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1.
N Engl J Med ; 381(6): 520-530, 2019 08 08.
Artículo en Inglés | MEDLINE | ID: mdl-31173679

RESUMEN

BACKGROUND: Observational studies support an association between a low blood 25-hydroxyvitamin D level and the risk of type 2 diabetes. However, whether vitamin D supplementation lowers the risk of diabetes is unknown. METHODS: We randomly assigned adults who met at least two of three glycemic criteria for prediabetes (fasting plasma glucose level, 100 to 125 mg per deciliter; plasma glucose level 2 hours after a 75-g oral glucose load, 140 to 199 mg per deciliter; and glycated hemoglobin level, 5.7 to 6.4%) and no diagnostic criteria for diabetes to receive 4000 IU per day of vitamin D3 or placebo, regardless of the baseline serum 25-hydroxyvitamin D level. The primary outcome in this time-to-event analysis was new-onset diabetes, and the trial design was event-driven, with a target number of diabetes events of 508. RESULTS: A total of 2423 participants underwent randomization (1211 to the vitamin D group and 1212 to the placebo group). By month 24, the mean serum 25-hydroxyvitamin D level in the vitamin D group was 54.3 ng per milliliter (from 27.7 ng per milliliter at baseline), as compared with 28.8 ng per milliliter in the placebo group (from 28.2 ng per milliliter at baseline). After a median follow-up of 2.5 years, the primary outcome of diabetes occurred in 293 participants in the vitamin D group and 323 in the placebo group (9.39 and 10.66 events per 100 person-years, respectively). The hazard ratio for vitamin D as compared with placebo was 0.88 (95% confidence interval, 0.75 to 1.04; P = 0.12). The incidence of adverse events did not differ significantly between the two groups. CONCLUSIONS: Among persons at high risk for type 2 diabetes not selected for vitamin D insufficiency, vitamin D3 supplementation at a dose of 4000 IU per day did not result in a significantly lower risk of diabetes than placebo. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases and others; D2d ClinicalTrials.gov number, NCT01942694.).


Asunto(s)
Colecalciferol/uso terapéutico , Diabetes Mellitus Tipo 2/prevención & control , Suplementos Dietéticos , Estado Prediabético/tratamiento farmacológico , Vitaminas/uso terapéutico , Administración Oral , Anciano , Colecalciferol/administración & dosificación , Supervivencia sin Enfermedad , Método Doble Ciego , Femenino , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Estado Prediabético/sangre , Factores de Riesgo , Insuficiencia del Tratamiento , Vitamina D/análogos & derivados , Vitamina D/sangre , Vitaminas/administración & dosificación
2.
J Biopharm Stat ; 27(5): 797-808, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28166460

RESUMEN

We evaluate properties of sample size re-estimation (SSR) designs similar to the promising zone design considered by Mehta and Pocock (2011). We evaluate these designs under the assumption of a true effect size of 1.1 down to 0.4 of the protocol-specified effect size by six measures: 1. The probability of a sample size increase, 2. The mean proportional increase in sample size given an increase; 3 and 4. The mean true conditional power with and without a sample size increase; 5 and 6. The expected increase in sample size and power due to the SSR procedure. These measures show the probability of a sample size increase and the cost/benefit for given true effect sizes, particularly when the SSR may either be pursuing a small effect size of little clinical importance or be unnecessary when the true effect size is close to the protocol-specified effect size. The results show the clear superiority of conducting the SSR late in the study and the inefficiency of a mid-study SSR. The results indicate that waiting until late in the study for the SSR yields a smaller, better targeted set of studies with a greater increase in overall power than a mid-study SSR.


Asunto(s)
Investigación Biomédica/estadística & datos numéricos , Tamaño de la Muestra , Modificador del Efecto Epidemiológico , Humanos
3.
PLoS Med ; 13(6): e1002038, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-27327774

