Maintenance of statin use over 3 years following acute coronary syndromes: a national data linkage study (ANZACS-QI-2)

Assessing the gaps in cardiovascular disease risk assessment and management in primary care for Māori and Pacific peoples in Aotearoa New Zealand- a systematic review

Background

Māori and Pacific peoples carry the highest burden of cardiovascular disease in New Zealand (NZ). This systematic review aimed to determine access to evidence-based cardiovascular disease risk assessment (CVDRA) and management in primary care for Māori and Pacific peoples compared with other ethnicities in NZ, as well as factors contributing to reduced access.

Methods

In this systematic review with a narrative synthesis, keywords related to Māori and Pacific peoples, cardiovascular disease, and primary care were used to search MEDLINE (OVID), EMBASE, Scopus, CINAHL, NZresearch.org, National Library Catalogue (Te Puna), Index New Zealand (INNZ), and Australia/New Zealand Reference Centre, grey literature and hand search sources from 1 January 2000 to 31 December 2024. Two reviewers screened texts and three reviewers extracted data and assessed quality. High quality was defined using Western (Mixed Methods Appraisal Tool, MMAT, ≥80% compliance) and Indigenous (CONSolIDated critERtia for strengthening the reporting of health research involving Indigenous Peoples, CONSIDER) research tools. The protocol for this systematic review was registered at: https://doi.org/10.17605/OSF.IO/VUDE9.

Findings

A total of 2765 texts were identified of which 69 were included. This review identified inadequate levels of CVDRA in Māori and Pacific peoples when measured against the 90% national target. While the provision of primary prevention medications was higher (antihypertensives) or similar (lipid-lowering) compared to that for other ethnic groups, adherence was lower for Māori and Pacific peoples compared to other groups. Māori and Pacific peoples were less likely than others to receive antiplatelets and lipid-lowering therapy for secondary prevention. Evidence for antihypertensives in secondary prevention and combination therapy (in primary or secondary prevention) was mixed. Māori and Pacific peoples experienced reduced access to revascularisation compared with other ethnic groups, an inequity that persisted over time. Factors contributing to CVDRA and management were provision of adequate health literacy, relationships with providers and whānau, access to care, and cultural safety. While 64% of studies were ≥80% compliant with the MMAT, suggesting high quality from a Western research perspective, 71% of studies had an adapted CONSIDER score ≤2, suggesting low quality from an Indigenous perspective. The CONSIDER domains with the highest levels of reporting were Prioritisation, and Analysis and interpretation, while Capacity and Dissemination were the least reported domains. Qualitative studies had generally higher levels of CONSIDER reporting than mixed methods and quantitative studies. Kaupapa Māori Research was of the highest quality, followed by studies focused on Māori and/or Pacific peoples, while studies not focused on Māori and/or Pacific peoples had the lowest levels of CONSIDER reporting.

Interpretation

Extensive and inequitable gaps in CVDRA and management for Māori and Pacific peoples were identified. Opportunities for reducing these gaps include providing adequate CVD literacy, involvement of whanāu, patient-provider relationships, access to care, and enhancing cultural safety. Our findings will contribute to the development of a cardiovascular care equity roadmap in NZ. There are opportunities to improve reporting against the adapted CONSIDER criteria, which involves critical inquiry and a strength-based approach inclusive of Māori and Pacific values, particularly in quantitative research and research including but not focusing on Māori and Pacific peoples.

Funding

The Heart Foundation of New Zealand and Healthier Lives National Science Challenge, grant number 1819.

Is there a difference in ischaemic heart disease deaths that occur without a preceding hospital admission in people who live in rural compared with urban areas of Aotearoa New Zealand? An observational study

OBJECTIVES

Unlike comparable countries, acute coronary syndrome (ACS) mortality is similar among patients who present to rural and urban hospitals in Aotearoa New Zealand (NZ). The aim of this study was to determine whether differences in ischaemic heart disease (IHD) deaths that occurred without a preceding hospital admission in rural and urban populations explained this finding.

