Statistical analysis plan for the Pneumatic CompREssion for PreVENting Venous Thromboembolism (PREVENT) trial: a study protocol for a randomized controlled trial

Abstract

BackgroundThe Pneumatic CompREssion for Preventing VENous Thromboembolism (PREVENT) trial evaluates the effect of adjunctive intermittent pneumatic compression (IPC) with pharmacologic thromboprophylaxis compared to pharmacologic thromboprophylaxis alone on venous thromboembolism (VTE) in critically ill adults.Methods/designIn this multicenter randomized trial, critically ill patients receiving pharmacologic thromboprophylaxis will be randomized to an IPC or a no IPC (control) group. The primary outcome is “incident” proximal lower-extremity deep vein thrombosis (DVT) within 28 days after randomization. Radiologists interpreting the lower-extremity ultrasonography will be blinded to intervention allocation, whereas the patients and treating team will be unblinded. The trial has 80% power to detect a 3% absolute risk reduction in the rate of proximal DVT from 7% to 4%.DiscussionConsistent with international guidelines, we have developed a detailed plan to guide the analysis of the PREVENT trial. This plan specifies the statistical methods for the evaluation of primary and secondary outcomes, and defines covariates for adjusted analyses a priori. Application of this statistical analysis plan to the PREVENT trial will facilitate unbiased analyses of clinical data.Trial registrationClinicalTrials.gov, ID: NCT02040103. Registered on 3 November 2013;Current controlled trials, ID: ISRCTN44653506. Registered on 30 October 2013.Electronic supplementary materialThe online version of this article (10.1186/s13063-018-2534-6) contains supplementary material, which is available to authorized users.

The effect of intermittent pneumatic compression on deep-vein thrombosis and ventilation-free days in critically ill patients with heart failure

“…The PREVENT trial (Pneumatic Compression for Preventing Venous Thromboembolism trial, Clinicaltrials.gov: NCT02040103 and Current controlled trials: ISRCTN44653506) 29 , 30 evaluated whether adjunctive IPC combined with pharmacologic thromboprophylaxis with unfractionated heparin or low-molecular-weight heparin compared to pharmacologic thromboprophylaxis alone, reduced incident proximal lower-limb DVT. The trial was conducted at 20 sites in Saudi Arabia, Canada, Australia, and India.…”

“…In the current study, we performed an a priori determined analysis 29 , 30 of critically ill patients with HF. The presence of HF was determined by the treating teams according to local practices, which was based on the reported symptoms and signs that were typical of congestion with compatible findings on chest radiography, elevated natriuretic peptide biomarkers and/or cardiac imaging 33 , 34 .…”

Surveillance or no surveillance for deep venous thrombosis and outcomes of critically ill patients

“…The trial protocol and statistical analysis plan have been published previously. [ 9 , 10 ] The trial is registered at Clinicaltrials.gov: NCT02040103 and Current controlled trials: ISRCTN44653506. The PREVENT trial is being conducted in 19 sites in Saudi Arabia, Canada, Australia, and India.…”

The journey to zero deep-vein thrombosis in critically ill patients

“…[2] The trial examined whether the addition of pneumatic compression to pharmacological thromboprophylaxis reduced the incidence of DVT in critically ill patients. [234] In this commentary, we review the lessons learned and implications of the PREVENT trial on clinical practice.…”

“…The PREVENT trial examined whether the addition of pneumatic compression to pharmacological thromboprophylaxis reduced the incidence of DVT in critically ill patients. [234] The study was conducted in twenty ICUs from Saudi Arabia, Canada, Australia, and India, and was sponsored by King Abdulaziz City for Science and Technology and King Abdullah International Medical Research Center, Riyadh, Saudi Arabia.…”