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Biomedical subjects

Amar K Das

Publications and source records attributed to Amar K Das.

13 recordsLinked to original sources
PubMed2006

Temporal representation and reasoning in medicine: Research directions and challenges.

OBJECTIVE: The main aim of this paper is to propose and discuss promising directions of research in the field of temporal representation and reasoning in medicine, taking into account the recent scientific literature and challenging issues of current interest as viewed from the different research perspectives of the authors of the paper. BACKGROUND: Temporal representation and reasoning in medicine is a well-known field of research in the medical as well as computer science community. It encompasses several topics, such as summarizing data from temporal clinical databases, reasoning on temporal clinical data for therapeutic assessments, and modeling uncertainty in clinical knowledge and data. It is also related to several medical tasks, such as monitoring intensive care patients, providing treatments for chronic patients, as well as planning and scheduling clinical routine activities within complex healthcare organizations. METHODOLOGY: The authors jointly identified significant research areas based on their importance as for temporal representation and reasoning issues; the subjects were considered to be promising topics of future activity. Every subject was addressed in detail by one or two authors and then discussed with the entire team to achieve a consensus about future fields of research. RESULTS: We identified and focused on four research areas, namely (i) fuzzy logic, time, and medicine, (ii) temporal reasoning and data mining, (iii) health information systems, business processes, and time, and (iv) temporal clinical databases. For every area, we first highlighted a few basic notions that would permit any reader--including those who are unfamiliar with the topic--to understand the main goals. We then discuss interesting and promising directions of research, taking into account the recent literature and underlining the yet unresolved medical/clinical issues that deserve further scientific investigation. The considered research areas are by no means disjointed, because they share common theoretical and methodological features. Moreover, subjects of imminent interest in medicine are represented in many of the fields considered. CONCLUSIONS: We propose and discuss promising subjects of future research that deserve investigation to develop software systems that will properly manage the multifaceted temporal aspects of information and knowledge encountered by physicians during their clinical work. As the subjects of research have resulted from merging the different perspectives of the authors involved in this study, we hope the paper will succeed in stimulating discussion and multidisciplinary work in the described fields of research.

Artificial Intelligence↗
PubMed2006

Depression in African Americans: breaking barriers to detection and treatment.

OBJECTIVE: Recent studies in primary care settings indicate that African Americans face health disparities in the treatment of major depression. We reviewed the literature to find evidence of specific patient, physician, and practice-setting factors related to such barriers. DATA SOURCES: We searched for and retrieved articles in Medline (1966-2004) and hand-checked bibliographies to find additional articles that were relevant to the evaluation and treatment of African Americans with depression. STUDY SELECTION AND DATA EXTRACTION: Two investigators (AKD, MO) independently examined the abstracts retrieved from the literature search, and excluded articles that did not match a predefined search strategy. Two other investigators (HLC, MMW) identified potential articles through bibliographic review. In the extracted set articles, we examined cited barriers to diagnosis and effective management. RESULTS: We found 24 articles that fulfilled our criteria. These studies indicate that African Americans face a number of barriers in the recognition and treatment of major depression including clinical presentation with somatization, stigma about diagnosis, competing clinical demands of comorbid general medical problems, problems with the physician-patient relationship, and lack of comprehensive primary care services. CONCLUSIONS: Research indicates that African Americans who have depression may be frequently under diagnosed and inadequately managed in primary care as a result of patient, physician, and treatment-setting factors. Our systematic review can assist family physicians in understanding how to overcome such barriers to the diagnosis and treatment of depressive disorders in African American patients.

Adult↗
PubMed2005

Customizing clinical narratives for the electronic medical record interface using cognitive methods.

OBJECTIVE: As healthcare practice transitions from paper-based to computer-based records, there is increasing need to determine an effective electronic format for clinical narratives. Our research focuses on utilizing a cognitive science methodology to guide the conversion of medical texts to a more structured, user-customized presentation in the electronic medical record (EMR). DESIGN: We studied the use of discharge summaries by psychiatrists with varying expertise-experts, intermediates, and novices. Experts were given two hypothetical emergency care scenarios with narrative discharge summaries and asked to verbalize their clinical assessment. Based on the results, the narratives were presented in a more structured form. Intermediate and novice subjects received a narrative and a structured discharge summary, and were asked to verbalize their assessments of each. MEASUREMENTS: A qualitative comparison of the interview transcripts of all subjects was done by analysis of recall and inference made with respect to level of expertise. RESULTS: For intermediate and novice subjects, recall was greater with the structured form than with the narrative. Novices were also able to make more inferences (not always accurate) from the structured form than with the narrative. Errors occurred in assessments using the narrative form but not the structured form. CONCLUSIONS: Our cognitive methods to study discharge summary use enabled us to extract a conceptual representation of clinical narratives from end-users. This method allowed us to identify clinically relevant information that can be used to structure medical text for the EMR and potentially improve recall and reduce errors.

Cognitive Science↗
PubMed2005

Screening for bipolar disorder in a primary care practice.

