Assessing the risk of intentional self-harm in montelukast users: an updated Sentinel System analysis using ICD-10 coding

BACKGROUND

Montelukast prescribing information includes a Boxed Warning issued in March 2020 regarding neuropsychiatric adverse events. A previous Sentinel System study of asthma patients from 2000 to 2015 did not demonstrate an increased risk of intentional self-harm measured using the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) codes, with montelukast compared to inhaled corticosteroids (ICS).

METHODS

Using a new user cohort study design, we examined intentional self-harm events in patients aged 10 years and older who were incident users of either montelukast or ICS as monotherapy, with a diagnosis of asthma, between October 1, 2015, to June 30, 2022, in the Sentinel System. We measured intentional self-harm using ICD-10-CM codes, which may have better accuracy for capturing suicide attempts than ICD-9-CM codes. We used inverse probability of treatment weighting to balance baseline covariates. We performed subgroup analyses by age group, sex, psychiatric history, and pre/post Boxed Warning era and conducted sensitivity analyses varying type of care setting of the outcome and exposure episode gaps.

RESULTS

Among 752,230 and 724,855 patients in the montelukast and ICS exposure groups respectively, we found no association between montelukast use and self-harm compared to ICS use [Hazard Ratio (95% Confidence Interval): 0.96 (0.85, 1.08)]. This finding was consistent across all subgroups, and sensitivity analyses.

CONCLUSION

Our results cannot exclude other neuropsychiatric idiosyncratic reactions to montelukast. Compared to the previous Sentinel study, this study identified about double the rate of self-harm events, suggesting a greater sensitivity of ICD-10 codes for measuring self-harm than ICD-9.

Biosimilars approvals by thirteen regulatory authorities: A cross-national comparison

Biosimilars are biological medicines highly similar to a previously licensed reference product and their licensing is expected to improve access to biological therapies. This study aims to present an overview of biosimilars approval by thirteen regulatory authorities (RA). The study is a cross-national comparison of regulatory decisions involving biosimilars in Argentina, Australia, Brazil, Chile, Canada, Colombia, Europe, Hungary, Guatemala, Italy, Mexico, Peru and United States. We examined publicly available documents containing information regarding the approval of biosimilars and investigated the publication of public assessment reports for registration applications, guidelines for biosimilars licensing, and products approved. Data extraction was conducted by a network of researchers and regulatory experts. All the RA had issued guidance documents establishing the requirements for the licensing of biosimilars. However, only three RA had published public assessment reports for registration applications. In total, the investigated jurisdictions had from 19 to 78 biosimilars approved, most of them licensed from 2018 to 2020. In spite of the advance in the number of products in recent years, some challenges still persist. Limited access to information regarding the assessment of biosimilars by RA can affect confidence, which may ultimately impact adoption of these products in practice.

Identifying COVID-19 cases and extracting patient reported symptoms from Reddit using natural language processing

We used social media data from "covid19positive" subreddit, from 03/2020 to 03/2022 to identify COVID-19 cases and extract their reported symptoms automatically using natural language processing (NLP). We trained a Bidirectional Encoder Representations from Transformers classification model with chunking to identify COVID-19 cases; also, we developed a novel QuadArm model, which incorporates Question-answering, dual-corpus expansion, Adaptive rotation clustering, and mapping, to extract symptoms. Our classification model achieved a 91.2% accuracy for the early period (03/2020-05/2020) and was applied to the Delta (07/2021-09/2021) and Omicron (12/2021-03/2022) periods for case identification. We identified 310, 8794, and 12,094 COVID-positive authors in the three periods, respectively. The top five common symptoms extracted in the early period were coughing (57%), fever (55%), loss of sense of smell (41%), headache (40%), and sore throat (40%). During the Delta period, these symptoms remained as the top five symptoms with percent authors reporting symptoms reduced to half or fewer than the early period. During the Omicron period, loss of sense of smell was reported less while sore throat was reported more. Our study demonstrated that NLP can be used to identify COVID-19 cases accurately and extracted symptoms efficiently.

A collaborative study of the impact of N-nitrosamines presence and ARB recall on ARB utilization - results from IQVIA™ Disease Analyzer Germany

PURPOSE

Regulators are increasingly concerned with  the impact of recalls on drug adherence. In 2018, N-nitrosamines impurities were detected in valsartan containing medical products. Concerned products were immediately recalled in July 2018 by regulatory agencies internationally. In Germany, recalls were issued for valsartan, losartan and irbesartan from July 2018 to March 2019. This study examined angiotensin II receptor blocker (ARB) utilization trends and switching patterns in Germany before and after July 2018.

METHODS

Patients prescribed ARBs from January 2014 to June 2020 in general practices in Germany were included in a collaborative framework common protocol drug utilization study led by the US Food and Drug Administration. Trends in monthly and quarterly proportions of total ARB prescribing were analysed for individual ARBs using descriptive statistics and interrupted time series analysis. The rate of switching to an alternative ARB was analysed before and after the recalls.

