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1.
J Biopharm Stat ; : 1-20, 2023 Oct 12.
Artículo en Inglés | MEDLINE | ID: mdl-37823377

RESUMEN

There are good reasons to perform a randomized controlled trial (RCT) even in early phases of clinical development. However, the low sample sizes in those settings lead to high variability of the treatment effect estimate. The variability could be reduced by adding external control data if available. For the common setting of suitable subject-level control group data only available from one external (clinical trial or real-world) data source, we evaluate different analysis options for estimating the treatment effect via hazard ratios. The impact of the external control data is usually guided by the level of similarity with the current RCT data. Such level of similarity can be determined via outcome and/or baseline covariate data comparisons. We provide an overview over existing methods, propose a novel option for a combined assessment of outcome and baseline data, and compare a selected set of approaches in a simulation study under varying assumptions regarding observable and unobservable confounder distributions using a time-to-event model. Our various simulation scenarios also reflect the differences between external clinical trial and real-world data. Data combinations via simple outcome-based borrowing or simple propensity score weighting with baseline covariate data are not recommended. Analysis options which conflate outcome and baseline covariate data perform best in our simulation study.

2.
Gynecol Obstet Invest ; 88(4): 214-225, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37369184

RESUMEN

OBJECTIVES: The aim of the study was to evaluate dosing of recombinant human luteinizing hormone (r-hLH) or human menopausal gonadotrophin (hMG)-derived medications with LH activity in ovarian stimulation (OS) cycles for in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI). DESIGN: A non-interventional study was performed to analyse data from the German RecDate database (January 2007-December 2011). PARTICIPANTS/MATERIALS, SETTING, METHODS: Starting/total r-hLH/hMG dose, OS duration/cycle number, r-hLH/hMG initiation day (first day of administration), and population/cycle characteristics were assessed in women (≥18 years) undergoing OS for IVF/ICSI using r-hLH or hMG-derived medications (excluding corifollitropin alfa, clomiphene citrate, letrozole, mini/micro-dose human chorionic gonadotrophin, and urofollitropin alone). Data were summarized descriptively. RESULTS: 67,858 identified cycles utilized medications containing r-hLH (10,749), hMG (56,432), or both (677). Mean (standard deviation) OS duration with r-hLH and hMG was 10.1 (4.43) and 9.8 (6.16) days, respectively. Median (25th-75th percentile) r-hLH starting dose (75.0 [75.0-150.0] IU) was consistent across patients regardless of age, infertility diagnosis, or gonadotrophin-releasing hormone (GnRH) protocol. Median (25th-75th percentile) hMG-derived LH activity starting dose was 225.0 (150.0-300.0) IU, regardless of GnRH protocol, but was lower in women aged <35 years and those with ovulation disorders/polycystic ovary syndrome. Median (25th-75th percentile) total dose for r-hLH (750.0 [337.5-1,125.0] IU) and hMG-derived LH activity (1,575.0 [750.0-2,625.0] IU) varied according to patients' age, infertility diagnosis, cycle number, and r-hLH/hMG initiation day. GnRH antagonist use resulted in a numerically higher median total hMG-derived LH activity dose than GnRH agonist use. LIMITATIONS: The data used in this study were taken from electronic medical records relating to a specific timeframe (2007-2011) and therefore may not accurately reflect current clinical practice; however, it is likely that the differences between the two compounds would be maintained. Additionally, secondary data sources may suffer from uniformity and quality issues. CONCLUSIONS: The standard of care for OS cycles is described with respect to IVF/ICSI treatment including an LH component in Germany during the specified timeframe.


Asunto(s)
Infertilidad , Semen , Humanos , Femenino , Masculino , Hormona Luteinizante , Menotropinas/uso terapéutico , Inducción de la Ovulación/métodos , Hormona Liberadora de Gonadotropina , Fertilización In Vitro/métodos , Menopausia , Fertilidad
3.
Int J Clin Pract ; 2022: 6124559, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35989866

RESUMEN

Aim: The aim of the study was to compare the effectiveness of beta-blockers with other antihypertensive classes in reducing all-cause mortality, cardiovascular-related mortality and the risk of cerebrocardiovascular events. Methods: This noninterventional study was conducted within the UK Clinical Practice Research Datalink. Hypertensive patients who initiated antihypertensive monotherapy were allocated to one of five cohorts: beta-blockers; angiotensin-converting enzyme inhibitors (ACEi); angiotensin II receptor blockers (ARB); calcium channel blockers (CCB); and diuretics. Differences in outcomes were assessed using Cox proportional hazard models with competing risks. Results: A total of 44,404 patients were prescribed beta-blockers (75% atenolol), 132,545 ACEi, 12,018 ARB, 91,731 CCB, and 106,547 diuretics. At baseline, patients in the beta-blocker cohort presented more frequently with angina, arrhythmia, and atrial fibrillation. The risk of all-cause mortality was lower for those treated with ACEi, ARB, and CCB, and no difference was observed compared with diuretics (adjusted hazard ratio versus beta-blockers (98.75% CI), for ACEi 0.71 (0.61, 0.83), ARB 0.67 (0.51, 0.88), CCB 0.76 (0.66, 0.88), diuretics 1.06 (0.93, 1.22)). No differences were seen in the risk of cardiovascular mortality for patients treated with beta-blockers, ARB, CCB, and diuretics, while a lower risk in patients treated with ACEi was observed (ACEi 0.63 (0.43, 0.91), ARB 0.64 (0.32, 1.28), CCB 0.71 (0.49, 1.03), diuretics 0.97 (0.69, 1.37)). Conclusions: These data add to the limited pool of evidence from real-world studies exploring the effectiveness of beta-blockers versus other antihypertensive classes. Discrepancies to previously published studies might be partly explained by differences in the selected populations and in the follow-up time.