RESUMEN

BACKGROUND: Under-five mortality is declining in Ghana and many other countries. Very few studies have measured under-five mortality-and its social and environmental risk factors-at fine spatial resolutions, which is relevant for policy purposes. Our aim was to estimate under-five mortality and its social and environmental risk factors at the district level in Ghana. METHODS AND FINDINGS: We used 10% random samples of Ghana's 2000 and 2010 National Population and Housing Censuses. We applied indirect demographic methods and a Bayesian spatial model to the information on total number of children ever born and children surviving to estimate under-five mortality (probability of dying by 5 y of age, 5q0) for each of Ghana's 110 districts. We also used the census data to estimate the distributions of households or persons in each district in terms of fuel used for cooking, sanitation facility, drinking water source, and parental education. Median district 5q0 declined from 99 deaths per 1,000 live births in 2000 to 70 in 2010. The decline ranged from <5% in some northern districts, where 5q0 had been higher in 2000, to >40% in southern districts, where it had been lower in 2000, exacerbating existing inequalities. Primary education increased in men and women, and more households had access to improved water and sanitation and cleaner cooking fuels. Higher use of liquefied petroleum gas for cooking was associated with lower 5q0 in multivariate analysis. CONCLUSIONS: Under-five mortality has declined in all of Ghana's districts, but the cross-district inequality in mortality has increased. There is a need for additional data, including on healthcare, and additional environmental and socioeconomic measurements, to understand the reasons for the variations in mortality levels and trends.


Asunto(s)
Mortalidad del Niño , Mortalidad Infantil , Factores Socioeconómicos , Teorema de Bayes , Censos , Preescolar , Femenino , Geografía , Ghana , Humanos , Lactante , Recién Nacido , Masculino , Factores de Riesgo
7.
Am J Ther ; 20(3): 235-46, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23615317

RESUMEN

Smoking is a major modifiable risk factor for cardiovascular (CV) disease. Varenicline is a pharmacological aid for smoking cessation. To explore the CV safety of varenicline, we investigated the incidence of CV events in varenicline-treated subjects across all phase 2-4 randomized placebo-controlled clinical trials of ≥12-week treatment duration conducted in smokers aged ≥18 years and sponsored by the drug manufacturer. This manuscript reports a subject-level meta-analysis of time to major adverse cardiovascular events (MACE; defined as CV-related death, nonfatal myocardial infarction, nonfatal stroke) and time to MACE+ (defined as MACE plus worsening or any procedure for peripheral vascular disease, hospitalization for angina, or performance of coronary revascularization). All events were adjudicated by an independent adjudication committee, blind to treatment assignment. Events were assessed during treatment and up to 30 days after the last treatment dose. The primary analytical method was a stratified logrank time-to-event analysis; secondary analyses were meta-analyses of incidence rate ratios and rate differences. Overall, 7002 subjects were included (varenicline: 4190; placebo: 2812) from 15 studies. MACE were reported by 13 varenicline subjects (0.31%) and 6 placebo subjects (0.21%) [hazard ratio, 1.95; 95% confidence interval (CI): 0.79-4.82; P = 0.15; risk difference, 0.006 events per subject-year; 95% CI: -0.003, 0.015, P = 0.19]. MACE+ were reported by 26 varenicline subjects (0.62%) and 12 placebo subjects (0.43%) (hazard ratio, 1.74; 95% CI: 0.91-3.34, P = 0.10; risk difference, 0.010; 95% CI: -0.002, 0.022, P = 0.11). This subject-level meta-analysis of MACE or MACE+ up to 30 days posttreatment in placebo-controlled clinical trials of varenicline found a trend toward increased incidence of these events in varenicline-treated patients that did not reach statistical significance. The overall number of events was low and the absolute risk of CV events with varenicline was small.


Asunto(s)
Benzazepinas/efectos adversos , Enfermedades Cardiovasculares/inducido químicamente , Agonistas Nicotínicos/efectos adversos , Quinoxalinas/efectos adversos , Cese del Hábito de Fumar/métodos , Angina Inestable/inducido químicamente , Angina Inestable/epidemiología , Angina Inestable/terapia , Enfermedades Cardiovasculares/epidemiología , Enfermedades Cardiovasculares/mortalidad , Enfermedades Cardiovasculares/terapia , Método Doble Ciego , Humanos , Incidencia , Infarto del Miocardio/inducido químicamente , Infarto del Miocardio/epidemiología , Enfermedades Vasculares Periféricas/inducido químicamente , Enfermedades Vasculares Periféricas/epidemiología , Enfermedades Vasculares Periféricas/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto , Medición de Riesgo , Accidente Cerebrovascular/inducido químicamente , Accidente Cerebrovascular/epidemiología , Resultado del Tratamiento , Vareniclina
8.
Prev Sci ; 14(2): 111-20, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21562742