DESIGN

Retrospective observational study using the National Mortality Collection (MORT) and National Minimum Dataset (NMDS) for hospital discharges datasets.

SETTING

People in NZ who died from IHD were categorised based on their rural-urban status (U1 (major urban), U2 (large urban) and rural) using the Geographic Classification for Health and prioritised ethnicity (Māori-NZ's Indigenous population and non-Māori).

PARTICIPANTS

All people 20+ years who died from IHD between July 2011 and December 2018.

PRIMARY AND SECONDARY OUTCOMES

The outcome was the lack of a hospital admission preceding IHD death, identified by linking the NMDS with MORT. This was measured for the 30 days and 1 year prior to death and for all-cause and IHD hospitalisations separately.

RESULTS

Of the 37 296 deaths, a similar percentage of rural and urban residents died without an all-cause (rural 63.2%, U2 60.8%, U1 62.8%) or IHD (rural 70.9%, U2 69.0%, U1 70.1%) admission in the preceding 30 days, or without an all-cause (rural 32.8%, U2 35.5%, U1 35.5%) or IHD (rural 52.7%, U2 52.6%, U1 51.9%) admission in the preceding year. Exceptions were deaths that occurred without a prior admission for rural non-Māori aged 55-64 (higher odds) and 75+ years (lower odds) compared with U1 non-Māori 55-64 and 75+ years, respectively, across all four outcome measures.

CONCLUSIONS

This study suggests that the lack of difference in ACS mortality for patients who present to NZ rural and urban hospitals is not explained by IHD death that occurred without a recent preceding hospital admission.

Multivariate Sequential Analytics for Cardiovascular Disease Event Prediction

BACKGROUND

Automated clinical decision support for risk assessment is a powerful tool in combating cardiovascular disease (CVD), enabling targeted early intervention that could avoid issues of overtreatment or undertreatment. However, current CVD risk prediction models use observations at baseline without explicitly representing patient history as a time series.

OBJECTIVE

The aim of this study is to examine whether by explicitly modelling the temporal dimension of patient history event prediction may be improved.

METHODS

This study investigates methods for multivariate sequential modelling with a particular emphasis on long short-term memory (LSTM) recurrent neural networks. Data from a CVD decision support tool is linked to routinely collected national datasets including pharmaceutical dispensing, hospitalization, laboratory test results, and deaths. The study uses a 2-year observation and a 5-year prediction window. Selected methods are applied to the linked dataset. The experiments performed focus on CVD event prediction. CVD death or hospitalization in a 5-year interval was predicted for patients with history of lipid-lowering therapy.

RESULTS

The results of the experiments showed temporal models are valuable for CVD event prediction over a 5-year interval. This is especially the case for LSTM, which produced the best predictive performance among all models compared achieving AUROC of 0.801 and average precision of 0.425. The non-temporal model comparator ridge classifier (RC) trained using all quarterly data or by aggregating quarterly data (averaging time-varying features) was highly competitive achieving AUROC of 0.799 and average precision of 0.420 and AUROC of 0.800 and average precision of 0.421, respectively.

CONCLUSION

This study provides evidence that the use of deep temporal models particularly LSTM in clinical decision support for chronic disease would be advantageous with LSTM significantly improving on commonly used regression models such as logistic regression and Cox proportional hazards on the task of CVD event prediction.

Medication adherence prediction through temporal modelling in cardiovascular disease management

Background

Chronic conditions place a considerable burden on modern healthcare systems. Within New Zealand and worldwide cardiovascular disease (CVD) affects a significant proportion of the population and it is the leading cause of death. Like other chronic diseases, the course of cardiovascular disease is usually prolonged and its management necessarily long-term. Despite being highly effective in reducing CVD risk, non-adherence to long-term medication continues to be a longstanding challenge in healthcare delivery. The study investigates the benefits of integrating patient history and assesses the contribution of explicitly temporal models to medication adherence prediction in the context of lipid-lowering therapy.

