In recent years, there has been increased interest in symbolic data analysis, including for exploratory analysis, supervised and unsupervised learning, time series analysis, etc. Traditional ...statistical approaches that are designed to analyze single‐valued data are not suitable because they cannot incorporate the additional information on data structure available in symbolic data, and thus new techniques have been proposed for symbolic data to bridge this gap. In this article, we develop a regularized convex clustering approach for grouping histogram‐valued data. The convex clustering is a relaxation of hierarchical clustering methods, where prototypes are grouped by having exactly the same value in each group via penalization of parameters. We apply two different distance metrics to measure (dis)similarity between histograms. Various numerical examples confirm that the proposed method shows better performance than other competitors.
•In January 2012, carisoprodol became a Schedule IV controlled substance in the US.•Two years after the federal scheduling, its dispensing decreased by about 20%.•This effect was not modified by the ...existing state-level scheduling status.•The decrease was most pronounced among younger patients and patients with injury.
In January 2012, the Drug Enforcement Agency (DEA) classified carisoprodol as a Schedule IV controlled substance at the US federal level. We aimed to examine the effect of this policy on the use of carisoprodol in a commercially-insured population.
This interrupted time series study included individuals with musculoskeletal disorders in the IBM MarketScan Commercial Database between December 2009 and February 2014. We used comparative segmented linear regression to assess changes in the proportions of patients who filled/newly filled carisoprodol each month.
A total of 13.3 million patients were included. 29 states with no scheduling prior to the DEA classification had lower baseline prevalence of carisoprodol use compared to 17 states that had scheduled carisoprodol individually before 2010 (11.0 vs. 21.1 patients with fills per 1000 patients). The federal scheduling was associated with an immediate decline (–1.12 per 1000 patients, p < 0.01) and decreasing trend in prevalence (–0.07 per 1000 patients per month, p = 0.02). This effect was not modified by existing state-level scheduling status. During the first, second, third, and fourth 6-month periods after federal scheduling, the relative difference between observed and predicted prevalence was 7.8%, 10.5%, 13.4%, and 19.8%. Similar patterns were observed for carisoprodol initiation. Overall, declining use was more pronounced among younger age groups and patients with injury.
Schedule IV controlled substance classification at the federal level was associated with a moderate reduction in the dispensing of carisoprodol regardless of whether scheduling was already present at the state level.
To evaluate the impact of the 12 January 2010 earthquake on HIV cases from Haiti's national HIV surveillance system and assess the characteristics of people living with HIV 1-year before and after ...the earthquake.
An interrupted time-series design and cross-sectional analysis.
We used autoregressive integrated moving average structures to model abrupt changes to the monthly, incident HIV case counts from HIV care clinics as reported to the Haitian Active Longitudinal Tracking of HIV System (French acronym SALVH) by clinical networks (n = 3) and earthquake instrumental intensity zones (n = 4). Preearthquake and postearthquake differences in patient-level characteristics including clinical values were examined using the χ test, t tests, Wilcoxon rank-sum test.
In the month immediately following the earthquake, all three clinical networks experienced statistically significant declines in cases reported: iSanté (-31.4%), Groupe Haïtien d'Etude du Sarcome de Kaposi et des Infections Opportunistes (-29.9%) and Zamni Lasante (-32.2%). Zone 8 (the most severe) was the only area with a statistically significant decline (-45.5%). Of the three clinical networks, only iSanté returned to preearthquake reporting levels by the end of our study period. Patient-level characteristics did not change dramatically after the earthquake.
Despite case reporting declines, especially in clinics near the earthquake epicenter, SALVH remained intact with less impact than expected. This national system is a critical component of Haiti's strategic health information system initiative and plays a central role to HIV monitoring and evaluation efforts.
Purpose
The opioid crisis remains a major public health concern in the United States. Naloxone is used to reverse opioid overdoses. This study examined Medicaid expansion on naloxone prescriptions in ...retail pharmacies in metropolitan (metro) and nonmetropolitan (nonmetro) areas (2011‐2017).
