Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
JAMA Netw Open ; 6(12): e2346840, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-38100110

RESUMEN

Importance: The MORDOR (Macrolides Oraux pour Réduire les Décès avec un Oeil sur la Résistance) trial demonstrated that mass azithromycin administration reduced mortality by 18% among children aged 1 to 59 months in Niger. The identification of high-risk subgroups to target with this intervention could reduce the risk of antimicrobial resistance. Objective: To evaluate whether distance to the nearest primary health center modifies the effect of azithromycin administration to children aged 1 to 59 months on child mortality. Design, Setting, and Participants: The MORDOR cluster randomized trial was conducted from December 1, 2014, to July 31, 2017; this post hoc secondary analysis was conducted in 2023 among 594 clusters (communities or grappes) in the Boboye and Loga departments in Niger. All children aged 1 to 59 months in eligible communities were evaluated. Interventions: Biannual (twice-yearly) administration of a single dose of oral azithromycin or matching placebo over 2 years. Main Outcomes and Measures: A population-based census was used to monitor mortality and person-time at risk (trial primary outcome). Community distance to a primary health center was calculated as kilometers between the center of each community and the nearest health center. Negative binomial regression was used to evaluate the interaction between distance and the effect of azithromycin on the incidence of all-cause mortality among children aged 1 to 59 months. Results: Between December 1, 2014, and July 31, 2017, a total of 594 communities were enrolled, with 76 092 children (mean [SD] age, 31 [2] months; 39 022 [51.3%] male) included at baseline, for a mean (SD) of 128 (91) children per community. Median (IQR) distance to the nearest primary health center was 5.0 (3.2-7.1) km. Over 2 years, 145 693 person-years at risk were monitored and 3615 deaths were recorded. Overall, mortality rates were 27.5 deaths (95% CI, 26.2-28.7 deaths) per 1000 person-years at risk in the placebo arm and 22.5 deaths (95% CI, 21.4-23.5 deaths) per 1000 person-years at risk in the azithromycin arm. For each kilometer increase in distance in the placebo arm, mortality increased by 5% (adjusted incidence rate ratio, 1.05; 95% CI, 1.03-1.07; P < .001). The effect of azithromycin on mortality varied significantly by distance (interaction P = .02). Mortality reduction with azithromycin compared with placebo was 0% at 0 km from the health center (95% CI, -19% to 17%), 4% at 1 km (95% CI, -12% to 17%), 16% at 5 km (95% CI, 7% to 23%), and 28% at 10 km (95% CI, 17% to 38%). Conclusions and Relevance: In this secondary analysis of a cluster randomized trial of mass azithromycin administration for child mortality, children younger than 5 years who lived farthest from health facilities appeared to benefit the most from azithromycin administration. These findings may help guide the allocation of resources to ensure that those with the least access to existing health resources are prioritized in program implementation. Trial Registration: ClinicalTrials.gov Identifier: NCT02047981.


Asunto(s)
Azitromicina , Centros de Acondicionamiento , Niño , Masculino , Humanos , Adulto , Femenino , Azitromicina/uso terapéutico , Niger/epidemiología , Administración Masiva de Medicamentos , Instituciones de Salud
2.
Nat Cardiovasc Res ; 3(1): 46-59, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-38314318

RESUMEN

Cardiovascular and renal conditions have both shared and distinct determinants. In this study, we applied unsupervised clustering to multiple rounds of the National Health and Nutrition Examination Survey from 1988 to 2018, and identified 10 cardiometabolic and renal phenotypes. These included a 'low risk' phenotype; two groups with average risk factor levels but different heights; one group with low body-mass index and high levels of high-density lipoprotein cholesterol; five phenotypes with high levels of one or two related risk factors ('high heart rate', 'high cholesterol', 'high blood pressure', 'severe obesity' and 'severe hyperglycemia'); and one phenotype with low diastolic blood pressure (DBP) and low estimated glomerular filtration rate (eGFR). Prevalence of the 'high blood pressure' and 'high cholesterol' phenotypes decreased over time, contrasted by a rise in the 'severe obesity' and 'low DBP, low eGFR' phenotypes. The cardiometabolic and renal traits of the US population have shifted from phenotypes with high blood pressure and cholesterol toward poor kidney function, hyperglycemia and severe obesity.