Asunto(s)
Antihipertensivos , Hipertensión , Antagonistas Adrenérgicos beta/uso terapéutico , Antagonistas de Receptores de Angiotensina/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Antihipertensivos/uso terapéutico , Bloqueadores de los Canales de Calcio/uso terapéutico , Diuréticos/uso terapéutico , Humanos , Hipertensión/tratamiento farmacológico
4.
Pharm Stat ; 21(3): 625-640, 2022 05.
Artículo en Inglés | MEDLINE | ID: mdl-35060676

RESUMEN

In early clinical development, randomized controlled trials (RCT) or single-arm trials with external controls (SATwEC) are design options, which allow adjustment for confounding: RCT via design, SATwEC via analysis using propensity score methods. SATwEC requires less investment than RCT. However, if the confounder space substantially differs between the experimental and external control group, the SATwEC might lead to inappropriate decisions for further development. We develop an adaptive two-stage design (ATD) for early clinical development that reduces the risk of unreliable decision-making at the end of a SATwEC. In Stage I, subjects are solely assigned to the experimental group. If at the interim the propensity score distributions of internal and external data are comparable based on the preference score, the subjects in stage II will again be solely assigned to the experimental arm; if not, a randomized stage II will be conducted. In a simulation study guided by a motivating example, data is generated using a time-to-event model with observable and unobservable confounders. The confounder space is varied to investigate the impact on false go/stop probabilities as well as a loss function, which reflects the quality of treatment effect estimates and decision-making. The proposed ATD provides a compromise between optimizing quality (as expressed by false go/stop probabilities and the loss function) and investment (defined by sample size and trial duration).


Asunto(s)
Proyectos de Investigación , Simulación por Computador , Grupos Control , Humanos , Puntaje de Propensión , Tamaño de la Muestra
5.
Reprod Biol Endocrinol ; 19(1): 90, 2021 Jun 16.
Artículo en Inglés | MEDLINE | ID: mdl-34134695

RESUMEN

BACKGROUND: This study compared the effectiveness of recombinant human follicle-stimulating hormone alfa (r-hFSH-alfa; GONAL-f®) with urinary highly purified human menopausal gonadotropin (hMG HP; Menogon HP®), during assisted reproductive technology (ART) treatments in Germany. METHODS: Data were collected from 71 German fertility centres between 01 January 2007 and 31 December 2012, for women undergoing a first stimulation cycle of ART treatment with r-hFSH-alfa or hMG HP. Primary outcomes were live birth, ongoing pregnancy and clinical pregnancy, based on cumulative data (fresh and frozen-thawed embryo transfers), analysed per patient (pP), per complete cycle (pCC) and per first complete cycle (pFC). Secondary outcomes were pregnancy loss (analysed per clinical pregnancy), cancelled cycles (analysed pCC), total drug usage per oocyte retrieved and time-to-live birth (TTLB; per calendar week and per cycle). RESULTS: Twenty-eight thousand six hundred forty-one women initiated a first treatment cycle (r-hFSH-alfa: 17,725 [61.9%]; hMG HP: 10,916 [38.1%]). After adjustment for confounding variables, treatment with r-hFSH-alfa versus hMG HP was associated with a significantly higher probability of live birth (hazard ratio [HR]-pP [95% confidence interval (CI)]: 1.10 [1.04, 1.16]; HR-pCC [95% CI]: 1.13 [1.08, 1.19]; relative risk [RR]-pFC [95% CI]: 1.09 [1.05, 1.15], ongoing pregnancy (HR-pP [95% CI]: 1.10 [1.04, 1.16]; HR-pCC [95% CI]: 1.13 [1.08, 1.19]; RR-pFC [95% CI]: 1.10 [1.05, 1.15]) and clinical pregnancy (HR-pP [95% CI]: 1.10 [1.05, 1.14]; HR-pCC [95% CI]: 1.14 [1.10, 1.19]; RR-pFC [95% CI]: 1.10 [1.06, 1.14]). Women treated with r-hFSH-alfa versus hMG HP had no statistically significant difference in pregnancy loss (HR [95% CI]: 1.07 [0.98, 1.17], were less likely to have a cycle cancellation (HR [95% CI]: 0.91 [0.84, 0.99]) and had no statistically significant difference in TTLB when measured in weeks (HR [95% CI]: 1.02 [0.97, 1.07]; p = 0.548); however, r-hFSH-alfa was associated with a significantly shorter TTLB when measured in cycles versus hMG HP (HR [95% CI]: 1.07 [1.02, 1.13]; p = 0.003). There was an average of 47% less drug used per oocyte retrieved with r-hFSH-alfa versus hMG HP. CONCLUSIONS: This large (> 28,000 women), real-world study demonstrated significantly higher rates of cumulative live birth, cumulative ongoing pregnancy and cumulative clinical pregnancy with r-hFSH-alfa versus hMG HP.


