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1.
Homeopathy ; 110(3): 222-226, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33662992

RESUMEN

The recent questions about homeopathy raised by some sceptics have focused an awareness on this therapy and led different protagonists among the scientific community to seek a much-needed re-assessment. The inputs coming from external but benevolent experts will broaden the knowledge and the consciousness of the whole medical community, and more widely of the public, about the meaning and the value of homeopathy.Looking at this from the point of view of the human sciences gives a perspective on the universality of the philosophy that underlies homeopathic thinking, which is particularly visible in the methodological similarities between homeopathic provings and sociological or anthropological observations. It also explains how this view of health and care coincides with the expectations of the public, who no longer want a limited mechanical approach to the human body or more generally to the environment.The input to homeopathy of the human sciences, with their methodological tools and approaches, and highlighting the possibilities offered by mixed-methods research, could enable these notions to be heard and shared in the wider scientific community.


Asunto(s)
Homeopatía/normas , Homeopatía/métodos , Homeopatía/tendencias , Humanos , Proyectos de Investigación/normas , Proyectos de Investigación/estadística & datos numéricos
2.
J Biopharm Stat ; 30(5): 916-940, 2020 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-32511941

RESUMEN

We present and evaluate a method for predicting individual treatment benefits based on random effects logistic regression models of binary outcomes that change over time. The method uses empirical Bayes predictors based on patients' characteristics and responses to treatment. It is applicable to both 1-dimentional and 2-dimentional personalized medicine models. Comparisons between predicted and true benefits for simulated new patients using correlations, relative biases and mean-squared errors were used to evaluate prediction performance. The predicted benefits had relatively small biases and relatively high correlations with the true benefits in the simulated new patients. The predictors also captured estimated overall population trends in the evolution of individual benefits. The proposed approach can be used to retrospectively evaluate patients' responses in a clinical trial, or to retrospectively or prospectively predict individual benefits of different treatments for new patients using patients' characteristics and previous responses. The method is used to examine changes in the disorganized dimension of antipsychotic-naïve patients from an antipsychotic randomized clinical trial. Retrospective prediction of individual benefits revealed that more cannabis users had slower and lower responses to antipsychotic treatment as compared to non-cannabis users, revealing cannabis use as a negative prognostic factor for psychotic disorders in the disorganized dimension.


Asunto(s)
Antipsicóticos/uso terapéutico , Abuso de Marihuana/complicaciones , Fumar Marihuana/efectos adversos , Trastornos Psicóticos/tratamiento farmacológico , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/estadística & datos numéricos , Antipsicóticos/efectos adversos , Teorema de Bayes , Simulación por Computador , Interpretación Estadística de Datos , Humanos , Modelos Logísticos , Estudios Longitudinales , Abuso de Marihuana/psicología , Fumar Marihuana/psicología , Modelos Estadísticos , Método de Montecarlo , Trastornos Psicóticos/diagnóstico , Trastornos Psicóticos/psicología , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
3.
J Biopharm Stat ; 30(5): 873-881, 2020 09 02.
Artículo en Inglés | MEDLINE | ID: mdl-32394789

RESUMEN

Raw materials for traditional Chinese medicine (TCM) are often from different resources and its final product may also be made by different sites. Therefore, variabilities from different resources such as site-to-site or within site component-to-component may be expected. Consequently, test for consistency in raw materials, in-process materials, and/or final product has become an important issue in the quality control (QC) process in TCM development. In this paper, a statistical QC process for raw materials and/or the final product of TCM is proposed based on a two sided [Formula: see text]-content, [Formula: see text]-confidence tolerance interval. More specifically, we construct the tolerance interval for a random-effects model to assess the QC of TCM products from different regions and possibly different product batches. The products can be claimed to be consistency when the constructed tolerance interval is within the permitted range. Given the region and batch effects, sample sizes can also be calculated to ensure the desired measure of goodness. An example is presented to illustrate the proposed approach.


