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1.
N Engl J Med ; 383(27): 2616-2627, 2020 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-33326713

RESUMEN

BACKGROUND: Chronic subdural hematoma is a common neurologic disorder that is especially prevalent among older people. The effect of dexamethasone on outcomes in patients with chronic subdural hematoma has not been well studied. METHODS: We conducted a multicenter, randomized trial in the United Kingdom that enrolled adult patients with symptomatic chronic subdural hematoma. The patients were assigned in a 1:1 ratio to receive a 2-week tapering course of oral dexamethasone, starting at 8 mg twice daily, or placebo. The decision to surgically evacuate the hematoma was made by the treating clinician. The primary outcome was a score of 0 to 3, representing a favorable outcome, on the modified Rankin scale at 6 months after randomization; scores range from 0 (no symptoms) to 6 (death). RESULTS: From August 2015 through November 2019, a total of 748 patients were included in the trial after randomization - 375 were assigned to the dexamethasone group and 373 to the placebo group. The mean age of the patients was 74 years, and 94% underwent surgery to evacuate their hematomas during the index admission; 60% in both groups had a score of 1 to 3 on the modified Rankin scale at admission. In a modified intention-to-treat analysis that excluded the patients who withdrew consent for participation in the trial or who were lost to follow-up, leaving a total of 680 patients, a favorable outcome was reported in 286 of 341 patients (83.9%) in the dexamethasone group and in 306 of 339 patients (90.3%) in the placebo group (difference, -6.4 percentage points [95% confidence interval, -11.4 to -1.4] in favor of the placebo group; P = 0.01). Among the patients with available data, repeat surgery for recurrence of the hematoma was performed in 6 of 349 patients (1.7%) in the dexamethasone group and in 25 of 350 patients (7.1%) in the placebo group. More adverse events occurred in the dexamethasone group than in the placebo group. CONCLUSIONS: Among adults with symptomatic chronic subdural hematoma, most of whom had undergone surgery to remove their hematomas during the index admission, treatment with dexamethasone resulted in fewer favorable outcomes and more adverse events than placebo at 6 months, but fewer repeat operations were performed in the dexamethasone group. (Funded by the National Institute for Health Research Health Technology Assessment Programme; Dex-CSDH ISRCTN number, ISRCTN80782810.).


Asunto(s)
Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Hematoma Subdural Crónico/tratamiento farmacológico , Administración Oral , Anciano , Terapia Combinada , Dexametasona/administración & dosificación , Dexametasona/efectos adversos , Personas con Discapacidad , Femenino , Glucocorticoides/administración & dosificación , Glucocorticoides/efectos adversos , Hematoma Subdural Crónico/complicaciones , Hematoma Subdural Crónico/mortalidad , Hematoma Subdural Crónico/cirugía , Humanos , Análisis de Intención de Tratar , Masculino , Persona de Mediana Edad , Reoperación/estadística & datos numéricos , Índice de Severidad de la Enfermedad , Resultado del Tratamiento
2.
Psychooncology ; 26(12): 2094-2100, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28332254

RESUMEN

OBJECTIVES: To establish older women's (≥75 years) information preferences regarding 2 breast cancer treatment options: surgery plus adjuvant endocrine therapy versus primary endocrine therapy. To quantify women's preferences for the mode of information presentation and decision-making (DM) style. METHODS: This was a UK multicentre survey of women, ≥75 years, who had been offered a choice between PET and surgery at diagnosis of breast cancer. A questionnaire was developed including 2 validated scales of decision regret and DM preferences. RESULTS: Questionnaires were sent to 247 women, and 101 were returned (response rate 41%). The median age of participants was 82 (range 75 to 99), with 58 having had surgery and 37 having PET. Practical details about the impact, safety, and efficacy of treatment were of most interest to participants. Of least interest were cosmetic outcomes after surgery. Information provided verbally by doctors and nurses, supported by booklets, was preferred. There was little interest in technology-based sources of information. There was equal preference for a patient- or doctor-centred DM style and lower preference for a shared DM style. The majority (74%) experienced their preferred DM style. Levels of decision regret were low (15.73, scale 0-100). CONCLUSIONS: Women strongly preferred face to face information. Written formats were also helpful but not computer-based resources. Information that was found helpful to women in the DM process was identified. The study demonstrates many women achieved their preferred DM style, with a preference for involvement, and expressed low levels of decision regret.


