scholarly journals Design and analysis of a clinical trial using previous trials as historical control

2019 ◽  
Vol 16 (5) ◽  
pp. 531-538 ◽  
Author(s):  
David Alan Schoenfeld ◽  
Dianne M Finkelstein ◽  
Eric Macklin ◽  
Neta Zach ◽  
David L Ennist ◽  
...  

Background/AimsFor single arm trials, a treatment is evaluated by comparing an outcome estimate to historically reported outcome estimates. Such a historically controlled trial is often analyzed as if the estimates from previous trials were known without variation and there is no trial-to-trial variation in their estimands. We develop a test of treatment efficacy and sample size calculation for historically controlled trials that considers these sources of variation.MethodsWe fit a Bayesian hierarchical model, providing a sample from the posterior predictive distribution of the outcome estimand of a new trial, which, along with the standard error of the estimate, can be used to calculate the probability that the estimate exceeds a threshold. We then calculate criteria for statistical significance as a function of the standard error of the new trial and calculate sample size as a function of difference to be detected. We apply these methods to clinical trials for amyotrophic lateral sclerosis using data from the placebo groups of 16 trials.ResultsWe find that when attempting to detect the small to moderate effect sizes usually assumed in amyotrophic lateral sclerosis clinical trials, historically controlled trials would require a greater total number of patients than concurrently controlled trials, and only when an effect size is extraordinarily large is a historically controlled trial a reasonable alternative. We also show that utilizing patient level data for the prognostic covariates can reduce the sample size required for a historically controlled trial.ConclusionThis article quantifies when historically controlled trials would not provide any sample size advantage, despite dispensing with a control group.

Author(s):  
Laura Ortega-Hombrados ◽  
Guadalupe Molina-Torres ◽  
Alejandro Galán-Mercant ◽  
Eduardo Sánchez- Guerrero ◽  
Manuel González-Sánchez ◽  
...  

What do you want to do ?New mailCopyBackground: to analyze the changes that a therapeutic physical exercise program is capable of causing in the functionality of patients suffering from ALS and in addition, to analyze the respiratory capacity. Methods: a systematic review of the PubMed, SCOPUS, Cochrane, SciELO, PEDro, CINAHL and MEDline databases is carried out. The information was filtered using the following MeSH terms: "Amyotrophic lateral sclerosis", "Physical Therapy", "Physical and Rehabilitation Medicine". Clinical trials published in the last 5 years were included in which one of the interventions was therapeutic physical exercise in patients with ALS, which included the ALSFRS-R as a result variable. Results: 10 clinical trials with a total of 421 patients were analyzed, of which 183 underwent rehabilitation with physical exercise and were part of the case group; the rest belong to the control group and their treatment was mostly passive. The observed trend is of a decrease of approximately 6 points in the ALSFRS-R scale at 6 months in the case groups; however, no behavior pattern was met in the controls. Conclusions: Therapeutic physical exercise could contribute to slow down the deterioration of the musculature of people with ALS, thus facilitating the performance of their daily activities.


2010 ◽  
Vol 17 (1-2) ◽  
pp. 30-34
Author(s):  
Virginijus ŠAPOKA ◽  
Vytautas KASIULEVIČIUS ◽  
Janina DIDŽIAPETRIENĖ

Randomized controlled trials (RCTs) and systematic reviews are the most reliable methods of determining the effects of treatment. The randomization procedure gives a randomized controlled trial its strength. Random allocation means that all participants have the same chance of being assigned to each of the study groups. The choice of which end point(s) to select is critical to any study design. Intention-to-treat is the preferred approach to the analysis of clinical trials. Sample size calculations and data analyses have an important impact on the planning, interpretation, and conclusions of randomized trials. In this article, we discuss the problematic areas that can affect the outcome of a trial, such as blinding, sample size calculation, randomization; concealment allocation; intention of treating the analysis; selection of end points; selection of traditional versus equivalence testing, early stopped trials, selective publications. Keywords: randomized controlled trials, sample size, outcomes, type of analyses


Trials ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Nadir Kharma ◽  
Stefan Roehrig ◽  
Ahmed Atef Shible ◽  
Moustafa Sayed Elshafei ◽  
Dema Osman ◽  
...  