Asunto(s)
Medicamentos Herbarios Chinos/normas , Medicina Tradicional China/normas , Proyectos de Investigación/estadística & datos numéricos , Simulación por Computador , Interpretación Estadística de Datos , Humanos , Modelos Estadísticos , Análisis Numérico Asistido por Computador , Control de Calidad , Tamaño de la Muestra
4.
PLoS One ; 15(4): e0231785, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32298372

RESUMEN

Understanding of interactional dynamics between several processes is one of the most important challenges in psychology and psychosomatic medicine. Researchers exploring behavior or other psychological phenomena mostly deal with ordinal or interval data. Missing values and consequential non-equidistant measurements represent a general problem of longitudinal studies from this field. The majority of process-oriented methodologies was originally designed for equidistant data measured on ratio scales. Therefore, the goal of this article is to clarify the conditions for satisfactory performance of longitudinal methods with data typical in psychological and psychosomatic research. This study examines the performance of the Johansen test, a procedure incorporating a set of sophisticated time series techniques, in reference to data quality utilizing a Monte Carlo method. The main results of the conducted simulation studies are: (1) Time series analyses require samples of at least 70 observations for an accurate estimation and inference. (2) Discrete data and failing equidistance of measurements due to irregular missing values appear unproblematic. (3) Relevant characteristics of stationary processes can be adequately captured using 5- or 7-point ordinal scales. (4) For trending processes, at least 10-point scales are necessary to ensure an acceptable quality of estimation and inference.


Asunto(s)
Psicometría/métodos , Interpretación Estadística de Datos , Humanos , Estudios Longitudinales , Modelos Estadísticos , Método de Montecarlo , Proyectos de Investigación/estadística & datos numéricos
6.
J Biopharm Stat ; 30(4): 649-661, 2020 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-32163305

RESUMEN

In clinical trials, the efficacy of treatment might be dependent on the value of a covariate variable. Therefore, it might be possible to detect the region over the covariate variable where the two treatments under investigation do not have significantly different efficacy or the region of superiority of one treatment. The non-significant region can be verified to be a confidence interval for the abscissa of the intersection point of two regression lines, and each of the complementary regions of the confidence interval corresponds to a region of superiority. In this study, we develop a method of constructing the confidence interval based on the concept of a generalized pivotal quantity, so as to perform the task of detecting the possible three regions for a clinical trial. Two real-world examples are given to illustrate the application of our proposed method, and a simulation study is conducted to evaluate its performance.


Asunto(s)
Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/estadística & datos numéricos , Antihipertensivos/uso terapéutico , Calcio/uso terapéutico , Simulación por Computador , Interpretación Estadística de Datos , Femenino , Humanos , Hipertensión/diagnóstico , Hipertensión/tratamiento farmacológico , Hipertensión/fisiopatología , Recién Nacido de Bajo Peso , Recién Nacido Pequeño para la Edad Gestacional , Conducta Materna , Modelos Estadísticos , Embarazo , Nacimiento Prematuro/etiología , Efectos Tardíos de la Exposición Prenatal , Medición de Riesgo , Factores de Riesgo , Fumar/efectos adversos , Resultado del Tratamiento
7.
J Pharmacol Toxicol Methods ; 100: 106602, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31238094

RESUMEN

Regulatory guidelines recommend specialised safety pharmacology assessments in animals to characterise drug-induced effects on the central nervous system (CNS) prior to first-in-human trials, including the functional observational battery or Irwin test (here collectively termed neurofunctional assessments). These assessments effectively detect overtly neurotoxic drugs; however, the suitability of the in vivo assessments to readily detect more subtle drug effects on the nervous system has been questioned. A survey was formulated by an international expert working group convened by the (NC3Rs) to capture practice in CNS neurofunctional assessment tests and opinions on the perceived impact of in vivo test battery endpoints. Impact was defined as "the impact of measures alone/in combination on decision making in drug development or candidate selection when using the neurofunctional assessment". The results demonstrate that rodents are predominantly used for small molecule assessments, whereas non-rodents are frequently used to test biotherapeutics. Practice varied between respondents in terms of experimental design. Subsets of test battery endpoints were consistently considered highly impactful (e.g. convulsions, stereotypic behaviors); however, the perceived impact level of other endpoints varied depending whether drugs were designed for CNS targets. Many endpoints were considered to have no or minimal impact, whereas a subset of endpoints in CNS test batteries appears more impactful than others. A critical evaluation is required to assess whether the translational value of CNS in vivo safety pharmacology assessments could be increased by modifying or augmenting standard CNS test batteries. A revised approach to CNS safety assessment has the potential to reduce animal numbers without compromising patient safety.


