A cluster-randomised trial of a multifaceted quality improvement intervention in Brazilian intensive care units (Checklist-ICU trial): statistical analysis plan

BACKGROUND

The Checklist During Multidisciplinary Visits for Reduction of Mortality in Intensive Care Units (Checklist- ICU) trial is a pragmatic, two-arm, cluster-randomised trial involving 118 intensive care units in Brazil, with the primary objective of determining if a multifaceted qualityimprovement intervention with a daily checklist, definition of daily care goals during multidisciplinary daily rounds and clinician prompts can reduce inhospital mortality.

OBJECTIVE

To describe our trial statistical analysis plan (SAP).

METHODS

This is an ongoing trial conducted in two phases. In the preparatory observational phase, we collect three sets of baseline data: ICU characteristics; patient characteristics, processes of care and outcomes; and completed safety attitudes questionnaires (SAQs). In the randomised phase, ICUs are assigned to the experimental or control arms and we collect patient data and repeat the SAQ.

RESULTS

Our SAP includes the prespecified model for the primary and secondary outcome analyses, which account for the cluster-randomised design and availability of baseline data. We also detail the multiple mediation models that we will use to assess our secondary hypothesis (that the effect of the intervention on inhospital mortality is mediated not only through care processes targeted by the checklist, but also through changes in safety culture). We describe our approach to sensitivity and subgroup analyses and missing data.

CONCLUSION

We report our SAP before closing our study database and starting analysis. We anticipate that this should prevent analysis bias and enhance the utility of results.

Vessel remodeling and plaque distribution in side branch of complex coronary bifurcation lesions: a grayscale intravascular ultrasound study

To investigate vessel remodeling and plaque distribution in side branch (SB) of true coronary bifurcation lesions with SB disease extending from its ostium. A total of 62 patients with single de novo true bifurcation lesions with SB with severe and extensive disease were enrolled. Of that, 45 patients/lesions underwent pre-intervention intravascular ultrasound (IVUS) at the SB. Left anterior descending was the most prevalent target vessel (>85%). All lesions had significant involvement of both branches of the bifurcation, and the majority were classified as type 1,1,1 according to the Medina classification. Considering the subset with IVUS imaging, mean lesion length, reference diameter and % diameter stenosis in the SB were 8.88 ± 4.61 mm, 2.68 ± 0.59, and 70.2 ± 16.0%, respectively. Also, mean proximal (take-off) and distal (carina) angles were 142.3 ± 21.9° and 60.7 ± 22.4°, respectively. At minimum lumena area (MLA) site, mean external elastic membrane and MLA cross-sectional areas were 6.70 ± 2.08 and 1.87 ± 0.93 mm2, respectively; given that the mean distance measured between the SB origin and MLA site was <1 mm. In addition, mean plaque burden was 67.9% and mean remodeling index was 0.78 ± 0.21. Importantly, only 9 cases out of 45 presented remodeling index > 1.0. Also, plaque distribution analysis within the SB ostium demonstrated preferable plaque positioning in the opposite side to the flow divider. In conclusions, significant negative remodeling is a frequent encounter in SB of complex coronary bifurcation lesions presenting with extensive and severe disease; in addition, plaque distribution in the SB ostium appears to be asymmetric in relation to the parent vessel, as plaque burden is mostly found in regions of low wall shear stress including the opposite side to the flow divider within the bifurcation anatomy.