285 research outputs found
Local variations in spatial synchrony of influenza epidemics
Background: Understanding the mechanism of influenza spread across multiple geographic scales is not complete. While the mechanism of dissemination across regions and states of the United States has been described, understanding the determinants of dissemination between counties has not been elucidated. The paucity of high resolution spatial-temporal influenza incidence data to evaluate disease structure is often not available. Methodology and Findings: We report on the underlying relationship between the spread of influenza and human movement between counties of one state. Significant synchrony in the timing of epidemics exists across the entire state and decay with distance (regional correlation = 62%). Synchrony as a function of population size display evidence of hierarchical spread with more synchronized epidemics occurring among the most populated counties. A gravity model describing movement between two populations is a stronger predictor of influenza spread than adult movement to and from workplaces suggesting that non-routine and leisure travel drive local epidemics. Conclusions: These findings highlight the complex nature of influenza spread across multiple geographic scales. © 2012 Stark et al
Impact of changing the measles vaccine vial size on Niger's vaccine supply chain: a computational model
<p>Abstract</p> <p>Background</p> <p>Many countries, such as Niger, are considering changing their vaccine vial size presentation and may want to evaluate the subsequent impact on their supply chains, the series of steps required to get vaccines from their manufacturers to patients. The measles vaccine is particularly important in Niger, a country prone to measles outbreaks.</p> <p>Methods</p> <p>We developed a detailed discrete event simulation model of the vaccine supply chain representing every vaccine, storage location, refrigerator, freezer, and transport device (e.g., cold trucks, 4 × 4 trucks, and vaccine carriers) in the Niger Expanded Programme on Immunization (EPI). Experiments simulated the impact of replacing the 10-dose measles vial size with 5-dose, 2-dose and 1-dose vial sizes.</p> <p>Results</p> <p>Switching from the 10-dose to the 5-dose, 2-dose and 1-dose vial sizes decreased the average availability of EPI vaccines for arriving patients from 83% to 82%, 81% and 78%, respectively for a 100% target population size. The switches also changed transport vehicle's utilization from a mean of 58% (range: 4-164%) to means of 59% (range: 4-164%), 62% (range: 4-175%), and 67% (range: 5-192%), respectively, between the regional and district stores, and from a mean of 160% (range: 83-300%) to means of 161% (range: 82-322%), 175% (range: 78-344%), and 198% (range: 88-402%), respectively, between the district to integrated health centres (IHC). The switch also changed district level storage utilization from a mean of 65% to means of 64%, 66% and 68% (range for all scenarios: 3-100%). Finally, accounting for vaccine administration, wastage, and disposal, replacing the 10-dose vial with the 5 or 1-dose vials would increase the cost per immunized patient from 0.71US and $1.26US, respectively.</p> <p>Conclusions</p> <p>The switch from the 10-dose measles vaccines to smaller vial sizes could overwhelm the capacities of many storage facilities and transport vehicles as well as increase the cost per vaccinated child.</p
EFFECT OF CONCURRENT SUBSTANCE USE DISORDER ON THE EFFECTIVENESS OF SINGLE AND COMBINATION ANTIDEPRESSANT MEDICATIONS FOR THE TREATMENT OF MAJOR DEPRESSION: AN EXPLORATORY ANALYSIS OF A SINGLE-BLIND RANDOMIZED TRIAL: Effect of Concurrent Substance Use Disorder
The co-occurrence of substance use disorder (SUD) and major depressive disorder (MDD) is common and is often thought to impair response to antidepressant therapy. These patients are often excluded from clinical trials, resulting in a significant knowledge gap regarding optimal pharmacotherapy for the treatment of MDD with concurrent SUD
Family history of mood disorder and characteristics of major depressive disorder: A STAR*D (sequenced treatment alternatives to relieve depression) study
Wstęp. Klinicyści rutynowo pytają pacjentów z depresją o występowanie chorób psychicznych w rodzinie. Nie
wiadomo jednak, czy pacjenci, w których rodzinie występowały tego typu schorzenia różnią się od osób z negatywnym
wywiadem rodzinnym w tym kierunku. W badaniu porównano cechy demograficzne i kliniczne dużej
grupy pacjentów ambulatoryjnych zgłaszających się do lekarza z powodu depresji bez objawów psychotycznych.
Pacjenci udzielili informacji na temat krewnych pierwszego stopnia chorujÄ…cych na depresjÄ™ lub chorobÄ™ afektywnÄ…
dwubiegunowÄ….
Metody. Osoby poddane badaniu rekrutowano do wieloośrodkowego badania klinicznego - Sekwencyjne
Alternatywy Terapeutyczne w Leczeniu Depresji (STAR*D, Sequenced Treatment Alternatives to Relieve Depression).