3.
Med Decis Making ; 42(4): 500-512, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-34605718

RESUMEN

BACKGROUND: An established risk model may demonstrate miscalibration, meaning predicted risks do not accurately capture event rates. In some instances, investigators can identify and address the cause of miscalibration. In other circumstances, it may be appropriate to recalibrate the risk model. Existing recalibration methods do not account for settings in which the risk score will be used for risk-based clinical decision making. METHODS: We propose 2 new methods for risk model recalibration when the intended purpose of the risk model is to prescribe an intervention to high-risk individuals. Our measure of risk model clinical utility is standardized net benefit. The first method is a weighted strategy that prioritizes good calibration at or around the critical risk threshold. The second method uses constrained optimization to produce a recalibrated risk model with maximum possible net benefit, thereby prioritizing good calibration around the critical risk threshold. We also propose a graphical tool for assessing the potential for recalibration to improve the net benefit of a risk model. We illustrate these methods by recalibrating the American College of Cardiology (ACC)-American Heart Association (AHA) atherosclerotic cardiovascular disease (ASCVD) risk score within the Multi-Ethnic Study of Atherosclerosis (MESA) cohort. RESULTS: New methods are implemented in the R package ClinicalUtilityRecal. Recalibrating the ACC-AHA-ASCVD risk score for a MESA subcohort results in higher estimated net benefit using the proposed methods compared with existing methods, with improved calibration in the most clinically impactful regions of risk. CONCLUSION: The proposed methods target good calibration for critical risks and can improve the net benefit of a risk model. We recommend constrained optimization when the risk model net benefit is paramount. The weighted approach can be considered when good calibration over an interval of risks is important.


Asunto(s)
Aterosclerosis , Cardiología , American Heart Association , Humanos , Medición de Riesgo/métodos , Factores de Riesgo , Estados Unidos
4.
Lancet ; 398(10302): 772-785, 2021 08 28.
Artículo en Inglés | MEDLINE | ID: mdl-34454675

RESUMEN

BACKGROUND: Stillbirths are a major public health issue and a sensitive marker of the quality of care around pregnancy and birth. The UN Global Strategy for Women's, Children's and Adolescents' Health (2016-30) and the Every Newborn Action Plan (led by UNICEF and WHO) call for an end to preventable stillbirths. A first step to prevent stillbirths is obtaining standardised measurement of stillbirth rates across countries. We estimated stillbirth rates and their trends for 195 countries from 2000 to 2019 and assessed progress over time. METHODS: For a systematic assessment, we created a dataset of 2833 country-year datapoints from 171 countries relevant to stillbirth rates, including data from registration and health information systems, household-based surveys, and population-based studies. After data quality assessment and exclusions, we used 1531 datapoints to estimate country-specific stillbirth rates for 195 countries from 2000 to 2019 using a Bayesian hierarchical temporal sparse regression model, according to a definition of stillbirth of at least 28 weeks' gestational age. Our model combined covariates with a temporal smoothing process such that estimates were informed by data for country-periods with high quality data, while being based on covariates for country-periods with little or no data on stillbirth rates. Bias and additional uncertainty associated with observations based on alternative stillbirth definitions and source types, and observations that were subject to non-sampling errors, were included in the model. We compared the estimated stillbirth rates and trends to previously reported mortality estimates in children younger than 5 years. FINDINGS: Globally in 2019, an estimated 2·0 million babies (90% uncertainty interval [UI] 1·9-2·2) were stillborn at 28 weeks or more of gestation, with a global stillbirth rate of 13·9 stillbirths (90% UI 13·5-15·4) per 1000 total births. Stillbirth rates in 2019 varied widely across regions, from 22·8 stillbirths (19·8-27·7) per 1000 total births in west and central Africa to 2·9 (2·7-3·0) in western Europe. After west and central Africa, eastern and southern Africa and south Asia had the second and third highest stillbirth rates in 2019. The global annual rate of reduction in stillbirth rate was estimated at 2·3% (90% UI 1·7-2·7) from 2000 to 2019, which was lower than the 2·9% (2·5-3·2) annual rate of reduction in neonatal mortality rate (for neonates aged <28 days) and the 4·3% (3·8-4·7) annual rate of reduction in mortality rate among children aged 1-59 months during the same period. Based on the lower bound of the 90% UIs, 114 countries had an estimated decrease in stillbirth rate since 2000, with four countries having a decrease of at least 50·0%, 28 having a decrease of 25·0-49·9%, 50 having a decrease of 10·0-24·9%, and 32 having a decrease of less than 10·0%. For the remaining 81 countries, we found no decrease in stillbirth rate since 2000. Of these countries, 34 were in sub-Saharan Africa, 16 were in east Asia and the Pacific, and 15 were in Latin America and the Caribbean. INTERPRETATION: Progress in reducing the rate of stillbirths has been slow compared with decreases in the mortality rate of children younger than 5 years. Accelerated improvements are most needed in the regions and countries with high stillbirth rates, particularly in sub-Saharan Africa. Future prevention of stillbirths needs increased efforts to raise public awareness, improve data collection, assess progress, and understand public health priorities locally, all of which require investment. FUNDING: Bill & Melinda Gates Foundation and the UK Foreign, Commonwealth and Development Office.


