Factors associated with antihypertensive drug discontinuation among Chinese patients: a cohort study

Personalized hypertension treatment recommendations by a data-driven model

BACKGROUND

Hypertension is a prevalent cardiovascular disease with severe longer-term implications. Conventional management based on clinical guidelines does not facilitate personalized treatment that accounts for a richer set of patient characteristics.

METHODS

Records from 1/1/2012 to 1/1/2020 at the Boston Medical Center were used, selecting patients with either a hypertension diagnosis or meeting diagnostic criteria (≥ 130 mmHg systolic or ≥ 90 mmHg diastolic, n = 42,752). Models were developed to recommend a class of antihypertensive medications for each patient based on their characteristics. Regression immunized against outliers was combined with a nearest neighbor approach to associate with each patient an affinity group of other patients. This group was then used to make predictions of future Systolic Blood Pressure (SBP) under each prescription type. For each patient, we leveraged these predictions to select the class of medication that minimized their future predicted SBP.

RESULTS

The proposed model, built with a distributionally robust learning procedure, leads to a reduction of 14.28 mmHg in SBP, on average. This reduction is 70.30% larger than the reduction achieved by the standard-of-care and 7.08% better than the corresponding reduction achieved by the 2nd best model which uses ordinary least squares regression. All derived models outperform following the previous prescription or the current ground truth prescription in the record. We randomly sampled and manually reviewed 350 patient records; 87.71% of these model-generated prescription recommendations passed a sanity check by clinicians.

CONCLUSION

Our data-driven approach for personalized hypertension treatment yielded significant improvement compared to the standard-of-care. The model implied potential benefits of computationally deprescribing and can support situations with clinical equipoise.

Factors affecting the changes in antihypertensive medications in patients with hypertension

As frequent changes in anti-hypertensive (HTN) medications may reduce adherence to the treatments, identifying modifiable factors leading to changes in anti-HTN medications can help clinicians optimize treatment strategies for individual patients. We performed this study to explore the pattern of anti-HTN medications and to identify factors that are associated with the changes in anti-HTN medications. To this end, we used a clinical database of Seoul National University Hospital, extracted, transformed, and loaded by the observational medical outcomes partnership common data model. Demographic and all recorded clinical diagnoses, medications, and procedures data of eligible subjects were collected. Of 636 subjects who were eligible for this study, 297 subjects with a record of ≥1 anti-HTN medication changes and other 297 subjects without a record of medication change were selected for the study population. High diastolic blood pressure (adjusted odds ratio [OR]: 1.02, 95% confidence interval [CI]: 1.001–1.040, p = 0.040), arrhythmia (adjusted OR: 10.01, 95% CI: 1.86–185.57, p = 0.030), and angina pectoris with antianginal agents (adjusted OR: 4.85, CI: 1.05–23.89, p = 0.046) were associated with the changes in anti-HTN medications, indicating that any patients with these covariates require additional attention to reduce the likelihood of changing anti-HTN medications.

Clinical use of azelnidipine in the treatment of hypertension in Chinese patients

Background

Hypertension is the most common chronic disease and the calcium channel antagonist is the most popularly used antihypertensive drug in Chinese patients. Azelnidipine is a third generation and long-acting dihydropyridine calcium channel antagonist. A series of research has demonstrated that azelnidipine produced an effective antihypertensive effect in patients with essential hypertension. Now it is need to summarize clinical use of azelnidipine in the treatment of hypertension in Chinese patients.

Methods

Relevant literature was identified by performing searches in PubMed and CNKI (China National Knowledge Infrastructure), covering the period from January 2003 (the year azelnidipine was launched) to July 2014. We included studies that described pharmacology of azelnidipine, especially the pharmacokinetics, clinical efficacy, and safety and tolerability of azelnidipine in a Chinese population. The full text of each article was strictly reviewed, and data interpretation was performed.

Results

In Chinese healthy volunteers, a single-dose oral administration of azelnidipine 8–16 mg had a peak plasma concentration of 1.66–23.06 ng/mL and time to peak plasma concentration was 2.6–4.0 hours and the area under the plasma concentration versus time curve from time 0 hour to 96 hours was 17.9–429 ng/mL·h and elimination half-life was 16.0–28.0 hours. A number of clinical trials have demonstrated that azelnidipine produced a significant reduction in blood pressure in Chinese patients with mild-to-moderate hypertension, which was similar to that of other effective antihypertensive drugs such as amlodipine, zofenopril, and nifedipine. In addition to its antihypertensive effect, azelnidipine had other cardiovascular protective effects as well, like anti-oxidative action, decreasing heart rate, and improving systolic and diastolic function. Azelnidipine was generally well tolerated in Chinese patients and no severe adverse events were observed.