Methods

Data from a CVD risk assessment tool is linked to routinely collected national and regional data sets including pharmaceutical dispensing, hospitalisation, lab test results and deaths. The study extracts a sub-cohort from 564,180 patients who had primary CVD risk assessment for analysis. Based on community pharmaceutical dispensing record, proportion of days covered (PDC) $$\ge$$ ≥  80 is used as the threshold for adherence. Two years (8 quarters) of patient history before their CVD risk assessment is used as the observation window to predict patient adherence in the subsequent 5 years (20 quarters). The predictive performance of temporal deep learning models long short-term memory (LSTM) and simple recurrent neural networks (Simple RNN) are compared against non-temporal models multilayer perceptron (MLP), ridge classifier (RC) and logistic regression (LR). Further, the study investigates the effect of lengthening the observation window on the task of adherence prediction.

Results

Temporal models that use sequential data outperform non-temporal models, with LSTM producing the best predictive performance achieving a ROC AUC of 0.805. A performance gap is observed between models that can discover non-linear interactions between predictor variables and their linear counter parts, with neural network (NN) based models significantly outperforming linear models. Additionally, the predictive advantage of temporal models become more pronounced when the length of the observation window is increased.

Conclusion

The findings of the study provide evidence that using deep temporal models to integrate patient history in adherence prediction is advantageous. In particular, the RNN architecture LSTM significantly outperforms all other model comparators.

The importance of considering both primary and secondary diagnostic codes when using administrative health data to study acute coronary syndrome epidemiology (ANZACS-QI 47)

AIMS

Routinely collected health administrative data have become an important data source for investigators assessing disease epidemiology. Our aim was to investigate the implications of identifying acute coronary syndrome (ACS) events in New Zealand (NZ) national hospitalization data using either the first (primary) or subsequent (secondary) codes.

METHODS AND RESULTS

Using national health datasets, we identified all NZ hospitalizations (2014-16) for patients ≥20 years with a primary or secondary International Classification of Diseases 10th Revision, Australian Modification (ICD10-AM) ACS code. Outcomes included 1-year all-cause and cause-specific mortality, hospitalized non-fatal myocardial infarction, heart failure, stroke, or major bleeding, and a composite comprising these outcomes. Of 35 646 ACS hospitalizations, 78.5% were primary and 21.5% secondary diagnoses. Compared to primary coding, patients with a secondary diagnosis were older (mean 77 vs. 69 years), more likely to be females (48% vs. 36%), had more comorbidity, and were less likely to receive coronary angiography or revascularization. Higher adverse event rates were observed for the secondary diagnosis group including a three-fold higher 1-year mortality (40% vs. 13%) and two-fold higher composite adverse outcome (54% vs. 26%). The use of primary codes alone, rather than combined primary and secondary codes, resulted in overestimation of coronary angiography and revascularization rates, and underestimation of the 1-year case fatality (13.1% vs. 19.0%) and composite adverse event rate (26% vs. 32%).

CONCLUSION

Patient characteristics and outcomes of ACS events recorded as primary vs. secondary codes are very different. These findings have important implications for designing studies utilizing ICD10-AM codes.

Statin Utilization among Patients with Acute Coronary Syndrome: Systematic Review

BACKGROUND: The early use of statin with intensive regimen has been recommended by the recent guidelines as the prevention of acute coronary syndrome (ACS) related events among the high-risk patients. Meanwhile, the inconsistent statin utilization for targeted patient in current practice is still an issue. AIM: This study aims to review the utilization rate of statin among patients with ACS. METHODS: A systematic search of relevant studies published between inceptions to June 2020 was conducted in PubMed. Patients and intervention domains were used to build up the searching formula. A study was eligible for inclusion if it was an original study of patients with ACS and it examined the utilization of statin. The risk of bias was assessed using Axis and NOS checklist. RESULTS: Among the 49 eligible studies, 38 were cohort studies while the others were cross-sectional studies. The utilization rate of statin at hospital admission ranged from 16% to 61% while 25% to 75% during the hospitalization. Of the total studies, 35 studies reported the statin rate at discharge ranging from 58% to 99%. Almost all studies revealed the reduction of statin utilization rate along the follow-up period. The number of statins prescribed was found to be lower among female and elderly patients. CONCLUSION: Despite the established benefits of statin among patients with ACS, our study revealed that statin was underutilized for secondary prevention after ACS. To improve patients’ clinical outcomes with ACS, efforts should be made to increase optimal treatment and compliance with a statin.