Abstract Objectives To assess the effect of anticoagulation with bivalirudin administered intravenously on gas-exchange in patients with COVID-19 and respiratory failure using invasive mechanical ventilation. Trial design This is a single centre parallel group, superiority, randomized (1:1 allocation ratio) controlled trial. Participants All patients admitted to the Hamad Medical Corporation -ICU in Qatar for COVID-19 associated respiratory distress and in need of mechanical ventilation are screened for eligibility. Inclusion criteria: all adult patients admitted to the ICU who test positive for COVID-19 by PCR-test and in need for mechanical ventilation are eligible for inclusion. Upon crossing the limit of D-dimers (1.2 mg/L) these patients are routinely treated with an increased dose of anticoagulant according to our local protocol. This will be the start of randomization. Exclusion criteria: pregnancy, allergic to the drug, inherited coagulation abnormalities, no informed consent. Intervention and comparator The intervention group will receive the anticoagulant bivalirudin intravenously with a target aPTT of 45-70 sec for three days while the control group will stay on the standard treatment with low-molecular-weight heparins /unfractionated heparin subcutaneously (see scheme in Additional file 1). All other treatment will be unchanged and left to the attending physicians. Main outcomes As a surrogate parameter for clinical improvement and primary outcome we will use the PaO2/FiO2 (P/F) ratio. Randomisation After inclusion, the patients will be randomized using a closed envelope method into the conventional treatment group, which uses the standard strategy and the experimental group which receives anticoagulation treatment with bivalirudin using an allocation ratio of 1:1. Blinding (masking) Due to logistical and safety reasons (assessment of aPTT to titrate the study drug) only the data-analyst will be blinded to the groups. Numbers to be randomised (sample size) We performed a sample size calculation and assumed the data for P/F ratio (according to literature) is normally distributed and used the mean which would be: 160 and SD is 80. We expect the treatment will improve this by 30%. In order to reach a power of 80% we would need 44 patients per group (in total 88 patients). Taking approximately 10% of dropout into account we will include 100 patients (50 in each group). Trial Status The local registration number is MRC-05-082 with the protocol version number 2. The date of approval is 18th June 2020. Recruitment started on 28th June and is expected to end in November 2020. Trial registration The protocol is registered before starting subject recruitment under the title: “Anticoagulation in patients suffering from COVID-19 disease. The ANTI-CO Trial” in ClinicalTrials.org with the registration number: NCT04445935. Registered on 24 June 2020. Full protocol The full protocol is attached as an additional file, accessible from the Trials website (Additional file 2). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.


2017 ◽  
Vol 89 (2) ◽  
pp. 156-161 ◽  
Author(s):  
Ruben P A van Eijk ◽  
Marinus J C Eijkemans ◽  
Toby A Ferguson ◽  
Stavros Nikolakopoulos ◽  
Jan H Veldink ◽  
...  

ObjectivesPlasma creatinine is a predictor of survival in amyotrophic lateral sclerosis (ALS). It remains, however, to be established whether it can monitor disease progression and serve as surrogate endpoint in clinical trials.MethodsWe used clinical trial data from three cohorts of clinical trial participants in the LITRA, EMPOWER and PROACT studies. Longitudinal associations between functional decline, muscle strength and survival with plasma creatinine were assessed. Results were translated to trial design in terms of sample size and power.ResultsA total of 13 564 measurements were obtained for 1241 patients. The variability between patients in rate of decline was lower in plasma creatinine than in ALS functional rating scale–Revised (ALSFRS-R; p<0.001). The average rate of decline was faster in the ALSFRS-R, with less between-patient variability at baseline (p<0.001). Plasma creatinine had strong longitudinal correlations with the ALSFRS-R (0.43 (0.39–0.46), p<0.001), muscle strength (0.55 (0.51–0.58), p<0.001) and overall mortality (HR 0.88 (0.86–0.91, p<0.001)). Using plasma creatinine as outcome could reduce the sample size in trials by 21.5% at 18 months. For trials up to 10 months, the ALSFRS-R required a lower sample size.ConclusionsPlasma creatinine is an inexpensive and easily accessible biomarker that exhibits less variability between patients with ALS over time and is predictive for the patient’s functional status, muscle strength and mortality risk. Plasma creatinine may, therefore, increase the power to detect treatment effects and could be incorporated in future ALS clinical trials as potential surrogate outcome.


2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Benjamin G. Jones ◽  
Adam J. Streeter ◽  
Amy Baker ◽  
Rana Moyeed ◽  
Siobhan Creanor