Conclusion

Azelnidipine is effective and safe in the treatment of hypertension in Chinese patients.

Socioeconomic status and nonadherence to antihypertensive drugs: a systematic review and meta-analysis

BACKGROUND

Although conventional wisdom suggests that low socioeconomic status (SES) is a robust predictor of medication nonadherence, the strength of this association remains unclear.

OBJECTIVES

1) To estimate the proportion of studies that identified SES as a potential risk indicator of nonadherence, 2) to describe the type of SES measurements, and 3) to quantify the association between SES and nonadherence to antihypertensive pharmacotherapy.

METHODS

A systematic review and meta-analysis research design was used. We searched multiple electronic databases for studies in English or French examining nonadherence to antihypertensive medications measured by electronic prescription databases where explanatory factors were considered. Two authors independently assessed quality, described the SES measure(s), and recorded its association with nonadherence to antihypertensives. A random-effects model meta-analysis was performed, and heterogeneity was examined by using the I(2) statistic.

RESULTS

Fifty-six studies with 4,780,293 subjects met the inclusion criteria. Twenty-four of these studies (43%) did not report any SES measures. When it was reported (n = 32), only seven (13%) examined more than one component but none performed a multidimensional assessment. Most of the studies relied on income or income-related measures (such as prescription-drug benefits or co-payments) (27 of 32 [84%]). Meta-analysis could be quantified in 40 cohorts reported in 30 studies. Overall, the pooled adjusted risk estimate for nonadherence according to SES (high vs. low) was 0.89 (95% confidence interval 0.87-0.92; I(2) = 95%; P < 0.001). Similar patterns were observed in all subgroups examined.

CONCLUSIONS

Published studies have not found a strong association between low SES and nonadherence to antihypertensive medications. However, important limitations in the assessment of SES can be identified in virtually all studies. Future studies are required to ascertain whether a stronger association is observed when SES is determined by comprehensive measures.

Prevalence of complications among Chinese diabetic patients in urban primary care clinics: a cross-sectional study

BACKGROUND

A territory-wide diabetes management program (Risk Assessment Management Program - RAMP) was recently established, providing comprehensive management for all diabetics, helping to delineate current level of control and complications prevalence among primary care diabetic patients in Hong Kong.

METHOD

This cross-sectional study captured anonymous clinical data from RAMP patients. Data obtained include sociodemographic details, type of diabetes, illness duration, family history, drug usage, coexisting illnesses, diabetic complications and other clinical parameters.

RESULTS

Data from 15,856 type 2 diabetic patients were analyzed. 57.1% were above 60 years old, with mean disease duration of 7.3 years. Hypertension was the commonest coexisting chronic illness (57.6%). 30.2% and 61.8% have their systolic and diastolic pressure controlled to below 130 mmHg and 80 mmHg respectively. Over half (51.5%) had an HbA1c level of less than 7.0%. 88.4% did not achieve target lipid level. 15% were on diet control alone. Only 22.2% were on statins. In patients with microalbuminuria and macroalbuminuria, 40.7% and 54.5% were on angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB) respectively. 12.9%, 38.8% and 2.4% had diabetic retinopathy, nephropathy and neuropathy respectively. Overall, 37.9%, 7.3% and 0.4% had single, two and three concurrent microvascular complications respectively.

CONCLUSION

The level of diabetic control is comparable with other developed countries. We demonstrated a high prevalence of microvascular complications among Chinese primary care patients despite achieving adequate HbA1c levels, highlighting the importance of managing all aspects of diabetes including weight, lipid and blood pressure. Efforts to improve holistic management must be tailored according to the needs of our population, with the challenges that the majority have low educational background and in the older age group.

Time to achieve first blood pressure control after diagnosis among hypertensive patients at primary health care clinics: a preliminary study

This study aimed to examine the duration to achieve first blood pressure (BP) control after the diagnosis of hypertension. This was a retrospective cohort study on 195 hypertensive patients' (age ≥18 years) records from a primary health care clinic. The median time to achieve first BP control was 7.2 months (95% confidence interval [CI] = 4.99-9.35). Cox proportional hazards regression results showed female patients were 1.5 times more likely to achieve BP control when compared with male patients (hazard ratio [HR] = 1.50, 95% CI 1.09-2.09, P = .013). Those with monotherapy were 2 times more likely (HR = 2.09, 95% CI = 1.39-3.13, P < 0.001) and those on 2 drugs were 3.5 times more likely (HR = 3.49, 95% CI = 1.65-7.40, P = .001) to achieve BP control than those with nonpharmacological treatment. The median time to achieve BP control was longer than the recommended time. Doctors may need to consider starting the pharmacological treatment early and be more aggressive in hypertensive management for male patients.