RESULTS

The proportion of valsartan prescriptions immediately decreased from 35.9 to 17.8% following the first recalls in July 2018, mirrored by an increased proportion for candesartan. Increased switching from valsartan to candesartan was observed. No increased switching was observed after losartan recalls, whereas for irbesartan, increased switching was observed 6-12 months after the last recall. Increased switching from ARBs to angiotensin-converting enzyme (ACE) inhibitors or ARB treatment discontinuations were not observed.

CONCLUSION

This study showed that patients were able to continue ARB treatment despite the July 2018-March 2019 recalls, although many patients needed to switch to an alternative ARB. The duration of the impact of ARB recalls appeared to be limited.

Valsartan, Losartan and Irbesartan use in the USA, UK, Canada and Denmark after the nitrosamine recalls: a descriptive cohort study

OBJECTIVES

To examine valsartan, losartan and irbesartan usage and switching patterns in the USA, UK, Canada and Denmark before and after July 2018, when the first Angiotensin-Receptor-Blocker (ARB) (valsartan) was recalled.

DESIGN

Retrospective cohort study.

SETTING

USA, Canadian administrative healthcare data, Danish National Prescription Registry and UK primary care electronic health records.

PARTICIPANTS

Patients aged 18 years and older between January 2014 and December 2020.

INTERVENTION

Valsartan, losartan and irbesartan.

MAIN OUTCOME

Monthly percentages of individual ARB episodes, new users and switches to another ARB, ACE inhibitors (ACEI) or calcium channel blockers containing products.

RESULTS

We identified 10.8, 3.2, 1.8 and 1.2 million ARB users in the USA, UK, Canada and Denmark, respectively. Overall proportions of valsartan, losartan and irbesartan use were 18.4%, 67.9% and 5.2% in the USA; 3.1%, 48.3% and 10.2% in the UK, 16.3%, 11.4% and 18.3% in Canada, 1%, 93.5% and 0.6% in Denmark. In July 2018, we observed an immediate steep decline in the proportion of valsartan use in the USA and Canada. A similar trend was observed in Denmark; however, the decline was only minimal. We observed no change in trends of ARB use in the UK. Accompanying the valsartan decline was an increase in switching to other ARBs in the USA, Canada and Denmark. There was a small increase in switching to ACEI relative to the valsartan-to-other-ARBs switch. We also observed increased switching from other affected ARBs, losartan and irbesartan, to other ARBs throughout 2019, in the USA and Canada, although the usage trends in the USA remained unchanged.

CONCLUSION

The first recall notice for valsartan resulted in substantial decline in usage due to increased switching to other ARBs. Subsequent notices for losartan and irbesartan were also associated with increased switching around the time of the recall, however, overall usage trends remained unchanged.

Social media for early characterization of pandemic symptoms: A qualitative analysis of patient-reported COVID-19 experiences

BACKGROUND

Patients use social media forums to discuss their medical history and healthcare experiences, providing early insight into real-world patient experiences. We analyzed COVID-19 patient experiences from Reddit social media posts.

METHODS

We extracted Reddit Application Programming Interface data for the subreddit/COVID-19 positive from March to August 2020 and selected users tagged as "Tested Positive" or "Tested Positive- Me" flair and who posted at least thirty times in any calendar month, excluding users who explicitly stated location outside of the U.S. For tested-positive patients (users), we created and reviewed individual case profiles summarizing their COVID-19 symptoms, testing, and medications or treatments. Data were imported to Nvivo qualitative analysis software and qualitative coding was conducted.

FINDING

There were 31 759 posts and comments from 720 users in March to May 2020 (Q1) and 40 446 posts and comments from 1649 users from June to August 2020 (Q2). Final count of "Tested Positive" was 1296 users (280 in Q1 and 1016 in Q2). Across both quarters, frequently reported symptoms included sore throat, headaches, fevers, or chills. Loss of sense of smell or taste were reported by users in early March, prior to the inclusion of this symptom to the CDC list in April and GI-related symptoms and fatigue were reported in the March to May data, before they were added as a COVID-19 associated symptom in July 2020. Users also reported in-depth descriptions of their symptoms, motivations for testing, and long-term impacts such as post-viral fatigue.

INTERPRETATION

Social media data can potentially serve as an early surveillance data source in a pandemic and offer preliminary insights into patient disease experiences.

Comparative Risk of Angioedema With Sacubitril-Valsartan vs Renin-Angiotensin-Aldosterone Inhibitors

BACKGROUND

Data on angioedema risk among sacubitril-valsartan (SV) users in real-world settings are limited.

OBJECTIVES

We sought to evaluate the risk of angioedema among SV new users compared with angiotensin-converting enzyme (ACE) inhibitor and angiotensin-receptor-blocker (ARB) new users separately.

