Validity of a prescription claims database to estimate medication adherence in older persons

Investigating the Time-Varying Nature of Medication Adherence Predictors: An Experimental Approach Using Andersen's Behavioral Model of Health Services Use

Medication adherence is a crucial factor for managing chronic conditions, especially in aging adults. Previous studies have identified predictors of medication adherence. However, current methods fail to capture the time-varying nature of how risk factors can influence adherence behavior. This objective of this study was to implement multitrajectory group-based models to compare a time-varying to a time-fixed approach to identifying non-adherence risk factors. The study population comprised 11,068 Medicare beneficiaries aged 65 and older taking select medications for hypertension, high blood cholesterol, and oral diabetes medications, between 2008 and 2016. Time-fixed predictors (e.g., sex, education) were examined using generalized multinomial logistic regression, while time-varying predictors were explored through multitrajectory group-based modeling. Several predisposing, enabling, and need characteristics were identified as risk factors for following at least one non-adherence trajectory. Time-varying predictors displayed an alternative representation of those risk factors, especially depression symptoms. This study highlights the dynamic nature of medication adherence predictors and the utility of multitrajectory modeling. Findings suggest that targeted interventions can be developed by addressing the key time-varying factors affecting adherence.

Untangling areas of improvement in secondary prevention of ischemic stroke in patients with atrial fibrillation

Improvement of post-stroke outcomes relies on patient adherence and appropriate therapy maintenance by physicians. However, comprehensive evaluation of these factors is often overlooked. This study assesses secondary stroke prevention by differentiating patient adherence to antithrombotic treatments (ATT) from physician-initiated interruptions or switches. We analyzed a population-based retrospective cohort (n = 10,343) of post-stroke patients with atrial fibrillation using the VID database (2010-2017). Secondary prevention was evaluated based on patients' primary and secondary adherence to ATT at two years (percentage of days covered-PDC-and persistence/discontinuation) and physician prescription patterns (initiation, interruption, switching, restart). E-prescription and dispensing data were linked. Three ATT strategies were identified: oral anticoagulants (OAC), antiplatelets (APT), or combination therapy (OAC + APT), prescribed to 54%, 23%, and 17% of patients, respectively. Primary adherence was high for all ATTs (≈90%). OAC discontinuation was highest (16%), but frequently restarted (73.4%). APT treatment was interrupted the most (14%) and restarted the least (38.5%) by physicians, followed by OAC (interrupted in 11%, restarted in 65%). Overall, 17% of patients switched treatments, with OAC + APT being switched the most (76%), mainly to OAC (53.8%). Identifying areas for improvement in secondary stroke prevention requires considering both patient adherence and physician prescription patterns (initiation, interruptions, and restarts).

Trajectories of P2Y12 inhibitor adherence in patients with acute coronary syndromes

PURPOSE

P2Y12 inhibitors (P2Y12i) reduce cardiac events after acute coronary syndromes (ACS). However, suboptimal P2Y12i adherence persists. We aimed to examine P2Y12i non-adherence using group-based trajectory methods and to identify adherence predictors.

METHODS

We conducted a population-based, retrospective cohort study using administrative data in Ontario, Canada of patients ≥65 years admitted for ACS between April 2014 and March 2018 with a P2Y12i dispensed within 7 days of discharge. We used group-based trajectory models to characterize longitudinal 1-year adherence patterns. Predictors associated with each adherence trajectory were identified by multinomial logistic regression.

RESULTS

We included 11 917 patients using clopidogrel and 9763 using ticagrelor, aged [mean ± SD]: 77.33 ± 8.31/73.59 ± 6.79 years; men: 56.2%/65.4%, respectively. We identified 3 longitudinal adherence trajectories, that differed by agent: 75% of clopidogrel and 68% of ticagrelor patients showed a consistently adherent trajectory, while 13%/17% were gradually, and 12%/15% were rapidly non-adherent, respectively (p < 0.001). Differing baseline characteristics in each cohort were associated with observed adherence trajectories. Concomitant atrial fibrillation and prior bleeding history were associated with non-adherence among clopidogrel users. Among ticagrelor users, women and older persons were more likely to be rapidly non-adherent, adherence declining steeply starting 1 month post-ACS.

CONCLUSIONS

We identified distinct adherence trajectories for clopidogrel and ticagrelor post-ACS, with 3 out of 4 clopidogrel patients but only 2 out of 3 ticagrelor patients in the consistently adherent trajectory. Intensive interventions targeted to the period of steep adherence decline post-ACS, particularly for women and older persons initiating ticagrelor, and patients with atrial fibrillation on clopidogrel should be considered and investigated further.

Real-World Dispensing Patterns of Inhalation Medication in Young Adult Asthma: An Inception Cohort Study

Purpose

The Global Initiative for Asthma (GINA) suggests a step-wise approach for pharmacological treatment of asthma. Valid study of real-world treatment patterns using dispensing databases includes proper measurement of medication adherence. We aim to explore such patterns by applying a time-varying proportion of days covered (tPDC)-based algorithm.

Patients and Methods

We designed a retrospective inception cohort study using the University of Groningen IADB.nl community pharmacy dispensing database. Included were 19,184 young adults who initiated asthma medication anywhere between 1994 and 2021, in the Netherlands. Main treatment steps were defined as: 1 - SABA/ICS-formoterol as needed, 2 - low dose ICS, 3 - low dose ICS + LABA or tiotropium, or intermediate dose ICS, 4 - intermediate to high dose ICS + LABA or tiotropium, triple therapy, or high dose ICS, 5 - treatment prescribed by a specialist. Changes in treatment steps were determined using a time-varying proportion of days covered (tPDC)-based algorithm. Individual drug treatment trajectories were visualized over time using a lasagna plot.

Results

At initiation, of the 19,184 included individuals, 52%, 7%, 15%, 16%, and 10% started treatment in steps 1 to 5, respectively. The median (IQR) follow-up time was 3 (1-7) years. Median (IQR) number of switches was 1 (0-3). Comparing starting step to last observed step, 37% never switched between treatment steps, 20% of individuals stepped down and 22% stepped up.

Conclusion

The low proportion of treatment switches between steps indicates that tailoring of treatment to patients' needs might be suboptimal. The tPDC-based algorithm functions well in translating dispensing data into continuous drug-utilization data, enabling a more granular assessment of treatment patterns among asthma patients.

Impact of prescription length supply policy on patient medication adherence in Thailand

BACKGROUND

Phramongkutklao Hospital is one of the largest military hospitals in Thailand. Beginning in 2016, an institutional policy was implemented in which medication prescription length was increased from 30 to 90 days. However, there have been no formal investigations into how this policy has impacted medication adherence among patients in hospitals. As such, this study evaluated how prescription length impacted medication adherence among dyslipidemia and type-2 diabetes patients who were treated at Phramongkutklao Hospital.

METHODS

This pre-post implementation study compared patients who received prescription lengths of 30 and 90 days based on information recorded in the hospital database between 2014 and 2017. Therein, we used the medication possession ratio (MPR) to estimate patient adherence. Focusing on patients with universal coverage insurance, we employed the difference-in-difference method to examine changes in adherence from before and after policy implementation, then conducted a logistic regression to test for associations between the predictors and adherence.

RESULTS

We analyzed data from a total of 2,046 patients, with equal amounts of 1,023 placed into the control group (no change to 90-day prescription length) and intervention group (change from 30 to 90-day prescription length). First, we found that increased prescription length was associated with 4% and 5% higher MPRs among dyslipidemia and diabetes patients in the intervention group, respectively. Second, we found that medication adherence was correlated with sex, comorbidities, history of hospitalization, and the number of prescribed medications.

CONCLUSION

Increasing the prescription length from 30 to 90 days improved medication adherence in both the dyslipidemia and type-2 diabetes patients. This shows that the policy change was successful for patients in the hospital considered for this study.

The population effect of a national policy to incentivize chronic disease management in primary care in stroke: a population-based cohort study using an emulated target trial approach

Background

Governments are investing in primary care policies that support chronic disease management. Large scale population-based evaluations are lacking. We aim to determine the effectiveness of government-funded chronic disease management policies to improve long-term outcomes (survival, hospital presentations, and preventive medication adherence) following stroke/Transient Ischemic Attack (TIA).

Methods

Using a population-based cohort we utilized the target trial methodology. Participants were identified through the Australian Stroke Clinical Registry (January 2012-December 2016) from 42 hospitals in the states of Victoria and Queensland and linked with state and national hospital, primary care, pharmaceutical, aged care, and death datasets. Registrants living in the community, not receiving palliative care and who survived to 18 months following stroke/TIA were included. The comparison was a Medicare claim for policy-supported chronic disease management, 7-18 months following stroke/TIA versus usual care. Outcomes were modelled using multi-level, mixed-effects inverse probability of treatment weighted regression.

Findings

12,368 registrants were eligible (42% female, median age 70 years, 26% TIA), 45% had a chronic disease management claim. The difference in mean outcomes for participants with a claim, compared to those without, showed a 26% lesser mortality rate (adjusted hazard ratio [aHR]: 0.74, 95% confidence interval [CI]: 0.62, 0.87) and a greater adjusted Odds Ratio [aOR] of being adherent with preventive medications: antithrombotics (aOR: 1.16, 95% CI: 1.07, 1.26); lipid-lowering (aOR: 1.23, 95% CI: 1.13, 1.33). Impacts on hospital presentations were variable.

Interpretation

Government policies that financially support primary care physicians to provide structured chronic disease management improve survival in the long-term following stroke/TIA.

Funding

National Health and Medical Research Council Australia.

Dispensing patterns of mental health medications before and during the COVID-19 pandemic in Alberta, Canada: An interrupted time series analysis

BACKGROUND

The COVID-19 pandemic has negatively impacted the general population in all aspects of life. Estimates of mental health medication dispensing in Alberta were investigated to elucidate areas of need within mental health and pharmacy practice during the pandemic.

METHODS

We employed an interrupted time series analysis using linear regression models to estimate community and outpatient medication dispensing trends of 46 medications used to treat mental health disorders. Three parameters were examined. The first was the medication dispensing slope before COVID-19. The second was the immediate effect of COVID-19 on dispensing (i.e., the difference in dispensing rate between the month before and after the first case of COVID-19) and the third was the medication dispensing slope during COVID-19.

RESULTS

Dispensing rates of 61% (n = 34) of the examined medications remained similar before and during the COVID-19 pandemic. However, eight medications (i.e., amitriptyline, escitalopram, fluoxetine, paroxetine, bupropion, desvenlafaxine, venlafaxine, and oxazepam) showed an immediate and significant increase in dispensing rate following the onset of the pandemic that was sustained over the first 13-months of the pandemic.