Methods
We used population average models to evaluate the association of Medicaid expansion at the state level on the number of naloxone prescriptions dispensed and the percentage paid by Medicaid, including adjustment for opioid‐related and state‐level policy covariates. Difference‐in‐difference modeling was performed as a sensitivity analysis.
Findings
States that expanded Medicaid had higher unadjusted naloxone dispensing rates and Medicaid‐paid percentage of naloxone in metro and nonmetro areas. Medicaid expansion was not associated with the number of naloxone dispensed in either metro (adjusted rate ratio (ARR) = 1.26, 95% CI: 0.80, 1.97) or nonmetro (ARR = 0.67, 95% CI: 0.37, 1.19) areas after covariate adjustment. In metro areas, Medicaid expansion was associated with a significant increase of 3.86 percentage points (95% CI: 0.09, 7.63) in the Medicaid‐paid percentage of naloxone dispensing compared to nonexpansion states, but this association was not significant in nonmetro areas. There was also a significant time by Medicaid expansion interaction on the Medicaid‐paid percentage of naloxone dispensed (metro: estimate = 0.74, 95% CI: 0.36, 1.12; nonmetro: estimate = 0.68, 95% CI: 0.17, 1.18).
Conclusions
Medicaid expansion increased naloxone access by increasing the Medicaid‐paid percentage of naloxone prescriptions in metro areas. States with Medicaid expansion had a faster rate of increase in the Medicaid‐paid percentage of naloxone than states without Medicaid expansion in nonmetro areas.
The persistence of the nation’s opioid epidemic has called on criminal justice and public health agencies to collaborate more than ever. This epidemiological criminology framework highlights the ...surveillance of public health and safety, often using data science approaches, to inform best practices. The purpose of our article is to delineate the main benefits and challenges of adopting data science approaches for epidemiological criminology partnerships, research, and policy. We offer “lessons learned” from our opioid research in Delaware and Florida to advise future researchers, especially those working closely with policymakers and practitioners in translating science into impactful best practices. We begin with a description of our projects, pivot to the challenges we have faced in contributing to science and policy, and close with recommendations for future research, public advocacy, and practice.
Purpose
In drug studies, research designs requiring no prior exposure to certain drug classes may restrict important populations. Since abuse‐deterrent formulations (ADF) of opioids are routinely ...prescribed after other opioids, choice of study design, identification of appropriate comparators, and addressing confounding by “indication” are important considerations in ADF post‐marketing studies.
Methods
In a retrospective cohort study using claims data (2006–2018) from a North Carolina private insurer NC claims and Merative MarketScan MarketScan, we identified patients (18–64 years old) initiating ADF or non‐ADF extended‐release/long‐acting (ER/LA) opioids. We compared patient characteristics and described opioid treatment history between treatment groups, classifying patients as traditional (no opioid claims during prior six‐month washout period) or prevalent new users.
Results
We identified 8415 (NC claims) and 147 978 (MarketScan) ADF, and 10 114 (NC claims) and 232 028 (MarketScan) non‐ADF ER/LA opioid initiators. Most had prior opioid exposure (ranging 64%–74%), and key clinical differences included higher prevalence of recent acute or chronic pain and surgery among patients initiating ADFs compared to non‐ADF ER/LA initiators. Concurrent immediate‐release opioid prescriptions at initiation were more common in prevalent new users than traditional new users.
Conclusions
Careful consideration of the study design, comparator choice, and confounding by “indication” is crucial when examining ADF opioid use‐related outcomes.
This study aimed to examine mental health conditions of children diagnosed with neonatal abstinence syndrome (NAS) in a commercially insured population and compare them with a multistate ...Medicaid-insured population identified in prior research.
Data from the IBM MarketScan Commercial Database from January 1, 2009, to September 30, 2015, were used to identify mental health conditions among children ages 1-5 both with and without NAS. Frequency analyses were conducted to ascertain intrapopulation differences and differences between the commercially insured and Medicaid populations.