METHODS

We conducted a propensity score-matched cohort study, comparing SV new users (no use of SV, ACE inhibitor, ARB 6 months before) and SV new users with prior use (within 183 or 14 days) of ACE inhibitor or ARB (ACE inhibitor-SV and ARB-SV users; recent ACE inhibitor-SV and recent ARB-SV users, respectively) vs ACE inhibitor and ARB new users separately.

RESULTS

Compared with ACE inhibitor, SV new (HR: 0.18; 95% CI: 0.11-0.29) and ACE inhibitor-SV users (HR: 0.31; 95% CI: 0.23-0.43) showed lower risk of angioedema. On the other hand, there was no difference in angioedema risk when SV new users (HR: 0.59; 95% CI: 0.35-1.01) or ARB-SV users (HR: 0.85; 95% CI: 0.58-1.26) were compared with ARB new users. Compared with SV new users, ACE inhibitor-SV users (HR: 1.62; 95% CI: 0.91-2.89) trended toward higher angioedema risk, which intensified when the ACE inhibitor to SV switch occurred within 14 days (recent ACE inhibitor-SV) (HR: 1.98; 95% CI: 1.11-3.53). Similarly, ARB-SV users (HR: 2.03; 95% CI: 1.16-3.54) experienced an increased risk compared with SV new users, which intensified for the more recent switchers (recent ARB-SV) (HR: 2.45; 95% CI: 1.36-4.43).

CONCLUSIONS

We did not observe an increased risk of angioedema among SV new users compared with ACE inhibitor or ARB users. However, there was an increased risk of angioedema among SV users who recently switched from ACE inhibitor or ARB compared with SV new users.

A cohort study to assess risk of cutaneous small vessel vasculitis among users of different oral anticoagulants

PURPOSE

Cutaneous small vessel vasculitis (CSVV) was identified as a safety signal among patients treated with direct oral anticoagulants (DOAC). This study aimed to determine if CSVV risk differed among patients with atrial fibrillation (Afib) who newly initiated warfarin or a DOAC.

METHODS

We identified enrollees aged ≥21 years diagnosed with Afib who newly initiated rivaroxaban, dabigatran, apixaban, and warfarin in the Sentinel Distributed Database from October 19, 2010 to February 29, 2020. We selected and followed patients who did not have evidence of the following in the 183 days prior to initiating treatment: CSVV diagnosis, dispensing of other study drugs, select autoimmune diseases or autoimmune medications, cancer diagnoses or chemotherapeutic treatment, kidney dialysis or transplant, alternative anticoagulation indications, or an institutional (nursing home, hospice, hospital) stay on the treatment initiation date (index date) until CSVV outcome or pre-specified censoring. We conducted 1:1 propensity score matching in six comparisons.

RESULTS

CSVV incidence rates for DOACs and warfarin ranged from 3.3 to 5.6 per 10 000-person years in our matched Afib population. The adjusted CSVV hazard ratio (HR) and 95% confidence interval (CI) was 0.94 (0.64, 1.39) for rivaroxaban versus warfarin; 1.17 (0.67, 2.06) for dabigatran vs. warfarin; 0.85 (0.62, 1.16) for apixaban vs. warfarin; 0.86 (0.49, 1.50) for rivaroxaban vs. dabigatran; 0.99 (0.68, 1.45) for rivaroxaban versus apixaban; and 1.70 (0.90, 3.21) for dabigatran versus apixaban.

CONCLUSION

We did not find significant evidence of differential CSVV risk in pair-wise comparisons of DOACs and warfarin.

Risk of Covid-19-Related Hospitalization and More Severe Outcomes in Medicare Beneficiaries Treated with Renin-Angiotensin-Aldosterone System Inhibitors for Hypertension

BACKGROUND

There are theoretical concerns that angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) could increase the risk of severe Covid-19.

OBJECTIVE

To determine if ACEIs and ARBs are associated with an increased risk of Covid-19 hospitalization overall, or hospitalization involving intensive care unit (ICU) admission, invasive mechanical ventilation, or death.

DESIGN

Observational case-control study.

PARTICIPANTS

Medicare beneficiaries aged ≥ 66 years with hypertension, treated with ACEIs, ARBs, calcium channel blockers (CCBs), or thiazide diuretics.

MAIN MEASURES

Adjusted odds ratios (OR) and 95% confidence intervals (CI) for the outcomes of Covid-19 hospitalization, or hospitalization involving ICU admission, invasive mechanical ventilation, or death.