Asunto(s)
Salud Global , Mortalidad Infantil/tendencias , Mortinato/epidemiología , Femenino , Edad Gestacional , Humanos , Lactante , Recién Nacido , Modelos Estadísticos , Embarazo
5.
Curr Org Synth ; 17(1): 73-80, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32103720

RESUMEN

AIMS AND OBJECTIVES: An efficient and facile DBU catalysed synthesis of highly significant motif 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidines under solvent-free condition has been reported. MATERIALS AND METHODS: To a round bottom flask, 1.0 mmol of chalcone (1), 1.5 mmol of 3-amino-1,2,4- triazole (2) and 30 mol% of DBU were added at 70 °C and stirred in solvent-free condition. After the completion of the reaction (monitored by TLC), water (10 ml) was added. The aqueous layer was extracted with ethyl acetate (3 ×10 ml). The combined organic layers were dried over anhydrous Na2SO4. The combined organic layers were evaporated under reduced pressure and the resulting crude product was purified by column chromatography by using ethyl acetate and hexane as eluent. RESULTS: Reaction using chalcone and 3-amino-1,2,4-triazole as model substrates were carried out under different reaction conditions and it was observed that 30 mol% of DBU under the solvent-free condition at 70 °C was the optimum temperature for the proposed synthesis. CONCLUSION: Use of DBU (an organocatalyst) as a base, operational simplicity, high yield of products and short reaction time are some of the significant advantages associated with the proposed strategy.

6.
Stat Commun Infect Dis ; 12(1)2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34141052

RESUMEN

The relationship between hormonal contraceptive method use and sexually transmitted infections (STIs) is not well understood. Studies that implement routine screening for STIs among different contraceptive users, such as the ASPIRE HIV-1 prevention trial, can be useful for identifying potential risk factors of STIs. However, the complex nature of non-random data can lead to challenges in estimation of associations for potential risk factors. In particular, if screening for the disease is not random (i.e. it is driven by symptoms or other clinical indicators), estimates of association can suffer from bias, often referred to as informative sampling bias. Time-varying predictors and potential stratification variables can further contribute to difficulty in obtaining unbiased estimates. In this paper, we estimate the association between time-varying contraceptive use and STI acquisition, in the presence of informative sampling, by extending the work Buzkova (2010). We use a two-step procedure to jointly model the non-random screening process and sexually transmitted infection risk. In the first step, inverse intensity rate ratios (IIRR) weights are estimated. In the second step, a weighted proportional rate model is fit to estimate the IIRR weighted hazard ratio. We apply the method to evaluate the relationship between hormonal contraception and risk of sexually transmitted infections among women participating in a biomedical HIV-1 prevention trial. We compare our results using the proposed weighted method to those generated using conventional approaches that do not account for potential informative sampling bias or do not use the full potential of the data. Using the IIRR weighted approach we found DMPA users have a significantly decreased hazard of T. vaginalis acquisition compared to IUD users (HR: 0.44, 95% CI: (0.25, 0.83)), which is consistent with the literature. We did not find significant increased or decreased hazard of other STIs for hormonal contraceptive users compared to non-hormonal IUD users.

7.
J Int AIDS Soc ; 22(2): e25257, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30816632

RESUMEN

INTRODUCTION: In many African settings, women concurrently face substantial risk of human immunodeficiency virus type 1 (HIV-1) infection, sexually transmitted infections (STIs) and unintended pregnancies. Few studies have evaluated STI risk among users of hormonal implants and copper intrauterine devices (IUDs) although these long-acting reversible contraceptive methods are being promoted widely because of their benefits. Within a prospective study of women at risk for HIV-1, we compared the risk of acquisition of Chlamydia trachomatis, Neisseria gonorrhoeae and Trichomonas vaginalis among women using different contraceptive methods. METHODS: MTN-020/ASPIRE was a randomized trial of the dapivirine vaginal ring for HIV-1 prevention among 2629 women aged 18 to 45 years from Malawi, South Africa, Uganda and Zimbabwe, of whom 2264 used copper IUDs or progestin-based injectables or implants during follow-up. Screening for the above STIs occurred semi-annually. RESULTS: Over 3440 person-years of follow-up, 408 cases of C. trachomatis (incidence 11.86/100 person-years), 196 of N. gonorrhoeae (5.70/100 person-years) and 213 cases of T. vaginalis (6.19/100 person-years) were detected. C. trachomatis and N. gonorrhoeae incidence were not significantly different across contraceptive methods. T. vaginalis incidence was significantly higher for copper IUD users compared to depot medroxyprogesterone acetate (DMPA), implant and norethisterone enanthate users. CONCLUSION: Among African women at high HIV-1 risk, STIs were common. Risk of cervical infections did not differ across contraceptive methods. Significantly higher rates of T. vaginalis were observed among progestin-based methods compared to copper IUD users. Overall, these findings call for more intensive routine screening for STIs, and they support current World Health Organization guidance that women should have a wide range of contraceptive options.


