scholarly journals Statistical reanalysis of vascular event outcomes in primary and secondary vascular prevention trials

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Lisa J. Woodhouse ◽  
Alan A. Montgomery ◽  
Jonathan Mant ◽  
Barry R. Davis ◽  
Ale Algra ◽  
...  
Keyword(s):  
Potential Role ◽  
Statistical Test ◽  
Outcome Data ◽  
Vascular Event ◽  
Binary Outcomes ◽  
Vascular Outcome ◽  
Individual Participant ◽  
Prevention Trials ◽  
Randomised Controlled ◽  
Ordered Categorical

Abstract Background Vascular prevention trials typically use dichotomous event outcomes although this may be inefficient statistically and gives no indication of event severity. We assessed whether ordinal outcomes would be more efficient and how to best analyse them. Methods Chief investigators of vascular prevention randomised controlled trials that showed evidence of either benefit or harm, or were included in a systematic review that overall showed benefit or harm, shared individual participant data from their trials. Ordered categorical versions of vascular event outcomes (such as stroke and myocardial infarction) were analysed using 15 statistical techniques and their results then ranked, with the result with the smallest p-value given the smallest rank. Friedman and Duncan’s multiple range tests were performed to assess differences between tests by comparing the average ranks for each statistical test. Results Data from 35 trials (254,223 participants) were shared with the collaboration. 13 trials had more than two treatment arms, resulting in 59 comparisons. Analysis approaches (Mann Whitney U, ordinal logistic regression, multiple regression, bootstrapping) that used ordinal outcome data had a smaller average rank and therefore appeared to be more efficient statistically than those that analysed the original binary outcomes. Conclusions Ordinal vascular outcome measures appear to be more efficient statistically than binary outcomes and provide information on the severity of event. We suggest a potential role for using ordinal outcomes in vascular prevention trials.

scholarly journals Systematic review of definitions and methods of measuring falls in randomised controlled fall prevention trials

2006 ◽  
Vol 35 (1) ◽  
pp. 5-10 ◽  
Author(s):  
Klaus Hauer ◽  
Sarah E. Lamb ◽  
Ellen C. Jorstad ◽  
Chris Todd ◽  
Clemens Becker
Keyword(s):  
Systematic Review ◽  
Fall Prevention ◽  
Prevention Trials ◽  
Randomised Controlled

scholarly journals The impact of a run-in period on treatment effects in cardiovascular prevention randomised control trials: A protocol for a comprehensive review and meta-analysis

2020 ◽  
Vol 3 ◽  
pp. 82
Author(s):  
Robert Murphy ◽  
Emer McGrath ◽  
Aoife Nolan ◽  
Andrew Smyth ◽  
Michelle Canavan ◽  
...  
Keyword(s):  
Randomised Controlled Trials ◽  
Treatment Effects ◽  
Meta Analysis ◽  
Cardiovascular Prevention ◽  
Controlled Trials ◽  
Loss To Follow Up ◽  
Relative Risks ◽  
Prevention Trials ◽  
Randomised Controlled

Background: A run-in period is often employed in randomised controlled trials to increase adherence to the intervention and reduce participant loss to follow-up in the trial population. However, it is uncertain whether use of a run-in period affects the magnitude of treatment effect. Methods: We will conduct a sensitive search for systematic reviews of cardiovascular preventative trials and a complete meta-analysis of treatment effects comparing cardiovascular prevention trials using a run-in period (“run-in trials”) with matched cardiovascular prevention trials that did not use a run-in period (“non-run-in trials”). We describe a comprehensive matching process which will match run-in trials with non-run-in trials by patient populations, interventions, and outcomes. For each pair of run-in trial and matched non-run-in trial(s), we will estimate the ratio of relative risks and 95% confidence interval. We will evaluate differences in treatment effect between run-in and non-run-in trials and our and our priamry outcome will be the ratio of relative risks for matched run-in and non-run-in trials for their reported cardiovascular composite outcome. Our secondary outcomes are comparisons of mortality, loss to follow up, frequency of adverse events and methodological quality of trials. Conclusions: This study will answer a key question about what influence a run-in period has on the magnitude of treatment effects in randomised controlled trials for cardiovascular prevention therapies.