Asunto(s)
Desarrollo de Medicamentos/métodos , Evaluación Preclínica de Medicamentos/métodos , Modelos Animales , Farmacología/métodos , Animales , Sistema Nervioso Central/efectos de los fármacos , Desarrollo de Medicamentos/legislación & jurisprudencia , Desarrollo de Medicamentos/estadística & datos numéricos , Evaluación Preclínica de Medicamentos/estadística & datos numéricos , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos/prevención & control , Humanos , Farmacología/legislación & jurisprudencia , Proyectos de Investigación/legislación & jurisprudencia , Proyectos de Investigación/estadística & datos numéricos , Encuestas y Cuestionarios
8.
Curr Pharm Biotechnol ; 20(10): 858-873, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30526454

RESUMEN

BACKGROUND: In this study, silver nanoparticles (AgNPs) were synthesized using Banana Peel Extract (BPE), and characterized using UV- Vis absorbance spectroscopy, X-Ray Powder Diffraction (XRD), Atomic Force Microscopy (AFM), and Fourier Transform Infrared Spectroscopy (FTIR). UV-Vis absorbance spectroscopy showed the characteristic plasmon resonance of AgNPs at 433 nm. The synthesized AgNPs were tested for their antibacterial and antioxidant properties. METHODS: Nanoparticle size (between 5 and 9 nm) was measured using AFM, whereas their crystallinity was shown by XRD. FTIR identified the ligands that surround the nanoparticle surface. The synthesis conditions were optimised using Central Composite Design (CCD) under Response Surface Methodology (RSM). Silver nitrate (AgNO3) and BPE concentrations (0.25-2.25 mM, 0.2-1.96 % v/v respectively), incubation period (24-120 h) and pH level (2.3-10.1) were chosen as the four independent factors. The fitting parameters (i.e. the wavelength at peak maximum, the peak area, and the peak width) of a Voigt function of the UV- Vis spectra were chosen as the responses. The antibacterial properties of the AgNPs were tested against Escherichia coli and Staphylococcus aureus using the tube dilution test. The synthesized nanoparticles were tested for total phenolic composition (TPC) using the Folin - Ciocalteau method, whereas their radical scavenging activity using the 1,1-diphenyl-2- picrylhydrazyl (DPPH) free radical assay. RESULTS: An optimum combination of all independent factors was identified (BPE concentration 1.7 % v/v, AgNO3 concentration 1.75 mM, incubation period 48 h, pH level 4.3), giving minimum peak wavelength and peak width. The nanoparticles inhibited the growth of E. coli, whereas S. aureus growth was not affected. However, no superiority of AgNPs compared to AgNO3 used for their fabrication (1.75 mM), with respect to antibacterial action, could be here demonstrated. AgNPs were found to present moderate antioxidant activity (44.71± 3.01%), as measured using DPPH assay, while the BPE (used for their fabrication) presented alone (100%) an antioxidant action equal to 86±1%, something expected due to its higher total phenolic content (TPC) compared to that of nanoparticles. CONCLUSION: Altogether, the results of this study highlight the potential of an eco-friendly method to synthesize nanoparticles and its promising optimization through statistical experimental design. Future research on the potential influence of other synthesis parameters on nanoparticles yield and properties could further promote their useful biological activities towards their successful application in the food industry and other settings.


Asunto(s)
Antibacterianos/síntesis química , Antioxidantes/síntesis química , Nanopartículas del Metal/química , Musa/química , Nanotecnología/métodos , Extractos Vegetales/química , Plata/farmacología , Análisis de Varianza , Antibacterianos/farmacología , Antioxidantes/farmacología , Compuestos de Bifenilo/química , Escherichia coli/efectos de los fármacos , Humanos , Picratos/química , Proyectos de Investigación/estadística & datos numéricos , Plata/química , Staphylococcus aureus/efectos de los fármacos
9.
Trials ; 19(1): 442, 2018 Aug 16.
Artículo en Inglés | MEDLINE | ID: mdl-30115104