Asunto(s)
Hormona Folículo Estimulante Humana/administración & dosificación , Hormonas Glicoproteicas de Subunidad alfa/administración & dosificación , Infertilidad Femenina/tratamiento farmacológico , Infertilidad Femenina/epidemiología , Menotropinas/administración & dosificación , Técnicas Reproductivas Asistidas , Adulto , Bases de Datos Factuales , Femenino , Alemania/epidemiología , Humanos , Infertilidad Femenina/sangre , Nacimiento Vivo/epidemiología , Menotropinas/orina , Embarazo , Resultado del Tratamiento
6.
Neuropediatrics ; 52(1): 12-18, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33065751

RESUMEN

INTRODUCTION: Long-term survivors of craniospinal irradiation have an increased risk for stroke which increases with radiation dose and follow-up time. Radiotherapy induces structural changes of the cerebral vasculature, affecting both, large, and small vessels. It is unknown how these structural changes affect functional mechanisms of cerebral blood flow regulation such as cerebral autoregulation and neurovascular coupling. METHODS: Using the transcranial Doppler, we compared dynamic cerebral autoregulation and neurovascular coupling of 12 patients after long-term survival of craniospinal irradiation due to a malignant pediatric brain tumor of the posterior fossa and 12 age- and sex-matched healthy patients. Mean arterial blood pressure and cerebral blood flow velocities in the middle and posterior cerebral artery were recorded at rest during normal breathing to assess cerebral autoregulation (transfer function parameters phase and gain, as well as the correlation coefficient indices Mx, Sx, and Dx), and during 10 cycles of a visual task to assess neurovascular coupling (parameters time delay, natural frequency, gain, attenuation, and rate time). RESULTS: Parameters of cerebral autoregulation showed a consistent trend toward reduced cerebral autoregulation in patients that did not reach statistical significance. Neurovascular coupling was not altered after craniospinal irradiation. CONCLUSION: In this pilot study, we demonstrated a trend toward reduced cerebral autoregulation, and no alteration of neurovascular coupling after irradiation in long-term survivors of malignant pediatric brain tumors of the posterior fossa.


Asunto(s)
Encéfalo/fisiopatología , Supervivientes de Cáncer , Irradiación Craneoespinal/efectos adversos , Hemodinámica/fisiología , Homeostasis/fisiología , Neoplasias Infratentoriales/radioterapia , Acoplamiento Neurovascular/fisiología , Encéfalo/diagnóstico por imagen , Niño , Estudios de Seguimiento , Humanos , Proyectos Piloto , Ultrasonografía Doppler Transcraneal
7.
Stat Med ; 39(4): 481-493, 2020 02 20.
Artículo en Inglés | MEDLINE | ID: mdl-31788835

RESUMEN

Both delayed study entry (left-truncation) and competing risks are common phenomena in observational time-to-event studies. For example, in studies conducted by Teratology Information Services (TIS) on adverse drug reactions during pregnancy, the natural time scale is gestational age, but women enter the study after time origin and upon contact with the service. Competing risks are present, because an elective termination may be precluded by a spontaneous abortion. If left-truncation is entirely random, the Aalen-Johansen estimator is the canonical estimator of the cumulative incidence functions of the competing events. If the assumption of random left-truncation is in doubt, we propose a new semiparametric estimator of the cumulative incidence function. The dependence between entry time and time-to-event is modeled using a cause-specific Cox proportional hazards model and the marginal (unconditional) estimates are derived via inverse probability weighting arguments. We apply the new estimator to data about coumarin usage during pregnancy. Here, the concern is that the cause-specific hazard of experiencing an induced abortion may depend on the time when seeking advice by a TIS, which also is the time of left-truncation or study entry. While the aims of counseling by a TIS are to reduce the rate of elective terminations based on irrational overestimation of drug risks and to lead to better and safer medical treatment of maternal disease, it is conceivable that women considering an induced abortion are more likely to seek counseling. The new estimator is also evaluated in extensive simulation studies and found preferable compared to the Aalen-Johansen estimator in non-misspecified scenarios and to at least provide for a sensitivity analysis otherwise.


