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2.
Life Sci ; 282: 119819, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34256038

RESUMO

AIMS: Gulf War Illness (GWI) is a chronic, debilitating, multi-symptom condition affecting as many as one-third of the nearly 700,000 U.S. troops deployed to the Middle East during the 1990-1991 Gulf War (GW). The treatment of GWI relies on symptom management. A common challenge in studying the efficacy of interventions for symptom management is participant recruitment related to factors such as the burden of travelling to study sites and the widespread dispersion of Veterans with GWI. The goal of this study is to assess the efficacy of a novel low-risk therapeutic agent, Bacopa monnieri, for cognitive function in Veterans with GWI and to evaluate the utility of a remote patient-centric study design developed to promote recruitment and minimize participant burden. MAIN METHODS: To promote effective participant recruitment, we developed a remote patient-centric study design. Participants will be recruited online through social media and through a web-based research volunteer list of GW Veterans. An online assessment platform will be used, and laboratory blood draws will be performed at clinical laboratory sites that are local to participants. Furthermore, the assigned intervention will be mailed to each participant. SIGNIFICANCE: These study design adaptations will open participation to Veterans nearly nationwide and reduce administrative costs while maintaining methodologic rigor and participant safety in a randomized, placebo-controlled phase II clinical trial.


Assuntos
Bacopa , Disfunção Cognitiva/tratamento farmacológico , Síndrome do Golfo Pérsico/tratamento farmacológico , Veteranos , Idoso , Humanos , Masculino , Pessoa de Meia-Idade
3.
Pharm Stat ; 19(5): 720-732, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32338443

RESUMO

In monitoring clinical trials, the question of futility, or whether the data thus far suggest that the results at the final analysis are unlikely to be statistically successful, is regularly of interest over the course of a study. However, the opposite viewpoint of whether the study is sufficiently demonstrating proof of concept (POC) and should continue is a valuable consideration and ultimately should be addressed with high POC power so that a promising study is not prematurely terminated. Conditional power is often used to assess futility, and this article interconnects the ideas of assessing POC for the purpose of study continuation with conditional power, while highlighting the importance of the POC type I error and the POC type II error for study continuation or not at the interim analysis. Methods for analyzing subgroups motivate the interim analyses to maintain high POC power via an adjusted interim POC significance level criterion for study continuation or testing against an inferiority margin. Furthermore, two versions of conditional power based on the assumed effect size or the observed interim effect size are considered. Graphical displays illustrate the relationship of the POC type II error for premature study termination to the POC type I error for study continuation and the associated conditional power criteria.


Assuntos
Ensaios Clínicos como Assunto/métodos , Projetos de Pesquisa , Humanos , Futilidade Médica , Estudo de Prova de Conceito , Tamanho da Amostra
4.
Can Urol Assoc J ; 14(4): 99-104, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31702546

RESUMO

INTRODUCTION: Urolithiasis causes a significant impact on health-related quality of life (HRQOL). Patients with kidney stones have high levels of stress and anxiety. Symptom resolution often requires treatment. Travel distance is a barrier to care but little is known about its effects on HRQOL. We hypothesize that increased distance to treatment site is associated with decreased HRQOL. METHODS: Patients with a history of stones were enrolled at 11 tertiary centers as part of the QOL Stone Consortium of North America. HRQOL data were obtained using the Wisconsin Stone Quality of Life questionnaire (WISQOL). We calculated distance between patient and treatment site using national ZIP codes. We used linear models to evaluate the effect of distance on HRQOL, while also considering demographics data, stones/symptom status, and distance. RESULTS: Of the 1676 enrolled patients, 52% were male, 86% non-Latino White, and the mean age was 53 years. Mean distance to treatment site was 63.3 km (range 0-3774), with 74% reporting current stones and 45% current symptoms. WISQOL score and distance were negatively correlated for patients reporting current stones and symptoms (p=0.0010). Linear modelling revealed decreased WISQOL scores for patients with symptoms as distance increased from treatment site (p=0.0001), with a 4.7-point decrease for every 100 km traveled. CONCLUSIONS: Stone disease imposes significant burden on patients' HRQOL due to a variety of factors. Patients with active stone symptoms report worse HRQOL with increased distance to their treatment site. Possible etiologies include travel burden, increased disease burden, decreased healthcare use, and delays in care.

5.
J Biopharm Stat ; 29(4): 696-713, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31304861

RESUMO

The sequential parallel comparison design (SPCD), with sequence groups P:P, P:T, and T:T, together with the exclusion of the second-period information from placebo responders in the first period, can serve usefully for studies with highly favorable placebo response, for example, psychiatric clinical trials. This paper presents a methodology for the first-period treatment difference in the overall population and the second-period treatment difference in the placebo nonresponders for the first period, as well as other available sources of information that could be of potential interest. Without any assumptions, a hypothesis testing method is proposed based on the randomization distribution of comparisons using the covariance structure for the randomized population under the null hypothesis to control type I error. Randomization-based analysis of covariance (ANCOVA) is introduced to adjust for baseline and for the observations that serve as baselines for the second period. Related methods are proposed for the study population as a simple random sample of an almost infinite population. The statistical properties of the proposed methods are described with simulation studies; and the use of the methods is illustrated for an example based on the data from the ADAPT-A clinical trial.