RESUMEN

BACKGROUND: Partial factorial trials compare two or more pairs of treatments on overlapping patient groups, randomising some (but not all) patients to more than one comparison. The aims of this research were to compare different methods for conducting and analysing economic evaluations on partial factorial trials and assess the implications of considering factors simultaneously rather than drawing independent conclusions about each comparison. METHODS: We estimated total costs and quality-adjusted life years (QALYs) within 10 years of surgery for 2252 patients in the Knee Arthroplasty Trial who were randomised to one or more comparisons of different surgical types. We compared three analytical methods: an "at-the-margins" analysis including all patients randomised to each comparison (assuming no interaction); an "inside-the-table" analysis that included interactions but focused on those patients randomised to two comparisons; and a Bayesian vetted bootstrap, which used results from patients randomised to one comparison as priors when estimating outcomes for patients randomised to two comparisons. Outcomes comprised incremental costs, QALYs and net benefits. RESULTS: Qualitative interactions were observed for costs, QALYs and net benefits. Bayesian bootstrapping generally produced smaller standard errors than inside-the-table analysis and gave conclusions that were consistent with at-the-margins analysis, while allowing for these interactions. By contrast, inside-the-table gave different conclusions about which intervention had the highest net benefits compared with other analyses. CONCLUSIONS: All analyses of partial factorial trials should explore interactions and assess whether results are sensitive to assumptions about interactions, either as a primary analysis or as a sensitivity analysis. For partial factorial trials closely mirroring routine clinical practice, at-the-margins analysis may provide a reasonable estimate of average costs and benefits for the whole trial population, even in the presence of interactions. However, such conclusions will be misleading if there are large interactions or if the proportion of patients allocated to different treatments differs markedly from what occurs in clinical practice. The Bayesian bootstrap provides an alternative to at-the-margins analysis for analysing clinical or economic endpoints from partial factorial trials, which allows for interactions while making use of the whole sample. The same techniques could be applied to analyses of clinical endpoints. TRIAL REGISTRATION: ISRCTN, ISRCTN45837371 . Registered on 25 April 2003.


Asunto(s)
Artroplastia de Reemplazo de Rodilla , Costos de la Atención en Salud , Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Artroplastia de Reemplazo de Rodilla/efectos adversos , Artroplastia de Reemplazo de Rodilla/economía , Artroplastia de Reemplazo de Rodilla/métodos , Artroplastia de Reemplazo de Rodilla/estadística & datos numéricos , Teorema de Bayes , Análisis Costo-Beneficio , Interpretación Estadística de Datos , Costos de la Atención en Salud/estadística & datos numéricos , Humanos , Modelos Económicos , Modelos Estadísticos , Años de Vida Ajustados por Calidad de Vida , Ensayos Clínicos Controlados Aleatorios como Asunto/economía , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/estadística & datos numéricos , Factores de Tiempo , Resultado del Tratamiento
10.
Am Heart J ; 204: 139-150, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30118942

RESUMEN

BACKGROUND: The Food and Drug Administration (FDA) initiated the Expedited Access Pathway (EAP) to accelerate approval of novel therapies targeting unmet needs for life-threatening conditions. EAP allows for the possibility of initial FDA approval using intermediate end points with postapproval demonstration of improved outcomes. OBJECTIVE: Describe the EAP process using the BeAT-HF trial as a case study. METHODS: BeAT-HF will examine the safety and effectiveness of baroreflex activation therapy (BAT) in heart failure patients with reduced ejection fraction using an Expedited and Extended Phase design. In the Expedited Phase, BAT plus guideline-directed medical therapy (GDMT) will be compared at 6 months postimplant to GDMT alone using 3 intermediate end points: 6-minute hall walk distance, Minnesota Living with Heart Failure Questionnaire, and N-terminal pro-B-type natriuretic peptide. The rate of heart failure morbidity and cardiovascular mortality will be compared between the arms to evaluate early trending using predictive probability modeling. Sample size of 264 patients randomized 1:1 to BAT + GDMT versus GDMT alone provides 81% power for the Expedited Phase intermediate end points. For the Extended Phase, the heart failure morbidity and cardiovascular mortality end point is based on an expected event rate of 0.4 events/patient/year in the GDMT arm. With an adaptive sample size selection design for robustness to inaccurate assumptions, a sample size of 480-960 randomized patients followed ≥2 years allows detecting a 30% reduction in the primary end point with a power of 97.5%. CONCLUSION: Through a unique collaboration with FDA under the EAP, the BeAT-HF trial design allows for the possibility of approval of BAT, initially for symptom relief and subsequently for outcomes improvement.