Asunto(s)
Aborto Espontáneo , Simulación por Computador , Femenino , Humanos , Incidencia , Modelos Estadísticos , Embarazo , Probabilidad , Modelos de Riesgos Proporcionales
8.
Stat Med ; 38(20): 3747-3763, 2019 09 10.
Artículo en Inglés | MEDLINE | ID: mdl-31162707

RESUMEN

We consider nonparametric and semiparametric resampling of multistate event histories by simulating multistate trajectories from an empirical multivariate hazard measure. One advantage of our approach is that it does not necessarily require individual patient data, but may be based on published information. This is also attractive for both study planning and simulating realistic real-world event history data in general. The concept extends to left-truncation and right-censoring mechanisms, nondegenerate initial distributions, and nonproportional as well as non-Markov settings. A special focus is on its connection to simulating survival data with time-dependent covariates. For the case of qualitative time-dependent exposures, we demonstrate that our proposal gives a more natural interpretation of how such data evolve over the course of time than many of the competing approaches. The multistate perspective avoids any latent failure time structure and sampling spaces impossible in real life, whereas its parsimony follows the principle of Occam's razor. We also suggest empirical simulation as a novel bootstrap procedure to assess estimation uncertainty in the absence of individual patient data. This is not possible for established procedures such as Efron's bootstrap. A simulation study investigating the effect of liver functionality on survival in patients with liver cirrhosis serves as a proof of concept. Example code is provided.


Asunto(s)
Análisis Multivariante , Análisis de Supervivencia , Algoritmos , Simulación por Computador , Humanos , Probabilidad , Tiempo
9.
Biom J ; 61(5): 1290-1302, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-29984423

RESUMEN

A pregnancy may end up with (at least) three possible events: live birth, spontaneous abortion, or elective termination, yielding a competing risks issue when studying an association between a risk factor and a pregnancy outcome. Cumulative incidences (probabilities to end up with the different outcomes depending on gestational age) can be estimated via the Aalen-Johansen estimate. Another issue is that women are usually not entering such an observational study from the first day of pregnancy, resulting in delayed entries. As in traditional survival analysis, this can be solved by considering "at risk" at a given gestational age only for those women who entered the study before that age. However, the number of women at risk at an early gestational age might be extremely low, such that the estimates of cumulative incidence may increase exaggeratedly at that age because of a single event. One solution to reduce the problem has been recently proposed in the literature, which is to ignore simply those early events, creating a small mean bias but enhancing stability of estimates. In the present paper, we propose an alternative computationally simple approach to tackle this problem that consists to postpone to later gestational ages (rather than to ignore) those early events. The two approaches are compared with respect to bias, stability, and sensitivity on the smoothing parameter via simulations reproducing realistic pregnancy scenarios, and are illustrated with data from a study on the effects of statins on pregnancy outcomes. We also outline that all three approaches are asymptotically equivalent.


Asunto(s)
Biometría/métodos , Resultado del Embarazo , Aborto Espontáneo , Adulto , Femenino , Humanos , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacología , Incidencia , Modelos Estadísticos , Parto/efectos de los fármacos , Embarazo
10.
Biom J ; 61(2): 290-298, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30117183

RESUMEN

Pseudo-observations have been introduced as a way to perform regression analysis of a mean value parameter related to a right-censored time-to-event outcome, such as the survival probability or the restricted mean survival time. Since the introduction of the approach there have been several extensions from the original setting. However, the proper definition and performance of pseudo-observations under left-truncation has not yet been addressed. Here, we look at two types of pseudo-observations under right-censoring and left-truncation. We explored their performance in a simulation study and applied them to data on diabetes patients with left-truncation.


Asunto(s)
Bioestadística/métodos , Análisis de Regresión , Análisis de Varianza , Diabetes Mellitus/diagnóstico , Diabetes Mellitus/epidemiología , Humanos , Análisis de Supervivencia
11.
Biom J ; 60(6): 1135-1150, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30198195

RESUMEN

The expected excess length-of-stay is an established concept to assess the health and economic impact of nosocomial, that is, hospital-acquired infections such as ventilation-acquired pneumonia in intensive care. Estimation must account for the timing of infection as in a multistate perspective, because common retrospective comparisons yield inflated estimates due to time-dependent bias. Since occurrence of ventilation-acquired pneumonia is closely linked to ventilation status, we suggest a multistate model incorporating time-dependent mechanical ventilation as additional states. The appeal is that the expected excess length-of-stay decomposes into extra days spent under ventilation and not under ventilation. This is not only highly relevant from a patient's perspective regarding quality of life, but also from an economic point of view, because ventilation is a major cost driver. The challenge is that estimation involves complex functionals of the matrix of transition probabilities, which in turn are based on the transition hazards. To address heterogeneity between patients, which is a common phenomenon in observational hospital epidemiology, we apply pseudovalue regression to adjust the ventilation-specific quantities for baseline confounding. The performance of our proposal is assessed by simulation and the methods are illustrated on data provided by 12 French intensive care units. Preliminary results indicate that the expected excess length-of-stay associated with ventilation-acquired pneumonia is mainly triggered by extra days spent under mechanical ventilation, and that the excess is most pronounced for intensive care patients with fewer comorbidities at baseline. We also find that such a decomposition is challenging for early times. Example code is provided.