Oceniono różnice w cechach klinicznych i demograficznych u pacjentów z dodatnim i ujemnym wywiadem rodzinnym
w kierunku zaburzeń afektywnych, po skorygowaniu ich pod względem wieku, płci, rasy i grupy etnicznej.
Wyniki. Wśród pacjentów z dodatnim wywiadem rodzinnym w kierunku zaburzeń afektywnych (n = 2265;
56,5%) przeważały kobiety; depresja rozpoczęła się u nich wcześniej niż u pacjentów z ujemnym wywiadem
rodzinnym w kierunku zaburzeń afektywnych (n = 1740; 43,5%). Nie znaleziono znaczących różnic w zakresie
objawów depresyjnych, nasilenia depresji, jej nawrotowości, podtypów choroby, czy też funkcjonowania w ciągu
dnia.
Wnioski. Kobiety 2-krotnie częściej niż mężczyźni zgłaszały występowanie zaburzeń afektywnych w rodzinie,
dodatni wywiad rodzinny wiązał się z wcześniejszym wystąpieniem choroby u probanta. Młody wiek w chwili
zachorowania na depresję wydaje się charakteryzować rodzinny (a co za tym idzie uwarunkowany genetycznie)
podtyp depresji, co jest zgodne z wynikami wcześniejszych badań.Introduction. Clinicians routinely ask patients with major depressive disorder (MDD) about their family history. It
is unknown, however, if patients who report a positive family history differ from those who do not. This study
compared the demographic and clinical features of a large cohort of treatment-seeking outpatients with nonpsychotic
MDD who reported that they did or did not have at least one firstdegree relative who had either MDD
or bipolar disorder.
Methods. Subjects were recruited for the STAR*D multicenter trial. Differences in demographic and clinical features
for patients with and without a family history of mood disorders were assessed after correcting for age, sex,
race, and ethnicity.
Results. Patients with a family history of mood disorder (n = 2265; 56.5%) were more frequently women and
had an earlier age of onset of depression, as compared to those without such a history (n = 1740; 43.5%). No
meaningful differences were found in depressive symptoms, severity, recurrence, depressive subtype, or daily
function.
Conclusions. Women were twice as likely as men to report a positive family history of mood disorder, and
a positive family history was associated with younger age of onset of MDD in the proband. Consistent with prior
research, early age of onset appears to define a familial and, by extension, genetic subtype of major depressive
disorder
Classification and Regression Tree (CART) analysis to predict influenza in primary care patients
Abstract
Background
The use of neuraminidase-inhibiting anti-viral medication to treat influenza is relatively infrequent. Rapid, cost-effective methods for diagnosing influenza are needed to enable appropriate prescribing. Multi-viral respiratory panels using reverse transcription polymerase chain reaction (PCR) assays to diagnose influenza are accurate but expensive and more time-consuming than low sensitivity rapid influenza tests. Influenza clinical decision algorithms are both rapid and inexpensive, but most are based on regression analyses that do not account for higher order interactions. This study used classification and regression trees (CART) modeling to estimate probabilities of influenza.
Methods
Eligible enrollees ≥ 5 years old (n = 4,173) who presented at ambulatory centers for treatment of acute respiratory illness (≤7 days) with cough or fever in 2011–2012, provided nasal and pharyngeal swabs for PCR testing for influenza, information on demographics, symptoms, personal characteristics and self-reported influenza vaccination status.
Results
Antiviral medication was prescribed for just 15Â % of those with PCR-confirmed influenza. An algorithm that included fever, cough, and fatigue had sensitivity of 84Â %, specificity of 48Â %, positive predictive value (PPV) of 23Â % and negative predictive value (NPV) of 94Â % for the development sample.