Pharmacoepidemiological profiles of oral hypoglycemic agents among 28,773 Chinese patients with diabetes

AIMS

This study examined the rates of discontinuation of Oral Hypoglycemic Agents (OHAs) in diabetes patients, and to evaluate the associations between discontinuation of OHAs, socioeconomic status and the number of comorbidities.

METHODS

A cohort study from January 2004 to June 2007 was conducted and followed up through December 2007. We included all primary care clinics in one large territories of Hong Kong involving 28,773 Chinese diabetes patients. Multivariate regression analyses controlled for age, gender, payment status (fee-payers vs. fee waivers; fee-waivers represented those less able to pay for consultation fees and were regarded as having lower socioeconomic status), service type delivered by the clinics, district of residence, visit type (new vs. follow-up), the number of comorbidities and the drug class (sulphonylureas vs. biguanide vs. combination therapy).

RESULTS

9.9% discontinued their medications within 180 days of their prescriptions. Fee waivers (adjusted odds ratio [AOR] for fee payers=0.81, 95% C.I. 0.73-0.89, p<0.001) and the absence of comorbidities (AOR for ≥one morbidity=0.59-0.62, p<0.001) were associated with medication discontinuation.

CONCLUSIONS

Diabetes patients with lower ability to pay and without comorbidities were significantly associated with OHAs discontinuation. They should be the target groups for medication counseling programmes.

First-fill medication discontinuations and nonadherence to antihypertensive therapy: an observational study

BACKGROUND

Medication nonadherence is a barrier to successfully managing hypertension, but little is known about the contribution that immediate discontinuations have on antihypertensive (AHT) nonadherence. The purpose of this study was to determine the proportion of new AHT users who discontinue after a single dispensation, and to examine potential predictors of these discontinuations.

METHODS

This retrospective cohort study utilizing linked administrative data from Saskatchewan, Canada. Subjects were ≥40 years of age and received a new AHT between 1994-2002. The primary end point was the proportion of subjects who discontinued their AHT after the first dispensation (first-fill discontinuation). The proportion of nonadherence attributed to first-fill discontinuations was then calculated. Multivariate regression identified factors associated with first-fill discontinuations.

RESULTS

52,039 subjects were included in the analyses. Mean age was 59.4 (s.d. 12.5) years, and 42% were male. Overall, 25,812/52,039 (50%) subjects were nonadherent at 1 year; first-fill discontinuations accounted for 39.1% (10,081/25,812) of this nonadherence. Approximately 20% (10,081/52,039) of all subjects discontinued all AHT therapy after the first fill. A higher chronic disease score (adjusted odds ratio (OR) 1.09, 95% confidence interval (CI) 1.08-1.11) and antidepressant medication usage during the observation year (adjusted OR 1.17, 95% CI 1.09-1.26) was associated with increased risk for first-fill discontinuations. Older age, starting AHT therapy after 1994, frequent physician visits, or use of a statin, acetylsalicylic acid, warfarin or antihyperglycemic during the observation year was associated with a lower risk for first-fill discontinuations.

CONCLUSION

A substantial proportion of nonadherence to AHT medications is due to discontinuations after only a single dispensation.

Finasteride adherence-associated factors in Chinese benign prostatic hyperplasia patients

OBJECTIVES

Medication noncompliance is a recognized problem worldwide. This study evaluated the factors associated with compliance, discontinuation and switching of finasteride among Chinese benign prostatic hyperplasia patients.

MATERIALS AND METHODS

A retrospective cohort study was conducted with 682 outpatients newly diagnosed with benign prostatic hyperplasia and prescribed with finasteride from January 2008 to December 2009, taken from a database. We evaluated their compliance by medication possession ratios, discontinuation and switching rate after the prescription for an average observation period of 15 months. Multiple association factors were identified and evaluated using multivariate logistic regression analyses.