Asunto(s)
Anticoncepción , Infecciones por VIH/prevención & control , Enfermedades de Transmisión Sexual/prevención & control , Adolescente , Adulto , Dispositivos Anticonceptivos Femeninos , Femenino , Infecciones por VIH/epidemiología , Humanos , Incidencia , Malaui/epidemiología , Persona de Mediana Edad , Embarazo , Estudios Prospectivos , Enfermedades de Transmisión Sexual/epidemiología , Sudáfrica/epidemiología , Uganda/epidemiología , Mujeres/psicología , Adulto Joven , Zimbabwe/epidemiología
8.
Photochem Photobiol ; 95(2): 522-531, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30182431

RESUMEN

In this study, titanium tetra-isopropoxide was used as a precursor of TiO2 for in situ coating on cotton fabric by sol-gel method. Subsequently, silver nitrate was used as doping agent to prepare silver-doped TiO2 -coated cotton fabric during hydrothermal treatment. The treated samples were characterized through field-emission scanning electron microscopy, energy-dispersive X-ray analysis, inductively coupled plasma-mass spectroscopy and UV-visible absorption spectroscopy to study morphology, composition of deposited elements and light absorption behavior of treated samples. X-ray photoelectron spectroscopy was carried out to analyze the electronic state of silver in TiO2 -coated fabric after hydrothermal treatment. Doping of silver on TiO2 -coated fabric and subsequent hydrothermal treatment was found to enhance dye decolorization rate of rhodamine B dye solution in both UV and visible light radiations with respect to undoped TiO2 . The study shows that an optimal level of silver-doped TiO2 -coated fabric can be used repeatedly for dye decolorization without significant loss in its photocatalytic activity. The self-cleaning properties of samples were also studied using methylene blue as a staining agent. It was observed that the presence of 1.8% silver on the weight of titanium in doped samples provides almost 82% of stain degradation.

9.
Photochem Photobiol ; 94(3): 503-511, 2018 05.
Artículo en Inglés | MEDLINE | ID: mdl-29349783

RESUMEN

In this article, the deposition of TiO2 on cotton fabric using sol-gel technique has been described. Various process routes (pad-dry-cure, pad-dry-hydrothermal and pad-dry-solvothermal) were examined to impart a stable coating of TiO2 on fabric. The role of precursor concentration, process temperature and time of treatment were studied to aim at a wash durable, UV protective and self-cleaning property in the treated fabric. EDX and ICP-MS techniques were used to examine the add-on percentage of TiO2 on cotton fabrics treated via different routes. It has been found that the TiO2 remains largely amorphous and nondurable if it is given a short thermal treatment. To convert the deposited TiO2 to its anatase crystal form, a prolonged hydrothermal treatment for at least 3 h needs to be given. TiO2 deposition levels of less than 0.1% were found to be effective in imparting reasonable degree of UV protection and self-cleaning property to the cotton fabric. The self-cleaning ability of the treated fabric against coffee stain was also studied and was found to be related to the process route and the deposition levels of TiO2 .

10.
J Acquir Immune Defic Syndr ; 70(2): 212-7, 2015 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-26049280

RESUMEN

A recent analysis from South Africa reported no association between age-disparate relationships and HIV-1 acquisition. We assessed the association between male partner age and HIV-1 acquisition among South African women participating in the VOICE trial. Of 4077 women enrolled, 3789 had complete data; 26% and 5% reported having a partner >5 and >10 years older at enrollment, respectively. Reporting a partner >5 years older (hazard ratio = 1.00; 95% confidence interval: 0.74 to 1.35) or >10 older (hazard ratio = 0.92; 95% confidence interval: 0.49 to 1.74) was not associated with HIV-1 acquisition. These data corroborate recent reports and may suggest a shift in local epidemiology of heterosexual HIV-1 transmission.


Asunto(s)
Infecciones por VIH/transmisión , VIH-1 , Parejas Sexuales , Adolescente , Adulto , Envejecimiento , Estudios de Cohortes , Femenino , Infecciones por VIH/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Sudáfrica/epidemiología , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...