The NAS rate in the Medicaid population was 28.7 times higher than in the commercially insured population. Although the sample of children with NAS was small, and the results must be interpreted with caution, elevated rates of childhood mental health conditions observed in the commercially insured population were comparable to the Medicaid population.
This analysis emphasizes the difference in rates of NAS between commercially insured and Medicaid populations.
Objective
To test whether Medicaid expansion is associated with (a) a greater number of naloxone prescriptions dispensed and (b) a higher proportion of naloxone prescriptions paid by Medicaid.
Data ...Sources/Study Setting
We used the IQVIA National Prescription Audit to obtain data on per state per quarter naloxone prescription dispensing for the period 2011‐16.
Study Design
In this quasi‐experimental design study, the impact of Medicaid expansion on naloxone prescription dispensing was examined using difference‐in‐difference estimation models. State‐level covariates including pharmacy‐based naloxone laws (standing/protocol orders and direct authority to dispense naloxone), third‐party prescribing laws, opioid analgesic prescribing rates, opioid‐involved overdose death rates, and population size were controlled for in the analysis.
Principal Findings
Medicaid expansion was associated with 38 additional naloxone prescriptions dispensed per state per quarter compared to nonexpansion controls, on average (P = .030). Also, Medicaid expansion resulted in an average increase of 9.86 percent in the share of naloxone prescriptions paid by Medicaid per state per quarter (P < .001).
Conclusions
Our study found that Medicaid expansion increased naloxone availability. This finding suggests that it will be important to consider naloxone access when making federal‐ and state‐level decisions affecting Medicaid coverage.
We present our open-source pipeline for quickly enhancing open data sets with research-focused expansions and show its effectiveness on a cornerstone open data set released by the Cook County ...government in Illinois. The City of Chicago and Cook County were both early adopters of open data portals and have made a wide variety of data available to the public; we focus on the medical examiner case archive which provides information about deaths recorded by Cook County's Office of the Medical Examiner, including overdoses invaluable to substance use disorder research. Our pipeline derives key variables from open data and links to other publicly available data sets in support of accelerating translational research on substance use disorders. Our methods apply to location-based analyses of overdoses in general and, as an example, we highlight their impact on opioid research. We provide our pipeline as open-source software to act as open infrastructure for open data to help fill the gap between data release and data use.
•Propoxyphene-involved deaths declined 84% two years following market withdrawal.•Propoxyphene has been detected in recent deaths and other drug data sources.•Drug surveillance should continue ...post-withdrawal with a systematic phase-out.
The synthetic opioid propoxyphene was a schedule IV controlled substance with multiple reported health risks before the US Food and Drug Administration issued a request for voluntary market withdrawal in November 2010. The purpose of this study is to investigate the characteristics and occurrences of propoxyphene-related deaths in Florida before and after voluntary market removal. Decedent-level toxicology data from Florida’s Medical Examiners Commission was used to compare the temporal, polysubstance use, sociodemographic, and geographic profiles associated with propoxyphene-involved deaths for a pre-withdrawal (November 2008–November 2010) and post-withdrawal (December 2010–December 2012) period. Sensitivity analyses using multiple data sources, including Florida’s Prescription Drug Monitoring Program and other states’ data, were conducted to examine potential reporting bias. Results showed that the number of propoxyphene-involved deaths declined by 84% from 580 deaths to 92 deaths after market withdrawal. The co-occurrence of other prevalent drugs, such as oxycodone (17.2% to 26.1%, p=0.0422) increased significantly in the post-withdrawal study period. A larger proportion of the propoxyphene-related deaths were reported from South Florida after the withdrawal (28.4% to 56.5%, p<0.0001). No significant changes in age and race/ethnicity were observed. Sensitivity analyses revealed that several deaths occurred in other states after market withdrawal, as recently as 2016. Our findings are consistent with previous studies that propoxyphene was still available after removal from the US market. Continued surveillance is recommended after highly abused opioids are withdrawn from the market due to on-going safety risks.
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