Factors associated with non-adherence to angiotensin-converting enzyme inhibitors and angiotensin receptor blockers in older patients with peripheral arterial disease.

Introduction: As in other chronic conditions, medication adherence is important in the treatment of peripheral arterial disease (PAD). Our study aimed at a) analysing non-adherence to angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in groups of older ACEI and ARB users with PAD, and b) identifying characteristics associated with non-adherence. Methods: We focused on the implementation phase of adherence (i.e., after treatment initiation and before possible discontinuation of treatment). The study cohort included ACEI/ARB users aged ≥65 years in whom PAD was newly diagnosed during 2012. Non-adherence was defined as Proportion of Days Covered (PDC) < 80%. Results: Among 7,080 ACEI/ARB users (6,578 ACEI and 502 ARB users), there was no significant difference in the overall proportion of non-adherent patients between ACEI and ARB users (13.9% and 15.3%, respectively). There were differences in factors associated with non-adherence between the groups of persistent and non-persistent (i.e., discontinued treatment at some point during follow-up) ACEI and ARB users. Increasing age, dementia and bronchial asthma were associated with non-adherence in persistent ACEI users. General practitioner as index prescriber was associated with adherence in the groups of non-persistent ACEI users and persistent ARB users. Conclusion: Identified factors associated with non-adherence may help in determining the groups of patients who require increased attention.

Reinitiation and Subsequent Discontinuation of Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers among New and Prevalent Users Aged 65 Years or More with Peripheral Arterial Disease.

Angiotensin-converting enzyme inhibitors (ACEIs) or angiotensin-receptor blockers (ARBs) are recommended in the treatment of arterial hypertension in patients with peripheral arterial disease (PAD). The aims of our study were: (a) to analyse the extent of reinitiation and subsequent discontinuation in older hypertensive PAD patients non-persistent with ACEIs/ARBs; (b) to determine patient and medication factors associated with reinitiation and subsequent discontinuation; and (c) to compare these factors between prevalent and new users. The analysis of reinitiation was performed on a sample of 1642 non-persistent patients aged ≥65 years with PAD newly diagnosed in 2012. Patients reinitiating ACEIs/ARBs were used for the analysis of subsequent discontinuation identified according to the treatment gap period of at least 6 months without any prescription of ACEI/ARB. In the group of non-persistent patients, 875 (53.3%) patients reinitiated ACEIs/ARBs during a follow-up (24.8 months on average). Within this group, subsequent discontinuation was identified in 414 (47.3%) patients. Being a new user was associated with subsequent discontinuation, but not with reinitiation. Myocardial infarction during non-persistence and after reinitiation was associated with reinitiation and lower likelihood of subsequent discontinuation, respectively. Being a prevalent or a new user is associated with the use of medication also after initial discontinuation.

Gender Differences in Non-Persistence with Angiotensin-Converting Enzyme Inhibitors and Angiotensin Receptor Blockers among Older Hypertensive Patients with Peripheral Arterial Disease.

The beneficial effects of angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) in hypertensive patients with peripheral arterial disease (PAD) depends on long-term persistence. The aims of our study were to analyse gender differences in non-persistence with ACEIs/ARBs, and to identify the characteristics associated with the likelihood of non-persistence. Our study cohort included 7080 hypertensive patients (4005 women and 3075 men) aged ≥65 years, treated with ACEIs/ARBs, in whom PAD was diagnosed between 1 January and 31 December 2012. Non-persistence was identified according to a treatment gap of 6 months without ACEI/ARB prescriptions. The characteristics associated with non-persistence were identified using the Cox regression model. At the end of the 5-year follow-up, 23.2% of the whole study cohort, 22.3% of men, and 23.9% of women were non-persistent with ACEIs/ARBs, with no significant gender differences in persistence. While a number of characteristics were associated with non-persistence, only three characteristics had consistent, statistically significant associations in both genders: being a new ACEI/ARB user increased the likelihood of non-persistence, and general practitioner as index prescriber and increasing the overall number of medications decreased the likelihood of non-persistence. Information on the differences in characteristics that are associated with non-persistence between genders may help to better identify patients for whom special attention should be paid to improve their persistence.

Adherence to Antiplatelet Medications among Persistent and Non-Persistent Older Patients with Peripheral Arterial Disease.