CONTEXT: Bipolar disorder consists of episodes of manic and depressive symptoms. Efforts to screen for depression in a primary care setting without assessment of past manic symptoms can lead to incorrect diagnosis and treatment of bipolar disorder. OBJECTIVES: To screen for bipolar disorder in adult primary care patients and to examine its clinical presentation and effect on functioning. DESIGN, SETTING, AND PARTICIPANTS: A systematic sample of 1157 patients between 18 and 70 years of age who were seeking primary care at an urban general medicine clinic serving a low-income population. The study was conducted between December 2001 and January 2003. MAIN OUTCOME MEASURES: Prevalence of bipolar disorder, its treatment and patient functioning. Study measures included the Mood Disorder Questionnaire, the PRIME-MD Patient Health Questionnaire, the Medical Outcomes Study 12-Item Short Form health survey, the Sheehan Disability Scale, data on past mental health treatments, and a review of medical records and International Classification of Diseases, Ninth Revision codes for each visit dating from 6 months prior to the screening day. RESULTS: The prevalence of receiving positive screening results for lifetime bipolar disorder was 9.8% (n = 112; 95% confidence interval, 8.0%-11.5%) and did not differ significantly by age, sex, or race/ethnicity. Eighty-one patients (72.3%) who screened positive for bipolar disorder sought professional help for their symptoms, but only 9 (8.4%) reported receiving a diagnosis of bipolar disorder. Seventy-five patients (68.2%) who screened positive for bipolar disorder had a current major depressive episode or an anxiety or substance use disorder. Of 112 patients, only 7 (6.5%) reported taking a mood-stabilizing agent in the past month. Primary care physicians recorded evidence of current depression in 47 patients (49.0%) who screened positive for bipolar disorder, but did not record a bipolar disorder diagnosis either in administrative billing or the medical record of any of these patients. Patients who screened positive for bipolar disorder reported worse health-related quality of life as well as increased social and family life impairment compared with those who screened negative. CONCLUSIONS: In an urban general medicine clinic, a positive screen for bipolar disorder appears to be common, clinically significant, and underrecognized. Because of the risks associated with treating bipolar disorder with antidepressant monotherapy, efforts are needed to educate primary care physicians about the screening, management, and pharmacotherapy of bipolar disorders.

Adult↗
PubMed2005

Computational method for temporal pattern discovery in biomedical genomic databases.

With the rapid growth of biomedical research databases, opportunities for scientific inquiry have expanded quickly and led to a demand for computational methods that can extract biologically relevant patterns among vast amounts of data. A significant challenge is identifying temporal relationships among genotypic and clinical (phenotypic) data. Few software tools are available for such pattern matching, and they are not interoperable with existing databases. We are developing and validating a novel software method for temporal pattern discovery in biomedical genomics. In this paper, we present an efficient and flexible query algorithm (called TEMF) to extract statistical patterns from time-oriented relational databases. We show that TEMF - as an extension to our modular temporal querying application (Chronus II) - can express a wide range of complex temporal aggregations without the need for data processing in a statistical software package. We show the expressivity of TEMF using example queries from the Stanford HIV Database.

Artificial Intelligence↗
PubMed2005

Bipolar depression in a low-income primary care clinic.

OBJECTIVE: This study estimated the proportion of patients attending an urban general medical practice with current major depression and a history of bipolar disorder and compared the history, presentation, and treatment of patients with unipolar and bipolar depression. METHOD: A group of 1,143 patients was assessed with measures of past and current mental health and treatment. Patients were partitioned into bipolar and unipolar groups based on a predefined cutoff on the Mood Disorder Questionnaire. The groups were compared on sociodemographic characteristics, depressive symptoms, comorbid mental disorders, and mental health treatment. RESULTS: Approximately one-quarter of the patients with major depression had lifetime bipolar depression. Patients with unipolar and bipolar depression did not significantly differ on background or health characteristics. Patients with bipolar depression were significantly more likely to report hallucinations, current suicidal ideation, and low self-esteem than patients with unipolar depression but less likely to report disturbed appetite. Patients with bipolar depression were significantly more likely to have an alcohol use disorder and to report inpatient psychiatric care and antipsychotic treatment during the past month than patients with unipolar depression. Nearly one-half of the patients with bipolar depression had taken an antidepressant in the last month, but most were not also being treated with an antipsychotic or mood stabilizer. CONCLUSIONS: Bipolar depression is common in urban general medicine practice. When patients took antidepressants, they seldom received concurrent antimanic medications. Because of the risks of treating bipolar disorder with antidepressant monotherapy, physicians should assess their depressed patients for mania before prescribing antidepressants.

Adolescent↗
PubMed2004

Bipolar disorder.

Explore the source record for details and available documents.

Antidepressive Agents↗
PubMed2004

Modeling electronic discharge summaries as a simple temporal constraint satisfaction problem.