Linking Australian Stroke Clinical Registry data with Australian government Medicare and medication dispensing claims data and the potential for bias

OBJECTIVE

We aim to report the accuracy of linking data from a non-government-held clinical quality registry to national claims data and identify associated sources of systematic bias.

METHODS

Patients with stroke or transient ischaemic attack admitted to hospitals participating in the Australian Stroke Clinical Registry (AuSCR) were linked with Medicare and medication dispensings through the Australian Medicare enrolment file (MEF). The proportion of registrants in the datasets was calculated and factors associated with a non-merge assessed using multivariable analyses.

RESULTS

A total of 17,980 AuSCR registrants (January 2010 - July 2014) were submitted for linkage (median age 76 years; 46% female; 67% ischaemic stroke); the proportion merged was 97% MEF, 93% Medicare and 95% medication dispensings. Data from registrants born in Asia were less likely to link with the MEF (adjusted Odds Ratio [aOR]: 0.20; 95%Confidence Interval [CI]: 0.15, 0.27). Data for those aged 85-plus compared to those under 65 years were less likely to merge with Medicare (aOR 0.25; 95%CI:0.21, 0.30) but more likely to merge with dispensing claims data (aOR: 2.15 (95%CI:1.71, 2.69). Implications for public health: Linkage between the AuSCR, a national clinical quality registry and Commonwealth datasets was achieved and potential sources of bias were identified.

Statin adherence is lower in primary than secondary prevention: A national follow-up study of new users

BACKGROUND

Maintaining adherence to statins reduces the risk of an initial cardiovascular disease (CVD) event in high-risk individuals (primary prevention) and additional CVD events following the first event (secondary prevention). The effectiveness of statin therapy is limited by the level of adherence maintained by the patient. We undertook a nationwide study to compare adherence and discontinuation in primary and secondary prevention patients.

METHODS

Dispensing data from New Zealand community pharmacies were used to identify patients who received their first statin dispensing between 2006 and 2011. The Medication Possession Ratio (MPR) and proportion who discontinued statin medication was calculated for the year following first statin dispensing for patients with a minimum of two dispensings. Adherence was defined as an MPR ≥ 0.8. Previous CVD was identified using hospital discharge records. Multivariable logistic regression was used to control for demographic and statin characteristics.

RESULTS

Between 2006 and 2011 289,666 new statin users were identified with 238,855 (82.5%) receiving the statin for primary prevention compared to 50,811 (17.5%) who received it for secondary prevention. The secondary prevention group was 1.55 (95% CI 1.51-1.59) times as likely to be adherent and 0.67 (95% CI 0.65-0.69) times as likely to discontinue statin treatment than the primary prevention group. An early gap in statin coverage increased the odds of discontinuing statin treatment.

CONCLUSION

Adherence to statin medication is higher in secondary prevention than primary prevention. Within each group, a range of demographic and treatment factors further influences adherence.

Increased risk of 2-year death in patients who discontinued their use of statins

OBJECTIVE

This study examined the association between statin usage (discontinued, reduced or continued) and two-year death following a 21% increase in the Pharmaceutical Benefits Scheme (PBS) consumer co-payment in Western Australia.

METHODS

A retrospective observational study in Western Australia using linked administrative Commonwealth PBS data and State hospital inpatient and death data (n = 207,066) was undertaken. We explored the two-year all-cause and ischemic heart disease(IHD)/stroke-specific-death in individuals who discontinued, reduced or continued statin medication following the January 2005 PBS co-payment increase, overall, by beneficiary status (general population vs. social security recipients) and by a history of admission for ischemic heart disease or stroke. Non-cardiovascular (CVD)-related death was also considered.