Asunto(s)
Biometría/métodos , Unidades de Cuidados Intensivos , Tiempo de Internación , Neumonía Asociada al Ventilador/epidemiología , Respiración Artificial/efectos adversos , Humanos , Modelos Estadísticos , Neumonía Asociada al Ventilador/microbiología , Pseudomonas aeruginosa/fisiología , Análisis de Regresión , Factores de Tiempo
12.
Euro Surveill ; 21(33)2016 Aug 18.
Artículo en Inglés | MEDLINE | ID: mdl-27562950

RESUMEN

We performed a multicentre retrospective cohort study including 606,649 acute inpatient episodes at 10 European hospitals in 2010 and 2011 to estimate the impact of antimicrobial resistance on hospital mortality, excess length of stay (LOS) and cost. Bloodstream infections (BSI) caused by third-generation cephalosporin-resistant Enterobacteriaceae (3GCRE), meticillin-susceptible (MSSA) and -resistant Staphylococcus aureus (MRSA) increased the daily risk of hospital death (adjusted hazard ratio (HR) = 1.80; 95% confidence interval (CI): 1.34-2.42, HR = 1.81; 95% CI: 1.49-2.20 and HR = 2.42; 95% CI: 1.66-3.51, respectively) and prolonged LOS (9.3 days; 95% CI: 9.2-9.4, 11.5 days; 95% CI: 11.5-11.6 and 13.3 days; 95% CI: 13.2-13.4, respectively). BSI with third-generation cephalosporin-susceptible Enterobacteriaceae (3GCSE) significantly increased LOS (5.9 days; 95% CI: 5.8-5.9) but not hazard of death (1.16; 95% CI: 0.98-1.36). 3GCRE significantly increased the hazard of death (1.63; 95% CI: 1.13-2.35), excess LOS (4.9 days; 95% CI: 1.1-8.7) and cost compared with susceptible strains, whereas meticillin resistance did not. The annual cost of 3GCRE BSI was higher than of MRSA BSI. While BSI with S. aureus had greater impact on mortality, excess LOS and cost than Enterobacteriaceae per infection, the impact of antimicrobial resistance was greater for Enterobacteriaceae.


Asunto(s)
Antibacterianos/uso terapéutico , Infecciones por Enterobacteriaceae/mortalidad , Enterobacteriaceae/efectos de los fármacos , Costos de la Atención en Salud/estadística & datos numéricos , Tiempo de Internación/economía , Infecciones Estafilocócicas/mortalidad , Staphylococcus aureus/efectos de los fármacos , Anciano , Antibacterianos/farmacología , Resistencia a las Cefalosporinas , Enterobacteriaceae/aislamiento & purificación , Infecciones por Enterobacteriaceae/tratamiento farmacológico , Infecciones por Enterobacteriaceae/economía , Europa (Continente)/epidemiología , Femenino , Mortalidad Hospitalaria , Hospitales , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Staphylococcus aureus Resistente a Meticilina/aislamiento & purificación , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Estudios Retrospectivos , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/economía , Staphylococcus aureus/aislamiento & purificación , Resultado del Tratamiento
13.
Pharm Stat ; 15(4): 297-305, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26929180

RESUMEN

The aim of this work is to shed some light on common issues in the statistical analysis of adverse events (AEs) in clinical trials, when the main outcome is a time-to-event endpoint. To begin, we show that AEs are always subject to competing risks. That is, the occurrence of a certain AE may be precluded by occurrence of the main time-to-event outcome or by occurrence of another (fatal) AE. This has raised concerns on 'informative' censoring. We show that, in general, neither simple proportions nor Kaplan-Meier estimates of AE occurrence should be used, but common survival techniques for hazards that censor the competing event are still valid, but incomplete analyses. They must be complemented by an analogous analysis of the competing event for inference on the cumulative AE probability. The commonly used incidence rate (or incidence density) is a valid estimator of the AE hazard assuming it to be time constant. An estimator of the cumulative AE probability can be derived if the incidence rate of AE is combined with an estimator of the competing hazard. We discuss less restrictive analyses using non-parametric and semi-parametric approaches. We first consider time-to-first-AE analyses and then briefly discuss how they can be extended to the analysis of recurrent AEs. We will give a practical presentation with illustration of the methods by a simple example. Copyright © 2016 John Wiley & Sons, Ltd.