OBJECTIVE: To model the temporal information contained in medical narrative reports as a simple temporal constraint satisfaction problem. DESIGN: A constraint satisfaction problem is defined by time points and constraints (inequalities between points). A time interval comprises a pair of points and a constraint. Five complete electronic discharge summaries and paragraphs from 226 other discharge summaries were studied. Medical events were represented as intervals, and assertions about events were represented as constraints. Through a consensus process, a set of encoding procedures and a list of issues related to encoding were generated. MEASUREMENTS: Instances of temporal disjunction and contradiction and distribution of temporal constraints were used. RESULTS: An average of 95 medical events (range, 46-151) and 234 temporal assertions (range, 118-388) were identified per complete discharge summary. Nondefinitional assertions were explicit (36%) or implicit (64%) and absolute (17%), qualitative (72%), or metric (11%). Implicit assertions were based on domain knowledge and assumptions, e.g., the section of the report determined the ordering of events. Issues included linking events, intermittence, periodicity, granularity, vagueness, ambiguity, uncertainty, and plans. ions such as intermittence were not represented explicitly. The temporal network was sparse: Only 0.80% (range, 0.42%-1.38%) of possible constraints were instantiated. No instances of discontinuous temporal disjunction were found in the complete summaries or the 226 paragraphs. One instance of temporal contradiction was found (intrareport rate of 0.2 with a 95% confidence interval of 0.005-1.114). CONCLUSION: A simple temporal constraint satisfaction problem appears sufficient to represent most temporal assertions in discharge summaries and may be useful for encoding electronic medical records.

Algorithms↗
PubMed2003

Specifying design criteria for electronic medical record interface using cognitive framework.

As the healthcare industry transitions from paper to electronic medical records (EMRs), medical informatics researchers face the task of ensuring that the electronic presentation of the information remains usable and effective while capitalizing on the ability of EMRs to tailor information to different users. In our research, we focus on utilizing formal cognitive science methodology to guide the conversion of paper-based narrative discharge summaries to a more dynamic, structured electronic version. In this paper, we present the results of a cognitive analytic study (1) that determines a 'core' component in medical narratives and (2) that compares the use of structured and narrative texts by physicians with varying expertise. Specifically, we studied six psychiatrists at three levels of expertise- experts, intermediates, and novices. The subjects were given two clinical case scenarios with discharge summaries and asked to verbalize their thoughts as they read through the summaries. The interview transcripts were analyzed for recalls and inferences generated in the verbalization. Based on experts' verbalizations, the discharge summaries were organized into a more structured form and used in the interview of other subjects. Novice-level subjects had more recall with the structured than with the narrative format. More errors were also made in recall with the narrative than with the structured text. We discuss how these results are valuable in designing an EMR interface to reduce errors and to support users of different expertise.

Cognition↗
PubMed2002

Computers in psychiatry: a review of past programs and an analysis of historical trends.

In a variety of clinical settings, computers are playing an increasing role in managing or retrieving clinical information. A recent survey of physician computer use suggests that psychiatrists, in comparison to other types of medical specialists, may be using computers less in routine care. In this paper, we present a literature review of 57 articles on computer programs in psychiatry that were published since 1966 in five major peer-reviewed journals. We divide the types of programs that have been developed into four categories: (1) diagnostic and decision support, (2) patient screening and therapy, (3) data collection and management, and (4) data modeling. Among the first three categories, we found trends in publications during the past three decades of research. We provide a discussion of representative computer programs. Our analysis of past programs reveals a number of design problems that may be a barrier to the more widespread use of computers in psychiatry.

Computers↗
PubMed2002

SYNCHRONUS: a reusable software module for temporal integration.

Querying time-stamped data in clinical databases is an essential step in the actuation of many decision-support rules. Since previous methods of temporal data management are not readily transferable among legacy databases, developers must create de novo querying methods that allow temporal integration of a decision-support program and existing database. In this paper, we outline four software-engineering principles that support a general, reusable approach to temporal integration. We then describe the design and implementation of SYNCHRONUS, a software module that advances our prior work on temporal querying. We show how this module satisfies the four principles for the task of temporal integration. SYNCHRONUS can help developers to overcome the software-engineering burden of temporal model heterogeneity within decision-support architectures.

Algorithms↗
PubMedDate not supplied

Depression in US Hispanics: diagnostic and management considerations in family practice.

US Hispanics, currently the largest minority group in the country, face disparities in the recognition and treatment of major depression. This article provides an evidence-based review of the prevalence, presentation, and management of major depression in primary care in this heterogeneous ethnic group. Under-recognition of depression in adult Hispanic Americans may be related to language differences, health literacy barriers, somatic presentations, and use of cultural idioms of distress. Hispanic patients are often agreeable to treatment but as a group may tend to prefer psychotherapy or combined counseling and medication to pharmacotherapy alone. Recent studies have found both psychological and pharmacologic treatment options are efficacious in this minority group. Treatment adherence should be actively monitored to help ensure its effectiveness. To help reduce the number of depressed Hispanic patients who pass through primary care undetected or inadequately treated, family physicians should make a concerted effort to increase their awareness of the presentation of major depression in this population and actively promote adherence to effective treatments.

Acculturation↗