Abstract Background In a cluster randomised controlled trial (CRCT), randomisation units are “clusters” such as schools or GP practices. This has methodological implications for study design and statistical analysis, since clustering often leads to correlation between observations which, if not accounted for, can lead to spurious conclusions of efficacy/effectiveness. Bayesian methodology offers a flexible, intuitive framework to deal with such issues, but its use within CRCT design and analysis appears limited. This review aims to explore and quantify the use of Bayesian methodology in the design and analysis of CRCTs, and appraise the quality of reporting against CONSORT guidelines. Methods We sought to identify all reported/published CRCTs that incorporated Bayesian methodology and papers reporting development of new Bayesian methodology in this context, without restriction on publication date or location. We searched Medline and Embase and the Cochrane Central Register of Controlled Trials (CENTRAL). Reporting quality metrics according to the CONSORT extension for CRCTs were collected, as well as demographic data, type and nature of Bayesian methodology used, journal endorsement of CONSORT guidelines, and statistician involvement. Results Twenty-seven publications were included, six from an additional hand search. Eleven (40.7%) were reports of CRCT results: seven (25.9%) were primary results papers and four (14.8%) reported secondary results. Thirteen papers (48.1%) reported Bayesian methodological developments, the remaining three (11.1%) compared different methods. Four (57.1%) of the primary results papers described the method of sample size calculation; none clearly accounted for clustering. Six (85.7%) clearly accounted for clustering in the analysis. All results papers reported use of Bayesian methods in the analysis but none in the design or sample size calculation. Conclusions The popularity of the CRCT design has increased rapidly in the last twenty years but this has not been mirrored by an uptake of Bayesian methodology in this context. Of studies using Bayesian methodology, there were some differences in reporting quality compared to CRCTs in general, but this study provided insufficient data to draw firm conclusions. There is an opportunity to further develop Bayesian methodology for the design and analysis of CRCTs in order to expand the accessibility, availability, and, ultimately, use of this approach.


2019 ◽  
pp. jnnp-2019-320998 ◽  
Author(s):  
Ruben P A van Eijk ◽  
Stavros Nikolakopoulos ◽  
Kit C B Roes ◽  
Bas M Middelkoop ◽  
Toby A Ferguson ◽  
...  

BackgroundFunding and resources for low prevalent neurodegenerative disorders such as amyotrophic lateral sclerosis (ALS) are limited, and optimising their use is vital for efficient drug development. In this study, we review the design assumptions for pivotal ALS clinical trials with time-to-event endpoints and provide optimised settings for future trials.MethodsWe extracted design settings from 13 completed placebo-controlled trials. Optimal assumptions were estimated using parametric survival models in individual participant data (n=4991). Designs were compared in terms of sample size, trial duration, drug use and costs.ResultsPrevious trials overestimated the hazard rate by 18.9% (95% CI 3.4% to 34.5%, p=0.021). The median expected HR was 0.56 (range 0.33–0.66). Additionally, we found evidence for an increasing mean hazard rate over time (Weibull shape parameter of 2.03, 95% CI 1.93 to 2.15, p<0.001), which affects the design and planning of future clinical trials. Incorporating accrual time and assuming an increasing hazard rate at the design stage reduced sample size by 33.2% (95% CI 27.9 to 39.4), trial duration by 17.4% (95% CI 11.6 to 23.3), drug use by 14.3% (95% CI 9.6 to 19.0) and follow-up costs by 21.2% (95% CI 15.6 to 26.8).ConclusionsImplementing distributional knowledge and incorporating accrual at the design stage could achieve large gains in the efficiency of ALS clinical trials with time-to-event endpoints. We provide an open-source platform that helps investigators to make more accurate sample size calculations and optimise the use of their available resources.


Author(s):  
Laura Ortega-Hombrados ◽  
Guadalupe Molina Torres ◽  
Alejandro Galán-Mercant ◽  
Eduardo Sánchez-Guerrero ◽  
Manuel Gonzalez-Sanchez ◽  
...  

Background: to analyze the changes that a therapeutic physical exercise program is capable of causing in the functionality of patients suffering from ALS and in addition, to analyze the respiratory capacity. Methods: a systematic review of the PubMed, SCOPUS, Cochrane, SciELO, PEDro, CINAHL and MEDline databases is carried out. The information was filtered using the following MeSH terms: "Amyotrophic lateral sclerosis", "Physical Therapy", "Physical and Rehabilitation Medicine". Clinical trials published in the last 5 years were included in which one of the interventions was therapeutic physical exercise in patients with ALS, which included the ALSFRS-R as a result variable. Results: 10 clinical trials with a total of 421 patients were analyzed, of which 183 underwent rehabilitation with physical exercise and were part of the case group; the rest belong to the control group and their treatment was mostly passive. The observed trend is of a decrease of approximately 6 points in the ALSFRS-R scale at 6 months in the case groups; however, no behavior pattern was met in the controls. Conclusions: Therapeutic physical exercise could contribute to slow down the deterioration of the musculature of people with ALS, thus facilitating the performance of their daily activities.What do you want to do ?New mailCopy


2021 ◽  
Vol 14 (8) ◽  
pp. 705
Author(s):  
Hideki Houzen ◽  
Takahiro Kano ◽  
Kazuhiro Horiuchi ◽  
Masahiro Wakita ◽  
Azusa Nagai ◽  
...  