Secondary prevention of peripheral arterial disease (PAD) includes administration of antiplatelet agents, and adherence to medication is a requirement for an effective treatment. The aim of this study was to analyse adherence measured using the proportion of days covered (PDC) index separately in persistent and non-persistent patients, and to identify patient- and medication-related characteristics associated with non-adherence in these patient groups. The study cohort of 9178 patients aged ≥ 65 years in whom PAD was diagnosed in 1/-12/2012 included 6146 persistent and 3032 non-persistent patients. Non-adherence was identified as PDC < 80%. Characteristics associated with non-adherence were determined using the binary logistic regression model. In the group of persistent patients, 15.3% of subjects were identified as non-adherent, while among non-persistent patients, 26.9% of subjects were non-adherent to antiplatelet medication. Administration of dual antiplatelet therapy (aspirin and clopidogrel) and a general practitioner as index prescriber were associated with adherence in both patient groups. Our study revealed a relatively high proportion of adherent patients not only in the group of persistent patients but also in the group of non-persistent patients before discontinuation. These results indicate that most non-persistent PAD patients discontinue antiplatelet treatment rapidly after a certain period of adherence.

Reinitiation and Subsequent Discontinuation of Antiplatelet Treatment in Nonpersistent Older Patients with Peripheral Arterial Disease.

The successful treatment of peripheral arterial disease (PAD) depends on adequate adherence to medications including antiplatelet agents. The aims of this study were (a) to identify the proportion of nonpersistent patients who reinitiated antiplatelet therapy and how many of them discontinued therapy after reinitiation, and (b) to identify patient- and medication-related characteristics associated with the likelihood of reinitiation and discontinuation among reinitiators. The analysis of reinitiation was conducted on 3032 nonpersistent users of antiplatelet agents aged ≥65 years, with PAD newly diagnosed in 2012. Discontinuation (i.e., a treatment gap of ≥6 months without antiplatelet medication prescription) was analysed in 2006 reinitiating patients. To identify factors associated with the likelihood of reinitiation and discontinuation, Cox regression with time-dependent covariates was used. Reinitiation was recorded in 2006 (66.2%) of 3032 patients who had discontinued antiplatelet medication. Among these 2006 reinitiators, 1078 (53.7%) patients discontinued antiplatelet therapy again. Ischemic stroke and myocardial infarction during nonpersistence and bronchial asthma/chronic obstructive pulmonary disease were associated with an increased likelihood of reinitiation. University education was associated with discontinuation among reinitiators. Factors associated with the probability of reinitiation and discontinuation in reinitiators make it possible to identify older PAD patients in whom "stop-starting" behaviour may be expected.

Non-Persistence With Antiplatelet Medications Among Older Patients With Peripheral Arterial Disease.

Introduction: Antiplatelet therapy needs to be administered life-long in patients with peripheral arterial disease (PAD). Our study was aimed at 1) the analysis of non-persistence with antiplatelet medication in older PAD patients and 2) identification of patient- and medication-related characteristics associated with non-persistence. Methods: The study data was retrieved from the database of the General Health Insurance Company. The study cohort of 9,178 patients aged ≥ 65 years and treated with antiplatelet medications was selected from 21,433 patients in whom PAD was newly diagnosed between 01/2012 and 12/2012. Patients with a 6 months treatment gap without antiplatelet medication prescription were classified as non-persistent. Characteristics associated with non-persistence were identified using the Cox regression. Results: At the end of the 5 years follow-up, 3,032 (33.0%) patients were non-persistent. Age, history of ischemic stroke or myocardial infarction, clopidogrel or combination of aspirin with clopidogrel used at the index date, higher co-payment, general practitioner as index prescriber and higher overall number of medications were associated with persistence, whereas female sex, atrial fibrillation, anxiety disorders, bronchial asthma/chronic obstructive pulmonary disease, being a new antiplatelet medication user (therapy initiated in association with PAD diagnosis), and use of anticoagulants or antiarrhythmic agents were associated with non-persistence. Conclusion: In patients with an increased probability of non-persistence, an increased attention should be paid to improvement of persistence.

Non-Adherence to Statin Treatment in Older Patients with Peripheral Arterial Disease Depending on Persistence Status.