Asunto(s)
Simulación por Computador/estadística & datos numéricos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/epidemiología , Estadística como Asunto/métodos , Ensayos Clínicos como Asunto/estadística & datos numéricos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/diagnóstico , Humanos , Estimación de Kaplan-Meier , Factores de Riesgo , Factores de Tiempo
14.
Cerebrovasc Dis ; 40(5-6): 205-14, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26402300

RESUMEN

BACKGROUND: Currently, there are 2 strategies to increase the effect of systemic thrombolysis with alteplase (rtPA) in acute major stroke: endovascular treatment via stent retrieval and ultrasound enhancement (sonothrombolysis). This study compares these 2 approaches in patients with proximal intracranial occlusion of the anterior circulation. METHODS: Consecutive data on the treatment outcome of acute middle cerebral artery (M1) or carotid T occlusion were collected from 2 stroke centers: one center used rtPA plus endovascular stent retrieval as standard treatment and the other rtPA plus ultrasound (sonothrombolysis). The primary outcome was functional independence (modified Rankin scale (mRS) 0-2) after neurorehabilitation. RESULTS: A total of 132 patients were assessed (n = 73 endovascular, n = 59 sonothrombolysis). The rate of functional independence was higher for endovascular treatment (adjusted OR 3.89 (95% CI 1.36-12.58)). Additionally, ordinal mRS analysis favored the endovascular strategy (adjusted common OR 1.70 (95% CI 0.88-3.31)). Subgroup analysis showed that endovascular treatment was superior for carotid T occlusion (adjusted common OR 5.61 (95% CI 1.60-20.93)), but not for middle cerebral artery occlusion (adjusted common OR 1.07 (95% CI 0.47-2.43)). Symptomatic intracerebral hemorrhage occurred in 3 patients from the endovascular group. CONCLUSIONS: This observational study suggests that endovascular treatment of acute major anterior circulation stroke is superior to sonothrombolysis in terms of functional outcome. This benefit seems to pertain primarily to patients with carotid T occlusion, whereas patients with M1 occlusion seem to profit in a similar way from both methods. ( CLINICAL TRIAL REGISTRATION: URL: http://www.germanctr.de. Unique identifier: DRKS0000x200B;5305.).


Asunto(s)
Isquemia Encefálica/etiología , Trombosis de las Arterias Carótidas/terapia , Procedimientos Endovasculares , Trombectomía , Terapia Trombolítica/métodos , Terapia por Ultrasonido , Enfermedad Aguda , Anciano , Daño Encefálico Crónico/epidemiología , Daño Encefálico Crónico/etiología , Isquemia Encefálica/rehabilitación , Trombosis de las Arterias Carótidas/complicaciones , Trombosis de las Arterias Carótidas/tratamiento farmacológico , Trombosis de las Arterias Carótidas/cirugía , Terapia Combinada , Femenino , Fibrinolíticos/uso terapéutico , Humanos , Masculino , Persona de Mediana Edad , Neuroimagen , Recuperación de la Función , Estudios Retrospectivos , Factores de Riesgo , Índice de Severidad de la Enfermedad , Método Simple Ciego , Stents , Activador de Tejido Plasminógeno/uso terapéutico
15.
Stroke ; 45(9): 2792-4, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25034711

RESUMEN

BACKGROUND AND PURPOSE: This study investigated whether a short testing of neurovascular coupling during midterm pregnancy could identify women at risk for subsequent preeclampsia. METHODS: Transcranial Doppler sonography of the posterior cerebral artery during a brief visual stimulation was analyzed in 68 women at midterm pregnancy, the primary clinical end point was preeclampsia. RESULTS: Women with bilateral notching of the uterine arteries showed an exaggerated visually evoked blood flow increase and longer time-to-peak. Neurovascular coupling was not significantly associated with the occurrence of preeclampsia. CONCLUSIONS: Neurovascular coupling was altered in women with impaired uteroplacentar vasoregulation but not a significant predictor of preeclampsia.


Asunto(s)
Preeclampsia/diagnóstico , Ultrasonografía Doppler Transcraneal/métodos , Adulto , Velocidad del Flujo Sanguíneo , Circulación Cerebrovascular/fisiología , Femenino , Hemodinámica , Humanos , Placenta/irrigación sanguínea , Arteria Cerebral Posterior/diagnóstico por imagen , Arteria Cerebral Posterior/fisiopatología , Embarazo , Complicaciones del Embarazo , Resultado del Tratamiento , Arteria Uterina , Útero/irrigación sanguínea , Adulto Joven
16.
Lifetime Data Anal ; 20(4): 495-513, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23807694

RESUMEN

Competing risks model time to first event and type of first event. An example from hospital epidemiology is the incidence of hospital-acquired infection, which has to account for hospital discharge of non-infected patients as a competing risk. An illness-death model would allow to further study hospital outcomes of infected patients. Such a model typically relies on a Markov assumption. However, it is conceivable that the future course of an infected patient does not only depend on the time since hospital admission and current infection status but also on the time since infection. We demonstrate how a modified competing risks model can be used for nonparametric estimation of transition probabilities when the Markov assumption is violated.