CONCLUSION

Initial increases in dispensing patterns of antidepressants may be attributed to a "stockpiling phenomenon" but the sustained higher levels of dispensing suggest an unfavorable shift in the population's mental health. Monitoring of medication dispensing patterns during COVID-19 may serve as a useful indicator of the population's mental health during the current pandemic and better prepare community pharmacists in future pandemic planning, medication dispensing strategies, and care of chronic medical conditions.

Polypharmacy and Potentially Inappropriate Medication Use in Older Adults With Systemic Lupus Erythematosus

OBJECTIVE

To assess the prevalence and potential risk factors for polypharmacy and prescribing of the potentially inappropriate medications, opioids and benzodiazepines/Z-drugs, in older adults with systemic lupus erythematosus (SLE).

METHODS

The study population comprised adults age ≥50 years meeting American College of Rheumatology or Systemic Lupus International Collaborating Clinics classification criteria followed at a tertiary care rheumatology clinic. Information on prescriptions filled in the 4 months preceding chart review was obtained from the Manitoba Drug Program Information Network. Clinical data, including age, sex, Charlson Comorbidity Index (CCI) score, Systemic Lupus Erythematosus Disease Activity Index 2000 score, prednisone use, SLE duration, and rural residence were abstracted from electronic medical records. Logistic regression analyses were performed to assess any association between polypharmacy (using 2 definitions: ≥5 and ≥10 medications), potentially inappropriate medication use, and clinical features.

RESULTS

A total of 206 patients (mean age 62 years, 91% female, 36% rural) were included: 148 (72%) filled ≥5 medications, 71 (35%) filled ≥10 medications, 63 (31%) used benzodiazepines/Z-drugs, and 50 (24%) used opioids. Among the 77 patients age ≥65 years, 57 (74%) filled ≥5 medications, and 26 (34%) filled ≥10 medications, compared to 30% and 4%, respectively, of Manitobans age ≥65 years (National Prescription Drug Utilization Information System, 2016). The odds of polypharmacy were greater with prednisone use (adjusted odds ratio [OR] 3.70 [95% confidence interval (95% CI) 1.40-9.79] for ≥5 medications), CCI score (adjusted OR 1.62 [95% CI 1.20-2.17]), and rural residence (adjusted OR 2.05 [95% CI 1.01-4.18]). Odds of benzodiazepine/Z-drug use were increased with polypharmacy (adjusted OR 4.35 [95% CI 1.69-11.22]), and odds of opioid use were increased with polypharmacy (adjusted OR 6.75 [95% CI 1.93-23.69]) and CCI score (adjusted OR 1.29 [95% CI 1.08-1.54]).

CONCLUSION

The prevalence of polypharmacy in this SLE cohort was higher than in the general Manitoban population. Polypharmacy is a strong marker for use of prescription benzodiazepines/Z-drugs and opioids.

Disagreement between pharmacy claims and direct interview to identify patients with non-adherence to chronic cardiometabolic medications

BACKGROUND

Accurate methods of identifying patients with suboptimal adherence to cardiometabolic medications are needed, and each approach has benefits and tradeoffs.

METHODS

We used data from a large trial of patients with poorly controlled cardiometabolic disease and evidence of medication non-adherence measured using pharmacy claims data whose adherence was subsequently assessed during a telephone consultation with a clinical pharmacist. We then evaluated if the pharmacist assessment agreed with the non-adherence measured using claims. When pharmacist and claims assessments disagreed, we identified reasons why claims were insufficient and used multivariable modified Poisson regression to identify patient characteristics associated with disagreement.

RESULTS

Of 1,069 patients identified as non-adherent using claims (proportion of days covered [PDC] <80%), 646 (60.4%) were confirmed as non-adherent on pharmacist interview. For the 423 patients (39.6%) where the interview disagreed with the claims, the most common reasons were paying cash or using an alternate insurance (36.6%), medication discontinuation or regimen change (32.8%), and recently becoming adherent (26.7%). Compared to patients whose claims and interview both showed non-adherence, patients whose interview disagreed with claims were less likely to miss outpatient office visits (RR:0.91, 95%CI:0.85-0.97) and more likely to have a baseline PDC above the median (RR:1.35, 95%CI:1.10-1.64).

CONCLUSIONS

Among patients identified as non-adherent by claims, 39.6% were observed to be adherent when assessed during pharmacist consultation. This discrepancy was largely driven by paying out-of-pocket, using alternative insurance, or medication discontinuation or change. These findings have important implications for using pharmacy claims to identify and intervene upon medication non-adherence.

Predictors of adherence and the role of primary non-adherence in antihormonal treatment of breast cancer

BACKGROUND

Antihormonal treatment for hormone receptor (HR) positive breast cancer has highly beneficial effects on both recurrence rates and survival. We investigate adherence and persistence in this group of patients.

METHODS

The study population comprised 1192 patients with HR-positive breast cancer who were prescribed adjuvant antihormonal treatment from 2004 to 2013. Adherence was defined as a medical possession ratio (MPR) of ≥80.

RESULTS

Of the 1192 included patients, 903 (75.8%) were adherent and 289 (24.2%) were non-adherent. Primary non-adherence was seen in 101 (8.5%) patients. The extremes of age (< 40 and ≥ 80 years) were associated with poor adherence. Patients with metastasis to axillary lymph nodes and those who received radiotherapy and/or chemotherapy were more likely to be adherent. Better adherence was also shown for those who switched medication at 2 years after diagnosis. Primary non-adherence seems to be associated with cancers with a good prognosis.

CONCLUSION

Adherence to antihormonal therapy for breast cancer is suboptimal. Primary non-adherence occurs among patients with a relatively good prognosis. Non-adherent patients tend to terminate their antihormonal therapy in the initial part of the treatment period. Targeted interventions to improve adherence should be focused on the first part of the treatment period.

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.

Racial Differences in Patient-Reported Symptoms and Adherence to Adjuvant Endocrine Therapy Among Women With Early-Stage, Hormone Receptor-Positive Breast Cancer

IMPORTANCE

Adjuvant endocrine therapy (AET) reduces breast cancer recurrence, but symptom burden is a key barrier to adherence. Black women have lower AET adherence and worse health outcomes than White women.

OBJECTIVE

To investigate the association between symptom burden and AET adherence differences by race.

DESIGN, SETTING, AND PARTICIPANTS

A retrospective cohort study using electronic health records with patient-reported data from a large cancer center in the US. Patients included Black and White women initiating AET therapy for early-stage breast cancer from August 2007 to December 2015 who were followed for 1 year from AET initiation. Sixty symptoms classified into 7 physical and 2 psychological symptom clusters were evaluated. For each cluster, the number of symptoms with moderate severity at baseline, and symptoms with 3-point or greater increases during AET were counted. Adherence was measured as the proportion of days covered by AET during the first-year follow-up. Multivariable regressions for patients' adherence adjusting for race, symptom measures, sociodemographic characteristics, and clinical characteristics were conducted. Kitagawa-Blinder-Oaxaca decomposition was used to quantify racial differences in adherence explained by symptoms and patient characteristics. Analyses were conducted from July 2021 to January 2022.

EXPOSURES

Physical and psychological symptoms at baseline and changes during AET.

RESULTS

Among 559 patients (168 [30.1%] Black and 391 [69.9%] White; mean [SD] age 65.5 [12.1] years), Black women received diagnoses younger (mean [SD] age at diagnosis, 58.7 [13.7] vs 68.5 [10.0] years old) than White women, with more advanced stages (30 Black participants [17.9%] vs 31 White participants [7.9%] had stage III disease at diagnosis), and lived in areas with fewer adults attaining high school education (mean [SD], 78.8% [7.8%] vs 84.0% [9.3%]). AET adherence in the first year was 78.8% for Black and 82.3% for White women. Black women reported higher severity in most symptom clusters than White women. Neuropsychological, vasomotor, musculoskeletal, cardiorespiratory, distress, and despair symptoms at baseline and increases during the follow-up were associated with 1.2 to 2.6 percentage points decreases in adherence, which corresponds to 4 to 9 missed days receiving AET in the first year. After adjusting for psychological symptoms, being Black was associated with 6.5 percentage points higher adherence than being White.

CONCLUSIONS AND RELEVANCE

In this cohort study, severe symptoms were associated with lower AET adherence. Black women had lower adherence rates that were explained by their higher symptom burden and baseline characteristics. These findings suggest that better symptom management with a focus on psychological symptoms could improve AET adherence and reduce racial disparities in cancer outcomes.

Melatonin usage in children and young adults, a registry-based cohort study

Sleep disorder is common in children and adolescents, particularly in those with attention deficit hyperactivity disorder (ADHD) or autism spectrum disorder (ASD). While non-pharmacological treatment is first line, occasionally an add-on of an oral drug is needed. The endogenous hormone melatonin is increasingly used for sleep disorders in children and adolescents. In this registry-based cohort study we follow dispensation of melatonin in young individuals, 0-25 years of age, in Stockholm, Sweden during 2016-2019. In all 9980 individuals, were dispensed melatonin in 2016 and followed for 3 years. Child psychiatrist was the most common prescribing specialty, 55% of all prescriptions. Only 20% had a recorded diagnosis of sleep disorder. The majority, 65% had a neuro psychiatric diagnose. Half of the individuals had at least 4 prescribed drugs dispensed during the follow-up. Almost half of our cohort were dispensed melatonin during the entire study period and doses and volumes of drug dispensed increased by 50 and 100%, respectively. Continuous medication was most common among children 6-12 years, where 7 out of 10 individuals were still adherent after three years. As long-term safety data is lacking, we find this concerning, and this illustrates the need of long-term follow-up of melatonin use in children and young individuals.

Long-Acting Injectable Antipsychotics in a Prescription Claims Data Source: A Validation Study

Background

The effectiveness of long-acting injectable antipsychotics (LAIAs) has been demonstrated in studies using prescription claims data. However, the validity of claims data for LAIAs has not been established.

Objective

We aimed to validate date dispensed, quantity dispensed and days supplied fields in prescription claims data, and to compare claims- and medical record-derived persistence estimates.

Methods

We evaluated LAIA dispensations in the Drug Programs Information Network prescription claims database from Manitoba, Canada against a random sample of medical records. Adults with one or more LAIA prescription between April 2015 and March 2016 were eligible. Results were stratified by LAIA type (first-generation LAIA, risperidone LAI or paliperidone LAI). Persistence estimates were assessed using Kaplan–Meier survival analysis and proportion of patients covered method.