Asunto(s)
Neoplasias de la Mama/psicología , Neoplasias de la Mama/terapia , Conducta de Elección , Toma de Decisiones , Técnicas de Apoyo para la Decisión , Participación del Paciente/psicología , Prioridad del Paciente , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/cirugía , Estudios Transversales , Femenino , Conocimientos, Actitudes y Práctica en Salud , Humanos , Estudios Retrospectivos , Encuestas y Cuestionarios
3.
BMC Med Res Methodol ; 16(1): 165, 2016 11 29.
Artículo en Inglés | MEDLINE | ID: mdl-27899073

RESUMEN

BACKGROUND: In an individually randomised controlled trial where the treatment is delivered by a health professional it seems likely that the effectiveness of the treatment, independent of any treatment effect, could depend on the skill, training or even enthusiasm of the health professional delivering it. This may then lead to a potential clustering of the outcomes for patients treated by the same health professional, but similar clustering may not occur in the control arm. Using four case studies, we aim to provide practical guidance and recommendations for the analysis of trials with some element of clustering in one arm. METHODS: Five approaches to the analysis of outcomes from an individually randomised controlled trial with clustering in one arm are identified in the literature. Some of these methods are applied to four case studies of completed randomised controlled trials with clustering in one arm with sample sizes ranging from 56 to 539. Results are obtained using the statistical packages R and Stata and summarised using a forest plot. RESULTS: The intra-cluster correlation coefficient (ICC) for each of the case studies was small (<0.05) indicating little dependence on the outcomes related to cluster allocations. All models fitted produced similar results, including the simplest approach of ignoring clustering for the case studies considered. CONCLUSIONS: A partially clustered approach, modelling the clustering in just one arm, most accurately represents the trial design and provides valid results. Modelling homogeneous variances between the clustered and unclustered arm is adequate in scenarios similar to the case studies considered. We recommend treating each participant in the unclustered arm as a single cluster. This approach is simple to implement in R and Stata and is recommended for the analysis of trials with clustering in one arm only. However, the case studies considered had small ICC values, limiting the generalisability of these results.


Asunto(s)
Algoritmos , Modelos Teóricos , Evaluación de Resultado en la Atención de Salud/estadística & datos numéricos , Ensayos Clínicos Controlados Aleatorios como Asunto/estadística & datos numéricos , Análisis por Conglomerados , Humanos , Evaluación de Resultado en la Atención de Salud/métodos , Evaluación de Resultado en la Atención de Salud/normas , Ensayos Clínicos Controlados Aleatorios como Asunto/métodos , Reproducibilidad de los Resultados , Proyectos de Investigación/normas , Tamaño de la Muestra
4.
Health Technol Assess ; 28(12): 1-122, 2024 03.
Artículo en Inglés | MEDLINE | ID: mdl-38512045