RESUMEN

In the analysis of prevention and intervention studies, it is often important to investigate whether treatment effects vary among subgroups of patients defined by individual characteristics. These "subgroup analyses" can provide information about how best to use a new prevention or intervention program. However, subgroup analyses can be misleading if they test data-driven hypotheses, employ inappropriate statistical methods, or fail to account for multiple testing. These problems have led to a general suspicion of findings from subgroup analyses. This article discusses sound methods for conducting subgroup analyses to detect moderators. Multiple authors have argued that, to assess whether a treatment effect varies across subgroups defined by patient characteristics, analyses should be based on tests for interaction rather than treatment comparisons within the subgroups. We discuss the concept of heterogeneity and its dependence on the metric used to describe treatment effects. We discuss issues of multiple comparisons related to subgroup analyses and the importance of considering multiplicity in the interpretation of results. We also discuss the types of questions that would lead to subgroup analyses and how different scientific goals may affect the study at the design stage. Finally, we discuss subgroup analyses based on post-baseline factors and the complexity associated with this type of subgroup analysis.


Asunto(s)
Variaciones Dependientes del Observador , Servicios Preventivos de Salud/organización & administración , Humanos
9.
J Pediatr ; 159(5): 743-749.e1-2, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21658712

RESUMEN

OBJECTIVE: To measure the changes in whole blood fatty acid levels in premature infants and evaluate associations between these changes and neonatal morbidities. STUDY DESIGN: This was a retrospective cohort study of 88 infants born at <30 weeks' gestation. Serial fatty acid profiles during the first postnatal month and infant outcomes, including chronic lung disease (CLD), retinopathy of prematurity, and late-onset sepsis, were analyzed. Regression modeling was applied to determine the association between fatty acid levels and neonatal morbidities. RESULTS: Docosahexaenoic acid (DHA) and arachidonic acid levels declined rapidly in the first postnatal week, with a concomitant increase in linoleic acid levels. Decreased DHA level was associated with an increased risk of CLD (OR, 2.5; 95% CI, 1.3-5.0). Decreased arachidonic acid level was associated with an increased risk of late-onset sepsis (hazard ratio, 1.4; 95% CI, 1.1-1.7). The balance of fatty acids was also a predictor of CLD and late-onset sepsis. An increased linoleic acid:DHA ratio was associated with an increased risk of CLD (OR, 8.6; 95% CI, 1.4-53.1) and late-onset sepsis (hazard ratio, 4.6; 95% CI, 1.5-14.1). CONCLUSION: Altered postnatal fatty acid levels in premature infants are associated with an increased risk of CLD and late-onset sepsis.


Asunto(s)
Ácido Araquidónico/sangre , Ácidos Docosahexaenoicos/sangre , Recien Nacido Prematuro/sangre , Enfermedades Pulmonares/sangre , Enfermedad Crónica , Estudios de Cohortes , Ácidos Grasos/sangre , Femenino , Humanos , Recién Nacido , Enfermedades Pulmonares/epidemiología , Masculino , Terapia por Inhalación de Oxígeno , Modelos de Riesgos Proporcionales , Retinopatía de la Prematuridad/sangre , Retinopatía de la Prematuridad/epidemiología , Estudios Retrospectivos , Sepsis/sangre , Sepsis/epidemiología
10.
Occup Environ Med ; 68(4): 279-85, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-20935283