Results

Claims data had high positive predictive value, ranging from 80.0% (95% CI 51.9–95.7) to 100.0% (95% CI 89.7–100.0), but low negative predictive value, ranging from 0.0% (95% CI 0.0–2.5) to 62.5% (95% CI 40.6–81.2). Quantity dispensed and days supplied exactly matched dose and dosing interval, respectively, for 99.7% and 97.1% of risperidone LAI doses, 100.0% and 76.6% of paliperidone doses, and 8.9% and 28.3% of first-generation LAIA doses. There were no significant differences in claims-derived versus medical record-derived persistence estimates.

Conclusions

Quantity dispensed and days supplied provide valid estimates of dose and dosing interval for second-generation LAIAs, but underestimated these parameters for first-generation LAIAs. However, a large proportion of medical record-confirmed doses were missing from claims data, and dose and dosing interval are underestimated in claims data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40801-022-00297-4.

Opioid Prescription Is Associated With Increased Survival in Older Adult Patients With Pancreatic Cancer in the United States: A Propensity Score Analysis

PURPOSE

Few studies have assessed the interaction between pain treatment and mortality in pancreatic cancer. The aim of this study was to investigate the association between receipt of opioid prescriptions and survival in adults with pancreatic cancer.

METHODS

The SEER-Medicare linked database was used to identify patients diagnosed with late-stage pancreatic cancer between 2007 and 2015. Kaplan-Meier models were used to assess the association between opioid prescriptions in the year after cancer diagnosis and survival. Cox proportional hazard models were used to determine the association between opioid receipt and survival, adjusting for propensity score and other relevant confounders including cancer-directed therapies and palliative care referral.

RESULTS

A total of 5,770 older adults with pancreatic cancer were identified; 1,678 (29.1%) were prescribed opioids for at least 60 days. Median survival was increased in those with opioid prescriptions (6.0 months) compared with those without (4.0 months, P < .0001). After adjustment for confounders, opioid prescriptions were still associated with improved survival (hazard ratio 0.80; 95% CI, 0.75 to 0.86). On multivariable analysis, opioid prescriptions were associated with older age, female sex, residing in nonmetro areas, and treatment with celiac plexus neurolysis, chemotherapy, and radiation.

CONCLUSION

Receipt of opioid prescriptions is associated with longer survival in patients with pancreatic cancer. This may be due to the impact of cancer-related pain, although further studies are needed to better understand the interaction between pain management, cancer-directed therapies, and systemic factors, such as palliative care, availability of opioids, and clinical practice culture.

Is Metformin Use Associated with Prolonged Overall Survival in Patients with Soft Tissue Sarcoma? A SEER-Medicare Study

BACKGROUND

Metformin, an oral drug used to treat patients with diabetes, has been associated with prolonged survival in patients with various visceral carcinomas. Although the exact mechanisms are unknown, preclinical translational studies demonstrate that metformin may impair tumor cellular metabolism, alter matrix turnover, and suppress oncogenic signaling pathways. Currently used chemotherapeutic agents have not been very successful in the adjuvant setting or for treating patients with metastatic sarcomas. We wanted to know whether metformin might be associated with improved survival in patients with a soft tissue sarcoma.

QUESTIONS/PURPOSES

In patients treated for a soft tissue sarcoma, we asked: (1) Is there an association between metformin use and longer survival? (2) How does this association differ, if at all, among patients with and without the diagnosis of diabetes?

METHODS

The Surveillance, Epidemiology, and End Results-Medicare (SEER-Medicare) database was used to identify patients with a diagnosis of soft tissue sarcoma from 2007 to 2016. Concomitant medication use was identified using National Drug Codes using the Medicare Part D event files. This database was chosen because of the large number of captured sarcoma patients, availability of tumor characteristics, and longitudinal linkage of Medicare data. A total of 14,650 patients were screened for inclusion. Patients with multiple malignancies, diagnosis at autopsy, or discrepant linkage to the Medicare database were excluded. Overall, 4606 patients were eligible for the study: 598 patients taking metformin and 4008 patients not taking metformin. A hazard of mortality (hazard ratio) was analyzed comparing patients taking metformin with those patient groups not taking metformin and expressed in terms of a 95% confidence interval. Cox regression analysis was used to control for patient-specific, disease-specific, and treatment-specific covariates.

RESULTS

Having adjusted for disease-, treatment-, and patient-specific characteristics, patients taking metformin experienced prolonged survival compared with all patients not taking metformin (HR 0.76 [95% CI 0.66 to 0.87]). Associated prolonged survival was also seen when patients taking metformin were compared with those patients not on metformin irrespective of a diabetes diagnosis (HR 0.79 [95% CI 0.66 to 0.94] compared with patients with a diagnosis of diabetes and HR 0.77 [95% CI 0.67 to 0.89] compared with patients who did not have a diagnosis of diabetes).

CONCLUSION

Without suggesting causation, we found that even after controlling for confounding variables such as Charlson comorbidity index, tumor grade, size, stage, and surgical/radiation treatment modalities, there was an association between metformin use and increased survival in patients with soft tissue sarcoma. When considered separately, this association persisted in patients not on metformin with and without a diabetes diagnosis. Although metformin is not normally prescribed to patients who do not have a diabetes diagnosis, these data support further study, and if these findings are substantiated, it might lead to the performance of multicenter, prospective clinical trials about the use of metformin as an adjuvant therapy for the treatment of soft tissue sarcoma in patients with and without a preexisting diabetes diagnosis.

LEVEL OF EVIDENCE

Level III, therapeutic study.

Type 2 Diabetes Management, Control and Outcomes During the COVID-19 Pandemic in Older US Veterans: an Observational Study

BACKGROUND

The COVID-19 pandemic required a change in outpatient care delivery models, including shifting from in-person to virtual visits, which may have impacted care of vulnerable patients.

OBJECTIVE

To describe the changes in management, control, and outcomes in older people with type 2 diabetes (T2D) associated with the shift from in-person to virtual visits.

DESIGN AND PARTICIPANTS

In veterans aged ≥ 65 years with T2D, we assessed the rates of visits (in person, virtual), A1c measurements, antidiabetic deintensification/intensification, ER visits and hospitalizations (for hypoglycemia, hyperglycemia, other causes), and A1c level, in March 2020 and April-November 2020 (pandemic period). We used negative binomial regression to assess change over time (reference: pre-pandemic period, July 2018 to February 2020), by baseline Charlson Comorbidity Index (CCI; > 2 vs. <= 2) and A1c level.

KEY RESULTS

Among 740,602 veterans (mean age 74.2 [SD 6.6] years), there were 55% (95% CI 52-58%) fewer in-person visits, 821% (95% CI 793-856%) more virtual visits, 6% (95% CI 1-11%) fewer A1c measurements, and 14% (95% CI 10-17%) more treatment intensification during the pandemic, relative to baseline. Patients with CCI > 2 had a 14% (95% CI 12-16%) smaller relative increase in virtual visits than those with CCI <= 2. We observed a seasonality of A1c level and treatment modification, but no association of either with the pandemic. After a decrease at the beginning of the pandemic, there was a rebound in other-cause (but not hypo- and hyperglycemia-related) ER visits and hospitalizations from June to November 2020.

CONCLUSION

Despite a shift to virtual visits and a decrease in A1c measurement during the pandemic, we observed no association with A1c level or short-term T2D-related outcomes, providing some reassurance about the adequacy of virtual visits. Further studies should assess the longer-term effects of shifting to virtual visits in different populations to help individualize care, improve efficiency, and maintain appropriate care while reducing overuse.

One-year care pathway after acute myocardial infarction in 2018: Prescription, medical care and medication adherence, using a French health insurance reimbursement database

BACKGROUND

Myocardial infarction is a major cause of morbidity and mortality. Guidelines have been published to optimize medical care and involve optimization of the care pathway and hospital-city coordination.

AIMS

To describe the myocardial infarction care pathway during the year following hospital discharge, and the use of and adherence to secondary prevention drugs.

METHODS

A cohort study was conducted using data from the main French health insurance reimbursement database of the ex-Aquitaine region. Information about the medical and pharmaceutical care of hospitalized patients in 2018 was collected for 12 months. Medication adherence was assessed by using the proportion of days covered by the treatment and persistence.

RESULTS

A total of 3015 patients were included, and the mean age was 66 years. Almost 76% of the patients had a reimbursement for BAS (combined prescription of beta-blocker/antiplatelet/lipid-lowering drug), BASI (combined prescription of beta-blocker/antiplatelet/lipid-lowering drug/angiotensin-converting enzyme inhibitor) or AS (combined prescription of antiplatelet/lipid-lowering drug) treatment. Medication adherence was around 83% for aspirin and 75% for lipid-lowering drugs for the 1-year persistence. During the same time, the proportion of days covered was suboptimal. Almost 4% of patients died after leaving hospital, 45% went to a cardiac rehabilitation centre and 23% had at least one hospital readmission, whatever the reason. Patients had a mean number of 11 general practitioner consultations during the year. Almost 41% of patients did not have a consultation with a cardiologist, and 38.4% had at least two consultations. Rehabilitation and general practitioner consultations were associated with adherence.

CONCLUSIONS

These new results provide clear information on the medical care environment of patients, and help us to improve care transition. Close collaboration between healthcare practitioners is very important in the early stages of outpatient follow-up.

Evidence of the association between adherence to treatment and mortality among patients with COPD monitored at a public disease management program in Brazil

Objective

To evaluate the association between adherence to treatment and mortality among Chronic Obstructive Pulmonary Disease (COPD) patients treated in the Brazilian public health system.

Methods

This is cohort study of moderate-to-severe COPD patients monitored in a public pharmaceutical care-based Disease Management Program (DMP). All subjects who died one year after the beginning of the cohort were age-matched with those who remained alive at the end of the cohort period. Treatment adherence was measured through pharmacy records. Patients who received at least 90% of the prescribed doses were considered adherent to treatment.

Results

Of the 333 patients (52.8% age ≥ 65 years, 67.9% male), 67.3% were adherent to treatment (adherence rate, 87.2%). Mortality was associated with lack of adherence (p = 0.04), presence of symptoms (mMRC ≥ 2) and COPD treatment use. The death was associated with non-adherence, presence of symptoms and previous hospitalization. After adjustment, non-adherent patients to treatment were almost twice times likely to die compared to those adherents (Hazard Ratio (HR) 1.86; CI 1.16-2.98, p = 0.01).