RESULTS

In the first six months of 2005, 3.3% discontinued, 12.5% reduced and 84.2% continued statin therapy. We found those who discontinued statins were also likely to discontinue at least two other medicines compared to those who continued therapy. There were 4,607 all-cause deaths. For IHD/stroke-specific death, there were 1,317. For all non-CVD-related death, there were 2,808 deaths during the 2-year follow-up period. Cox regression models, adjusted for demographic and clinical characteristics, showed a 39%-61% increase in the risk of all-cause death for individuals who reduced or discontinued statin medication compared to those who continued their statin medication (Discontinued: Adj HR = 1.61, 95% CI 1.40-1.85; Reduced: Adj HR = 1.39, 95% CI 1.28-1.51). For IHD/stroke-specific death, there was an increased risk of death by 28-76% (Discontinued: Adj sHR = 1.76, 95% CI 1.37-2.27; Reduced: Adj sHR = 1.28, 95% CI 1.10-1.49), and for non-CVD-related death, there was an increased risk of death by 44-57% (Discontinued: Adj sHR = 1.57, 95% CI 1.31-1.88; Reduced: Adj sHR = 1.44, 95% CI 1.30-1.60), for individuals who discontinued or reduced their statin medication compared to those who continued.

CONCLUSIONS

Patients who discontinued their statin therapy had a significantly increased risk of IHD and stroke death. Health professionals should be aware that large co-payment changes may be associated with patients discontinuing or reducing medicines to their health detriment. Factors that lead to such changes in patient medication-taking behaviour need to be considered and addressed at the clinical and policy levels.

Exploring patient and pharmacist perspectives on complex interventions for cardiovascular prevention: A qualitative descriptive process evaluation

BACKGROUND

The Assessing outcomes of enhanced Chronic disease Care through patient Education and a value-baSed formulary Study (ACCESS) is a randomized controlled trial evaluating two interventions targeting barriers to care among those at high risk of cardiovascular disease: copayment elimination for cardioprotective medications, and a tailored self-management support programme. We designed a process evaluation to better understand participant perspectives on the interventions.

DESIGN

We used a qualitative descriptive study design, collecting patient and pharmacist feedback via individual semi-structured telephone interviews and in-person focus groups. Data were analysed inductively using thematic analysis.

RESULTS

Fifty-three patients (39 interviews and 14 in two focus groups) and 20 pharmacists participated. Copayment elimination provided quality of life benefits: minimizing the need to 'cut-back', allowing 'peace of mind' and providing emotional support. Health-related benefits included: improving adherence to covered medications, and helping to afford non-covered goods. The only criticism was that not all medications and testing supplies were covered. Patients reported that the educational materials provided helpful information, acted as a reminder, improved confidence, improved adherence to medication, and helped initiate conversations with providers about indicated medication. Some participants felt that the educational materials were repetitive, overly medication-focused and not tailored enough. Pharmacists felt that their patients benefitted from both interventions, which improved patient adherence and communication with their patients.

CONCLUSION

The success of interventions intended to change behaviour is largely dependent upon participant's feelings that the intervention is helpful. This process evaluation provided insights into participants' perceptions on these interventions. Reception of both was largely positive with a few criticisms noted.

Interrupted time series analysis on first cardiovascular disease hospitalization for adherence to lipid-lowering therapy

PURPOSE

We analysed lipid-lowering medication adherence before and after the first hospitalization for cardiovascular disease (CVD) to explore the influence hospitalization has on patient medication adherence.

METHODS

We extracted a sub-cohort for analysis from 313,207 patients who had primary CVD risk assessment. Adherence was assessed as proportion of days covered (PDC) ≥ 80% based on community dispensing records. Adherence in the 4 quarters (360 days) before the first CVD hospitalization and 8 quarters (720 days) after hospital discharge was assessed for each individual in the sub-cohort. An interrupted time series design using generalized estimating equations was applied to compare the differences of population-level medication adherence rates before and after the first CVD hospitalization.