RESUMEN

OBJECTIVES: Slips and falls are a leading cause of injury at work. Few studies, however, have systematically examined risk factors of slipping outside the laboratory environment. This study examined the association between floor surface characteristics, slip-resistant shoes, floor cleaning frequency and the risk of slipping in limited-service restaurant workers. METHODS: 475 workers from 36 limited-service restaurants from three major chains in six states in the USA were recruited to participate in a prospective cohort study of workplace slipping. Kitchen floor surface roughness and coefficient of friction (COF) were measured in eight working areas and then averaged within each restaurant. The use of slip-resistant shoes was determined by examining the participant's shoes and noting the presence of a 'slip-resistant' marking on the sole. Restaurant managers reported the frequency of daily kitchen floor cleaning. Participants reported their slip experience and work hours weekly for up to 12 weeks. The survey materials were made available in three languages: English, Spanish and Portuguese. The associations between rate of slipping and risk factors were assessed using a multivariable negative binomial generalised estimating equation model. RESULTS: The mean of individual slipping rate varied among the restaurants from 0.02 to 2.49 slips per 40 work hours. After adjusting for age, gender, BMI, education, primary language, job tenure and restaurant chain, the use of slip-resistant shoes was associated with a 54% reduction in the reported rate of slipping (95% CI 37% to 64%), and the rate of slipping decreased by 21% (95% CI 5% to 34%) for each 0.1 increase in the mean kitchen COF. Increasing floor cleaning frequency was significantly associated with a decreasing rate of slipping when considered in isolation but not after statistical adjustment for other factors. CONCLUSION: These results provide support for the use of slip-resistant shoes and measures to increase COF as preventive interventions to reduce slips, falls and injuries.


Asunto(s)
Accidentes por Caídas/prevención & control , Accidentes de Trabajo/prevención & control , Pisos y Cubiertas de Piso/estadística & datos numéricos , Restaurantes/estadística & datos numéricos , Zapatos , Accidentes por Caídas/estadística & datos numéricos , Accidentes de Trabajo/estadística & datos numéricos , Adolescente , Adulto , Anciano , Planificación Ambiental , Femenino , Fricción , Humanos , Higiene , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Riesgo , Administración de la Seguridad/métodos , Propiedades de Superficie , Estados Unidos , Adulto Joven
11.
Occup Environ Med ; 68(8): 575-81, 2011 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-21097951

RESUMEN

OBJECTIVES: This nested case-crossover study examined the association between rushing, distraction and walking on a contaminated floor and the rate of slipping, and whether the effects varied according to weekly hours worked, job tenure and use of slip-resistant shoes. METHODS: At baseline, workers from 30 limited-service restaurants in the USA reported average work hours, average weekly duration of exposure to each transient risk factor and job tenure at the current location. Use of slip-resistant shoes was determined. During the following 12 weeks, participants reported weekly their slip experience and exposures to the three transient exposures at the time of slipping. The case-crossover design was used to estimate the rate ratios using the Mantel-Haenszel estimator for person-time data. RESULTS: Among 396 participants providing baseline information, 210 reported one or more slips with a total of 989 slips. Rate of slipping was 2.9 times higher when rushing as compared to working at a normal pace (95% CI 2.5 to 3.3). Rate of slipping was also significantly increased by distraction (rate ratio (RR) 1.7, 95% CI 1.5 to 2.0) and walking on a contaminated floor (RR 14.6, 95% CI 12.6 to 17.0). Use of slip-resistant shoes decreased the effects of rushing and walking on a contaminated floor. Rate ratios for all three transient factors decreased monotonically as job tenure increased. CONCLUSION: The results suggest the importance of these transient risk factors, particularly floor contamination, on rate of slipping in limited-service restaurant workers. Stable characteristics, such as slip-resistant shoes, reduced the effects of transient exposures.


Asunto(s)
Accidentes por Caídas/estadística & datos numéricos , Accidentes de Trabajo/estadística & datos numéricos , Restaurantes/estadística & datos numéricos , Adolescente , Adulto , Atención , Métodos Epidemiológicos , Femenino , Pisos y Cubiertas de Piso , Humanos , Masculino , Persona de Mediana Edad , Admisión y Programación de Personal/estadística & datos numéricos , Zapatos , Propiedades de Superficie , Estados Unidos/epidemiología , Adulto Joven
12.
Ann Neurol ; 65(4): 386-93, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19399887