Assuntos
Ensaios Clínicos Controlados Aleatórios como Assunto , Projetos de Pesquisa , Simulação por Computador , Humanos , Distribuição Aleatória
6.
J Am Med Dir Assoc ; 18(12): 1063-1068, 2017 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-29169736

RESUMO

RATIONALE: The prevalence of chronic obstructive pulmonary disease (COPD) and its associated comorbidities increase with age. However, little is understood about differences in the disease in patients over 65 years of age compared with younger patients. OBJECTIVES: To determine disease characteristics of COPD and its impact in older patients compared with younger patients. METHODS: We examined baseline characteristics of patients with COPD (global obstructive lung disease stage II-IV) in 2 large cohorts: Genetic Epidemiology of COPD Study (COPDGene) and Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints (ECLIPSE). We compared demographics, indices of disease severity, prevalence of comorbidities, exacerbation frequency, and quality of life scores in patients ≥65 years of age vs patients <65 years of age. We also tested for associations of age with disease characteristics and health outcomes. RESULTS: In the COPDGene cohort, older patients (n = 1663) had more severe disease as measured by forced expiratory volume in 1 second (1.22 vs 1.52 L, P < .001), use of long-term oxygen therapy (35% vs 22%, P < .001), 6-minute walk distance (355 vs 375 m, P < .001), and radiographic evidence of emphysema (14% vs 8%, P < .001) and air trapping (47% vs 36%, P < .001) and were more likely to have comorbidities compared with younger patients (n = 2027). Similarly, in the ECLIPSE cohort, older patients (n = 1030) had lower forced expiratory volume in 1 second (1.22 vs 1.34 L, P < .001), greater use of long-term oxygen therapy (7% vs 5%, P = .02), shorter 6- minute walk distance (360 vs 389 m, P < .001), and more radiographic evidence of emphysema (17% vs 14%, P = .009) than younger patients (n = 1131). In adjusted analyses of both cohorts, older age was associated with decreased frequency of exacerbations [odds ratio = 0.52, 95% confidence interval (CI) = 0.43-0.64 in COPDGene, odds ratio = 0.79, 95% CI = 0.64-0.99 in ECLIPSE] and a better quality of life (lower St. Georges respiratory questionnaire score) (ß = -8.7, 95% CI = -10.0 to -7.4 in COPDGene, ß = -4.4, 95% CI = -6.1 to -3.2 in ECLIPSE). CONCLUSIONS: Despite greater severity of illness, older patients with COPD had better quality of life and reported fewer exacerbations than younger patients. Although this observation needs to be explored further, it may be related to the fact that older patients change their expectations and learn to adapt to their disease.


Assuntos
Volume Expiratório Forçado/fisiologia , Predisposição Genética para Doença/epidemiologia , Doença Pulmonar Obstrutiva Crônica/epidemiologia , Doença Pulmonar Obstrutiva Crônica/genética , Qualidade de Vida , Fatores Etários , Idoso , Biomarcadores , Estudos de Coortes , Comorbidade , Progressão da Doença , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Razão de Chances , Valor Preditivo dos Testes , Prevalência , Prognóstico , Doença Pulmonar Obstrutiva Crônica/diagnóstico , Estudos Retrospectivos , Medição de Risco , Índice de Gravidade de Doença , Estatísticas não Paramétricas , Taxa de Sobrevida
7.
Heart Rhythm ; 13(9): 1777-83, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27108936

RESUMO

BACKGROUND: Vanoxerine is an oral, 1,4-dialkylpiperazine derivative antiarrhythmic drug being evaluated for pharmacological cardioversion of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to evaluate the safety and efficacy of vanoxerine for the restoration of sinus rhythm in subjects with recent onset AF or atrial flutter (AFL). METHODS: RESTORE SR (randomized, double-blind, placebo-controlled study to evaluate the safety and efficacy of a single oral dose of vanoxerine for the conversion of subjects with recent onset atrial fibrillation or flutter to normal sinus rhythm) was a prospective, multinational, randomized, double-blind, placebo-controlled trial that randomized subjects to a single oral dose of vanoxerine 400 mg or placebo (2:1 allocation). RESULTS: A total of 41 subjects were randomized in the study (placebo [n = 15] and vanoxerine [n = 26]). The study was terminated prematurely because of safety concerns. Overall, 61% (23 of 38) of the treated cohort had a history of AF/AFL and 66% (27 of 41) had structural heart disease (SHD). The primary efficacy end point-conversion to sinus rhythm through 24 hours-occurred in 20% (3 of 15) in the placebo arm vs 69% (18 of 26) in the vanoxerine arm (P = .0024). The mean length of stay was 4.2 ± 2.9 days in the placebo arm vs 4.7 ± 3.2 days in the vanoxerine arm (P = .6561). The primary safety end point (all-cause death, ventricular fibrillation/tachycardia requiring intervention, or torsades de pointes) occurred in no patient in the placebo arm vs 11.5% (3 of 26) in the vanoxerine arm. All 3 patients had torsades de pointes and underlying SHD. CONCLUSION: Vanoxerine is an oral, mixed ion channel blocker with IKr, INa, and L-type calcium channel activity. While oral therapy with 400 mg of vanoxerine appears effective for the termination of recent onset AF/AFL, its use was associated with a significant risk of ventricular proarrhythmia in patients with SHD.


Assuntos
Antiarrítmicos/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Flutter Atrial/tratamento farmacológico , Piperazinas/administração & dosagem , Taquicardia Ventricular/induzido quimicamente , Administração Oral , Idoso , Antiarrítmicos/efeitos adversos , Método Duplo-Cego , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Piperazinas/efeitos adversos , Estudos Prospectivos , Resultado do Tratamento
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