RESULTS

Overall, a significant improvement in medication adherence rate from before to after the hospitalization was observed (odds ratio (OR) 2.49 [1.74-3.57]) among the 946 patients included in the analysis. Patients having diabetes history had a higher OR of adherence before the hospitalization than patients without diabetes (1.50 [1.03-2.22]) but no significant difference after the hospitalization (OR 1.13 [0.89-1.43]). Before the first hospitalization, we observed that quarterly medication adherence rate was steady at around 55% (OR 0.97 [0.93-1.01), whereas the trend in adherence over the post-hospitalization period decreased significantly per quarter (OR 0.97 [0.94-0.99]).

CONCLUSIONS

Patients were more likely to adhere to lipid-lowering therapy after experiencing a first CVD hospitalization. The change in medication adherence rate is consistent with patients having heightened perception of disease severity following the hospitalization.

Data Resource: Vascular Risk in Adult New Zealanders (VARIANZ) datasets

INTRODUCTION

The Vascular Risk in Adult New Zealanders (VARIANZ) datasets contain a range of routinely-collected New Zealand health data relevant to cardiovascular disease (CVD) and related conditions. The datasets enable exploration of cardiovascular-related treatment, service utilisation, outcomes and prognosis.

PROCESSES

Each dataset is constructed by anonymised individual-level linkage of eight national administrative health databases to identify all New Zealand adults aged ≥20 years who have recorded contact with publicly-funded New Zealand health services during a given year from 2006 onwards, when data quality is considered sufficient.

DATA CONTENTS

Individual-level data for each VARIANZ dataset can include variables covering demography, dispensing of cardiovascular disease (CVD) preventive medications and prior hospitalisations for atherosclerotic CVD, heart failure, atrial fibrillation and diabetes. If required, VARIANZ datasets can be individually linked to follow-up national routinely collected health data in subsequent years, including all-cause mortality events and fatal/non-fatal CVD events, to create VARIANZ longitudinal cohorts. Bespoke linkage can also be undertaken to include other national and regional administrative health data such as non-CVD related hospitalisations in order to explore CVD comorbidities or novel risk factors. Furthermore, a subset of the VARIANZ datasets based on specific health contacts (such as CVD hospitalisations only) can also be identified, and some data can be requested for years prior to 2006. The New Zealand routinely-collected health databases used to construct the VARIANZ datasets do not capture primary care diagnostic classifications or certain CVD risk factor data such as smoking status, blood pressure or lipid profiles.

CONCLUSION

The Vascular Risk in Adult New Zealanders (VARIANZ) datasets capture the majority of the New Zealand population in a given year and are available from 2006 onwards, or earlier than 2006 for some datasets based on specific health contacts. VARIANZ data can be used to explore a range of research questions regarding management, outcomes and prognosis for CVD.

A Systematic Review and Meta-analysis of the Factors Associated With Nonadherence and Discontinuation of Statins Among People Aged ≥65 Years

Background

Older individuals (aged ≥65 years) are commonly prescribed statins but may experience a range of barriers in adhering to therapy. The factors associated with poor statin adherence and/or discontinuation among this population have not been comprehensively reviewed.

Methods

We conducted a systematic review to identify English articles published through December 12, 2016 that reported factors associated with nonadherence and/or discontinuation of statins among older persons. Data were pooled via random-effects meta-analysis techniques.