Asunto(s)
Infección Hospitalaria/epidemiología , Riesgo , Estadísticas no Paramétricas , Simulación por Computador , Infección Hospitalaria/mortalidad , Infección Hospitalaria/transmisión , Humanos , Estimación de Kaplan-Meier , Tablas de Vida , Cadenas de Markov , Modelos Estadísticos , Probabilidad , Procesos Estocásticos , Análisis de Supervivencia
17.
J Clin Psychopharmacol ; 33(4): 453-62, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23764684

RESUMEN

Women of childbearing age are often affected with psychotic disorders, requiring the use of antipsychotic medication during pregnancy. In the present study, we prospectively followed the pregnancies of 561 women exposed to second-generation antipsychotic agents (SGAs; study cohort) and compared these to 284 pregnant women exposed to first-generation antipsychotic agents (FGAs; comparison cohort I) and to 1122 pregnant women using drugs known as not harmful to the unborn (comparison cohort II). Subjects were enrolled through the Institute's consultation service. Major malformation rates of SGA exposed were higher compared to comparison cohort II (adjusted odds ratio, 2.17; 95% confidence interval, 1.20-3.91), possibly reflecting a detection bias concerning atrial and ventricular septal defects. Postnatal disorders occurred significantly more often in infants prenatally exposed to SGAs (15.6%) and FGAs (21.6%) compared to 4.2% of comparison cohort II. Cumulative incidences of elective terminations of pregnancy were significantly higher in both the study cohort (17%) and comparison cohort I (21%) compared to comparison cohort II (3%), whereas the rates of spontaneous abortions did not differ. The numbers of stillbirths and neonatal deaths were within the reference range. Preterm birth and low birth weight were more common in infants exposed to FGAs. To conclude, our findings did not reveal a major teratogenic risk for SGAs, making the better studied drugs of this group a treatment option during pregnancy. Because neonates exposed to SGAs or FGAs in the last gestational week are at higher risk of postnatal disorders, delivery should be planned in clinics with neonatal intensive care units.


Asunto(s)
Antipsicóticos/uso terapéutico , Complicaciones del Embarazo/tratamiento farmacológico , Trastornos Psicóticos/tratamiento farmacológico , Anomalías Inducidas por Medicamentos/etiología , Anomalías Inducidas por Medicamentos/mortalidad , Aborto Inducido , Aborto Espontáneo/inducido químicamente , Aborto Espontáneo/mortalidad , Adulto , Antipsicóticos/efectos adversos , Antipsicóticos/clasificación , Estudios de Casos y Controles , Femenino , Edad Gestacional , Humanos , Lactante , Mortalidad Infantil , Recién Nacido de Bajo Peso , Recién Nacido , Modelos Logísticos , Oportunidad Relativa , Embarazo , Complicaciones del Embarazo/diagnóstico , Complicaciones del Embarazo/psicología , Nacimiento Prematuro , Efectos Tardíos de la Exposición Prenatal , Estudios Prospectivos , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Medición de Riesgo , Factores de Riesgo , Mortinato , Resultado del Tratamiento
18.
Cancer Med ; 12(4): 4195-4205, 2023 02.
Artículo en Inglés | MEDLINE | ID: mdl-36263922

RESUMEN

BACKGROUND: Limited data are available regarding second-line (2 L) treatment for advanced or metastatic biliary tract cancers (BTC) in the US real-world setting. This study explores the rapidly evolving and growing treatment landscape in the 2 L setting for advanced or metastatic BTC with a large cohort of patients treated in a community oncology setting. METHODS: Adult patients with BTC initiating 2 L treatment after a platinum-containing first-line between 1/1/10- and 6/30/19 were identified from the US Oncology Network electronic healthcare record database and followed through 12/31/19. Baseline patient and treatment characteristics were analyzed descriptively, including overall response rate (ORR) in the real-world clinical setting. Kaplan-Meier methods were used to measure duration of response, progression-free survival (PFS), and overall survival (OS). RESULTS: The overall population (N = 160) included 74 patients (46.3%) with intrahepatic cholangiocarcinoma, 41 (25.6%) with extrahepatic cholangiocarcinoma, and 45 (28.1%) with gallbladder cancer. Thirty unique 2 L regimens were recorded for the study population, with folinic acid, fluorouracil and oxaliplatin (FOLFOX, 34.4%) and capecitabine monotherapy (20.0%) being the most common. ORR was 7.5% (95% CI, 3.9%-12.7%). From 2 L initiation, median PFS was 2.8 months (95% CI, 2.4-3.3 months), and median OS was 5.2 months (95% CI, 4.2-6.7 months). CONCLUSION: Results from this study provide real-world evidence that although patients treated in the community oncology setting receive a wide variety of 2 L treatments, the regimens are consistent with those recommended by guidelines. Although responses are observed with 2 L treatment, duration is brief and associated with poor OS in patients with advanced or metastatic disease.