Asunto(s)
Barorreflejo/fisiología , Aprobación de Drogas/métodos , Terapia por Estimulación Eléctrica/métodos , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Teorema de Bayes , Arterias Carótidas/fisiología , Terapia por Estimulación Eléctrica/instrumentación , Humanos , Evaluación del Resultado de la Atención al Paciente , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto/economía , Proyectos de Investigación/estadística & datos numéricos , Volumen Sistólico , Estados Unidos , United States Food and Drug Administration
11.
J Oncol Pract ; 13(12): e982-e991, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-29019706

RESUMEN

PURPOSE: The National Cancer Institute (NCI) requirement that clinical trials at NCI-designated cancer centers undergo institutional scientific review in addition to institutional review board evaluation is unique among medical specialties. We sought to evaluate the effect of this process on protocol activation timelines. METHODS: We analyzed oncology clinical trials that underwent full board review by the Harold C. Simmons Comprehensive Cancer Center Protocol Review and Monitoring Committee (PRMC) from January 1, 2009, through June 30, 2013. We analyzed associations between trial characteristics, PRMC decisions, protocol modifications, and process timelines using the χ2 test, Fisher's exact test, Wilcoxon rank sum test, Kruskal-Wallis test, and logistic regression. RESULTS: A total of 226 trials were analyzed. Of these, 77% were industry sponsored and 23% were investigator initiated. The median time from submission to PRMC approval was 55 days. The length of review was associated with trial phase, timing of approval, and number of committee changes/clarifications requested. The median process time was 35 days for those approved at first decision, 68 days for second decision, and 116 days for third decision ( P < .001). The median process time was 39 days if no changes/clarifications were requested, 64 days for one to three changes/clarifications, and 73 days for four or more changes/clarifications ( P < .001). Requested changes/clarifications had a greater effect on industry-sponsored trials than on investigator-initiated trials. CONCLUSION: NCI-mandated institutional scientific review of oncology clinical trials contributes substantially to protocol activation timelines. Further evaluation of this process and the value added to research quality is warranted.


Asunto(s)
Neoplasias/tratamiento farmacológico , Comités Consultivos/estadística & datos numéricos , Protocolos Clínicos , Comités de Ética en Investigación/estadística & datos numéricos , Humanos , National Cancer Institute (U.S.)/estadística & datos numéricos , Proyectos de Investigación/estadística & datos numéricos , Estados Unidos
12.
CPT Pharmacometrics Syst Pharmacol ; 5(8): 402-10, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27530374

RESUMEN

This study presents a pharmacokinetic-pharmacodynamic based clinical trial simulation framework for evaluating the performance of a fixed-sample Bayesian design (BD) and two alternative Bayesian sequential designs (BSDs) (i.e., a non-hierarchical (NON-H) and a semi-hierarchical (SEMI-H) one). Prior information was elicited from adult trials and weighted based on the expected similarity of response to treatment between the pediatric and adult populations. Study designs were evaluated in terms of: type I and II errors, sample size per arm (SS), trial duration (TD), and estimate precision. No substantial differences were observed between NON-H and SEMI-H. BSDs require, on average, smaller SS and TD compared to the BD, which, on the other hand, guarantees higher estimate precision. When large differences between children and adults are expected, BSDs can return very large SS. Bayesian approaches appear to outperform their frequentist counterparts in the design of pediatric trials even when little weight is given to prior information from adults.


