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Chou R.,Oregon Health And Science University | Shekelle P.,Veterans Affairs Greater Los Angeles Healthcare System
JAMA - Journal of the American Medical Association

Context Low back pain is extremely common. Early identification of patients more likely to develop persistent disabling symptoms could help guide decisions regarding follow-up and management. Objective To systematically review the usefulness of individual risk factors or risk prediction instruments for identifying patients more likely to develop persistent disabling low back pain. Data Sources Electronic searches of MEDLINE (1966-January 2010) and EMBASE (1974-February 2010) and review of the bibliographies of retrieved articles. Study Selection Prospective studies of patients with fewer than 8 weeks of low back pain from which likelihood ratios (LRs) were calculated for prediction of persistent disabling low back pain for findings attainable during the clinical evaluation. Data Extraction Two authors independently assessed studies and extracted data to estimate LRs. Data Synthesis A total of 20 studies evaluating 10 842 patients were identified. Presence of nonorganic signs (median [range] LR, 3.0 [1.7-4.6]), high levels of maladaptive pain coping behaviors (median [range] LR, 2.5 [2.2-2.8]), high baseline functional impairment (median [range] LR, 2.1 [1.2-2.7]), presence of psychiatric comorbidities (median [range] LR, 2.2 [1.9-2.3]), and low general health status (median [range] LR, 1.8 [1.1-2.0]) were the most useful predictors of worse outcomes at 1 year. Low levels of fear avoidance (median [range] LR, 0.39 [0.38-0.40]) and low baseline functional impairment (median [range] LR, 0.40 [0.10-0.52]) were the most useful items for predicting recovery at 1 year. Results were similar for outcomes at 3 to 6 months. Variables related to the work environment, baseline pain, and presence of radiculopathy were less useful for predicting worse outcomes (median LRs approximately 1.5), and a history of prior low back pain episodes and demographic variables were not useful (median LRs approximately 1.0). Several risk prediction instruments were useful for predicting outcomes, but none were extensively validated, and some validation studies showed LRs similar to estimates for individual risk factors. Conclusion The most helpful components for predicting persistent disabling low back pain were maladaptive pain coping behaviors, nonorganic signs, functional impairment, general health status, and presence of psychiatric comorbidities. © 2010 American Medical Association. All rights reserved. Source

Chou R.,Oregon Health And Science University | Qaseem A.,The American College | Owens D.K.,Veterans Affairs Palo Alto Healthcare System | Shekelle P.,Veterans Affairs Greater Los Angeles Healthcare System
Annals of Internal Medicine

Diagnostic imaging is indicated for patients with low back pain only if they have severe progressive neurologic deficits or signs or symptoms that suggest a serious or specific underlying condition. In other patients, evidence indicates that routine imaging is not associated with clinically meaningful benefits but can lead to harms. Addressing inefficiencies in diagnostic testing could minimize potential harms to patients and have a large effect on use of resources by reducing both direct and downstream costs. In this area, more testing does not equate to better care. Implementing a selective approach to low back imaging, as suggested by the American College of Physicians and American Pain Society guideline on low back pain, would provide better care to patients, improve outcomes, and reduce costs. © 2011 American College of Physicians. Source

Pinne M.,Research Service | Pinne M.,University of California at Los Angeles | Haake D.A.,Veterans Affairs Greater Los Angeles Healthcare System | Haake D.A.,University of California at Los Angeles

The agents of leptospirosis, a zoonosis with worldwide distribution, are pathogenic spirochetes belonging to the genus Leptospira. The leptospiral life cycle involves transmission via fresh water and colonization of the renal tubules of their reservoir hosts. Infection of accidental hosts, including humans, may result in life-threatening sequelae. Bacterial outer membrane proteins (OMPs), particularly those with surface-exposed regions, play crucial roles in pathogen virulence mechanisms and adaptation to environmental conditions, including those found in the mammalian host. Therefore, elucidation and characterization of the surface-exposed OMPs of Leptospira spp. is of great interest in the leptospirosis field. A thorough, multi-pronged approach for assessing surface exposure of leptospiral OMPs is essential. Herein, we present evidence for a sub-surface location for most or all of the major leptospiral lipoprotein, LipL32, based on surface immunofluorescence utilizing three different types of antibodies and four different permeabilization methods, as well as surface proteolysis of intact and lysed leptospires. We reevaluate prior evidence presented in support of LipL32 surface-exposure and present a novel perspective on a protein whose location has been misleading researchers, due in large part to its extraordinary abundance in leptospiral cells. Source

Meng F.,Veterans Affairs Greater Los Angeles Healthcare System
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium

Sentences and phrases that represent a certain meaning often exhibit patterns of variation where they differ from a basic structural form by one or two words. We present an algorithm that utilizes multiple sequence alignments (MSAs) to generate a representation of groups of phrases that possess the same semantic meaning but also share in common the same basic word sequence structure. The MSA enables the determination not only of the words that compose the basic word sequence, but also of the locations within the structure that exhibit variation. The algorithm can be utilized to generate patterns of text sequences that can be used as the basis for a pattern-based classifier, as a starting point to bootstrap the pattern building process for a regular expression-based classifiers, or serve to reveal the variation characteristics of sentences and phrases within a particular domain. Source

Singer A.E.,RAND Corporation | Meeker D.,University of Southern California | Teno J.M.,Brown University | Lynn J.,Altarum Institute | And 2 more authors.
Annals of Internal Medicine

Background: Calls for improvement in end-of-life care have focused attention on the management of pain and other troubling symptoms at the end of life. Objective: To describe changes in pain intensity and symptom prevalence during the last year of life from 1998 to 2010. Design: Observational study. Setting: The HRS (Health and Retirement Study), a nationally representative longitudinal survey of community-dwelling U.S. residents aged 51 years or older. Participants: 7204 HRS participants who died while enrolled in the study and their family respondents. Measurements: Proxy-reported pain during the last year of life and other symptoms for at least 1 month during the last year of life. Trends in pain intensity and symptom prevalence were analyzed for all decedents and within the categories of sudden death, cancer, congestive heart failure or chronic lung disease, and frailty. Results: Between 1998 and 2010, proxy reports of the prevalence of any pain increased for all decedents from 54.3% (95% CI, 51.6% to 57.1%) to 60.8% (CI, 58.2% to 63.4%), an increase of 11.9% (CI, 3.1% to 21.4%). Reported prevalences of depression and periodic confusion also increased for all decedents by 26.6% (CI, 14.5% to 40.1%) and 31.3% (CI, 18.6% to 45.1%), respectively. Individual symptoms increased in prevalence among specific decedent categories, except in cancer, which showed no significant changes. The prevalence of moderate or severe pain did not change among all decedents or in any specific decedent category. Limitation: Use of proxy reports and limited information about some patient and surrogate variables. Conclusion: Despite national efforts to improve end-of-life care, proxy reports of pain and other alarming symptoms in the last year of life increased from 1998 to 2010. © 2015 American College of Physicians. Source

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