Results

Forty-five articles reporting data from more than 1.8 million older statin users from 13 countries were included. The factors associated with increased statin nonadherence were black/non-white race (odds ratio [OR] 1.66, 95% confidence interval [CI] 1.39-1.98), female gender (OR 1.08, 95% CI 1.03-1.13), current smoker (OR 1.12, 95% CI 1.03-1.21), higher copayments (OR 1.38, 95% CI 1.25-1.52), new user (OR 1.58, 95% CI 1.21-2.07), lower number of concurrent cardiovascular medications (OR 1.08, 95% CI 1.06-1.09), primary prevention (OR 1.49, 95% CI 1.40-1.59), having respiratory disorders (OR 1.17, 95% CI 1.12-1.23) or depression (OR 1.11, 95% CI 1.06-1.16), and not having renal disease (OR 1.09, 95% CI 1.04-1.14). The factors associated with increased statin discontinuation were lower income status (OR 1.20, 95% CI 1.06-1.36), current smoker (OR 1.14, 95% CI 1.06-1.23), higher copayment (OR 1.61, 95% CI 1.53-1.70), higher number of medications (OR 1.04, 95% CI 1.01-1.06), presence of dementia (OR 1.18, 95% CI 1.02-1.36), cancer (OR 1.22, 95% CI 1.11-1.33) or respiratory disorders (OR 1.19, 95% CI 1.05-1.34), primary prevention (OR 1.66, 95% CI 1.24-2.22), and not having hypertension (OR 1.13, 95% CI 1.07-1.20) or diabetes (OR 1.09, 95% CI 1.04-1.15).

Conclusion

Interventions that target potentially modifiable factors including financial and social barriers, patients' perceptions about disease risk as well as polypharmacy may improve statin use in the older population.

Long-term statin adherence in patients after hospital discharge for new onset of atherosclerotic cardiovascular disease: a population-based study of real world prescriptions in Taiwan

BACKGROUND

Despite the recommendations of statins treatment for secondary prevention of atherosclerotic cardiovascular disease (ASCVD), treatment adherence and persistence are still a concern. This study examined the real world practice of long-term adherence and persistence to statins treatment initiated after hospital discharge for ASCVD, and their associated factors in a nationwide cohort.

METHODS

Post discharge statin prescriptions between 2006 and 2012 were extracted from the Taiwan National Health Insurance claims database. Good adherence, defined as proportion of days covered (PDC) ≥0.8 and mean medication possession ratio (MPR), was measured every 180-day period. Non-persistence was defined on the date patients failed to refill statin for 90 days after the end of the last prescription. Their associations with influential factors were analyzed using a generalized estimating equation and Cox's proportional hazard model.

RESULTS

There was a total of 185,252 post-discharge statin initiations (from 169,624 patients) and followed for 467,398 patient-years in the study cohort. Percentage of good adherence (mean MPR) was 71% (0.87) at 6-months; declined to 54% (0.68), 47% (0.59), and 42% (0.50) at end of year 1, 2, and 7, respectively. Persistence in statin treatment was 86, 67, 50, and 25% at 6-month, 1-, 2-, and 7-year, respectively. Comparing the statin-cohort initiated from year 2006 to 2012, 1-year persistence increased from 58 to 73%, and 1-year good adherence improved from 45 to 61%. Factors associated with sub-optimal adherence and non-persistence included: prescription by primary care clinics or non-cardiology specialties; patients' age > 75 years; no history of previous statin use; ASCVD events with ischemic stroke diagnosis; comorbidities of renal disease, liver disease, depression, and chronic obstructive pulmonary disease.

CONCLUSIONS

Despite the improving trends, long-term adherence and persistence of statin treatment were suboptimal in Taiwan. Strategies to maintain statin treatment adherence and persistence need to be implemented to further enhance the positive trend.

β-Blocker Adherence in Familial Long QT Syndrome

Background—

Long-term uninterrupted β-blockade significantly reduces cardiac events in long QT syndrome (LQTS). Despite this, data on nonadherence are scarce and quantified only on the day of cardiac arrest in LQTS literature. We aimed to describe β-blocker adherence, and predictors thereof, among patients with LQTS types 1 and 2.

Methods and Results—

Electronic health records and pharmacy dispensing data were reviewed for 90 patients with LQTS 1 and 2 who reside in Auckland, New Zealand, during a 34-month period. For each patient, the medication possession ratio (MPR: proportion of follow-up days patients were dispensed β-blocker) was calculated. Adequate adherence was characterized by an MPR ≥0.8 and ideal as MPR=1.0. Clinical and demographic features were assessed to determine whether they predicted adherence. Long-term β-blockers were prescribed to 74 patients (82%). Side effects were described as intolerable by 6 (8%) and their β-blockers were stopped. MPR was calculated in the remaining 68 patients >151.7 patient-years of follow-up. Median MPR was 0.79 (range, 0–1.3). Suboptimal adherence (MPR<0.8) was recorded in 35 (51%). Seven patients (10%) never took up a prescription (MPR=0). Adequate adherence was present in 33 (49%), including 9 (13%) who had ideal adherence. Age, sex, clinical presentation, family history of sudden death, ethnicity, and deprivation index did not predict adherence.