RESUMEN

Background: Chronic subdural haematoma is a collection of 'old blood' and its breakdown products in the subdural space and predominantly affects older people. Surgical evacuation remains the mainstay in the management of symptomatic cases. Objective: The Dex-CSDH (DEXamethasone in Chronic SubDural Haematoma) randomised trial investigated the clinical effectiveness and cost-effectiveness of dexamethasone in patients with a symptomatic chronic subdural haematoma. Design: This was a parallel, superiority, multicentre, pragmatic, randomised controlled trial. Assigned treatment was administered in a double-blind fashion. Outcome assessors were also blinded to treatment allocation. Setting: Neurosurgical units in the UK. Participants: Eligible participants included adults (aged ≥ 18 years) admitted to a neurosurgical unit with a symptomatic chronic subdural haematoma confirmed on cranial imaging. Interventions: Participants were randomly assigned in a 1 : 1 allocation to a 2-week tapering course of dexamethasone or placebo alongside standard care. Main outcome measures: The primary outcome was the Modified Rankin Scale score at 6 months dichotomised to a favourable (score of 0-3) or an unfavourable (score of 4-6) outcome. Secondary outcomes included the Modified Rankin Scale score at discharge and 3 months; number of chronic subdural haematoma-related surgical interventions undertaken during the index and subsequent admissions; Barthel Index and EuroQol 5-Dimension 5-Level utility index score reported at discharge, 3 months and 6 months; Glasgow Coma Scale score reported at discharge and 6 months; mortality at 30 days and 6 months; length of stay; discharge destination; and adverse events. An economic evaluation was also undertaken, during which the net monetary benefit was estimated at a willingness-to-pay threshold of £20,000 per quality-adjusted life-year. Results: A total of 748 patients were included after randomisation: 375 were assigned to dexamethasone and 373 were assigned to placebo. The mean age of the patients was 74 years and 94% underwent evacuation of their chronic subdural haematoma during the trial period. A total of 680 patients (91%) had 6-month primary outcome data available for analysis: 339 in the placebo arm and 341 in the dexamethasone arm. On a modified intention-to-treat analysis of the full study population, there was an absolute reduction in the proportion of favourable outcomes of 6.4% (95% confidence interval 11.4% to 1.4%; p = 0.01) in the dexamethasone arm compared with the control arm at 6 months. At 3 months, the between-group difference was also in favour of placebo (-8.2%, 95% confidence interval -13.3% to -3.1%). Serious adverse events occurred in 60 out of 375 (16.0%) in the dexamethasone arm and 24 out of 373 (6.4%) in the placebo arm. The net monetary benefit of dexamethasone compared with placebo was estimated to be -£97.19. Conclusions: This trial reports a higher rate of unfavourable outcomes at 6 months, and a higher rate of serious adverse events, in the dexamethasone arm than in the placebo arm. Dexamethasone was also not estimated to be cost-effective. Therefore, dexamethasone cannot be recommended for the treatment of chronic subdural haematoma in this population group. Future work and limitations: A total of 94% of individuals underwent surgery, meaning that this trial does not fully define the role of dexamethasone in conservatively managed haematomas, which is a potential area for future study. Trial registration: This trial is registered as ISRCTN80782810. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 13/15/02) and is published in full in Health Technology Assessment; Vol. 28, No. 12. See the NIHR Funding and Awards website for further award information.


Chronic subdural haematoma is one of the most common conditions managed in adult neurosurgery and mainly affects older people. It is an 'old' collection of blood and blood breakdown products found on the surface of the brain. Surgery to drain the liquid collection is effective, with most patients improving. Given that inflammation is involved in the disease process, a commonly used steroid, dexamethasone, has been used alongside surgery or instead of surgery since the 1970s. However, there is no consensus or high-quality studies confirming the effectiveness of dexamethasone for the treatment of chronic subdural haematoma. This study was designed to determine the effectiveness of adding dexamethasone to the normal treatment for patients with a symptomatic chronic subdural haematoma. The benefit of adding dexamethasone was measured using a disability score called the Modified Rankin Scale, which can be divided into favourable and unfavourable outcomes. This was assessed at 6 months after entry into the study. In total, 748 adults with a symptomatic chronic subdural haematoma treated in neurosurgical units in the UK participated. Each participant had an equal chance of receiving either dexamethasone or a placebo because they were assigned randomly. Neither the patients nor the investigators knew who received dexamethasone and who received placebo. Most patients in both groups had an operation to drain the haematoma and experienced significant functional improvement at 6 months compared with their initial admission to hospital. However, patients who received dexamethasone had a lower chance than patients who received placebo of favourable recovery at 6 months. Specifically, 84% of patients who received dexamethasone had recovered well at 6 months, compared with 90% of patients who received placebo. There were more complications in the group that received dexamethasone. This trial demonstrates that adding dexamethasone to standard treatment reduced the chance of a favourable outcome compared with standard treatment alone. Therefore, this study does not support the use of dexamethasone in treating patients with a symptomatic chronic subdural haematoma.


Asunto(s)
Hematoma Subdural Crónico , Adulto , Humanos , Anciano , Hematoma Subdural Crónico/tratamiento farmacológico , Hospitalización , Análisis Costo-Beneficio , Método Doble Ciego , Dexametasona/uso terapéutico
5.
Semin Perinatol ; 45(3): 151392, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33549333

RESUMEN

The optimal management of glucose levels in critical care remains an area for research due to the problems of balancing the risks of hyperglycemia versus hypoglycemia. This paper reports the first economic evaluation of real time continuous glucose monitoring to guide the clinical management of preterm infants, based on evidence from the REACT trial. Bivariate regression of costs (£, 2016-17 prices) and cases of adequate glucose control, with multiple imputation of missing data, was conducted. When the economic evaluation was restricted to the first week of life, real time continuous glucose monitoring was associated with increased costs and a statistically significant increase in adequate glucose control. When the assessment was performed over a time horizon extending to 36 weeks' corrected gestational age, real time CGM was dominant in health economic terms, i.e. associated with lower costs and better outcomes. These results largely remained robust to a range of sensitivity analyses and sub-group analyses designed to address uncertainty and heterogeneity surrounding the cost-effectiveness outcomes. This study suggests that the use of real time continuous glucose monitoring in preterm infants is associated with a high probability of cost-effectiveness.