The effectiveness of statins in secondary prevention of peripheral arterial disease (PAD) largely depends on patients' adherence to treatment. The aims of our study were: (a) to analyze non-adherence during the whole follow-up in persistent patients, and only during persistence for non-persistent patients; (b) to identify factors associated with non-adherence separately among persistent and non-persistent patients. A cohort of 8330 statin users aged ≥65 years, in whom PAD was newly diagnosed between January 2012-December 2012, included 5353 patients persistent with statin treatment, and 2977 subjects who became non-persistent during the 5-year follow-up. Non-adherence was defined using the proportion of days covered <80%. Patient- and statin-related characteristics associated with non-adherence were identified with binary logistic regression. A significantly higher proportion of non-adherent patients was found among non-persistent patients compared to persistent subjects (43.6% vs. 29.6%; p < 0.001). Associated with non-adherence in both persistent and non-persistent patients was high intensity statin treatment, while in non-persistent patients, it was employment and increasing number of medications. In patients with a poor adherence during their persistent period, an increased risk for discontinuation may be expected. However, there is also non-adherence among persistent patients. There are differences in factors associated with non-adherence depending on patients' persistence.

Factors Associated with Reinitiation of Statin Treatment in Older Patients with Peripheral Arterial Disease.

BACKGROUND: Long-term persistence represents a basic precondition of successful statin treatment in patients with peripheral arterial disease (PAD). OBJECTIVES: The aims of our study were evaluation of reinitiation in older PAD patients who were non-persistent with statin treatment, and identification of patient-related characteristics associated with the patient's probability of reinitiation. METHODS: Our study cohort included 2977 older patients (≥ 65 years) who were non-persistent with statin treatment in whom PAD was newly diagnosed in 2012. Reinitiation was defined as the first statin prescription recorded after discontinuation. To analyze factors associated with the patient´s probability of reinitiation, Cox regression with time-dependent covariates was applied. RESULTS: After post-discontinuation follow-up of a mean of 27 months, reinitiation of statin treatment was recorded for 1244 (41.8%) patients. Increasing age, Parkinson's disease, being a new statin user (patient in whom statin treatment was initiated in association with PAD diagnosis), general practitioner as the index prescriber who prescribed a statin for the first time after diagnosis of PAD, coadministration of loop diuretics, and longer persistence before discontinuation decreased the patient's likelihood of reinitiation, whereas myocardial infarction during non-persistence, high-intensity statin treatment, and increasing number of medications increased the patient's probability of reinitiation. CONCLUSIONS: In patients with characteristics associated with a lower probability of reinitiation, more concentrated outreach and further evaluation of these groups to identify interventions that might be helpful to encourage reinitiation are needed.

Patient-Associated Characteristics Influencing the Risk for Non-Persistence with Statins in Older Patients with Peripheral Arterial Disease.

BACKGROUND AND OBJECTIVES: Secondary prevention of peripheral arterial disease includes administration of statins regardless of the patient's serum cholesterol level. Our study aimed to identify patient-associated risk factors for statin non-persistence and comparison of the explanatory power of models based on clusters of patient-associated characteristics. METHODS: Our study cohort (n = 8330) was assembled from the database of the largest health insurance provider in the Slovak Republic. Statin users aged ≥ 65 years in whom peripheral arterial disease was diagnosed during 2012 were included. Patients were followed for 5 years; those with a treatment gap period of at least 6 months without statin prescription were classified as "non-persistent". The risk factors for non-persistence were identified within six models (sociodemographic, cardiovascular events, comorbid conditions, statin-related characteristics, cardiovascular co-medication and full model) using Cox regression. The explanatory power of models was assessed using Harrell's C-index. RESULTS: At the end of the follow-up, 35.7% of patients were found to be non-persistent. The full model had the highest explanatory power (C = 0.632). Female sex, atorvastatin and rosuvastatin as initially administered statins, being a new statin user and an increasing co-payment were associated with an increased risk for non-persistence. Increasing age, history of ischaemic stroke, diabetes mellitus, general practitioner as index prescriber, increasing overall number of medications and co-administration of certain cardiovascular co-medications were associated with a lower likelihood for non-persistence. CONCLUSIONS: Patients identified as high risk for non-persistence require special attention aimed at the improvement of their persistence with statin treatment.