Asunto(s)
Neoplasias de los Conductos Biliares , Neoplasias del Sistema Biliar , Colangiocarcinoma , Adulto , Humanos , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Neoplasias de los Conductos Biliares/patología , Fluorouracilo/uso terapéutico , Conductos Biliares Intrahepáticos/patología , Neoplasias del Sistema Biliar/patología
19.
Stroke ; 43(4): 987-93, 2012 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-22343638

RESUMEN

BACKGROUND AND PURPOSE: Silent ischemic brain lesions frequently occur in migraine with aura and are most often located in cerebellar border zones. This may imply an impairment of cerebellar blood flow autoregulation. This study investigated the characteristics of interictal cerebellar autoregulation in migraine with and without aura. METHODS: Thirty-four patients (n=17, migraine without aura; n=17, migraine with aura) and 35 age- and sex-matched controls were studied. Triple simultaneous transcranial Doppler monitoring of one posterior inferior cerebellar artery, right posterior cerebral artery, and left middle cerebral artery was performed. Autoregulation dynamics were assessed from spontaneous blood pressure fluctuations (correlation coefficient index Dx) and from respiratory-induced 0.1-Hz blood pressure oscillations (phase and gain). RESULTS: Compared with controls, the autoregulatory index Dx was higher (indicating less autoregulation) in the posterior inferior cerebellar artery (P=0.0062) and middle cerebral artery (P=0.0078) in migraine with aura, but not in migraine without aura. Phase and gain did not significantly differ between migraine patients and controls. No significant associations of autoregulation with clinical factors were found, including frequency of migraine attacks and orthostatic intolerance. CONCLUSIONS: This first-time analysis of cerebellar autoregulation in migraine did not show a specific cerebellar dysautoregulation in the interictal period. More static autoregulatory properties (index Dx) are, however, impaired in persons with migraine with aura both in the cerebellar and anterior circulation. The cerebellar predilection of ischemic lesions in migraine with aura might be a combination of altered autoregulation and additional factors, such as the end artery cerebellar angioarchitecture.


Asunto(s)
Cerebelo , Cerebro , Arteria Cerebral Media/fisiopatología , Migraña con Aura/fisiopatología , Migraña sin Aura/fisiopatología , Adulto , Presión Sanguínea , Cerebelo/irrigación sanguínea , Cerebelo/diagnóstico por imagen , Cerebelo/fisiopatología , Circulación Cerebrovascular , Cerebro/irrigación sanguínea , Cerebro/diagnóstico por imagen , Cerebro/fisiopatología , Femenino , Humanos , Masculino , Arteria Cerebral Media/diagnóstico por imagen , Migraña con Aura/diagnóstico por imagen , Migraña sin Aura/diagnóstico por imagen , Ultrasonografía Doppler Transcraneal
20.
Am J Med Genet A ; 158A(3): 588-96, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22319001

RESUMEN

After maternal exposure to mycophenolate in pregnancy a high number of fetal losses and a specific pattern of birth defects consisting of microtia, cleft lip, and other anomalies have been reported. However, so far, prospective data on pregnancy outcome allowing quantitative risk assessment are missing. We report on 57 prospectively ascertained pregnancies after maternal therapy with mycophenolate (mycophenolate mofetil or mycophenolate sodium) identified by European Teratology Information Services (ETIS) through their risk consultation process. The outcome of these prospective pregnancies was as follows: 16 spontaneous abortions, 12 elective terminations of pregnancy (ETOP) (including two late terminations for multiple malformations consistent with mycophenolate embryopathy), and 29 liveborn infants. The probability of spontaneous abortion was about 45% (95% CI 29 to 66%) estimated using survival analysis technique. Six out of 29 live born infants had major congenital defects: Two with external auditory canal atresia (EACA) (with and without microtia), one with tracheo-esophageal atresia, one with severe hydronephrosis, one with an atrial septal defect (ASD) and one with a myelomeningocele. Thus, at least four fetuses/infants of our prospective case series had a clinical phenotype consistent with mycophenolate embryopathy. Our results confirm a high incidence of major malformations (26%) after first trimester exposure to mycophenolate. Apart from exposure to mycophenololate, the underlying maternal disease and concomitant medication may also have contributed to the other poor pregnancy outcomes such as a high rate of spontaneous abortions, prematurity (62%), and low birth weight (31%).


Asunto(s)
Ácido Micofenólico/toxicidad , Teratógenos/toxicidad , Aborto Espontáneo , Anomalías Congénitas , Europa (Continente) , Femenino , Estudios de Seguimiento , Humanos , Recién Nacido , Embarazo , Resultado del Embarazo , Estudios Prospectivos
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