Asunto(s)
Glucemia , Hipoglucemia , Automonitorización de la Glucosa Sanguínea , Análisis Costo-Beneficio , Humanos , Hipoglucemia/prevención & control , Recién Nacido , Recien Nacido Prematuro
6.
Lancet Child Adolesc Health ; 5(4): 265-273, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33577770

RESUMEN

BACKGROUND: Hyperglycaemia and hypoglycaemia are common in preterm infants and have been associated with increased risk of mortality and morbidity. Interventions to reduce risk associated with these exposures are particularly challenging due to the infrequent measurement of blood glucose concentrations, with the potential of causing more harm instead of improving outcomes for these infants. Continuous glucose monitoring (CGM) is widely used in adults and children with diabetes to improve glucose control, but has not been approved for use in neonates. The REACT trial aimed to evaluate the efficacy and safety of CGM in preterm infants requiring intensive care. METHODS: This international, open-label, randomised controlled trial was done in 13 neonatal intensive care units in the UK, Spain, and the Netherlands. Infants were included if they were within 24 h of birth, had a birthweight of 1200 g or less, had a gestational age up to 33 weeks plus 6 days, and had parental written informed consent. Infants were randomly assigned (1:1) to real-time CGM or standard care (with masked CGM for comparison) using a central web randomisation system, stratified by recruiting centre and gestational age (<26 or ≥26 weeks). The primary efficacy outcome was the proportion of time sensor glucose concentration was 2·6-10 mmol/L for the first week of life. Safety outcomes related to hypoglycaemia (glucose concentrations <2·6 mmol/L) in the first 7 days of life. All outcomes were assessed on the basis of intention to treat in the full analysis set with available data. The study is registered with the International Standard Randomised Control Trials Registry, ISRCTN12793535. FINDINGS: Between July 4, 2016, and Jan 27, 2019, 182 infants were enrolled, 180 of whom were randomly assigned (85 to real-time CGM, 95 to standard care). 70 infants in the real-time CGM intervention group and 85 in the standard care group had CGM data and were included in the primary analysis. Compared with infants in the standard care group, infants managed using CGM had more time in the 2·6-10 mmol/L glucose concentration target range (mean proportion of time 84% [SD 22] vs 94% [11]; adjusted mean difference 8·9% [95% CI 3·4-14·4]), equivalent to 13 h (95% CI 5-21). More infants in the standard care group were exposed to at least one episode of sensor glucose concentration of less than 2·6 mmol/L for more than 1 h than those in the intervention group (13 [15%] of 85 vs four [6%] of 70). There were no serious adverse events related to the use of the device or episodes of infection. INTERPRETATION: Real-time CGM can reduce exposure to prolonged or severe hyperglycaemia and hypoglycaemia. Further studies using CGM are required to determine optimal glucose targets, strategies to obtain them, and the potential effect on long-term health outcomes. FUNDING: National Institute for Health Research Efficacy and Mechanisms Evaluation Programme.


Asunto(s)
Glucemia/metabolismo , Hiperglucemia/diagnóstico , Hipoglucemia/diagnóstico , Monitoreo Fisiológico/métodos , Femenino , Glucosa/administración & dosificación , Humanos , Hiperglucemia/metabolismo , Hiperglucemia/terapia , Hipoglucemia/metabolismo , Hipoglucemia/terapia , Hipoglucemiantes/uso terapéutico , Recien Nacido Extremadamente Prematuro , Recién Nacido , Recien Nacido Prematuro , Recién Nacido de muy Bajo Peso , Insulina/uso terapéutico , Unidades de Cuidado Intensivo Neonatal , Masculino , Países Bajos , España , Factores de Tiempo , Reino Unido
7.
Bone Joint J ; 101-B(11): 1408-1415, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31674250