RESUMEN

OBJECTIVE: Randomized, blinded trial of intramuscular gene transfer using plasmid vascular endothelial growth factor (VEGF) to treat diabetic polyneuropathy. METHODS: Diabetic patients with polyneuropathy were randomized to receive a VEGF-to-placebo ratio of 3:1. Three sets of injections were given at eight standardized sites adjacent to the sciatic, peroneal, and tibial nerves of one leg. Primary outcomes were change in symptom score at 6 months and a prespecified overall clinical and electrophysiological improvement score. Secondary outcomes were differences in symptoms, examination scores, visual analog pain scale, nerve conduction, and quantitative sensory testing. RESULTS: Thirty-nine patients received plasmid VEGF and 11 received placebo. Mean symptom score improved in both legs at 6 months, favoring VEGF over placebo (-1.2 +/- 0.5 vs -0.9 +/- 0.5; p < 0.01 after adjustment for change in the untreated leg) and compared with the untreated leg (-0.7 +/- 0.5; p = 0.02). The region of sensory loss and visual analog pain scale improved in the treated group (-1.5 vs -0.5; p = 0.01). Twelve of 39 VEGF versus 2 of 11 placebo patients met criterion for overall improvement. Other measures including nerve conduction potentials did not improve. There were 84 adverse events in VEGF patients, and 22 were serious; there were 51 events in placebo patients, and 2 were serious. INTERPRETATION: Intramuscular plasmid VEGF gene transfer improved diabetic neuropathic symptoms, meeting primary end-point criteria for efficacy but not affecting most secondary measures. Treatment was associated with more serious adverse events that did not reach statistical significance. These results are not conclusive but may justify further clinical study.


Asunto(s)
Neuropatías Diabéticas/terapia , Técnicas de Transferencia de Gen , Terapia Genética/métodos , Factor A de Crecimiento Endotelial Vascular/genética , Factor A de Crecimiento Endotelial Vascular/uso terapéutico , Anciano , Estudios de Cohortes , Neuropatías Diabéticas/metabolismo , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Conducción Nerviosa/genética , Dimensión del Dolor , Nervios Periféricos/fisiopatología , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
13.
Respirology ; 15(6): 881-5; discussion 885-6, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20624253

RESUMEN

There is controversy regarding the possibility that long-acting beta-agonists (LABA) may paradoxically contribute adversely to asthma mortality. While studies and meta-analyses indicate increased risk, epidemiological data indicate a slow fall in asthma mortality since the introduction of LABA. Advocates for LABA propose that mandatory simultaneous use of inhaled corticosteroids satisfactorily reduce any potential risk. In the face of lingering doubts, others propose that LABA should be withdrawn from use. In this pro-con article, Kazani et al. provide the rationale for a modified randomized controlled trial that would define the level of risk more clearly, and provide the basis for a clear judgment to be made. Sears argues that current knowledge about the risks associated with LABA, especially when prescribed as monotherapy, provides sufficient evidence for clinicians and licensing authorities alike, and that the logistics and likely outcomes for a large prospective study are unjustified.


Asunto(s)
Agonistas Adrenérgicos beta/efectos adversos , Asma/tratamiento farmacológico , Corticoesteroides/uso terapéutico , Agonistas Adrenérgicos beta/uso terapéutico , Antiasmáticos/uso terapéutico , Asma/mortalidad , Humanos , Metaanálisis como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto
14.
Eur Heart J ; 30(12): 1457-66, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19351691

RESUMEN

AIMS: To evaluate the associations of myocardial infarction (MI) and major bleeding with 1-year mortality. Both MI and major bleeding predict 1-year mortality in patients presenting with acute coronary syndrome (ACS). However, the risk of each of these events on the magnitude and timing of mortality has not been well studied. METHODS AND RESULTS: A multivariable Cox regression model was developed relating 13 independent baseline predictors to 1-year mortality for 13 819 patients with moderate and high-risk ACS enrolled in the Acute Catheterization and Urgent Intervention Triage strategy trial. After adjustment for baseline predictors, Cox models with major bleeding and recurrent MI as time-updated covariates estimated the effect of these events on mortality hazard over time. Within 30 days of randomization, 705 patients (5.1%) had an MI, 645 (4.7%) had a major bleed; 524 (3.8%) died within a year. The occurrence of an MI was associated with a hazard ratio of 3.1 compared with patients not yet having an MI, after adjustment for baseline predictors. However, MI within 30 days markedly increased the mortality risk for the first 2 days after the event (adjusted hazard ratio of 17.6), but this risk declined rapidly post-infarct (hazard ratio of 1.4 beyond 1 month after the MI event). In contrast, major bleeding had a prolonged association with mortality risk (hazard ratio of 3.5) which remained fairly steady over time throughout 1 year. CONCLUSION: After accounting for baseline predictors of mortality, major bleeds and MI have similar overall strength of association with mortality in the first year after ACS. MI is correlated with a dramatic increase in short-term risk, whereas major bleeding correlates with a more prolonged mortality risk.