Conclusion

Non-adherence to treatment was associated with higher mortality among moderate-to-severe COPD patients treated in the Brazilian public health system. Strategies to monitor and optimize adherence should be strengthened to reduce COPD-related mortality.

Adding a New Medication Versus Maximizing Dose to Intensify Hypertension Treatment in Older Adults : A Retrospective Observational Study

BACKGROUND

There are 2 approaches to intensifying antihypertensive treatment when target blood pressure is not reached, adding a new medication and maximizing dose. Which strategy is better is unknown.

OBJECTIVE

To assess the frequency of intensification by adding a new medication versus maximizing dose, as well as the association of each method with intensification sustainability and follow-up systolic blood pressure (SBP).

DESIGN

Large-scale, population-based, retrospective cohort study. Observational data were used to emulate a target trial with 2 groups, new medication and maximizing dose, who underwent intensification of their drug regimen.

SETTING

Veterans Health Administration (2011 to 2013).

PATIENTS

Veterans aged 65 years or older with hypertension, an SBP of 130 mm Hg or higher, and at least 1 antihypertensive medication at less than the maximum dose.

MEASUREMENTS

The following 2 intensification approaches were emulated: adding a new medication, defined as a total dose increase with new medication, and maximizing dose, defined as a total dose increase without new medication. Inverse probability weighting was used to assess the observational effectiveness of the intensification approach on sustainability of intensified treatment and follow-up SBP at 3 and 12 months.

RESULTS

Among 178 562 patients, 45 575 (25.5%) had intensification by adding a new medication and 132 987 (74.5%) by maximizing dose. Compared with maximizing dose, adding a new medication was associated with less intensification sustainability (average treatment effect, -15.2% [95% CI, -15.7% to -14.6%] at 3 months and -15.1% [CI, -15.6% to -14.5%] at 12 months) but a slightly larger reduction in mean SBP (-0.8 mm Hg [CI, -1.2 to -0.4 mm Hg] at 3 months and -1.1 mm Hg [CI, -1.6 to -0.6 mm Hg] at 12 months).

LIMITATION

Observational data; largely male population.

CONCLUSION

Adding a new antihypertensive medication was less frequent and was associated with less intensification sustainability but slightly larger reductions in SBP. Trials would provide the most definitive support for our findings.

PRIMARY FUNDING SOURCE

National Institute on Aging and Veterans Health Administration.

Huntington's Disease in Israel: A Population-Based Study Using 20 Years of Routinely-Collected Healthcare Data

BACKGROUND

Huntington's disease (HD) is a rare, genetic, neurodegenerative disease. Obtaining population-level data on epidemiology and disease management is challenging.

OBJECTIVE

To investigate the epidemiology, clinical manifestations, treatment, and healthcare utilization of patients with HD in Israel.

METHODS

Retrospective population-based cohort study, including 20 years of routinely collected data from Maccabi Healthcare Services, an insurer and healthcare provider for one-quarter of the Israeli population.

RESULTS

The study cohort included 109 adult patients (aged ≥18 years) diagnosed with HD, with mean age of 49.9 years and 56%females. The most common HD-related conditions were anxiety (40%), behavioral problems (34%), sleep disorders (21%), and falls (13%). Annual incidence rates for HD ranged from 0.17 to 1.34 per 100,000 from 2000 to 2018; the 2018 crude prevalence in adults was 4.36 per 100,000. Median survival from diagnosis was approximately 12 years (95%CI: 10.4-15.3). The most frequent symptomatic treatments were antidepressants (69%), antipsychotics (63%), and tetrabenazine (63%), the only drug approved for the treatment of HD chorea in Israel during the examined period. Patterns of healthcare utilization changed as disease duration increased, reflected by increased frequency of emergency department visits and home visits.

CONCLUSION

This retrospective population-based study provides insights into the prevalence, incidence, clinical profile, survival, and resource utilization of patients with HD in ethnically diverse Israel. The findings in this study are generally consistent with the international literature and demonstrate the value of routinely collected healthcare data as a complementary resource in HD research.

Clinical outcomes of modifying hypertension treatment intensity in older adults treated to low blood pressure

BACKGROUND/OBJECTIVES

Hypertension treatment reduces cardiovascular events. However, uncertainty remains about benefits and harms of deintensification or further intensification of antihypertensive medication when systolic blood pressure (SBP) is tightly controlled in older multimorbid patients, because of their frequent exclusion in trials. We assessed the association of hypertension treatment deintensification or intensification with clinical outcomes in older adults with tightly controlled SBP.

DESIGN

Longitudinal cohort study (2011-2013) with 9-month follow-up.

SETTING

U.S.-nationwide primary care Veterans Health Administration healthcare system.

PARTICIPANTS

Veterans aged 65 and older with baseline SBP <130 mmHg and ≥1 antihypertensive medication during ≥2 consecutive visits (N = 228,753).

EXPOSURE

Deintensification or intensification, compared with stable treatment.

MAIN OUTCOMES AND MEASURES

Cardiovascular events, syncope, or fall injury, as composite and distinct outcomes, within 9 months after exposure. Adjusted logistic regression and inverse probability of treatment weighting (IPTW, sensitivity analysis).

RESULTS

Among 228,753 patients (mean age 75 [SD 7.5] years), the composite outcome occurred in 11,982/93,793 (12.8%) patients with stable treatment, 14,768/72,672 (20.3%) with deintensification, and 11,821/62,288 (19.0%) with intensification. Adjusted absolute outcome risk (95% confidence interval) was higher for deintensification (18.3% [18.1%-18.6%]) and intensification (18.7% [18.4%-19.0%]), compared with stable treatment (14.8% [14.6%-15.0%]), p < 0.001 for both effects in the multivariable model). Deintensification was associated with fewer cardiovascular events than intensification. At baseline SBP <95 mmHg, cardiovascular event risk was similar for deintensification and stable treatment, and fall risk lower for deintensification than intensification. IPTW yielded similar results. Mean follow-up SBP was 124.1 mmHg for stable treatment, 125.1 mmHg after deintensification (p < 0.001), and 124.0 mmHg after intensification (p < 0.001).

CONCLUSION

Antihypertensive treatment deintensification in older patients with tightly controlled SBP was associated with worse outcomes than continuing same treatment intensity. Given higher mortality among patients with treatment modification, confounding by indication may not have been fully corrected by advanced statistical methods for observational data analysis.

Strategies for measuring prescription medication switching with pharmacy claims data: a scoping review protocol

OBJECTIVE

This scoping review will aim to compare strategies for measuring prescription medication switching with pharmacy claims data, with a focus on psychotropic vs non-psychotropic medications.

INTRODUCTION

Medication switching (ie, the replacement of one medication for another) is common and occurs due to several factors (such as adverse effects to a specific medication). In pharmacoepidemiology studies that use pharmacy claims data, it is important to identify and account for switches; however, due to data limitations and lack of a methodological standard, this can be challenging. The aim of this scoping review is to describe how studies have previously measured medication switching with pharmacy claims data in order to create a repository of common strategies and highlight areas for future research.

INCLUSION CRITERIA

This review will include studies that have used pharmacy claims data to measure medication switching as their primary independent or dependent variable. Studies conducted at the individual level (ie, not ecological), published between January 1, 1980, and October 31, 2020, and investigating orally administered, non-anti-infective medications will be considered. No age, population, or context restrictions are specified as inclusion criteria.

METHODS

JBI methodology and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for scoping reviews were used for this protocol. MEDLINE (PubMed), Embase (Ovid), Central (Cochrane Library), CINAHL (EBSCO), and Google Scholar will be searched with the assistance of a health sciences research librarian. Two reviewers will independently screen titles, abstracts, and full-text articles. Strategies for measuring medication switching will be narratively described and summarized overall and by broad medication class.

Factors associated with primary nonadherence to newly initiated direct oral anticoagulants in patients with nonvalvular atrial fibrillation

BACKGROUND: Direct oral anticoagulants (DOACs) are widely used for the prevention of stroke in nonvalvular atrial fibrillation (NVAF); however, real-world primary nonadherence (failing to collect the first prescription) has been measured in very few studies. OBJECTIVE: To report primary nonadherence in NVAF patients who are newly prescribed DOACs and identify associated factors. METHODS: This observational retrospective cohort study used a large primary care database in Catalonia. Patients with NVAF who were newly prescribed a DOAC between January 2009 and December 2015 were identified, and primary nonadherence was measured by comparing prescribing records to pharmacy claims data. Multivariable logistic regression was used to determine associated factors. RESULTS: A total of 12,257 patients met the inclusion and exclusion criteria; of these, 1,276 (10.4%) were primary nonadherent. Primary nonadherence was found to be 12.8% for apixaban, 8.6% for dabigatran, and 10.8% for rivaroxaban. Multivariable logistic regression indicated higher odds of primary nonadherence with apixaban and rivaroxaban compared to dabigatran (apixaban: OR = 1.61, 95% CI = 1.39-1.87; rivaroxaban: OR = 1.28, 95% CI = 1.11-1.47). Patients aged at least 80 years showed lower odds of primary nonadherence compared to those aged less than 65 years (OR = 0.78, 95% CI = 0.66-0.93). A diagnosis of chronic kidney disease was associated with primary nonadherence (OR = 1.27, 95% CI = 1.08-1.50). Whereas, diabetes (OR = 0.85, 95% CI = 0.74-0.97), hypertension (OR = 0.79, 95% CI = 0.70-0.91), and stroke/transient ischemic attack (OR = 0.70, 95% C I =0.59-0.82) were inversely associated with primary nonadherence. CONCLUSIONS: Overall, 10.4% of patients prescribed DOACs were primary nonadherent, failing to collect the first prescription. The percentage could have serious implications for patient outcomes and the real-world cost-effectiveness of prescribing DOACs in NVAF. Rates of primary nonadherence and associated factors may provide useful information for the design and evaluation of adherence interventions. DISCLOSURES: No outside funding was received for this study. The data for this study came from the European Medicines Agency PE-PV project (Grant/Award Number EMA/2015/27/PH). The authors have nothing to disclose. A preliminary version of this work was presented at the European Drug Utilisation Research Group (EuroDURG) Conference, Szeged, Hungary, March 5, 2020.

Machine Learning to Predict Tamoxifen Nonadherence Among US Commercially Insured Patients With Metastatic Breast Cancer

PURPOSE

Adherence to tamoxifen citrate among women diagnosed with metastatic breast cancer can improve survival and minimize recurrence. This study aimed to use real-world data and machine learning (ML) methods to classify tamoxifen nonadherence.