RESULTS

A total of 35,300 cases of hospitalized Covid-19 were matched to 228,228 controls on calendar date and neighborhood of residence. The median age of cases was 79 years, 57.4% were female, and the median duration of hospitalization was 8 days (interquartile range 5-12). ACEIs and ARBs were associated with a slight reduction in Covid-19 hospitalization risk compared with treatment with other first-line antihypertensives (OR for ACEIs 0.95, 95% CI 0.92-0.98; OR for ARBs 0.94, 95% CI 0.90-0.97). Similar results were obtained for hospitalizations involving ICU admission, invasive mechanical ventilation, or death. There were no meaningful differences in risk for ACEIs compared with ARBs. In an analysis restricted to monotherapy with a first-line agent, CCBs were associated with a small increased risk of Covid-19 hospitalization compared with ACEIs (OR 1.09, 95% CI 1.04-1.14), ARBs (OR 1.10, 95% CI 1.05-1.15), or thiazide diuretics (OR 1.11, 95% CI 1.03-1.19).

CONCLUSIONS

ACEIs and ARBs were not associated with an increased risk of Covid-19 hospitalization or with hospitalization involving ICU admission, invasive mechanical ventilation, or death. The finding of a small increased risk of Covid-19 hospitalization with CCBs was unexpected and could be due to residual confounding.

A General Propensity Score for Signal Identification Using Tree-Based Scan Statistics

The tree-based scan statistic (TreeScan; Martin Kulldorff, Harvard Medical School, Boston, Massachusetts) is a data-mining method that adjusts for multiple testing of correlated hypotheses when screening thousands of potential adverse events for signal identification. Simulation has demonstrated the promise of TreeScan with a propensity score (PS)-matched cohort design. However, it is unclear which variables to include in a PS for applied signal identification studies to simultaneously adjust for confounding across potential outcomes. We selected 4 pairs of medications with well-understood safety profiles. For each pair, we evaluated 5 candidate PSs with different combinations of 1) predefined general covariates (comorbidity, frailty, utilization), 2) empirically selected (data-driven) covariates, and 3) covariates tailored to the drug pair. For each pair, statistical alerting patterns were similar with alternative PSs (≤11 alerts in 7,996 outcomes scanned). Inclusion of covariates tailored to exposure did not appreciably affect screening results. Inclusion of empirically selected covariates can provide better proxy coverage for confounders but can also decrease statistical power. Unlike tailored covariates, empirical and predefined general covariates can be applied "out of the box" for signal identification. The choice of PS depends on the level of concern about residual confounding versus loss of power. Potential signals should be followed by pharmacoepidemiologic assessment where confounding control is tailored to the specific outcome(s) under investigation.

Risk of Severe Abnormal Uterine Bleeding Associated with Rivaroxaban Compared with Apixaban, Dabigatran and Warfarin

INTRODUCTION

There have been reports of clinically relevant uterine bleeding events among women of reproductive age exposed to rivaroxaban.

OBJECTIVE

The aim of this study was to compare the risk of severe abnormal uterine bleeding (SAUB) resulting in transfusion or surgical intervention among women on rivaroxaban versus apixaban, dabigatran and warfarin.

METHODS

We conducted a retrospective cohort study in the FDA's Sentinel System (10/2010-09/2015) among females aged 18+ years with venous thromboembolism (VTE), or atrial flutter/fibrillation (AF) who newly initiated a direct oral anticoagulant (DOAC; rivaroxaban, apixaban, dabigatran) or warfarin. We followed women from dispensing date until the earliest of transfusion or surgery following vaginal bleeding, disenrollment, exposure or study end date, or recorded death. We estimated hazard ratios (HRs) using Cox proportional hazards regression via propensity score stratification. Four pairwise comparisons were conducted for each intervention.

RESULTS

Overall, there was an increased risk of surgical intervention with rivaroxaban when compared with dabigatran (HR 1.19; 95% CI 1.03-1.38), apixaban (1.23; 1.04-1.47), and warfarin (1.34; 1.22-1.47). No difference in risk for surgical intervention was observed for dabigatran-apixaban comparisons. Increased risk of transfusion was observed for rivaroxaban compared with dabigatran (1.49; 1.03-2.17) only. For patients with no gynecological history, rivaroxaban was associated with risk of surgical intervention compared with dabigatran (1.22; 1.05-1.42), apixaban (1.25; 1.04-1.49), and warfarin (1.36; 1.23-1.50).

CONCLUSION

Our study found increased SAUB risk with rivaroxaban use compared with other DOACs or warfarin. Increased risk with rivaroxaban was present among women without underlying gynecological conditions. Women on anticoagulant therapy should be aware of a risk of SAUB.

Risk of Nonmelanoma Skin Cancer in Association With Use of Hydrochlorothiazide-Containing Products in the United States

Background

European studies reported an increased risk of nonmelanoma skin cancer associated with hydrochlorothiazide (HCTZ)-containing products. We examined the risks of basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) associated with HCTZ compared with angiotensin-converting enzyme inhibitors (ACEIs) in a US population.

Methods

We conducted a retrospective cohort study in the US Food and Drug Administration's Sentinel System. From the date of HCTZ or ACEI dispensing, patients were followed until a SCC or BCC diagnosis requiring excision or topical chemotherapy treatment on or within 30 days after the diagnosis date or a censoring event. Using Cox proportional hazards regression models, we estimated the hazard ratios (HRs), overall and separately by age, sex, and race. We also examined site- and age-adjusted incidence rate ratios (IRRs) by cumulative HCTZ dose within the matched cohort.