Conclusions
The CART algorithm has good sensitivity and high NPV, but low PPV for identifying influenza among outpatients ≥5 years. Thus, it is good at identifying a group who do not need testing or antivirals and had fair to good predictive performance for influenza. Further testing of the algorithm in other influenza seasons would help to optimize decisions for lab testing or treatment.http://deepblue.lib.umich.edu/bitstream/2027.42/134640/1/12879_2016_Article_1839.pd
The Impact of HAART on the Respiratory Complications of HIV Infection: Longitudinal Trends in the MACS and WIHS Cohorts
Objective: To review the incidence of respiratory conditions and their effect on mortality in HIV-infected and uninfected individuals prior to and during the era of highly active antiretroviral therapy (HAART). Design: Two large observational cohorts of HIV-infected and HIV-uninfected men (Multicenter AIDS Cohort Study [MACS]) and women (Women's Interagency HIV Study [WIHS]), followed since 1984 and 1994, respectively. Methods: Adjusted odds or hazards ratios for incident respiratory infections or non-infectious respiratory diagnoses, respectively, in HIV-infected compared to HIV-uninfected individuals in both the pre-HAART (MACS only) and HAART eras; and adjusted Cox proportional hazard ratios for mortality in HIV-infected persons with lung disease during the HAART era. Results: Compared to HIV-uninfected participants, HIV-infected individuals had more incident respiratory infections both pre-HAART (MACS, odds ratio [adjusted-OR], 2.4; 95% confidence interval [CI], 2.2-2.7; p<0.001) and after HAART availability (MACS, adjusted-OR, 1.5; 95%CI 1.3-1.7; p<0.001; WIHS adjusted-OR, 2.2; 95%CI 1.8-2.7; p<0.001). Chronic obstructive pulmonary disease was more common in MACS HIV-infected vs. HIV-uninfected participants pre-HAART (hazard ratio [adjusted-HR] 2.9; 95%CI, 1.02-8.4; p = 0.046). After HAART availability, non-infectious lung diseases were not significantly more common in HIV-infected participants in either MACS or WIHS participants. HIV-infected participants in the HAART era with respiratory infections had an increased risk of death compared to those without infections (MACS adjusted-HR, 1.5; 95%CI, 1.3-1.7; p<0.001; WIHS adjusted-HR, 1.9; 95%CI, 1.5-2.4; p<0.001). Conclusion: HIV infection remained a significant risk for infectious respiratory diseases after the introduction of HAART, and infectious respiratory diseases were associated with an increased risk of mortality. © 2013 Gingo et al
A Cautionary Tale: MARVELS Brown Dwarf Candidate Reveals Itself To Be A Very Long Period, Highly Eccentric Spectroscopic Stellar Binary
We report the discovery of a highly eccentric, double-lined spectroscopic
binary star system (TYC 3010-1494-1), comprising two solar-type stars that we
had initially identified as a single star with a brown dwarf companion. At the
moderate resolving power of the MARVELS spectrograph and the spectrographs used
for subsequent radial-velocity (RV) measurements (R ~ <30,000), this particular
stellar binary mimics a single-lined binary with an RV signal that would be
induced by a brown dwarf companion (Msin(i)~50 M_Jup) to a solar-type primary.
At least three properties of this system allow it to masquerade as a single
star with a very low-mass companion: its large eccentricity (e~0.8), its
relatively long period (P~238 days), and the approximately perpendicular
orientation of the semi-major axis with respect to the line of sight (omega~189
degrees). As a result of these properties, for ~95% of the orbit the two sets
of stellar spectral lines are completely blended, and the RV measurements based
on centroiding on the apparently single-lined spectrum is very well fit by an
orbit solution indicative of a brown dwarf companion on a more circular orbit
(e~0.3). Only during the ~5% of the orbit near periastron passage does the
true, double-lined nature and large RV amplitude of ~15 km/s reveal itself. The
discovery of this binary system is an important lesson for RV surveys searching
for substellar companions; at a given resolution and observing cadence, a
survey will be susceptible to these kinds of astrophysical false positives for
a range of orbital parameters. Finally, for surveys like MARVELS that lack the
resolution for a useful line bisector analysis, it is imperative to monitor the
peak of the cross-correlation function for suspicious changes in width or
shape, so that such false positives can be flagged during the candidate vetting
process.Comment: 16 pages, 11 figures, 6 table
Improving cost-effectiveness and access to cognitive behavior therapy for depression: providing remote-ready, computer-assisted psychotherapy in times of crisis and beyond
Introduction. There is growing evidence that computer-delivered or –assisted forms of cognitive-behavior therapy (CCBT) are helpful, but cost-effectiveness versus standard therapies is not well established.
Objective. To evaluate the cost-effectiveness of a therapist-supported method for CCBT in comparison to standard CBT.
Method. 154 drug-free MDD outpatients were randomly assigned to either 16 weeks of standard CBT (up to twenty 50-minute sessions) or CCBT using the Good Days Ahead program (including up to 5.5 hours of therapist contact). Outcomes were assessed at baseline, weeks 8 and 16, and at 3 and 6 months post-treatment. Economic analyses took into account the costs of services received and work/social role impairment.
Results. In the context of almost identical efficacy, a form of CCBT that used only about onethird the amount of therapist contact as conventional CBT was highly cost-effective compared to conventional therapy and reduced cost of treatment by $928 per patient.
Conclusions. A method of CCBT that blended internet-delivered modules and abbreviated therapeutic contact reduced the cost of treatment substantially without adversely affecting outcomes. Results suggest that use of this approach can more than double the access to CBT. Because clinician support in CCBT can be provided by telephone, videoconference, and/or email, this highly efficient form of treatment could be a major advance in remote treatment delivery
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