METHODS

A cohort of women diagnosed with metastatic breast cancer from 2012 to 2017 were identified from IBM MarketScan Commercial Claims and Encounters and Medicare claims databases. Patients with < 80% proportion of days coverage in the year following treatment initiation were classified as nonadherent. Training and internal validation cohorts were randomly generated (4:1 ratio). Clinical procedures, comorbidity, treatment, and health care encounter features in the year before tamoxifen initiation were used to train logistic regression, boosted logistic regression, random forest, and feedforward neural network models and were internally validated on the basis of area under receiver operating characteristic curve. The most predictive ML approach was evaluated to assess feature importance.

RESULTS

A total of 3,022 patients were included with 40% classified as nonadherent. All models had moderate predictive accuracy. Logistic regression (area under receiver operating characteristic 0.64) was interpreted with 94% sensitivity (95% CI, 89 to 92) and 0.31 specificity (95% CI, 29 to 33). The model accurately classified adherence (negative predictive value 89%) but was nondiscriminate for nonadherence (positive predictive value 48%). Variable importance identified top predictive factors, including age ≥ 55 years and pretreatment procedures (lymphatic nuclear medicine, radiation oncology, and arterial surgery).

CONCLUSION

ML using baseline administrative data predicts tamoxifen nonadherence. Screening at treatment initiation may support personalized care, improve health outcomes, and minimize cost. Baseline claims may not be sufficient to discriminate adherence. Further validation with enriched longitudinal data may improve model performance.

Factors associated with antihypertensive treatment intensification and deintensification in older outpatients

Background

New hypertension performance measures encourage more intensive treatment in older adults. Treatment intensification includes starting new medications and increasing the dose of old ones. Medication dose is particularly important to older adults, given their vulnerability to dose-related side effects. We previously validated a standardized measure of beneficial doses tested in hypertension trials, Hypertension Daily Dose (HDD).

Aim of the study

To test whether changes in treatment intensity using HDD was associated with systolic blood pressure (SBP) and patient characteristics.

Methods

Longitudinal study of all Veterans aged ≥65 years with a diagnosis of hypertension. We defined 3 groups of risk: 1) cardiovascular risk; 2) geriatric/frail; 3) low-risk (comparator). Using multinomial regression, we assessed the probability of deintensification, intensification, vs. stable treatment, according to SBP and group.

Results

Among 1,331,111 Veterans, 19.9% had deintensification, and 29.6% intensification. Deintensification decreased, while intensification increased, with SBP. Compared to low-risk patients, cardiovascular risk patients had 1.11 (95% CI 1.10-1.13) times the odds of intensifying, and geriatric/frail patients 1.45 (95%CI 1.43-1.47) times the odds of deintensifying.

Discussion

Patient-level HDD change was consistent with an expected association with cardiovascular risk and geriatric/frail conditions, suggesting that HDD can be used longitudinally to assess hypertension treatment modification in large health systems.

Depression, Anxiety, and Self-Directed Violence in Women With Endometriosis: A Retrospective Matched-Cohort Study

The purpose of this study was to compare the incidence of mental health outcomes in women in the United States with and without documented endometriosis. In a retrospective matched-cohort study using administrative health claims data from Optum's Clinformatics DataMart from May 1, 2000, through March 31, 2019, women aged 18-50 years with endometriosis (n = 72,677), identified by International Classification of Disease diagnosis codes (revisions 9 or 10), were matched 1:2 on age and calendar time to women without endometriosis (n = 147,251), with a median follow-up of 529 days (interquartile range, 195, 1,164). The rate per 1,000 person-years of anxiety, depression, and self-directed violence among women with endometriosis was 57.1, 47.7, and 0.9, respectively. Comparing women with endometriosis to those without, the adjusted hazard ratios and 95% confidence intervals were 1.38 (1.34, 1.42) for anxiety, 1.48 (1.44, 1.53) for depression, and 2.03 (1.60, 2.58) for self-directed violence. The association with depression was stronger among women younger than 35 years (P for heterogeneity < 0.01). Risk factors for incident depression, anxiety, and self-directed violence among women with endometriosis included endometriosis-related pain symptoms and prevalence of other chronic conditions associated with pain. The identification of risk factors for mental health conditions among women with endometriosis may improve patient-centered disease management.

Patterns of metformin monotherapy discontinuation and reinitiation in people with type 2 diabetes mellitus in New Zealand

Aim

To describe the patterns of discontinuation and reinitiation in new users of metformin monotherapy in New Zealand, overall and according to person- and healthcare-related factors.

Materials and methods

We created a cohort (n = 85,066) of all patients in New Zealand with type 2 diabetes mellitus who initiated metformin monotherapy between 1 January 2006 and 30 September 2014 from the national data collections, and followed them until the earlier of their death or 31 December 2015. Discontinuation was defined as a gap in possession of metformin monotherapy of ≥90 days. We explored patterns of discontinuation and reinitiation using competing risks methods.

Results

After 1 year of follow-up, 28% of cohort members had discontinued metformin monotherapy at least once; the corresponding figures after 2 and 5 years were 37% and 46%. The proportions who reinitiated metformin monotherapy within 1, 2, and 5 years of their first discontinuation were 23%, 49%, and 73%. Discontinuation after the first reinitiation was common (48% after 1 year). Discontinuation and reinitiation varied by age, ethnicity, and other person- and healthcare-related factors.

Discussion

Our findings highlight the dynamic nature of metformin monotherapy use, show that substantial periods of non-use are common, and identify priority populations for interventions to facilitate adherence.

Beta-blockers have no impact on survival in pancreatic ductal adenocarcinoma prior to cancer diagnosis

Previous studies have suggested that β-adrenergic signaling may regulate the growth of various cancers. The aim of our study is to investigate the association between the incidental use of beta-blockers for various conditions on the overall survival of patients with pancreatic ductal adenocarcinoma (PDAC). Patients with histologically-confirmed PDAC between 2007 and 2011 were extracted from Surveillance, Epidemiology, and End Results registry (SEER)-Medicare linked database. Kaplan Meier and multivariable Cox Proportional-Hazard models were used to examine the association between beta-blocker usage before diagnosis and overall survival adjusting for appropriate confounders. As an additional analysis we also examined continuous beta-blocker use before and after diagnosis. From 2007 to 2011, 13,731 patients were diagnosed with PDAC. Of these, 7130 patients had Medicare Part D coverage in the 6-month period before diagnosis, with 2564 (36%) of these patients using beta-blockers in this period. Patients receiving beta-blockers had a mean survival time of 5.1 months compared to 6 months for non-users (p < 0.01). In multivariable analysis, beta-blockers usage was not associated with improved survival (Hazard Ratio (HR) 1.04, 95%, Confidence Interval (CI) 0.98–1.1, p = 0.2). When patients were stratified by conditions with indications for beta-blocker usage, such as hypertension, coronary artery disease and cardiac arrhythmia, differences in survival were insignificant compared to non-users in all groups (p > 0.05). After stratification by receptor selectivity, this lack of association with survival persisted (p > 0.05 for all). As a subgroup analysis, looking at patients with continuous Medicare Part D coverage who used beta-blockers in the 6-month period before and after cancer diagnosis, we identified 7085 patients, of which 1750 (24.7%) had continuous beta blocker use. In multivariable analysis, continuous beta-blockers usage was associated with improved survival (Hazard Ratio (HR) 0.86, 95%, Confidence Interval (CI) 0.8–0.9, p < 0.01). Beta-blocker usage before diagnosis does not confer a survival advantage in patients with PDAC, though continuous use before and after diagnosis did confer a survival advantage. Prospective studies into the mechanism for this advantage are needed.

Healthcare utilization and expenditures associated with hyperkalemia management: a retrospective study of Medicare Advantage patients

AIMS

This study aimed to estimate the association of patiromer exposure vs. no potassium (K⁺) binder (NoKb) exposure with healthcare utilization and expenditures among a cohort of Medicare Advantage patients with hyperkalemia (HK).

METHODS

Using Optum's Clinformatics Data Mart (study period 2016-2019), the authors assessed propensity score-matched patients (1:1) with a serum K⁺ concentration ≥5.0 mmol/L and an HK diagnosis that were exposed to patiromer or NoKb on baseline characteristics. The following outcomes were compared: (1) inpatient/emergency department (ED) encounters, (2) inpatient costs greater than or equal to mean Medicare Advantage inpatient cost (i.e. $14,900), and (3) the relative healthcare spending rate. Logistic regression and zero-inflated negative binomial regression were used to analyze the outcomes.

RESULTS

The study cohort included 1,539 patiromer and NoKb matched pairs. Baseline characteristics were (patiromer/NoKb): age 74/75 years; female 42/40%; serum K⁺ 5.6/5.6 mmol/L; eGFR rate 36/36 mL/min/1.73 m²; low-income subsidy 42/41%, chronic kidney disease 96/96%; end-stage renal disease 12/12%; and congestive heart failure 37/36%. A total of 253 matched pairs (506 patients) remained uncensored and were analyzed at 6 months. Inpatient/ED encounters were observed for 25% (patiromer) and 37% (NoKb) (odds ratio [OR] 0.58, 95% confidence interval [CI]: 0.38-0.89). The relative odds of having inpatient costs ≥$14,900 were ∼50% less for patients exposed to patiromer vs. NoKb (OR [95% CI]: 0.47 [0.25-0.89]). The relative total healthcare spending rate (including inpatient, outpatient, ED, and pharmacy costs) was 19% less for patients exposed to patiromer vs. NoKb (spending rate ratio [95% CI]: 0.81 [0.67-0.98]).

CONCLUSION AND LIMITATIONS

Among Medicare Advantage patients with HK, patiromer exposure (vs. NoKb) was associated with statistically significant reductions in the proportion with inpatient/ED encounters, inpatient costs ≥$14,900, and lower total healthcare spending. Further research, with larger sample size, is warranted to fully validate these findings.