RESUMEN

AIMS: The aim of this study was to assess the feasibility of conducting a full-scale, appropriately powered, randomized controlled trial (RCT) comparing internal fracture fixation and distal femoral replacement (DFR) for distal femoral fractures in older patients. PATIENTS AND METHODS: Seven centres recruited patients into the study. Patients were eligible if they were greater than 65 years of age with a distal femoral fracture, and if the surgeon felt that they were suitable for either form of treatment. Outcome measures included the patients' willingness to participate, clinicians' willingness to recruit, rates of loss to follow-up, the ability to capture data, estimates of standard deviation to inform the sample size calculation, and the main determinants of cost. The primary clinical outcome measure was the EuroQol five-dimensional index (EQ-5D) at six months following injury. RESULTS: Of 36 patients who met the inclusion criteria, five declined to participate and eight were not recruited, leaving 23 patients to be randomized. One patient withdrew before surgery. Of the remaining patients, five (23%) withdrew during the follow-up period and six (26%) died. A 100% response rate was achieved for the EQ-5D at each follow-up point, excluding one missing datapoint at baseline. In the DFR group, the mean cost of the implant outweighed the mean cost of many other items, including theatre time, length of stay, and readmissions. For a powered RCT, a total sample size of 1400 would be required with 234 centres recruiting over three years. At six months, the EQ-5D utility index was lower in the DFR group. CONCLUSION: This study found that running a full-scale trial in this country would not be feasible. However, it may be feasible to undertake an international multicentre trial, and our findings provide some guidance about the power of such a study, the numbers required, and some challenges that should be anticipated and addressed. Cite this article: Bone Joint J 2019;101-B:1408-1415.


Asunto(s)
Artroplastia de Reemplazo de Rodilla/métodos , Fracturas del Fémur/cirugía , Fijación Interna de Fracturas/métodos , Anciano , Anciano de 80 o más Años , Estudios de Factibilidad , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Tempo Operativo , Estudios Prospectivos , Resultado del Tratamiento
8.
Trials ; 20(1): 698, 2019 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-31822298

RESUMEN

BACKGROUND: The incidence of chronic subdural haematoma (CSDH) is increasing. Although surgery remains the mainstay of management for symptomatic patients, uncertainty remains regarding the role of steroids. Hence, the Dex-CSDH trial was launched in the UK in 2015 aiming to determine whether, compared to placebo, dexamethasone can improve the 6-month functional outcome of patients with symptomatic CSDH by reducing the rate of surgical intervention and recurrence rate. METHODS AND DESIGN: Dex-CSDH is a multi-centre, pragmatic, parallel group, double-blind, randomised trial assessing the clinical utility of a 2-week course of dexamethasone following a CSDH. Seven hundred fifty patients were randomised to either dexamethasone or placebo. The primary outcome is the modified Rankin Scale at 6 months which is dichotomised to favourable (a score of 0-3) versus unfavourable (a score of 4-6). CONCLUSIONS: This paper and the accompanying additional material describe the statistical analysis plan for the trial. TRIAL REGISTRATION: ISRCTN, ISRCTN80782810. Registered on 7 November 2014. http://www.isrctn.com/ISRCTN80782810. EudraCT, 2014-004948-35. Registered on 20 March 2015.


Asunto(s)
Dexametasona/uso terapéutico , Glucocorticoides/uso terapéutico , Hematoma Subdural Crónico/tratamiento farmacológico , Ensayos Clínicos Fase III como Asunto , Interpretación Estadística de Datos , Dexametasona/efectos adversos , Evaluación de la Discapacidad , Método Doble Ciego , Glucocorticoides/efectos adversos , Hematoma Subdural Crónico/diagnóstico , Hematoma Subdural Crónico/mortalidad , Hematoma Subdural Crónico/fisiopatología , Humanos , Estudios Multicéntricos como Asunto , Ensayos Clínicos Pragmáticos como Asunto , Recuperación de la Función , Recurrencia , Factores de Tiempo , Resultado del Tratamiento , Reino Unido
9.
R J ; 9(2): 342-353, 2017 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-29564164

RESUMEN

Treatment switching in a randomised controlled trial occurs when participants change from their randomised treatment to the other trial treatment during the study. Failure to account for treatment switching in the analysis (i.e. by performing a standard intention-to-treat analysis) can lead to biased estimates of treatment efficacy. The rank preserving structural failure time model (RPSFTM) is a method used to adjust for treatment switching in trials with survival outcomes. The RPSFTM is due to Robins and Tsiatis (1991) and has been developed by White et al. (1997, 1999). The method is randomisation based and uses only the randomised treatment group, observed event times, and treatment history in order to estimate a causal treatment effect. The treatment effect, ψ, is estimated by balancing counter-factual event times (that would be observed if no treatment were received) between treatment groups. G-estimation is used to find the value of ψ such that a test statistic Z(ψ) = 0. This is usually the test statistic used in the intention-to-treat analysis, for example, the log rank test statistic. We present an R package that implements the method of rpsftm.