Results

Among 5.2 million propensity-score matched HCTZ and ACEI users, the incidence rate (per 1000 person-years) of BCC was 2.78 and 2.82, respectively, and 1.66 and 1.60 for SCC. Overall, there was no difference in risk between HCTZ and ACEIs for BCC (HR = 0.99, 95% confidence interval [CI] = 0.97 to 1.00), but there was an increased risk for SCC (HR = 1.04, 95% CI = 1.02 to 1.06). HCTZ use was associated with higher risks of BCC (HR = 1.09, 95% CI = 1.07 to 1.11) and SCC (HR = 1.15, 95% CI = 1.12 to 1.17) among Caucasians. Cumulative HCTZ dose of 50 000 mg or more was associated with an increased risk of SCC in the overall population (IRR = 1.19, 95% CI = 1.05 to 1.35) and among Caucasians (IRR = 1.27, 95% CI = 1.10 to 1.47).

Conclusions

Among Caucasians, we identified small increased risks of BCC and SCC with HCTZ compared with ACEI. Appropriate risk mitigation strategies should be taken while using HCTZ.

A Boxed Warning for Montelukast: The FDA Perspective

The U.S. Food and Drug Administration (FDA) became aware of postmarketing reports of neuropsychiatric adverse events with Singulair (montelukast) use in 2007. Over the years, the FDA has conducted reviews of the clinical trial safety data, focused analyses of postmarketing reports, and reviews of the published literature. These activities have resulted in successive labeling updates and public communications. However, there has been continued concern among stakeholders about the risk of neuropsychiatric events and the lack of awareness among prescribers and patients/caregivers. On the basis of these concerns, the FDA embarked on another comprehensive review and also conducted a new observational study using claims data in the Sentinel Distributed Database. In September 2019, the FDA held a public Advisory Committee meeting to discuss its review and solicit recommendations from the panel regarding labeling and communication strategies. After careful consideration of the available data and feedback received during the FDA Advisory Committee meeting, the FDA required a boxed warning and a revision specifically for the allergic rhinitis indication to reserve use of montelukast to patients who have an inadequate response or intolerance to alternative therapies. Based on benefit-risk considerations, the asthma indication was not changed. To provide insight into the process and rationale for the required labeling changes, we provide an overview of the decision-making framework we used.

Risk of serious spinal adverse events associated with epidural corticosteroid injections in the Medicare population

BACKGROUND

Epidural corticosteroid injections (ESIs) are widely performed and have an unquantified risk of serious spinal adverse events (SSAEs). We sought to determine the rate of SSAEs following ESI and to compare the rates by spinal level, injection approach and corticosteroid formulation.

METHODS

We included patients enrolled in Medicare parts A and B who had an ESI between 1 January 2009 and 30 September 2015. We identified potential cases as patients with spine-related diagnoses within 3 days after the first eligible ESI. Event categorization as probable, possible or non-case was based on review of medical records. The rates of probable and possible cases were expressed per 1 000 000 patients overall, and by spinal level, injection approach and corticosteroid formulation. A score test was used to compare these rates.

RESULTS

We identified 1 355 957 eligible ESIs during the study period. Of the 110 potential cases, 43 were selected for medical record review and 11 were categorized as probable, yielding a rate of 8.1 per 1 000 000 patients (95% CI 4.5 to 14.5). Risk of SSAEs was statistically higher with cervical/thoracic injections (29.4, 95% CI 12.5 to 68.8) compared with lumbar/sacral injections (5.1, 95% CI 2.3 to 11.0) (p value 0.001). Event rates for lumbar/sacral non-transforaminal injections was 8.8 (95% CI 4.0 to 19.1). Event rates for particulate (7.5, 95% CI 3.9 to 14.2) and non-particulate formulations (13.1, 95% CI 3.6 to 47.9) appeared similar (p value 0.47).

CONCLUSION

Between 2009 and 2015, rates of SSAEs following ESI in the Medicare population were low. Patients receiving cervical/thoracic ESIs were at higher risk of SSAE than those receiving lumbar/sacral ESIs. Event rates were similar for each corticosteroid formulation.

Risk of Stroke and Bleeding in Atrial Fibrillation Treated with Apixaban Compared with Warfarin

BACKGROUND

A previous FDA study reported a favorable benefit risk for apixaban compared with warfarin for stroke prevention in older non-valvular atrial fibrillation (NVAF) patients (≥ 65 years). However, it remains unclear whether this favorable benefit risk persists in other populations including younger users. We examined if a similar benefit risk was observed in the Sentinel System and if it varied by age group.

OBJECTIVE

To examine the risk of ischemic stroke, gastrointestinal (GI) bleeding, and intracranial hemorrhage (ICH) in apixaban users compared with warfarin users in Sentinel Distributed Database (SDD).