A randomised controlled trial of intrapleural balloon intercostal chest drains to prevent drain displacement

2021 ◽  
pp. 2101753
Author(s):  
Rachel M Mercer ◽  
Eleanor Mishra ◽  
Radhika Banka ◽  
John P Corcoran ◽  
Cyrus Daneshvar ◽  
...  
Keyword(s):  
Randomised Controlled Trial ◽  
Adverse Events ◽  
Standard Care ◽  
Primary Outcome ◽  
Controlled Trial ◽  
Clinical Problem ◽  
Outcome Data ◽  
Chest Drain ◽  
Drain Removal ◽  
Randomised Controlled

BackgroundChest drain displacement is a common clinical problem, occurring in 9–42% of cases and results in treatment failure or additional pleural procedures conferring unnecessary risk. A novel chest drain with an integrated intrapleural balloon may reduce the risk of displacement.MethodsProspective randomised controlled trial comparing the balloon drain to standard care (12 F chest drain with no balloon) with the primary outcome of objectively-defined unintentional or accidental chest drain displacement.Results267 patients were randomised (primary outcome data available in 257, 96.2%). Displacement occurred less frequently using the balloon drain (displacement 5/128, 3.9%; standard care displacement 13/129, 10.1%) but this was not statistically significant (Odds Ratio (OR) for drain displacement 0.36, 95% CI 0.13 to 1.0, χ2 1df=2.87, p=0.09). Adjusted analysis to account for minimisation factors and use of drain sutures demonstrated balloon drains were independently associated with reduced drain fall out rate (adjusted OR 0.27, 95% CI 0.08 to 0.87, p=0.028). Adverse events were higher in the balloon arm than the standard care arm (balloon drain 59/131, 45.0%; standard care 18/132, 13.6%; χ2 1df=31.3, p<0.0001).ConclusionBalloon drains reduce displacement compared with standard drains independent of the use of sutures but are associated with increased adverse events specifically during drain removal. The potential benefits of the novel drain should be weighed against the risks, but may be considered in practices where sutures are not routinely used.

Estimating the causal effects of treatment

2002 ◽  
Vol 11 (3) ◽  
pp. 206-215 ◽  
Author(s):  
Graham Dunn
Keyword(s):  
Causal Effect ◽  
Randomised Trial ◽  
Outcome Data ◽  
Causal Effects ◽  
Estimation Methods ◽  
Random Allocation ◽  
Statistical Research ◽  
Data Set ◽  
The One ◽  
Randomised Controlled

SUMMARYObjective – To provide a relatively non-technical review of recent statistical research on the analysis and interpretation of the results of randomised controlled trials in which there are possibly all three of the following types of protocol violation: non-adherence to allocated treatment, contamination (that is, patients receiving treatments other than the one to which they were allocated) and attrition (missing outcome data). Methods – The estimation methods involve the use of potential outcomes (counterfactuals) in the definition of a causal effect of treatment and in drawing valid inferences concerning its size. Results – The methods are explained through the use of simple arithmetical expressions involving the counts from three-way contingency tables (Outcome by Treatment Received by Random Allocation). Illustration is provided through the use of a hypothetical data set. Conclusions – Recent advances in statistical methodology enable one to estimate treatment effects from the results of randomised trials in which the treatment actually received is not necessarily the one to which the patient was allocated. These methods allow one to make adjustments to allow for both non-compliance and loss to follow-up. Even for such a 'broken' randomised trial, inference concerning causal effects is safer than that from data arising from an observational study that never involved random allocation in the first place.

scholarly journals Defining refractory rheumatoid arthritis

2018 ◽  
Vol 77 (7) ◽  
pp. 966-969 ◽  
Author(s):  
Maya H Buch
Keyword(s):  
Rheumatoid Arthritis ◽  
Controlled Trial ◽  
Real Life ◽  
Outcome Data ◽  
Refractory Disease ◽  
Persistent Inflammation ◽  
Antidrug Antibody ◽  
Underlying Mechanisms ◽  
Randomised Controlled ◽  
Future Evaluation

While biologic disease-modifying antirheumatic drugs (bDMARDs) have transformed outcomes of people with rheumatoid arthritis (RA), a proportion of patients are refractory to multiple bDMARDs. Definitions of refractory RA thus far have been arbitrary, and outcome data and impact of such cohorts remain limited. Extrapolation from randomised controlled trial and some real-life data suggest approximately 20% progress onto a third bDMARD with a more modest proportion failing additional bDMARDs. This viewpoint discusses an opinion of refractory RA disease and proposes key principles to accurately identify refractory cohorts. These include demonstrating presence of persistent inflammation despite multiple therapies and acknowledging development of antidrug antibody. Potential basis of refractory disease is summarised, and suggestions for an initial approach in the future evaluation of refractory disease are offered. Specific investigation of refractory RA disease is necessary to inform the clinical need and provide a basis for robust investigation of underlying mechanisms.

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