Mingfei Li

Off‐label use of second generation antipsychotics for post‐traumatic stress disorder in the Department of Veterans Affairs: time trends and sociodemographic, comorbidity, and regional correlates

Second generation antipsychotics (SGAs) are widely used for post‐traumatic stress disorder (PTSD), although without strong evidence base. With substantial numbers of veterans returning from Iraq/Afghanistan conflicts with PTSD, it is important to characterize the extent of SGA use and identify associated factors.

Effects of diagnostic inclusion criteria on prevalence and population characteristics in database research

OBJECTIVES Studies of serious mental illnesses that use administrative databases have employed various criteria to establish diagnoses of interest. Several studies have assessed the validity of diagnostic inclusion criteria against research diagnoses. However, no studies have examined the effect of diagnostic inclusion criteria on prevalence and population characteristics across such groups. METHODS Administrative data for 2003-2010 from the Department of Veterans Affairs were used to calculate prevalence rates and assess effects of varying the diagnostic inclusion criteria on population composition for bipolar disorder, schizophrenia, and posttraumatic stress disorder (PTSD). Specifically, for each diagnosis, mutually exclusive subpopulations were compared on the basis of the following inclusion criteria for a given diagnosis: one treatment encounter, two outpatient encounters or one inpatient encounter, and any two encounters. For bipolar disorder and schizophrenia, effects of excluding individuals who had a competing diagnosis of, respectively, schizophrenia or bipolar disorder in the prior 12 months and since 2002 were also determined. RESULTS In 2010, moving from the broadest definitions of bipolar disorder (N=120,382), schizophrenia (N=91,977), and PTSD (N=554,028) to the most restrictive definitions reduced prevalence rates by, respectively, 28.7%, 34.9%, and 25.7%, with temporal trends for 2003-2010 paralleling results in 2010. Population composition changes with changing diagnostic inclusion criteria were variable, with predominantly small odds ratios. CONCLUSIONS Population composition was relatively robust across common diagnostic inclusion criteria for each condition. Thus choice of criteria can focus on considerations of diagnostic validity and case-finding needs. Three mechanisms for the impact of diagnostic criteria on population composition in administrative data sets are discussed.

The Ascendancy of Second-Generation Antipsychotics as Frontline Antimanic Agents.

IntroductionKnowledge of the factors affecting the adoption of new medications can enhance mental health care and guide quality improvement and policy development. Food and Drug Administration indications for treating bipolar disorder with several second-generation antipsychotics (SGAs) in the 2000s represent an opportunity to identify factors that impact the spread of a then-innovative treatment through a new population. MethodsAnalysis of Department of Veterans Affairs administrative data identified the population of 170,811 veterans diagnosed with bipolar disorder from 2003 to 2010. We analyzed time trends and predictors of antimanic choice (SGA vs other) among the 40,512 outpatients with bipolar disorder who initiated their first VA outpatient antimanic prescription, using multinomial logistic regression in month-by-month analyses. We conducted classwise analyses and investigated prespecified predictors among specific agents. ResultsIn classwise analyses, SGAs supplanted lithium, valproate, and carbamazepine/oxcarbazepine as the most commonly initiated antimanics by 2007. Psychosis, but not other indices of severity, predicted SGA initiation. Demographic analyses did not identify substantial disparities in initiation of SGAs. Drug-specific analyses revealed some consideration of medical comorbidities in choosing among specific antimanic agents, although effect sizes were small. Most patients initiating an antimanic had received an antidepressant in the previous year. DiscussionSecond-generation antipsychotics quickly became the frontline antimanic treatment for bipolar disorder, although antidepressants most commonly predated antimanic prescriptions. Second-generation antipsychotics were used for a broad range of patients rather than being restricted to a severely ill subpopulation. The modest association of antimanic choice with relevant medical comorbidities suggests that continued attention to quality prescribing practices is warranted.

HIERARCHICAL MIXTURE MODELS FOR ASSESSING FINGERPRINT INDIVIDUALITY

The study of fingerprint individuality aims to determine to what extent a fingerprint uniquely identifies an individual. Recent court cases have highlighted the need for measures of fingerprint individuality when a person is identified based on fingerprint evidence. The main challenge in studies of fingerprint individuality is to adequately capture the variability of fingerprint features in a population. In this paper hierarchical mixture models are introduced to infer the extent of individualization. Hierarchical mixtures utilize complementary aspects of mixtures at different levels of the hierarchy. At the first (top) level, a mixture is used to represent homogeneous groups of fingerprints in the population, whereas at the second level, nested mixtures are used as flexible representations of distributions of features from each fingerprint. Inference for hierarchical mixtures is more challenging since the number of unknown mixture components arise in both the first and second levels of the hierarchy. A Bayesian approach based on reversible jump Markov chain Monte Carlo methodology is developed for the inference of all unknown parameters of hierarchical mixtures. The methodology is illustrated on fingerprint images from the NIST database and is used to make inference on fingerprint individuality estimates from this population.