DESIGN AND PARTICIPANTS

A retrospective new user cohort study was conducted among patients, 21 years and older initiating apixaban and warfarin for NVAF, between December 28, 2012, and June 30, 2018, in the SDD.

MAIN MEASURES

Cox proportional hazard regression was used to estimate the hazard ratios (HR) and 95% confidence intervals (95% CI) for each outcome (ischemic stroke, GI bleeding, and ICH) in propensity score matched apixaban users compared with the warfarin users. Subgroup analyses by age (21-64, 65-74, and 75+ years) were conducted.

KEY RESULTS

After matching, 55.3% and 58.4% (n = 55,038) of the apixaban and warfarin users were included in the main analysis. GI bleeding was the most common outcome. The HR (95% CI) for GI bleeding, ICH, and ischemic stroke in apixaban users compared with warfarin users were 0.57 (0.50-0.66), 0.53 (0.40-0.70), and 0.56 (0.45-0.71) respectively. The reduced risk of these outcomes in apixaban compared with warfarin users persisted across age groups.

CONCLUSION

In NVAF patients of all ages initiating either apixaban or warfarin for stroke prevention in the Sentinel System, apixaban was associated with a decreased risk of GI bleeding, ICH, and ischemic stroke compared with warfarin. Among patients less than 65 years of age, apixaban use was associated with a decreased risk of GI bleeding and ischemic stroke.

Complementary Use of U.S. FDA's Adverse Event Reporting System and Sentinel System to Characterize Direct Oral Anticoagulants-Associated Cutaneous Small Vessel Vasculitis

BACKGROUND

Cutaneous small vessel vasculitis (CSVV) has been reported after exposure to direct oral anticoagulants (DOACs), such as dabigatran, rivaroxaban, apixaban, and edoxaban.

OBJECTIVE

We used the U.S. Food and Drug Administration Adverse Event Reporting System (FAERS) to describe clinical characteristics associated with CSVV among DOAC-exposed patients. Furthermore, we characterized this signal in the Sentinel System to relate the clinical data from the individual FAERS cases to population-based electronic healthcare data.

METHODS

We queried FAERS for all cases of CSVV associated with DOACs from U.S. approval date of each DOAC through March 16, 2018. Within the Sentinel System, we identified incident CSVV cases using ICD-9 and ICD-10 diagnosis codes among adults aged ≥ 30 years who received a DOAC in the prior 90 days between January 1, 2010, and June 30, 2018. We excluded patients with evidence of select autoimmune diagnoses in the 183 days prior to their CSVV diagnoses and reported patient characteristics in the 183-day period prior to CSVV diagnoses.

RESULTS

In FAERS, we identified 50 cases of CSVV reported with rivaroxaban (n=26), apixaban (n=14), dabigatran (n=9), and edoxaban (n=1). Approximately 50% of the cases reported time to onset within 10 days after DOAC exposure. When specified, the predominant type of CSVV reported was leukocytoclastic vasculitis (n=31), followed by Henoch-Schonlein purpura (n=4). Hospitalization occurred in most of the cases (n=37). Switching of the offending agent after the development of CSVV was reported (n=26). Three rivaroxaban (n=3) cases and one dabigatran case (n=1) reported positive rechallenge. In the Sentinel system, we identified 3659 CSVV cases with prior DOAC exposure, with 85% of events occurring within 10 days.

CONCLUSIONS

The assessment of FAERS cases, combined with the temporal clustering of the Sentinel System cases suggest a possible causal relationship of DOACs and CSVV. Future efforts should characterize the risk of CSVV among the various DOAC users.

Development of an algorithm to detect methotrexate wrong frequency error using computerized health care data

PURPOSE

We validated an algorithm to detect frequency errors in computerized healthcare data and estimated the incidence of these errors in an integrated healthcare system.

METHODS

We applied Sentinel System analytic tools on the electronic health records of Kaiser Permanente, Northern California, January 1, 2010, through May 30, 2015,to identify rheumatoid arthritis (RA) patients with new use of methotrexate (365-day baseline period). We identified potential methotrexate frequency errors using ICD-9 code 995.20 (adverse drug event), Current Procedural Terminology (CPT) code 96409 for injection of leucovorin and prescription refill patterns. We performed chart review to confirm the frequency errors, assessed performance for detecting frequency errors, and estimated the incidence of chart-confirmed errors.

RESULTS

The study included 24,529 methotrexate dispensings among 3,668 RA patients. Among these, 722 (3%) had one dispensing and 23,807 (97.1%) had ≥2 dispensings during 1-year follow-up period. We flagged 653 (2.7%) with a potential medication error (46 with one dispensing and 607 with ≥2 dispensings). We sampled 94 for chart review, and confirmed three methotrexate errors. All three confirmed frequency errors involved a first methotrexate dispensing followed by injected rescue therapy, leucovorin, (positive predictive value, 60%; 95% confidence interval [CI], 15-95%). No potential errors were found among patients with ≥2 dispensings. We estimated the frequency error incidence among one methotrexate dispensing to be 0.4% (95%CI, 0.1% to 1.2%).