Asunto(s)
Síndrome Coronario Agudo/mortalidad , Hemorragia/mortalidad , Infarto del Miocardio/mortalidad , Síndrome Coronario Agudo/tratamiento farmacológico , Anciano , Angiografía Coronaria , Forma MB de la Creatina-Quinasa/sangre , Métodos Epidemiológicos , Femenino , Hemorragia/complicaciones , Hemorragia/terapia , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/complicaciones , Infarto del Miocardio/terapia , Terapia Trombolítica/métodos , Factores de Tiempo , Troponina/sangre
16.
N Engl J Med ; 355(21): 2203-16, 2006 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-17124018

RESUMEN

BACKGROUND: Current guidelines for patients with moderate- or high-risk acute coronary syndromes recommend an early invasive approach with concomitant antithrombotic therapy, including aspirin, clopidogrel, unfractionated or low-molecular-weight heparin, and glycoprotein IIb/IIIa inhibitors. We evaluated the role of thrombin-specific anticoagulation with bivalirudin in such patients. METHODS: We assigned 13,819 patients with acute coronary syndromes to one of three antithrombotic regimens: unfractionated heparin or enoxaparin plus a glycoprotein IIb/IIIa inhibitor, bivalirudin plus a glycoprotein IIb/IIIa inhibitor, or bivalirudin alone. The primary end points were a composite ischemia end point (death, myocardial infarction, or unplanned revascularization for ischemia), major bleeding, and the net clinical outcome, defined as the combination of composite ischemia or major bleeding. RESULTS: Bivalirudin plus a glycoprotein IIb/IIIa inhibitor, as compared with heparin plus a glycoprotein IIb/IIIa inhibitor, was associated with noninferior 30-day rates of the composite ischemia end point (7.7% and 7.3%, respectively), major bleeding (5.3% and 5.7%), and the net clinical outcome end point (11.8% and 11.7%). Bivalirudin alone, as compared with heparin plus a glycoprotein IIb/IIIa inhibitor, was associated with a noninferior rate of the composite ischemia end point (7.8% and 7.3%, respectively; P=0.32; relative risk, 1.08; 95% confidence interval [CI], 0.93 to 1.24) and significantly reduced rates of major bleeding (3.0% vs. 5.7%; P<0.001; relative risk, 0.53; 95% CI, 0.43 to 0.65) and the net clinical outcome end point (10.1% vs. 11.7%; P=0.02; relative risk, 0.86; 95% CI, 0.77 to 0.97). CONCLUSIONS: In patients with moderate- or high-risk acute coronary syndromes who were undergoing invasive treatment with glycoprotein IIb/IIIa inhibitors, bivalirudin was associated with rates of ischemia and bleeding that were similar to those with heparin. Bivalirudin alone was associated with similar rates of ischemia and significantly lower rates of bleeding. (ClinicalTrials.gov number, NCT00093158 [ClinicalTrials.gov].).


Asunto(s)
Angina Inestable/tratamiento farmacológico , Anticoagulantes/uso terapéutico , Fragmentos de Péptidos/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Angina Inestable/terapia , Angioplastia Coronaria con Balón , Anticoagulantes/efectos adversos , Puente de Arteria Coronaria , Quimioterapia Combinada , Enoxaparina/uso terapéutico , Femenino , Hemorragia/inducido químicamente , Heparina/uso terapéutico , Hirudinas/efectos adversos , Humanos , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/epidemiología , Fragmentos de Péptidos/efectos adversos , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Proteínas Recombinantes/efectos adversos , Proteínas Recombinantes/uso terapéutico
17.
Lancet ; 369(9565): 907-19, 2007 Mar 17.
Artículo en Inglés | MEDLINE | ID: mdl-17368152