Patterns of initiation of second generation antipsychotics for bipolar disorder: a month-by-month analysis of provider behavior

BackgroundSeveral second generation antipsychotics (SGAs) received FDA approval for bipolar disorder in the 2000s. Although efficacious, they have been costly and may cause significant side effects. Little is known about the factors associated with prescribers’ decisions to initiate SGA prescriptions for this condition.MethodsWe gathered administrative data from the Department of Veterans Affairs on 170,713 patients with bipolar disorder between fiscal years 2003–2010. Patients without a prior history of taking SGAs were considered eligible for SGA initiation during the study (n =126,556). Generalized estimating equations identified demographic, clinical, and comorbidity variables associated with initiation of an SGA prescription on a month-by-month basis.ResultsWhile the number of patients with bipolar disorder using SGAs nearly doubled between 2003 and 2010, analyses controlling for patient characteristics and the rise in the bipolar population revealed a 1.2% annual decline in SGA initiation during this period. Most medical comorbidities were only modestly associated with overall SGA initiation, although significant differences emerged among individual SGAs. Several markers of patient severity predicted SGA initiation, including previous hospitalizations, psychotic features, and a history of other antimanic prescriptions; these severity markers became less firmly linked to SGA initiation over time. Providers in the South were somewhat more likely to initiate SGA treatment.ConclusionsThe number of veterans with bipolar disorder prescribed SGAs is rising steadily, but this increase appears primarily driven by a corresponding increase in the bipolar population. Month-by-month analyses revealed that higher illness severity predicted SGA initiation, but that this association may be weakening over time.

Off-Label Prescribing of Second-Generation Antipsychotics to Elderly Veterans with Posttraumatic Stress Disorder and Dementia

To determine whether elderly veterans with posttraumatic stress disorder (PTSD) and dementia are more likely to be prescribed second‐generation antipsychotics (SGAs) than those with PTSD alone.

A population‐based study of the comparative effectiveness of second‐generation antipsychotics vs older antimanic agents in bipolar disorder

Numerous antimanic treatments have been introduced over the past two decades, particularly second‐generation antipsychotics (SGAs). However, it is not clear whether such newer agents provide any advantage over older treatments.

Kinematic Measures during a Clinical Diagnostic Technique for Human Neck Disorder: Inter- and Intraexaminer Comparisons

Diagnoses of human musculoskeletal dysfunction of the cervical spine are indicated by palpable clues of a patients structural compliance/noncompliance as this body segment responds to diagnostic motion demands applied by a clinician. This process includes assessments of motion range, motion performance, and changes in tissue responses. However, biomechanical quantification of these diagnostic actions and their reproducible components is lacking. As a result, this study sought to use objective kinematic measures to capture aspects of the diagnostic process to compare inter- and intraexaminer motion behaviors when performing a specific clinical diagnostic protocol. Pain-free volunteers and a group determined to be symptomatic based on a psychometric pain score were examined by two clinicians while three-dimensional kinematic data were collected. Intraexaminer diagnostic motion ranges of cervical lateral flexion and secondary rotations were consistent for each examiner and for each subject group. However, interexaminer comparisons for motion range, secondary rotations, and average velocities yielded consistently larger measures for one examiner for both subject groups (P < 0.05). This research demonstrates that fundamental aspects of the clinical diagnostic process for human neck disorders can be identified and measured using kinematic parameters. Further, these objective data have the potential to be linked to clinical decision making.

Socioeconomic Convergence in Europe One Decade After the EU Enlargement of 2004: Application of Self-Organizing Maps

This article uses self-organizing maps (SOMs) to examine convergence between European states, giving special attention to the states of Central and Eastern Europe (CEE) that joined the European Union (EU) during its monumental expansion in 2004. To augment the literature on income convergence, the robust conceptual framework employed here is based upon Terry Jordan’s much broader socioeconomic and political definition of Europe. Using associated variables, the study applies the Kohonen data visualization technique to highlight statistical clustering and movement of countries across three time periods from 2001 to 2013. Kohonen U-matrix and component maps reveal several distinct clusters of countries that remain stable over time, including Europe’s industrialized core and Scandinavia, as well as a cluster of laggard Soviet successor states at the opposite extreme. The eleven new EU countries that had been part of the eastern bloc show evidence of real (β-) convergence toward the European core, but at various paces. The Baltic states of Lithuania and Latvia experience some of the greatest observable convergence, followed by Estonia, the Visegrád states, and the former Yugoslav states of Croatia and Slovenia. Other countries that demonstrate considerable movement during the time period under investigation include some crisis-battered Mediterranean countries, plus Montenegro, Kosovo, and Turkey. While most of the evident statistical mobility is positive, Ireland experiences nominal and real divergence during the period 2011–13. In the context of Europe’s ongoing recession and the aftermath of the UK’s referendum, these findings have implications for two uncertainties: the very survival of the EU and its prospects for further expansion.

A Methodology for Quantifying Seated Lumbar Curvatures

To understand the role seating plays in the support of posture and spinal articulation, it is necessary to study the interface between a human and the seat. However, a method to quantify lumbar curvature in commercially available unmodified seats does not currently exist. This work sought to determine if the lumbar curvature for normal ranges of seated posture could be documented by using body landmarks located on the anterior portion of the body. The development of such a methodology will allow researchers to evaluate spinal articulation of a seated subject while in standard, commercially available seats and chairs. Anterior measurements of boney landmarks were used to quantify the relative positions of the ribcage and pelvis while simultaneous posterior measurements were made of lumbar curvature. The relationship between the anterior and the posterior measures was compared. The predictive capacity of this approach was evaluated by determining linear and second-order regressions for each of the four postures across all subjects and conducting a leave-one-out cross validation. The relationships between the anterior and posterior measures were approximated by linear and second-order polynomial regressions (r(2 ) =  0.829, 0.935 respectively) across all postures. The quantitative analysis showed that openness had a significant relationship with lumbar curvature, and a first-order regression was superior to a second-order regression. Average standard errors in the prediction were 5.9° for the maximum kyphotic posture, 9.9° for the comfortable posture, 12.8° for the straight and tall, and 22.2° for the maximum lordotic posture. These results show predictions of lumbar curvature are possible in seated postures by using a motion capture system and anterior measures. This method of lumbar curvature prediction shows potential for use in the assessment of seated spinal curvatures and the corresponding design of seating to accommodate those curvatures; however, additional inputs will be necessary to better predict the postures as lordosis is increased.