Asunto(s)
Teorema de Bayes , Modelos Estadísticos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/estadística & datos numéricos , Niño , Humanos , Método de Montecarlo , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Tamaño de la Muestra
13.
Am J Clin Nutr ; 104 Suppl 3: 924S-7S, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27534639

RESUMEN

No large, randomized, placebo-controlled trial of iodine supplementation in pregnant women in a region of mild or moderate iodine deficiency has been completed in which a primary outcome measure was an assessment of the neurobehavioral development of the offspring at age ≥2 y. In this article, I discuss considerations for the design of such a trial in a region of mild iodine deficiency, with a focus on statistical methods and approaches. Exposure and design issues include the ethics of using a placebo, the potential for overexposure to iodine, and the possibility of community randomization. The main scientific goal of the trial is important in determining the follow-up period. If the goal is to determine whether iodine supplementation during pregnancy improves neurobehavioral development in the offspring, then follow-up should continue until a reasonably reliable assessment can be conducted, which might be at age ≥2 y. Once the timing of assessment is decided, the impact of potential loss to follow-up should be considered so that appropriate statistical methods can be incorporated into the design. The minimum sample size can be calculated by using a sample size formula that incorporates noncompliance and assumes that a certain proportion of study participants do not have any outcome observed. To have sufficient power to detect a reasonably modest difference in neurobehavioral development scores using an assessment tool with an SD of 15, a large number of participants (>500/group) is required. The minimum adequate number of participants may be even larger (>1300/group) depending on the magnitude of the difference in outcome between the supplementation and placebo groups, the estimated proportion of the iodine-supplementation group that fails to take the supplement, and the estimated proportion of pregnancies that do not produce outcome measurements.


Asunto(s)
Desarrollo Infantil/efectos de los fármacos , Suplementos Dietéticos , Yodo/farmacología , Complicaciones del Embarazo/tratamiento farmacológico , Fenómenos Fisiologicos de la Nutrición Prenatal , Proyectos de Investigación , Oligoelementos/farmacología , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Yodo/deficiencia , Yodo/uso terapéutico , Estado Nutricional , Embarazo , Atención Prenatal , Proyectos de Investigación/estadística & datos numéricos , Oligoelementos/deficiencia , Oligoelementos/uso terapéutico
14.
J Altern Complement Med ; 22(9): 739-50, 2016 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-27463943

RESUMEN

BACKGROUND: Interpretation of the efficacy of reflexology is hindered by inconsistent research designs and complicated by professional views that criteria of randomized controlled trials (RCTs)are not ideal to research holistic complementary and alternative medicine practice. The influence of research designs on study outcomes is not known. This integrative review sought to evaluate this possibility. MATERIALS AND METHODS: Thirty-seven interventional studies (2000-2014) were identified; they had RCT or non-RCT design and compared reflexology outcomes against a control/comparison group. Viability of integrating RCT and non-RCT studies into a single database was first evaluated by appraisal of 16 reporting fields related to study setting and objectives, sample demographics, methodologic design, and treatment fidelity and assessment against Jadad score quality criteria for RCTs. For appraisal, the database was stratified into RCT/non-RCT or Jadad score of 3 or more or less than 3. Deficits in reporting were identified for blind assignment of participants, dropout/completion rate, and School of Reflexology. For comparison purposes, these fields were excluded from subsequent analysis for evidence of association between design fields and of fields with study outcomes. RESULTS: Thirty-one studies applied psychometric tools and 20 applied biometric tools (14 applied both). A total of 116 measures were used. Type of measure was associated with study objectives (p < 0.001; chi-square), in particular of psychometric measures with a collated "behavioral/cognitive" objective. Significant outcomes were more likely (p < 0.001; chi-square) for psychometric than for biometric measures. Neither type of outcome was associated with choice of RCT or non-RCT method, but psychometric responses were associated (p = 0.007) with a nonmassage control strategy. CONCLUSIONS: The review supports psychometric responses to reflexology when study design uses a nonmassage control strategy. Findings suggest that an evaluation of outcomes against sham reflexology massage and other forms of massage, as well as a narrower focus of study objective, may clarify whether there is a relationship between study design and efficacy of reflexology.


Asunto(s)
Masaje , Ensayos Clínicos Controlados Aleatorios como Asunto , Proyectos de Investigación , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto/normas , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Proyectos de Investigación/normas , Proyectos de Investigación/estadística & datos numéricos , Resultado del Tratamiento , Adulto Joven
15.
Am J Clin Nutr ; 104(2): 247-58, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-27413128

RESUMEN

In observational studies, treatment assignment is a nonrandom process and treatment groups may not be comparable in their baseline characteristics, a phenomenon known as confounding. Propensity score (PS) methods can be used to achieve comparability of treated and nontreated groups in terms of their observed covariates and, as such, control for confounding in estimating treatment effects. In this article, we provide a step-by-step guidance on how to use PS methods. For illustrative purposes, we used simulated data based on an observational study of the relation between oral nutritional supplementation and hospital length of stay. We focused on the key aspects of PS analysis, including covariate selection, PS estimation, covariate balance assessment, treatment effect estimation, and reporting. PS matching, stratification, covariate adjustment, and weighting are discussed. R codes and example data are provided to show the different steps in a PS analysis.