The Use and Concurrent Use of Side Effect Controlling Medications Among Women on Aromatase Inhibitors

Background: Women on aromatase inhibitors (AIs) as part of their breast cancer treatment often experience difficult to control side effects. Although there are several medications to manage the side effects of AI therapy, many of them are associated with their own risk, particularly sedation. The objective of this study was to describe the prescribing practices for side effect managing (SE) medications among women with breast cancer on AI therapy and to assess for combinations of medications that may present a clinical risk to patients. Methods: Retrospective data analysis using Surveillance, Epidemiology and End Results (SEER)-Medicare data of all women aged 66-90 years with stage I-III hormone positive breast cancer diagnosed between 2008 and 2014 who initiated AI therapy within 12 months of their diagnosis. We determined the percentage of patients prescribed an SE medication in the 12 months prior and in the 24 months after the initiation of AI therapy. We calculated the number of prescriptions and the number of days of overlapping (i.e., >1 SE) prescriptions, and examined predictors of overlapping prescriptions. Results: The use of SE medications was pervasive and increased after initiation of AI therapy. The most commonly prescribed medications were opiates (55.1%), selective serotonin reuptake inhibitors (22.6%), benzodiazepines (18.4%), tramadol (17.7%) and gabapentin (14.6%). In total 15.5% of patients had overlapping prescriptions; among those, 36.2% had three overlapping prescriptions. Prior use was the strongest predictor of overlapping prescriptions with an odds ratio of 7.9 (95% confidence interval: 7.17-8.77). Conclusion: Among women on AI therapy, the use of SE medications is common and many have overlapping prescriptions raising concern for potential harm from polypharmacy.

Impact of a Copayment Reduction Intervention on Medication Persistence and Cardiovascular Events in Hospitals With and Without Prior Medication Financial Assistance Programs

Background

Hospitals commonly provide a short‐term supply of free P2Y₁₂ inhibitors at discharge after myocardial infarction, but it is unclear if these programs improve medication persistence and outcomes. The ARTEMIS (Affordability and Real‐World Antiplatelet Treatment Effectiveness After Myocardial Infarction Study) trial randomized hospitals to usual care versus waived P2Y₁₂ inhibitor copayment costs for 1‐year post‐myocardial infarction. Whether the impact of this intervention differed between hospitals with and without pre‐existing medication assistance programs is unknown.

Methods and Results

In this post hoc analysis of the ARTEMIS trial, we examined the associations of pre‐study free medication programs and the randomized copayment voucher intervention with P2Y₁₂ inhibitor persistence (measured by pharmacy fills and patient report) and major adverse cardiovascular events using logistic regression models including a propensity score. Among 262 hospitals, 129 (49%) offered pre‐study free medication assistance. One‐year P2Y₁₂ inhibitor persistence and major adverse cardiovascular events risks were similar between patients treated at hospitals with and without free medication programs (adjusted odds ratio 0.93, 95% CI, 0.82–1.05 and hazard ratio 0.92, 95% CI, 0.80–1.07, respectively). The randomized copayment voucher intervention improved persistence, assessed by pharmacy fills, in both hospitals with (53.6% versus 44.0%, adjusted odds ratio 1.45, 95% CI, 1.20–1.75) and without (59.0% versus 48.3%, adjusted odds ratio 1.46, 95% CI, 1.25–1.70) free medication programs (P_interaction=0.71). Differences in patient‐reported persistence were not significant after adjustment.

Conclusions

While hospitals commonly report the ability to provide free short‐term P2Y₁₂ inhibitors, we did not find association of this with medication persistence or major adverse cardiovascular events among patients with insurance coverage for prescription medication enrolled in the ARTEMIS trial. An intervention that provided copayment assistance vouchers for 1 year was successful in improving medication persistence in hospitals with and without pre‐existing short‐term medication programs.

Registration

URL: https://www.clini​caltr​ials.gov/. Unique identifier: NCT02406677.

Hyperkalemia treatment modalities: A descriptive observational study focused on medication and healthcare resource utilization

Renin-angiotensin-aldosterone system inhibitor (RAASi) therapy has been shown to improve outcomes among patients with congestive heart failure, diabetes, or renal dysfunction. These patients are also at risk for the development of hyperkalemia (HK), often leading to down-titration and/or discontinuation of RAASi therapy. Patiromer is the first sodium-free, non-absorbed potassium (K⁺) binder approved for the treatment of hyperkalemia (HK) in over 50 years. We described the association between use of K⁺ binders (Patiromer and sodium polystyrene sulfonate [SPS]) and renin-angiotensin-aldosterone system inhibitor (RAASi), on healthcare resource utilization (HRU). The study population consisted of Medicare Advantage patients with HK (K⁺ ≥ 5.0 mmol/L) in Optum’s Clinformatics^® Data Mart between 1/1/2016–12/31/2017. Patiromer and (SPS) initiators, and HK patients not exposed to a K⁺ binder (NoKb) were included. The index date was the date of the first K⁺ binder dispensing or HK diagnosis. Outcomes assessed at 6 months post-index were: (1) K⁺ binder utilization, (2) RAASi continuation, and (3) HRU (pre- vs post-index). HRU change was analyzed using McNemar’s statistical test. Study cohorts included 610 (patiromer), 5556 (SPS), and 21,282 (NoKb) patients. Overall baseline patient characteristics were: mean age 75 years; female 49%, low-income subsidy 29%, chronic kidney disease 48% (63% for patiromer cohort), and congestive heart failure 29%. At 6 months post-index, 28% (patiromer) and 2% (SPS) remained continuously exposed to the index K⁺ binder. RAASi continued for 78% (patiromer), 57% (SPS), and 57% (NoKb). The difference (pre- vs post-index) in hospitalized patients was: –9.4% (patiromer; P<0.05), –7.2% (SPS), and +16.8% (NoKb; P<0.001). Disparate K⁺ binder utilization patterns were observed. The majority of patiromer patients continued RAASi therapy while the percentage of SPS patients that continued RAASi therapy was lower, overlapping CIs were observed. Following continuous patiromer exposure, statistically significant reductions in hospital admissions and emergency department visits were observed, continuous SPS exposure observed no statistically significant reductions in either hospitalizations or ED visits, while NoKb patients with continuous exposure had statistically significant increases in both. Further research, with a larger sample size using comparative analytic methods, is warranted.

Prediction and pattern analysis of medication refill adherence through electronic health records and dispensation data

BACKGROUND AND PURPOSE

Low adherence to medication in chronic disease patients leads to increased morbidity, mortality, and healthcare costs. The widespread adoption of electronic prescription and dispensation records allows a more comprehensive overview of medication utilization. In combination with electronic health records (EHR), such data provides new opportunities for identifying patients at risk of nonadherence and provide more targeted and effective interventions. The purpose of this article is to study the predictability of medication adherence for a cohort of hypertensive patients, focusing on healthcare utilization factors under various predictive scenarios. Furthermore, we discover common proportion of days covered patterns (PDC-patterns) for patients with index prescriptions and simulate medication-taking behaviours that might explain observed patterns.

PROCEDURES

We predict refill adherence focusing on factors of healthcare utilization, such as visits, prescription information and demographics of patient and prescriber. We train models with machine learning algorithms, using four different data splits: stratified random, patient, temporal forward prediction with and without index patients. We extract frequent, two-year long PDC-patterns using K-means clustering and investigate five simple models of medication-taking that can generate such PDC-patterns.

FINDINGS

Model performance varies between data splits (AUC test set: 0.77-0.89). Including historical information increases the performance slightly in most cases (approx. 1-2% absolute AUC uplift). Models show low predictive performance (AUC test set: 0.56-0.66) on index-prescriptions and patients with sudden drops in PDC (Recall: 0.58-0.63). We find 21 distinct two-year PDC-patterns, ranging from good adherence to intermittent gaps and early discontinuation in the first or second year. Simulations show that observed PDC-patterns can only be explained by specific medication consumption behaviours.

CONCLUSIONS

Prediction models developed using EHR exhibit bias towards patients with high healthcare utilization. Even though actual medication-taking is not observable, consumption patterns may not be as arbitrary, provided that medication refilling and consumption is linked.

Evaluation of weight change and hypoglycaemia as mediators in the association between insulin use and death

AIM

To evaluate whether weight change or hypoglycaemia mediates the association between insulin use and death.

MATERIALS AND METHODS

In a retrospective cohort of veterans who filled a new prescription for metformin and added insulin or sulphonylurea (2001-2012), we assessed change in body mass index (BMI) and hypoglycaemia during the first 12 months of treatment intensification. Cox proportional hazards models compared the risk of death between treatment groups. Using the difference method, we estimated the indirect effect and proportion mediated through each mediator. A sensitivity analysis assessed mediators in the first 6 months of intensified therapy.

RESULTS

Among 28 892 patients surviving 12 months, deaths per 1000 person-years were 15.4 for insulin users and 12.9 for sulphonylurea users (HR 1.20, 95% CI 0.87, 1.64). Change in BMI and hypoglycaemia mediated 13% (-98, 98) and -1% (-37, 71) of this association, respectively. Among 30 214 patients surviving 6 months, deaths per 1000 person-years were 34.8 for insulin users and 21.3 for sulphonylurea users (HR 1.66, 95% CI 1.28, 2.15). Change in BMI and hypoglycaemia mediated 9% (1, 23) and 0% (-9, 4) of this association, respectively.

CONCLUSIONS

We observed an increased risk of death among metformin users intensifying treatment with insulin versus sulphonylurea and surviving 6 months of intensified therapy, but not among those surviving 12 months. This association was mediated in part by weight change.

Bisphosphonate use and incident cardiovascular events among older breast cancer survivors

BACKGROUND

Cardiovascular disease (CVD) is a leading cause of mortality in early-stage breast cancer survivors. Recent studies suggest that bisphosphonates may decrease CVD risk in older patients.

OBJECTIVE

This study sought to assess whether bisphosphonate use is associated with lower rates of incident CVD events among early-stage breast cancer survivors.

METHODS

Longitudinal, population-based cohort study was conducted by using data from the Surveillance, Epidemiology and End Results registry linked to Medicare claims. We identified women >65 years with no history of CVD who were diagnosed with stage 0-III primary breast cancer between 2007 and 2010. Our primary outcome was a composite of incident angina pectoris, myocardial infarction, atrial fibrillation/flutter, heart failure, or stroke within 36 months of cancer diagnosis. Bisphosphonate use was defined as the presence of ≥1 pharmacy claim from 6 months prior to cancer diagnosis to the incident CVD event. We used propensity scores to create a matched group of breast cancer survivors without bisphosphonate exposure to compare rates of incident CVD events.

RESULTS

A total of 2178 breast cancer survivors had ≥1 bisphosphonate prescription; the average length of bisphosphonate use was 15 months. Analyses of the matched data showed that 13.0% of bisphosphonate users and 23.4% of non-bisphosphonate users experienced an incident CVD event (p < 0.0001) after breast cancer diagnosis. Bisphosphonate use was significantly associated with fewer incident CVD events (hazard ratio: 0.51, 95% confidence interval: 0.44 to 0.59).