RESUMEN

BACKGROUND: The aim of this study was to assess anticoagulation with the direct thrombin inhibitor bivalirudin during percutaneous coronary intervention in individuals with moderate and high-risk acute coronary syndromes. METHODS: 13,819 individuals in the Acute Catheterization and Urgent Intervention Triage strategy (ACUITY) trial were prospectively randomly assigned to receive heparin (unfractionated or enoxaparin) plus glycoprotein IIb/IIIa inhibitors, bivalirudin plus glycoprotein IIb/IIIa inhibitors, or bivalirudin alone. Of these individuals, 7789 underwent percutaneous coronary intervention after angiography. The effect of the three regimens on the primary 30-day endpoints of composite ischaemia (death, myocardial infarction, or unplanned revascularisation for ischaemia), major bleeding, and net clinical outcomes (composite ischaemia or major bleeding) was assessed in this subgroup. Analyses were done by intention to treat. This trial is registered with ClinicalTrials.gov, with the number NCT00093158. FINDINGS: Of the individuals who underwent percutaneous coronary intervention, 2561 received heparin plus glycoprotein IIb/IIIa inhibitors, 2609 received bivalirudin plus glycoprotein IIb/IIIa inhibitors, and 2619 received bivalirudin alone. 26 (0.3%) individuals dropped out or were lost to follow-up. There was no significant difference in the proportion of individuals with composite ischaemia, major bleeding, or net clinical outcomes at 30 days between those who received bivalirudin plus glycoprotein IIb/IIIa inhibitors and those who received heparin plus glycoprotein IIb/IIIa inhibitors (composite ischaemia: 243 [9%] patients vs 210 [8%] patients, p=0.16; major bleeding: 196 [8%] patients vs 174 [7%] patients, p=0.32; net clinical outcomes: 389 [15%] patients vs 341 [13%] patients, p=0.1). Rates of composite ischaemia were much the same in those who received bivalirudin alone and those who received heparin plus glycoprotein IIb/IIIa inhibitors (230 [9%] patients vs 210 [8%] patients, p=0.45); however, there were significantly fewer individuals who experienced major bleeding among those who received bivalirudin alone than among those who received heparin plus glycoprotein IIb/IIIa inhibitors (92 [4%] patients vs 174 [7%] patients, p<0.0001, relative risk 0.52, 95% CI 0.40-0.66), resulting in a trend towards better 30-day net clinical outcomes (303 [12%] patients vs 341 [13%] patients, p=0.057; 0.87, 0.75-1.00). INTERPRETATION: Substitution of unfractionated heparin or enoxaparin with bivalirudin results in comparable clinical outcomes in patients with moderate and high-risk acute coronary syndromes treated with glycoprotein IIb/IIIa inhibitors in whom percutaneous coronary intervention is done. Anticoagulation with bivalirudin alone suppresses adverse ischaemic events to a similar extent as does heparin plus glycoprotein IIb/IIIa inhibitors, while significantly lowering the risk of major haemorrhagic complications.


Asunto(s)
Angioplastia Coronaria con Balón , Anticoagulantes/uso terapéutico , Isquemia Miocárdica/terapia , Fragmentos de Péptidos/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Terapia Combinada/métodos , Quimioterapia Combinada , Enoxaparina/uso terapéutico , Femenino , Heparina/uso terapéutico , Hirudinas , Humanos , Masculino , Persona de Mediana Edad , Isquemia Miocárdica/diagnóstico , Inhibidores de Agregación Plaquetaria/uso terapéutico , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/antagonistas & inhibidores , Estudios Prospectivos , Proteínas Recombinantes/uso terapéutico , Resultado del Tratamiento
18.
Cancer Causes Control ; 19(10): 1305-18, 2008 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18704721

RESUMEN

OBJECTIVE: To test whether reported associations between race/ethnicity and breast cancer estrogen receptor (ER) status are inflated due to missing ER data, lack of socioeconomic data, and use of the odds ratio (OR) rather than the prevalence ratio (PR). METHODS: We geocoded and added census tract socioeconomic data to all cases of primary invasive breast cancer (n = 42,420) among women diagnosed between 1998 and 2002 in two California cancer registries (San Francisco Bay Area; Los Angeles County) and analyzed the data using log binomial regression. RESULTS: Adjusting for socioeconomic position and tumor characteristics, in models using the imputed data, reduced the PR for the black versus white excess risk of being ER--from 1.76 (95% CI: 1.66, 1.86; adjusted for age and catchment area) to 1.47 (95% CI: 1.38, 1.56). The latter parameter estimate was 16% greater (i.e., 1.56) in models excluding women with missing ER data, and was 43% greater when estimated using the OR (i.e., 1.82). CONCLUSION(S): Studies on race/ethnicity and ER status that fail to account for missing data and socioeconomic data and report the OR are likely to yield inflated estimates of racial/ethnic disparities in ER status.