RESULTS

The crude compliance level, discontinuation and switching rates were 29.3, 60.6 and 10.1%, respectively. Older age (≥60 years), combination therapy, medical insurance and chronic comorbidities were positively associated with good compliance. Younger age was significantly associated with drug discontinuation or switching. Those patients on finasteride monotherapy and without medical insurance were significantly associated with discontinuation of drugs.

CONCLUSIONS

Patients <60 years of age, on monotherapy and without medical insurance were less likely to be compliant with their newly initiated finasteride treatment. Consequently, more efforts should be made among this group to increase treatment adherence.

Subjects at risk of discontinuation of lipid-lowering agents: a 6-month cohort study among 12,875 patients in a chinese population

BACKGROUND

Dyslipidemia is a significant health problem, and persistent use of lipid-lowering agents among dyslipidemic patients is clinically important. However, few studies have evaluated the profiles of medication discontinuation among ethnic Chinese patients.

OBJECTIVE

The objective of this study was to evaluate the level of medication adherence among Chinese patients who were prescribed a lipid-lowering drug and to investigate factors that could help physicians identify patients at risk for discontinuing their medication.

METHODS

All patients who attended any primary care clinic in 1 territory of Hong Kong and were prescribed at least 1 lipid-lowering agent from January 2004 to June 2007 were included. The incidences of drug discontinuation within 180 days after drug prescriptions were measured, and the factors associated with discontinuation using binary logistic regression analyzes were evaluated.

RESULTS

Of the 12,875 eligible patients, the majority were prescribed fibrates (54.4%) and statins (45.1%). Among the patients, 17.0% discontinued their medication. Older patients (adjusted odds ratio [aOR] = 0.72-0.79 for patients >50 years), male subjects (aOR = 0.87; 95% CI, 0.78-0.97; P = 0.009), fee payers (aOR = 0.88; 95% CI, 0.78-0.99; P = 0.029), attendees in family medicine specialist clinics (aOR = 0.82; 95% CI, 0.70-0.96; P = 0.013), residents in rural districts (aOR = 0.52; 95% CI, 0.44-0.60; P < 0.001), follow-up visitors (aOR = 0.60; 95% CI, 0.54-0.66; P < 0.001), patients with comorbidities (aOR = 0.39; 95% CI, 0.35-0.44; P < 0.001 for 1 comorbidity and aOR = 0.28; 95% CI, 0.25-0.33; P < 0.001 for at least 2 comorbidities), and persons who use fibrates (aOR = 0.56; 95% CI, 0.49-0.64; P < 0.001) were significantly less likely to discontinue their medication.

CONCLUSIONS

The findings of these associated factors were new for ethnic Chinese patients. These findings could help physicians identify patients who had been prescribed a lipid-lowering agent who were at higher risk of discontinuing their medication. Their medication-taking behavior should be monitored more closely, and future studies should evaluate the reasons of drug discontinuation.

Individuals at risk of beta-blocker discontinuation: a cohort study in 19,177 Chinese patients

PURPOSE

This cohort study evaluated the factors associated with discontinuation of antihypertensive pharmacotherapy among Chinese patients who were prescribed beta-blockers. We tested the hypothesis that patients' age, gender, socioeconomic status, clinical settings and the number of comorbidities were significantly associated with the discontinuation of beta-blockers.

METHODS

From a validated clinical database we included all adult patients 18 years or older who were prescribed a beta-blocker in any government primary care clinic in one large territory of Hong Kong during 01 January 2004-30 June 2007. We evaluated the cumulative incidence of drug discontinuation within 180 days of the prescriptions and the factors associated with discontinuation of beta-blockers by multivariable regression analysis.

RESULTS

From a total of 19,177 eligible patients (mean age = 59.1 years), 20.8% discontinued their medication. Younger patients [aged <50 years; adjusted odds ratios (aOR) 0.41-0.52 for patients aged >or=50 years; p < 0.001], female gender (aOR 0.87 for males, p = 0.001), fee-waivers (aOR 0.78 for fee-payers, p < 0.001), attendances in family medicine specialist clinics (FMSC) (aOR 1.49, p < 0.001) and staff clinics (aOR 2.32, p < 0.001), residence in more urbanized areas (aOR 0.80 for North District, p < 0.001), new visits (aOR 0.55 for follow-up visits, p < 0.001) and absence of concomitant comorbidities (aOR 0.60 for one comorbidity, p < 0.001; aOR 0.56 for two comorbidities, p = 0.002) were positively associated with drug discontinuation.

CONCLUSIONS

Patients who were prescribed beta-blockers with these associated factors should be monitored more closely for antihypertensive drug adherence.