CONCLUSIONS

Bisphosphonate use is associated with lower incidence of CVD events among older early-stage breast cancer survivors. Future studies should prospectively evaluate whether bisphosphonate use can decrease CVD incidence.

Patterns of glucocorticoid prescribing and provider-level variation in a commercially insured incident rheumatoid arthritis population: A retrospective cohort study

OBJECTIVE

Glucocorticoids are common in RA management despite an unfavorable, exposure-dependent risk profile impacted by patient and provider-level factors. Existing work describing glucocorticoid use in RA is not generalizable and does not adequately examine provider factors. We aim to describe how providers prescribe glucocorticoids to commercially insured, newly diagnosed RA patients in the United States.

METHODS

This was a retrospective cohort study which used the national Optum© administrative database. We identified 9221 adults ages 18-65 with RA diagnosed 2010-2014. We assessed glucocorticoid dispensing 3 months pre-diagnosis through 12months post-diagnosis ("study period"), cumulatively stratified by calendar quarter and prescriber specialty (rheumatologist, primary care, other). We examined prescribing variation among individual rheumatologists by dividing quarterly distribution of per-patient dose and days' supply into quartiles.

RESULTS

6717 (72.8%) patients filled ≥1 glucocorticoid prescription during the study period. 2890 (31.3%) patients received ≥3 months' supply, with median (IQR) daily dose 10 (6.6) mg/day and days' supply 189 (143) days. 52.6% of patients received glucocorticoids 1-3 months post-diagnosis; 29.2% received glucocorticoids 10-12 months post-diagnosis. Among glucocorticoid users post-diagnosis, quarterly median daily dose and days' supply were consistently ≥10 mg/day and ≥30 days, respectively. Rheumatologists prescribed most glucocorticoids, with median per-quarter daily dose and days' supply 10 mg/day and 43-60 days. Individual rheumatologists' prescribing varied widely across all quarters.

CONCLUSION

Among commercially insured incident RA patients, receipt of ≥10 mg/day prednisone equivalent for months is common, typically prescribed by rheumatologists, and persists a year post-diagnosis in 29.2% of patients. Glucocorticoid prescribing varies widely across rheumatologists. Further work is warranted to identify provider factors explaining variation in glucocorticoid prescribing, and assess how these affect health outcomes.

Improving the accuracy of medication adherence measures using linked prescription and dispensation data: findings from the ESOSVAL cohort of patients treated with osteoporosis drugs

Objective: We compare estimates of proportion of days covered (PDC) based on dispensation-only data versus linked prescription and dispensation information, and we analyse their differences in a real-world cohort of patients with osteoporosis.Methods: Prospective cohort study. We compared four alternative measures of PDC, using dispensation-only data: a) with a fixed assessment interval; b) censoring the assessment interval at the moment of the last refill; and using linked prescription and dispensation data: c) considering a minimum prescription gap of three months to interpret interruption by the physician; and d) considering any prescription gap.Results: The mean PDC at 12 months for new users was 63.1% using dispensation-only data and a fixed interval, 86.0% using dispensation-only data and a last-refill interval, 81% using linked dispensation and prescription data and censoring any period without prescription, and 78.3% when using linked prescription and dispensation data and censoring periods of at least 3 months. For experienced users, the figures were 80.0%, 88.9%, 83% and 81%, respectively. Overall, dispensation-based measures presented issues of patient misclassification.Conclusions: Linked prescription and dispensation data allows for more precise PDC estimates than dispensation-only data, as both primary non-adherence and early non-adherence periods, and fully non-adherent patients, are all identified and accounted for.

Adherence and Persistence to Adjuvant Hormonal Therapy in Early-Stage Breast Cancer Patients: A Population-Based Retrospective Cohort Study in Israel

Background

Adjuvant hormonal therapy (HT) has been consistently proven to improve multiple outcomes in early breast cancer yet rates of adherence and persistence are variable.

Methods

We retrospectively identified women diagnosed with nonmetastatic breast cancer and initiating HT between January 2000 and December 2007 in a large Israeli health provider. Prescription records including the drug name, date of purchase, and the quantity of pills dispensed were collected. We used Cox proportional hazards and binary logistic models to analyze factors associated with early discontinuation (<5 years) and nonadherence (proportion of days covered, PDC <80%) of HT, respectively.

Results

A total of 4,178 women with breast cancer were identified with nearly 95% of patients treated with tamoxifen as the initial HT. Over the 5-year follow-up period, early discontinuation was identified in 955 (23%) patients. The mean PDC was 82.9% (SD 0.004). Younger age and low BMI were both associated with an increased risk of early discontinuation and nonadherence. A history of hypertension was associated with a higher likelihood of both outcomes.

Conclusion

Adherence and persistence with HT among Israeli breast cancer survivors are comparable to those in international reports. Interventions are necessary to identify and prevent suboptimal HT adherence.

Drug monitoring of tamoxifen metabolites predicts vaginal dryness and verifies a low discontinuation rate from the Norwegian Prescription Database

PURPOSE

Tamoxifen is an important targeted endocrine therapy in breast cancer. However, side effects and early discontinuation of tamoxifen remains a barrier for obtaining the improved outcome benefits of long-term tamoxifen treatment. Biomarkers predictive of tamoxifen side effects remain unidentified. The objective of this prospective population-based study was to investigate the value of tamoxifen metabolite concentrations as biomarkers for side effects. A second objective was to assess the validity of discontinuation rates obtained through pharmacy records with the use of tamoxifen drug monitoring.

METHODS

Longitudinal serum samples, patient-reported outcome measures and pharmacy records from 220 breast cancer patients were obtained over a 6-year period. Serum concentrations of tamoxifen metabolites were measured by LC-MS/MS. Associations between metabolite concentrations and side effects were analyzed by logistic regression and cross table analyses. To determine the validity of pharmacy records we compared longitudinal tamoxifen concentrations to discontinuation rates obtained through the Norwegian Prescription database (NorPD). Multivariable Cox regression models were performed to identify predictors of discontinuation.

RESULTS

At the 2nd year of follow-up, a significant association between vaginal dryness and high concentrations of tamoxifen, Z-4'-OHtam and tam-NoX was identified. NorPD showed a tamoxifen-discontinuation rate of 17.9% at 5 years and drug monitoring demonstrated similar rates. Nausea, vaginal dryness and chemotherapy-naive status were significant risk factors for tamoxifen discontinuation.

CONCLUSIONS

This real-world data study suggests that measurements of tamoxifen metabolite concentrations may be predictive of vaginal dryness in breast cancer patients and verifies NorPD as a reliable source of adherence data.

Association of statin use with Parkinson's disease: Dose-response relationship

BACKGROUND

There have been conflicting results on the association between statin use and Parkinson's disease (PD) incidence.

OBJECTIVES

This study investigated the association between time-varying status of statin use and incidence of PD while considering the dose-response relationship and total cholesterol level.

METHODS

Using the database of the Korean National Health Insurance Service from 2002 to 2015, we examined 76,043 subjects (≥60 years old) free of PD, dementia, and stroke at baseline. The dose of statin use was classified into the following four 6-month categories (<180, 180-365, 365-540, and ≥540 days) for each 2-year interval. The incidence of PD was identified by the prescription records for any anti-PD medication with a diagnosis of PD.

RESULTS

During 10 years of follow-up, 1,427 PD cases occurred. Statin "ever use" was significantly associated with a high risk of PD incidence (adjusted hazard ratio = 1.28; 95% confidence interval = 1.12-1.46) when compared with statin nonuse. In terms of a dose-response relationship, although a duration of statin use <365 days was associated with a higher risk of PD, the duration of statin use ≥365 days was not significantly associated with an increased risk of PD.

CONCLUSIONS

Statin use was associated with an elevated PD risk of PD, but long-term and adherent statin use was not significantly associated with elevated PD risk. However, there was no evidence of benefit with any statin treatment related to PD risk. Our study suggests that there is a complex relationship among cholesterol level, statin use, and PD risk that warrants further studies. © 2019 International Parkinson and Movement Disorder Society.

High adherence of patients with multiple myeloma who receive treatment with immunomodulatory drugs (IMIDS) in hematology/oncology group practices in Germany

PURPOSE

Immunomodulatory drugs (IMIDS) have changed the treatment and outcome of patients suffering from multiple myeloma. However, with the oral administration adherence becomes an issue. Since there is no "gold standard" in measuring adherence, we assessed the adherence of myeloma patients with the help of different data sources.

METHODS

All patients who have been receiving IMIDS for at least 3 months were eligible. Computer assisted personal interviews of patients and, if possible, their caregivers were carried out. Attending oncologists evaluated the patient's adherence with the help of a standardized questionnaire. In addition, a retrospective analysis of prescription data was conducted. All data were analyzed statistically using SPSS.

RESULTS

One hundred myeloma patients, 35% female, 65% male, with a median age of 70 years (37-86) were interviewed. Prescription data could be evaluated in terms of adherence in 78 patients (78%), 56 caregivers could be questioned (56%). Ninety-seven percent of patients rated themselves as adherent in taking IMIDS. Data from treating oncologists, caregivers and prescriptions supported this result. IMID therapies were rated as very effective and significant, toxicities were acceptable and dosing regimens simple/uncomplicated.

CONCLUSIONS

Myeloma patients seem to be highly adherent to IMID treatments.

The association of pre- and posthospital medication adherence in myocardial infarction patients

BACKGROUND

Nonadherence to optimal medical therapy following myocardial infarction (MI) is associated with adverse clinical outcomes such as stent thrombosis, recurrent cardiovascular events, and death. Whether adherence to medications prior to MI predicts post-MI medication adherence is unknown.

METHODS

We assessed adherence to P2Y₁₂ inhibitors and statins before and after admission for MI among 8,147 MI patients who had Medicare insurance with Part D prescription coverage. Adherence was defined as a proportion of days covered with medication fills ≥80%. Multivariable logistic regression was used to assess the association between pre- and post-MI P2Y₁₂ inhibitor adherence. As few patients were on P2Y₁₂ inhibitors pre-MI, we also examined the association of pre-MI statin adherence with post-MI P2Y₁₂ inhibitor and statin adherence.