Reports on the long-term survival effect of edaravone, which was approved for the treatment of amyotrophic lateral sclerosis (ALS) in 2015 in Japan, are rare. Herein, we report our retrospective analysis of 45 consecutive patients with ALS who initially visited our hospital between 2013 and 2018. Of these, 22 patients were treated with edaravone for an average duration of 26.6 (range, 2–64) months, whereas the remaining patients were not treated with edaravone and comprised the control group. There were no differences in baseline demographics between the two groups. The primary endpoint was tracheostomy positive-pressure ventilation (TPPV) or death, and the follow-up period ended in December 2020. The survival rate was significantly better in the edaravone group than in the control group based on the Kaplan–Meier analysis, which revealed that the median survival durations were 49 (9–88) and 25 (8–41) months in the edaravone and control groups, respectively (p = 0.001, log-rank test). There were no serious edaravone-associated adverse effects during the study period. Overall, the findings of this single-center retrospective study suggest that edaravone might prolong survival in patients with ALS.


Author(s):  
Emily Beswick ◽  
Deborah Forbes ◽  
Zack Hassan ◽  
Charis Wong ◽  
Judith Newton ◽  
...  

Abstract Background Amyotrophic lateral sclerosis (ALS) is increasingly recognised as a multi-system disorder, presenting with common and impactful non-motor symptoms, such as neuropsychiatric symtpoms, cognitive and behavioural changes, pain, disordered sleep, fatigue and problematic saliva. Aim/hypothesis We aimed to systematically review 25 years of ALS clinical trials data to identify if non-motor features were evaluated, in addition to the traditional measures of motor functioning and survival, and where evaluated to describe the instruments used to assess. We hypothesised that assessment of non-motor symptoms has been largely neglected in trial design and not evaluated with ALS-suitable instruments. Methods We reviewed clinical trials of investigative medicinal products in ALS, since the licensing of riluzole in 1994. Trial registry databases including WHO International Trials Registry, European Clinical Trials Register, clinicaltrials.gov, and PubMed were systematically searched for Phase II, III or IV trials registered, completed or published between 01/01/1994 and 16/09/2020. No language restrictions were applied. Results 237 clinical trials, including over 29,222 participants, were investigated for their use of non-motor outcome measures. These trials evaluated neuropsychiatric symptoms (75, 32%), cognitive impairment (16, 6.8%), behavioural change (34, 14%), pain (55, 23%), sleep disturbances (12, 5%) and fatigue (18, 8%). Problematic saliva was assessed as part of composite ALS-FRS(R) scores in 184 trials (78%) but with no focus on this as an isolated symptom. 31 (13%) trials including 3585 participants did not include any assessment of non-motor symptoms. Conclusions Non-motor symptoms such as neuropsychiatric, cognitive and behavioural changes, pain, disordered sleep, fatigue, and problematic saliva have not been consistently evaluated in trials for people with ALS. Where evaluated, non-symptoms were primarily assessed using instruments and impairment thresholds that are not adapted for people with ALS. Future trials should include non-motor symptom assessments to evaluate the additional potential therapeutic benefit of candidate drugs. PROPSERO registration CRD42020223648.


Metabolites ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 204
Author(s):  
Anissa Aharaz ◽  
Jens Henning Rasmussen ◽  
Helle Bach Ølgaard McNulty ◽  
Arne Cyron ◽  
Pia Keinicke Fabricius ◽  
...  

Medication deprescribing is essential to prevent inappropriate medication use in multimorbid patients. However, experience of deprescribing in Danish Subacute Medical Outpatient Clinics (SMOCs) is limited. The objective of our pilot study was to evaluate the feasibility and sustainability of a collaborative deprescribing intervention by a pharmacist and a physician to multimorbid patients in a SMOC. A randomized controlled pilot study was conducted, with phone follow-up at 30 and 365+ days. A senior pharmacist performed a systematic deprescribing intervention using the Screening Tool of Older Persons’ potentially inappropriate Prescriptions (STOPP) criteria, the Danish deprescribing list, and patient interviews. A senior physician received the proposed recommendations and decided which should be implemented. The main outcome was the number of patients having ≥1 medication where deprescribing status was sustained 30 days after inclusion. Out of 76 eligible patients, 72 (95%) were included and 67 (93%) completed the study (57% male; mean age 73 years; mean number of 10 prescribed medications). Nineteen patients (56%) in the intervention group and four (12%) in the control group had ≥1 medication where deprescribing status was sustained 30 days after inclusion (p = 0.015). In total, 37 medications were deprescribed in the intervention group and five in the control group. At 365+ days after inclusion, 97% and 100% of the deprescribed medications were sustained in the intervention and control groups, respectively. The three most frequently deprescribed medication groups were analgesics, cardiovascular, and gastrointestinal medications. In conclusion, a collaborative deprescribing intervention for multimorbid patients was feasible and resulted in sustainable deprescribing of medication in a SMOC.


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