 prescription for risperidone, olanzapine, or quetiapine were identified in the Quebec public prescription drug insurance plan database (from July 1, 2001, to December 31, 2004) and the Saskatchewan Health database (from January 1, 1999, to December 31, 2003). Compliance was assessed based on the medication possession ratio, which was estimated as the proportion of days for which medication was available over each month of follow-up (> or = 80% = good compliance; 50%-79% = moderate compliance; < 50% = poor compliance). The association between the early and long-term effects of compliance and the risks of hospitalization, suicide, and death were examined using Cox regression, with adjustment for baseline age, sex, and use of antidepressants, sedatives, and lithium (Quebec only).

RESULTS

respective 41,754 and 3291 patients were identified from the Quebec and Saskatchewan databases. Approximately half of the patients in each cohort were male and were aged < 45 years. Many patients had good compliance over the full follow-up period (Quebec, 61%; Saskatchewan, 45%); however, poor compliance was seen in 23% of patients from Quebec and 34% of those from Saskatchewan. Compared with poor compliance, the long-term effect of good compliance was associated with a significantly decreased risk of all-cause hospitalization (Quebec: adjusted hazard ratio [HR] = 0.60; 95% CI, 0.57-0.64; Saskatchewan: adjusted HR = 0.81; 95% CI, 0.69-0.95) and psychosis-related hospitalization (Quebec: adjusted HR = 0.37; 95% Cl, 0.34-0.40; Saskatchewan: adjusted HR = 0.45; 95% CI, 0.32-0.64). The Quebec data also indicated a significant association between good versus poor compliance and a decreased risk of death (adjusted HR = 0.58; 95% CI, 0.51-0.66) and suicide (adjusted HR = 0.68; 95% CI, 0.55-0.84) that was not observed in Saskatchewan.

CONCLUSION

In this retrospective analysis of patients with schizophrenia in Quebec and Saskatchewan, good compliance with atypical antipsychotic medications was associated with substantial reductions in the risk for all-cause and psychosis-related hospitalizations.