RESULTS

Pre-MI medication nonadherence was observed in 427 of 2,633 (16%) patients on preadmission P2Y₁₂ inhibitors and 1,233 of 6,934 (18%) patients on preadmission statins. Nonadherent patients were more likely to be of nonwhite race and have multiple prior hospital admissions. Patients who were nonadherent to P2Y₁₂ inhibitors pre-MI were substantially less likely to adhere to P2Y₁₂ inhibitors at 90 days (adjusted odds ratio [OR] 0.33, 95% CI 0.25-0.43) and 1 year post-MI (adjusted OR 0.29, 95% CI 0.21-0.39) compared with patients who were adherent pre-MI. Pre-MI statin nonadherence was also associated with lower post-MI adherence to P2Y₁₂ inhibitors at 90 days (adjusted OR 0.65, 95% CI 0.53-0.79) and 1 year (adjusted OR 0.37, 95% CI 0.29-0.54).

CONCLUSIONS

Prior medication adherence predicts post-MI adherence to P2Y₁₂ inhibitors. Increasing accessibility of medication adherence data in the medical record may be an important tool to identify patients at higher risk for post-MI medication nonadherence and target efforts to improve adherence.

Estimating Adherence Based on Prescription or Dispensation Information: Impact on Thresholds and Outcomes. A Real-World Study With Atrial Fibrillation Patients Treated With Oral Anticoagulants in Spain

Objective: To estimate drug exposure, Proportion of Days Covered (PDC) and percentage of patients with PDC ≥ 80% from a cohort of atrial fibrillation patients initiating oral anticoagulant (OAC) treatment. We employed three different approaches to estimate PDC, using either data from prescription and dispensing (PD cohort) or two common designs based on dispensing information only, requiring at least one (D1) or at least two (D2) refills for inclusion in the cohorts. Finally, we assessed the impact of adherence on health outcomes according to each method. Methods: Population-based retrospective cohort of all patients with Non Valvular Atrial Fibrillation (NVAF), who were newly prescribed acenocoumarol, apixaban, dabigatran or rivaroxaban from November 2011 to December 2015 in the region of Valencia (Spain). Patients were followed for 12 months to assess adherence using three different approaches (PD, D1 and D2 cohorts). To analyze the relationship between adherence (PDC ≥ 80) defined according to each method of calculation and health outcomes (death for any cause, stroke or bleeding) Cox regression models were used. For the identification of clinical events patients were followed from the end of the adherence assessment period to the end of the available follow-up period. Results: PD cohort included all patients with an OAC prescription (n = 38,802), D1 cohort excluded fully non-adherent patients (n = 265) and D2 cohort also excluded patients without two refills separated by 180 days (n = 2,614). PDC ≥ 80% ranged from 94% in the PD cohort to 75% in the D1 cohort. Drug exposure among adherent (PDC ≥ 80%) and non-adherent (PDC < 80%) patients was different between cohorts. In adjusted analysis, high adherence was associated with a reduced risk of death [Hazard Ratio (HR): from 0.82 to 0.86] and (except in the PD cohort) the risk for ischemic stroke (HR: from 0.61 to 0.64) without increasing the risk of bleeding. Conclusion: Common approaches to assess adherence using measures based on days' supply exclude groups of non-adherent patients and, also, misattribute periods of doctors' discontinuation to patient non-adherence, misestimating adherence overall. Physician-initiated discontinuation is a major contributor to reduced OAC exposure. When using the PDC80 threshold, very different groups of patients may be classified as adherent or non-adherent depending on the method used for the calculation of days' supply measures. High adherence and high exposure to OAC treatment in NVAF patients is associated with better health outcomes.

Secondary adherence to non-vitamin-K antagonist oral anticoagulants in patients with atrial fibrillation in Sweden and the Netherlands

OBJECTIVE

There is limited evidence on patients' adherence and the impact of the prescribed dosing regimen in non-vitamin-K oral anticoagulants (NOACs). We aimed to assess secondary adherence to NOACs and to determine the impact of the dosing regimen in patients with atrial fibrillation.

METHODS

Patients using a NOAC between 2009 and 2013 were identified from the nation-wide Swedish Prescribed Drug Register and the Dutch regional IADB.nl database. Patients using a consistent dosage for at least 180 consecutive days were included. Adherence was calculated using the medication possession ratio (MPR) and adjusted for overlapping dates. Adherence was defined as a MPR ≥0.8. Sensitivity analyses were performed using a MPR ≥0.9. Logistic regression was performed to compare secondary adherence and to explore the influence of the dosing regimen.

RESULTS

A total of 5254 Swedish and 430 Dutch NOAC users were included. The mean MPR was 96.0% (SD 7.8%) in Sweden and 95.1% (SD 10.1%) in the Netherlands. Multivariable logistic regression analysis showed that a twice daily regimen had a lower likelihood of being secondary adherent compared to a once daily regimen in Sweden (odds ratio [OR] 0.21 [95% CI 0.12-0.35]).

LIMITATIONS

The influence of selection bias introduced by the inclusion criterion of ≥2 dispensations covering at least 180 days could not be excluded.

CONCLUSIONS

This study demonstrated that secondary adherence was high in this specific setting among patients with at least two initial dispensations of a NOAC covering a minimum of 180 days. The use of NOACs in a once daily regimen showed higher adherence compared to a twice daily regimen.

Dynamic patterns and predictors of hydroxychloroquine nonadherence among Medicaid beneficiaries with systemic lupus erythematosus

BACKGROUND

Hydroxychloroquine (HCQ) is the standard of care medication for most SLE patients, however nonadherence is common. We investigated longitudinal patterns and predictors of nonadherence to HCQ in a U.S. SLE cohort of HCQ initiators.

METHODS

We used Medicaid data from 28 states to identify adults 18-65 years with prevalent SLE. We included HCQ initiators following ≥6 months without use, and required ≥1 year of follow-up after first dispensing (index date). We used the proportion of days covered (PDC) to describe overall HCQ adherence (<80% = nonadherent) and novel group-based trajectory models (GBTM) to examine monthly patterns (<80% of days/month covered = nonadherent), during the first year of use. Multivariable multinomial logistic regression models were used to examine predictors of nonadherence.

RESULTS

We identified 10,406 HCQ initiators with SLE. Mean age was 38 (±12) years, 94% were female, 42% black, 31% white; 85% had a mean PDC < 80%. In our 4-group GBTM, 17% were persistent adherers, 36% persistent nonadherers, and 47% formed two dynamic patterns of partial adherence. Adherence declined for most patients over the first year. Compared to persistent adherers, the odds of nonadherence were increased for blacks and Hispanics vs. whites and for younger ages vs. older; increased SLE-related comorbidities were associated with reduced odds of nonadherence for persistent nonadherers (0.95, 95% CI: 0.91-0.99).

CONCLUSIONS

Among HCQ initiators with SLE, we observed poor adherence which declined for most over the first year of use. HCQ adherence is a dynamic behavior and further studies of associated predictors, outcomes, and interventions should reflect this.

Primary Nonadherence to Oral Anticoagulants in Patients with Atrial Fibrillation: Real-World Data from a Population-Based Cohort

BACKGROUND

Primary nonadherence (not filling a first prescription) is an important yet unstudied aspect of adherence to oral anticoagulant (OAC) therapy.

OBJECTIVE

To estimate the rates of primary nonadherence to OACs and determine associated factors in real-world practice.

METHODS

This population-based retrospective cohort study set in the Valencia region of Spain (about 5 million inhabitants) included all patients with atrial fibrillation who were newly prescribed OACs during 2011-2014 (N = 18,715). Primary nonadherence was obtained by linking electronic prescription and dispensing data and assessed by type of OAC-vitamin K antagonists (VKAs) or non-VKA oral anticoagulants (NOACs). Covariates were obtained from diverse databases, including electronic medical records. Multivariate logistic regression models were used to assess characteristics associated with primary nonadherence, adjusting for a propensity score to minimize confounding by indication.

RESULTS

Primary nonadherence to OACs was 5.62% (VKA 4.29% vs. NOAC 10.81%; P < 0.001), with varying rates among specific drugs (acenocoumarol 4.2%, warfarin 10.9%, apixaban 5.0%, dabigatran 7.9%, and rivaroxaban 15.5%). After adjusting for potential confounders, the likelihood of not filling the first prescription was higher for NOAC patients than for VKA patients (OR = 2.76, 95% CI = 2.41-3.15). High coinsurance in the older groups (OR = 2.63, 95% CI = 1.47-4.69 for patients aged 66-75 years and OR = 3.02, 95% CI = 1.58-5.76 for patients aged > 75 years); being a non-Spanish European (OR = 1.49, 95% CI = 1.12-1.99); and having dementia (OR = 1.72, 95% CI = 1.37-2.16) were positively associated with primary nonadherence. Electronic transmission of prescriptions (OR = 0.85, 95% CI = 0.74-0.96); liver disease (OR = 0.73, 95% CI = 0.54-0.99); and polypharmacy (OR = 0.59, 95% CI = 0.50-0.70) were inversely associated with primary nonadherence.

CONCLUSIONS

Overall, primary nonadherence to OACs was relatively low (5%). However, important differences were found between VKAs and NOACs. After adjustment, patients prescribed NOACs nearly tripled the likelihood of nonadherence compared with patients prescribed VKAs, which could negatively affect their effectiveness in clinical practice. Identified correlates were similar to those shown in the limited evidence for other medications.

DISCLOSURES

This work was partially supported by the 2013 Collaboration Agreement between the Fundación para el Fomento de la Investigación Sanitaria y Biomédica (FISABIO) from the Valencia Ministry of Health and Boehringer Ingelheim, a nonconditioned program to conduct independent research in chronic health care, pharmacoepidemiology, and medical practice variation. Rodriguez-Bernal was funded by the Instituto de Salud Carlos III, Spanish Ministry of Health, and cofinanced by the European Regional Development Fund (grant number RD12/0001/0005). The views presented here are those of the authors and not necessarily those of the FISABIO Foundation, the Valencia Ministry of Health, or the study sponsors. The funding sources had no access to study data and did not participate in any way in the design or conduct of the study, data analysis, decisions regarding the dissemination of findings, the development of the manuscript, or its publication. Peiró has received fees for participation in scientific meetings and courses sponsored by Novartis and Ferrer International. In 2014, Sanfélix-Gimeno participated in an advisory meeting of Boehringer Ingelheim. García-Sempere is a former employee of Boehringer Ingelheim. Rodriguez-Bernal and Hurtado have no relationships relevant to the contents of this article to disclose. This work was previously submitted as an abstract (podium presentation) at the 31st International Society of Pharmacoepidemiology (ISPE) Annual Conference; August 22-26, 2015; Boston, Massachusetts.