Asunto(s)
Neoplasias de la Mama/etnología , Neoplasias de la Mama/epidemiología , Censos , Grupos Raciales/etnología , Receptores de Estrógenos/metabolismo , Negro o Afroamericano/etnología , Pueblo Asiatico/etnología , Neoplasias de la Mama/diagnóstico , California/epidemiología , California/etnología , Áreas de Influencia de Salud , Femenino , Hispánicos o Latinos/etnología , Humanos , Incidencia , Nativos de Hawái y Otras Islas del Pacífico/etnología , Invasividad Neoplásica , Oportunidad Relativa , Pobreza , Prevalencia , Sistema de Registros/estadística & datos numéricos , Análisis de Regresión , Factores Socioeconómicos , Población Blanca/etnología
19.
J Biopharm Stat ; 18(6): 1184-96, 2008.
Artículo en Inglés | MEDLINE | ID: mdl-18991116

RESUMEN

There is considerable interest in methods that use accumulated data to modify trial sample size. However, sample size re-estimation in group sequential designs has been controversial. We describe a method for sample size re-estimation at the penultimate stage of a group sequential design that achieves specified power against an alternative hypothesis corresponding to the current point estimate of the treatment effect.


Asunto(s)
Ensayos Clínicos como Asunto/estadística & datos numéricos , Interpretación Estadística de Datos , Modelos Estadísticos , Tamaño de la Muestra , Simulación por Computador , Humanos , Cadenas de Markov , Factores de Tiempo , Resultado del Tratamiento
20.
J Gen Intern Med ; 22(1): 92-7, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17351846

RESUMEN

BACKGROUND: Alcohol misuse is a growing public health concern for older adults, particularly among primary care patients. OBJECTIVES: To determine alcohol consumption patterns and the characteristics associated with at-risk drinking in a large sample of elderly primary care patients. DESIGN: Cross-sectional analysis of multisite screening data from 6 VA Medical Centers, 2 hospital-based health care networks, and 3 Community Health Centers. PARTICIPANTS: Patients, 43,606, aged 65 to 103 years, with scheduled primary care appointments were approached for screening; 27,714 (63.6%) consented to be screened. The final sample of persons with completed screens comprised 24,863 patients. MEASUREMENTS: Quantity and frequency of alcohol use, demographics, social support measures, and measures of depression/anxiety. RESULTS: Of the 24,863 older adults screened, 70.0% reported no consumption of alcohol in the past year, 21.5% were moderate drinkers (1-7 drinks/week), 4.1% were at-risk drinkers (8-14 drinks/week), and 4.5% were heavy (>14 drinks/week) or binge drinkers. Heavy drinking showed significant positive association with depressive/anxiety symptoms [Odds ratio (OR) (95% CI): 1.79 (1.30, 2.45)] and less social support [OR (95% CI): 2.01 (1.14, 2.56)]. Heavy drinking combined with binging was similarly positively associated with depressive/anxiety symptoms [OR (95%): 1.70 (1.33, 2.17)] and perceived poor health [OR (95% CI): 1.27 (1.03, 1.57)], while at-risk drinking was not associated with any of these variables. CONCLUSIONS: The majority of participants were nondrinkers; among alcohol users, at-risk drinkers did not differ significantly from moderate drinkers in their characteristics or for the 3 health parameters evaluated. In contrast, heavy drinking was associated with depression and anxiety and less social support, and heavy drinking combined with binge drinking was associated with depressive/anxiety symptoms and perceived poor health.


Asunto(s)
Consumo de Bebidas Alcohólicas/epidemiología , Factores de Edad , Anciano , Anciano de 80 o más Años , Consumo de Bebidas Alcohólicas/psicología , Ansiedad/epidemiología , Estudios Transversales , Depresión/epidemiología , Femenino , Estado de Salud , Humanos , Masculino , Atención Primaria de Salud , Grupos Raciales/estadística & datos numéricos , Distribución por Sexo , Factores Sexuales , Apoyo Social , Estados Unidos/epidemiología
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