Conclusions—

Adherence to β-blockers in LQTS is suboptimal in half of those with LQTS 1 and 2. Risk factors for nonadherence could not be identified in our population. Further research into β-blocker adherence is imperative in this high-risk population.

Ethnic differences in case fatality following an acute ischaemic heart disease event in New Zealand: ANZACS-QI 13

BACKGROUND

The aim of this study was to investigate ischaemic heart disease (IHD) case fatality in high-risk ethnic populations in New Zealand.

DESIGN

This is a national data-linkage study using anonymised hospitalisation and mortality data.

METHODS

Linked individual patient data were used to identify 35-84-year-olds who experienced IHD events (acute IHD hospitalisations and/or deaths) in 2009-2010. Subjects were classified as: (i) hospitalised with IHD and alive at 28 days post-event; (ii) hospitalised with IHD and died within 28 days; (iii) hospitalised with a non-IHD diagnosis and died from IHD within 28 days; or (iv) died from IHD but not hospitalised. Multinomial logistic regression was used to estimate the proportion of people in each group, as well as overall 28-day case fatality, adjusted for ethnic differences in demographic and comorbidity profiles.

RESULTS

A total of 26,885 people experienced IHD events (11.3% Māori, 4.0% Pacific and 2.5% Indian); 3.3% of people died within 28 days of IHD hospitalisations, 5.1% died of IHD within 28 days of non-IHD hospitalisations and 13.0% died of IHD without any recent hospitalisation. Overall adjusted case fatality was 12.6% in Indian, 20.5% in European, 26.0% in Pacific and 27.6% in Māori people. Compared to Europeans, the adjusted odds of death were approximately 50% higher in Māori and Pacific people and 50% lower in Indians, regardless of whether they were hospitalised.

CONCLUSIONS

Major ethnic inequalities in IHD case fatality occur with and without associated hospitalisations. Improvements in both primary prevention and hospital care will be required to reduce inequalities.

An algorithm to identify medication nonpersistence using electronic pharmacy databases

OBJECTIVE

Identifying patients who are medication nonpersistent (fail to refill in a timely manner) is important for healthcare operations and research. However, consistent methods to detect nonpersistence using electronic pharmacy records are presently lacking. We developed and validated a nonpersistence algorithm for chronically used medications.

MATERIALS AND METHODS

Refill patterns of adult diabetes patients (n = 14,349) prescribed cardiometabolic therapies were studied. We evaluated various grace periods (30-300 days) to identify medication nonpersistence, which is defined as a gap between refills that exceeds a threshold equal to the last days' supply dispensed plus a grace period plus days of stockpiled medication. Since data on medication stockpiles are typically unavailable for ongoing users, we compared nonpersistence to rates calculated using algorithms that ignored stockpiles.

RESULTS

When using grace periods equal to or greater than the number of days' supply dispensed (i.e., at least 100 days), this novel algorithm for medication nonpersistence gave consistent results whether or not it accounted for days of stockpiled medication. The agreement (Kappa coefficients) between nonpersistence rates using algorithms with versus without stockpiling improved with longer grace periods and ranged from 0.63 (for 30 days) to 0.98 (for a 300-day grace period).

CONCLUSIONS

Our method has utility for health care operations and research in prevalent (ongoing) and new user cohorts. The algorithm detects a subset of patients with inadequate medication-taking behavior not identified as primary nonadherent or secondary nonadherent. Healthcare systems can most comprehensively identify patients with short- or long-term medication underutilization by identifying primary nonadherence, secondary nonadherence, and nonpersistence.