Asunto(s)
Investigación Biomédica/métodos , Ciencias de la Nutrición/métodos , Puntaje de Propensión , Proyectos de Investigación/estadística & datos numéricos , Benchmarking , Suplementos Dietéticos , Humanos , Tiempo de Internación , Estudios Observacionales como Asunto , Proyectos de Investigación/normas
16.
J Biopharm Stat ; 26(2): 352-64, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-25616785

RESUMEN

This article illustrates the use of a multi-criteria decision making approach, based on desirability functions, to identify an appropriate adjuvant composition for an influenza vaccine to be used in elderly. The proposed adjuvant system contained two main elements: monophosphoryl lipid and α-tocopherol with squalene in an oil/water emulsion. The objective was to elicit a stronger immune response while maintaining an acceptable reactogenicity and safety profile. The study design, the statistical models, the choice of the desirability functions, the computation of the overall desirability index, and the assessment of the robustness of the ranking are all detailed in this manuscript.


Asunto(s)
Adyuvantes Inmunológicos/química , Ensayos Clínicos Fase II como Asunto , Toma de Decisiones , Vacunas contra la Influenza/química , Vacunas contra la Influenza/inmunología , Modelos Estadísticos , Adyuvantes Inmunológicos/administración & dosificación , Adyuvantes Inmunológicos/efectos adversos , Anciano , Ensayos Clínicos Fase II como Asunto/métodos , Ensayos Clínicos Fase II como Asunto/estadística & datos numéricos , Relación Dosis-Respuesta a Droga , Composición de Medicamentos/estadística & datos numéricos , Determinación de Punto Final , Humanos , Vacunas contra la Influenza/administración & dosificación , Vacunas contra la Influenza/efectos adversos , Gripe Humana/inmunología , Gripe Humana/prevención & control , Proyectos de Investigación/estadística & datos numéricos
17.
Trials ; 16: 495, 2015 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-26530985

RESUMEN

Randomized controlled trials (RCTs) are conducted under idealized and rigorously controlled conditions that may compromise their external validity. A literature review was conducted of published English language articles that reported the findings of studies assessing external validity by a comparison of the patient sample included in RCTs reporting on pharmaceutical interventions with patients from everyday clinical practice. The review focused on publications in the fields of cardiology, mental health, and oncology. A range of databases were interrogated (MEDLINE; EMBASE; Science Citation Index; Cochrane Methodology Register). Double-abstract review and data extraction were performed as per protocol specifications. Out of 5,456 de-duplicated abstracts, 52 studies met the inclusion criteria (cardiology, n = 20; mental health, n = 17; oncology, n = 15). Studies either performed an analysis of the baseline characteristics (demographic, socioeconomic, and clinical parameters) of RCT-enrolled patients compared with a real-world population, or assessed the proportion of real-world patients who would have been eligible for RCT inclusion following the application of RCT inclusion/exclusion criteria. Many of the included studies concluded that RCT samples are highly selected and have a lower risk profile than real-world populations, with the frequent exclusion of elderly patients and patients with co-morbidities. Calculation of ineligibility rates in individual studies showed that a high proportion of the general disease population was often excluded from trials. The majority of studies (n = 37 [71.2 %]) explicitly concluded that RCT samples were not broadly representative of real-world patients and that this may limit the external validity of the RCT. Authors made a number of recommendations to improve external validity. Findings from this review indicate that there is a need to improve the external validity of RCTs such that physicians treating patients in real-world settings have the appropriate evidence on which to base their clinical decisions. This goal could be achieved by trial design modification to include a more representative patient sample and by supplementing RCT evidence with data generated from observational studies. In general, a thoughtful approach to clinical evidence generation is required in which the trade-offs between internal and external validity are considered in a holistic and balanced manner.