CONCLUSION

Rescue therapy is a specific indicator of methotrexate overdose among first methotrexate dispensings. This method is generalizable to other medications with serious adverse events treated with antidotes.

Use of tumor necrosis factor-alpha inhibitors during pregnancy among women who delivered live born infants

PURPOSE

To describe the use of tumor necrosis factor-alpha inhibitors (TNFis) among pregnancies ending in a live birth and with a diagnosis of ankylosing spondylitis (AS), Crohn's disease (CD), juvenile idiopathic arthritis (JIA), psoriasis (PsO), psoriatic arthritis (PsA), rheumatoid arthritis (RA), or ulcerative colitis (UC).

METHODS

We identified pregnancies among women aged 15 to 54 years between 01/01/2004 and 09/30/2015 from 16 health plans participating in Sentinel. We inferred indication using ICD-9-CM codes in the 183-day period before conception. We assessed proportion of infliximab, etanercept, adalimumab, certolizumab pegol, and golimumab by calendar year, indication, and maternal age, and compared them to proportions in an age-matched, indication-matched, and date-matched non-pregnant cohort.

RESULTS

Among 19 681 pregnancies with at least one chronic inflammatory condition, 2990 (15.2%) received a TNFi. In both pregnancies and matched non-pregnant cohort, TNFi use was highest (34.4%; 55.8%) for PsA patients and lowest (6.2%; 13.4%) for PsO patients. Etanercept was most frequently used among AS/JIA/PsA/PsO/RA patients, while infliximab was the preferred TNFi for CD/UC patients. Except for infliximab and certolizumab, TNFi use during pregnancy decreased after the first trimester. Pregnancies among older pregnant women (45-54 years) were more likely to be treated compared with the matched non-pregnant cohort.

CONCLUSION

There was a preference for etanercept among pregnancies with AS/JIA/PsA/PsO/RA, despite the availability of other TNFis. Decline in TNFi use after the first trimester may be related to the desire to reduce TNFis transplacental transfer and to minimize infection risk to the fetus or baby associated with live vaccine immunizations after birth.

Concomitant use of buprenorphine for medication-assisted treatment of opioid use disorder and benzodiazepines: Using the prescription behavior surveillance system

BACKGROUND

Despite clinical guidelines discouraging the practice, it is well-documented that the concomitant use of benzodiazepines and opioid analgesics occurs regularly. Information on concomitant use of buprenorphine for medication-assisted treatment (MAT) of opioid use disorder (OUD) and benzodiazepines, however, is limited. Thus, we aimed to describe real-world drug dispensing patterns for the concomitant use of buprenorphine products approved for MAT and benzodiazepines.

METHODS

We examined concomitant use of buprenorphine for MAT and benzodiazepines using the 2013 Prescription Behavior Surveillance System data from eight states. For prescription-level analysis, we estimated the proportion of concomitant buprenorphine and benzodiazepine prescriptions and the proportions of concomitant prescriptions prescribed by the same provider (co-prescribing) and dispensed by the same pharmacy (co-dispensing) for each state. For patient-level analysis, we calculated the proportion of patients with ≥1 buprenorphine therapy episode overlapping with a benzodiazepine episode, i.e., concomitant users, and the proportion of concomitant users who experienced co-prescribing or co-dispensing.

RESULTS

In 2013, 1,925,072 prescriptions of buprenorphine products for MAT were dispensed to 190,907 patients in eight states. Approximately 1 in 8 buprenorphine prescriptions was used concomitantly with ≥1 benzodiazepine prescription(s). Co-prescribing proportions ranged from 22.2 to 64.6% across states, while co-dispensing proportions ranged from 54.7 to 91.0%. Approximately 17.7% of patients had >1 buprenorphine episode overlapping a benzodiazepine episode for ≥7 cumulative days' supply. Among these patients, 33.1-65.2% experienced co-prescribing, and 65.1-93.3% experienced co-dispensing.

CONCLUSIONS

The concomitant use of buprenorphine for MAT and benzodiazepines occurs frequently, with variations by state in co-prescribing and co-dispensing.

Bone mineral density testing, and bisphosphonate and oestrogen prescribing associated with depot medroxyprogesterone acetate utilization-The impact of the boxed warning

WHAT IS KNOWN AND OBJECTIVE

Depot medroxyprogesterone acetate (DMPA) prevents follicular maturation and ovulation, resulting in oestrogen deficiency. Oestrogen deficiency is particularly concerning as it is associated with decreases in bone mineral density (BMD) or bone mass. Widespread use of concurrent oestrogen or bisphosphonates with DMPA has been observed in a previous single-centre US study. The authors also reported that more than half of obstetrician-gynaecologists ordered BMD testing solely due to DMPA. The small sample size of the survey, potential for volunteer bias and recall bias limit the utility of this study. Given the study limitations, we sought to examine the trends of concurrent bone mineral density (BMD) testing, and bisphosphonate (BPA) and oral oestrogen-only (EST) prescribing during depot medroxyprogesterone (DMPA) use in a large administrative database.