10.
Trials ; 17(1): 150, 2016 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-26993469

RESUMEN

Adaptive designs have the potential to improve efficiency in the evaluation of new medical treatments in comparison to traditional fixed sample size designs. However, they are still not widely used in practice in clinical research. Little research has been conducted to investigate what adaptive designs are being undertaken. This review highlights the current state of registered adaptive designs and their characteristics. The review looked at phase II, II/III and III trials registered on ClinicalTrials.gov from 29 February 2000 to 1 June 2014, supplemented with trials from the National Institute for Health Research register and known adaptive trials. A range of adaptive design search terms were applied to the trials extracted from each database. Characteristics of the adaptive designs were then recorded including funder, therapeutic area and type of adaptation. The results in the paper suggest that the use of adaptive designs has increased. They seem to be most often used in phase II trials and in oncology. In phase III trials, the most popular form of adaptation is the group sequential design. The review failed to capture all trials with adaptive designs, which suggests that the reporting of adaptive designs, such as in clinical trials registers, needs much improving. We recommend that clinical trial registers should contain sections dedicated to the type and scope of the adaptation and that the term 'adaptive design' should be included in the trial title or at least in the brief summary or design sections.


Asunto(s)
Ensayos Clínicos como Asunto/métodos , Sistema de Registros , Proyectos de Investigación , Ensayos Clínicos como Asunto/normas , Recolección de Datos , Humanos , Control de Calidad , Proyectos de Investigación/normas , Terminología como Asunto
11.
Trials ; 16: 522, 2015 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-26573827

RESUMEN

BACKGROUND: Visceral leishmaniasis (VL) is a parasitic disease transmitted by sandflies and is fatal if left untreated. Phase II trials of new treatment regimens for VL are primarily carried out to evaluate safety and efficacy, while pharmacokinetic data are also important to inform future combination treatment regimens. The efficacy of VL treatments is evaluated at two time points, initial cure, when treatment is completed and definitive cure, commonly 6 months post end of treatment, to allow for slow response to treatment and detection of relapses. This paper investigates a generalization of the triangular design to impose a minimum sample size for pharmacokinetic or other analyses, and methods to estimate efficacy at extended follow-up accounting for the sequential design and changes in cure status during extended follow-up. METHODS: We provided R functions that generalize the triangular design to impose a minimum sample size before allowing stopping for efficacy. For estimation of efficacy at a second, extended, follow-up time, the performance of a shrinkage estimator (SHE), a probability tree estimator (PTE) and the maximum likelihood estimator (MLE) for estimation was assessed by simulation. RESULTS: The SHE and PTE are viable approaches to estimate an extended follow-up although the SHE performed better than the PTE: the bias and root mean square error were lower and coverage probabilities higher. CONCLUSIONS: Generalization of the triangular design is simple to implement for adaptations to meet requirements for pharmacokinetic analyses. Using the simple MLE approach to estimate efficacy at extended follow-up will lead to biased results, generally over-estimating treatment success. The SHE is recommended in trials of two or more treatments. The PTE is an acceptable alternative for one-arm trials or where use of the SHE is not possible due to computational complexity. TRIAL REGISTRATION: NCT01067443 , February 2010.


Asunto(s)
Leishmaniasis Visceral/tratamiento farmacológico , Modelos Estadísticos , Proyectos de Investigación/estadística & datos numéricos , Tripanocidas/farmacocinética , Simulación por Computador , Interpretación Estadística de Datos , Humanos , Kenia , Leishmaniasis Visceral/diagnóstico , Leishmaniasis Visceral/parasitología , Funciones de Verosimilitud , Probabilidad , Recurrencia , Inducción de Remisión , Tamaño de la Muestra , Sudán , Resultado del Tratamiento , Tripanocidas/administración & dosificación
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