Asunto(s)
Medicina Basada en la Evidencia/métodos , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Proyectos de Investigación , Cardiología , Interpretación Estadística de Datos , Medicina Basada en la Evidencia/estadística & datos numéricos , Humanos , Oncología Médica , Servicios de Salud Mental , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Reproducibilidad de los Resultados , Proyectos de Investigación/estadística & datos numéricos , Resultado del Tratamiento
18.
Stat Med ; 34(2): 181-96, 2015 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-25346484

RESUMEN

Stepped-wedge cluster randomised trials (SW-CRTs) are being used with increasing frequency in health service evaluation. Conventionally, these studies are cross-sectional in design with equally spaced steps, with an equal number of clusters randomised at each step and data collected at each and every step. Here we introduce several variations on this design and consider implications for power. One modification we consider is the incomplete cross-sectional SW-CRT, where the number of clusters varies at each step or where at some steps, for example, implementation or transition periods, data are not collected. We show that the parallel CRT with staggered but balanced randomisation can be considered a special case of the incomplete SW-CRT. As too can the parallel CRT with baseline measures. And we extend these designs to allow for multiple layers of clustering, for example, wards within a hospital. Building on results for complete designs, power and detectable difference are derived using a Wald test and obtaining the variance-covariance matrix of the treatment effect assuming a generalised linear mixed model. These variations are illustrated by several real examples. We recommend that whilst the impact of transition periods on power is likely to be small, where they are a feature of the design they should be incorporated. We also show examples in which the power of a SW-CRT increases as the intra-cluster correlation (ICC) increases and demonstrate that the impact of the ICC is likely to be smaller in a SW-CRT compared with a parallel CRT, especially where there are multiple levels of clustering. Finally, through this unified framework, the efficiency of the SW-CRT and the parallel CRT can be compared.


Asunto(s)
Investigación sobre Servicios de Salud/métodos , Partería/educación , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Proyectos de Investigación/estadística & datos numéricos , Interpretación Estadística de Datos , Investigación sobre Servicios de Salud/estadística & datos numéricos , Humanos , Trabajo de Parto Inducido/métodos , Trabajo de Parto Inducido/estadística & datos numéricos , Partería/métodos , Evaluación de Programas y Proyectos de Salud/métodos , Evaluación de Programas y Proyectos de Salud/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos
20.
Ann Noninvasive Electrocardiol ; 19(1): 70-81, 2014 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-24372708

RESUMEN

A collaboration between the Consortium for Innovation and Quality in Pharmaceutical Development and the Cardiac Safety Research Consortium has been formed to design a clinical study in healthy subjects demonstrating that the thorough QT (TQT) study can be replaced by robust ECG monitoring and exposure-response (ER) analysis of data generated from First-in-Man single ascending dose (SAD) studies. Six marketed drugs with well-characterized QTc effects were identified in discussions with FDA; five have caused QT prolongation above the threshold of regulatory concern. Twenty healthy subjects will be enrolled in a randomized, placebo-controlled study designed with the intent to have similar power to exclude small QTc effects as a SAD study. Two doses (low and high) of each drug will be given on separate, consecutive days to 9 subjects. Six subjects will receive placebo. Data will be analyzed using linear mixed-effects ER models. Criteria for QT-positive drugs will be the demonstration of an upper bound (UB) of the 2-sided 90% confidence interval (CI) of the projected QTc effect at the peak plasma level of the lower dose above the threshold of regulatory concern (currently 10 ms) and a positive slope of ER relationship. The criterion for QT-negative drug will be an UB of the CI of the projected QTc effect of the higher dose <10 ms. It is expected that a successful outcome in this study will provide evidence supporting replacement of the TQT study with ECG assessments in standard early clinical development studies for a new chemical entity.


Asunto(s)
Ensayos Clínicos Fase I como Asunto/métodos , Evaluación Preclínica de Medicamentos/métodos , Electrocardiografía/efectos de los fármacos , Electrocardiografía/métodos , Estudios Prospectivos , Proyectos de Investigación/estadística & datos numéricos , Relación Dosis-Respuesta a Droga , Electrocardiografía/estadística & datos numéricos , Humanos , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Valores de Referencia
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