METHODS

From IMS Health LifeLink™ database (2001-2013), we identified DMPA and combined hormonal contraceptive (CHC) users as women with no contraceptive claim 6 months before and after the defined episode. We examined concurrent use as the proportion of BPA or EST claims and concurrent therapy days during contraception use. We also determined the proportion of users who had a concurrent BMD test by calendar year.

RESULTS

We identified 203 477 DMPA episodes associated with 600 BPA and 7060 EST claims and 1 297 806 CHC episodes associated with 2792 BPA and 145 600 EST claims. Most concurrent BPA use overlapped with 10% or less of the DMPA episode, whereas most concurrent BPA use overlapped with >90%-100% of CHC episode. No difference was noted with concurrent EST use. Concurrent BMD testing was higher among DMPA users (0.68%) compared to CHC users (0.11%). Across calendar year, BMD testing peaked in 2004 and declined steadily to the baseline. Most DMPA concurrent BPA (69.3%) users had a BMD test.

CONCLUSION

Our findings indicate the absence of BST or EST use solely due to DMPA initiation and present alternative explanations. Published research and publicity leading to the final implementation of the boxed warning in 2004 may explain observed trends for BMD testing. The majority of patients who had a BMD test ordered were also receiving bisphosphonates, suggesting high-risk fracture status or appropriate monitoring.

What explains the different rates of human papillomavirus vaccination among adolescent males and females in the United States?

PURPOSE

To identify factors that explain differences in HPV vaccination rates for male and female adolescents and to determine self-reported barriers by parents affecting vaccination decisions.

METHODS

The sample included adolescents 13-17 years old with a vaccination record documented in the 2012 and 2013 National Immunization Survey-Teen dataset. A logistic regression model was developed with 13 socio-demographic factors and survey year, along with significant interaction pairs with gender.

RESULTS

Subjects included 20,355 and 18,350 adolescent boys and girls, respectively. About half of the females (56%) received at least one dose of HPV vaccine, compared to 28% of males. Several factors differed between males and females, including higher vaccination rates among non-Hispanic Black males and lower vaccination rates for non-Hispanic Black females compared to Whites; and a stronger association with health care provider recommendation among males. The most common parental reasons for not vaccinating their children included 'not recommended by a health care provider' for males (24%), and 'unnecessary' for females (18%).

CONCLUSION

We found a significant gender interaction with several socio-demographic variables in predicting vaccination uptake. These gender differences may be partially an artifact of timing, because male vaccination became routine approximately five years after female vaccination.

Palivizumab immunoprophylaxis effectiveness in children with cystic fibrosis

BACKGROUND

Evidence on the effectiveness of respiratory syncytial virus (RSV) immunoprophylaxis with palivizumab in children with cystic fibrosis (CF) is lacking.

METHODS

We utilized Medicaid Extract files from 27 states from 1999 to 2006 linked to the National Cystic Fibrosis Registry to establish a cohort of children 0-2 years with CF diagnosis. Eligible children entered the cohort after CF diagnosis and after RSV season onset, and were followed until season end, second birthday, death, or hospitalizations for reasons other then the study outcome. Two outcomes were examined: hospitalization for RSV infections (RSV-ha), or hospitalization for acute respiratory infections (ARI-ha). Palivizumab exposure was defined based on pharmacy or procedure claims as current (claim date plus 30 days), former (day 31-60 after a claim), and no exposure (days before the first or >60 days after any claim). Both outcomes were examined in a Cox regression model, adjusting for RSV risk factors and CF severity via exposure propensity score.

RESULTS

The matched cohort included 1,974 infants (2,875 infant seasons), who experienced 32 RSV-ha and 212 ARI-ha (3.9 and 26.2/1,000 season months, respectively). Compared to periods of no use, the adjusted hazard ratio for current use was 0.57 (95% confidence interval [CI]: 0.20-1.60) for RSV-related hospitalization and 0.85 (95% CI: 0.59-1.21) for ARI-related hospitalization. Each month of increasing age reduced the ARI-ha by 5.8%.

CONCLUSION

RSV hospitalization incidence was low suggesting either little contribution of the virus to respiratory infections in patients with CF or lack of RSV testing. Unadjusted and adjusted RSV-hospitalization incidence rates suggested potentially positive effects of palivizumab, but results were inconclusive due to small event rates. Hospitalizations for acute respiratory illness with possible RSV contribution showed no association with palivizumab use, suggesting limited overall effect of palivizumab. Younger age greatly increased infection risk.