Statistical analysis plan for a cluster-randomized crossover trial comparing the effectiveness and safety of a flexible family visitation model for delirium prevention in adult intensive care units (the ICU Visits Study)

Abstract

Background: Most adult intensive care units (ICUs) worldwide adopt restrictive family visitation models (RFVMs). However, evidence, mostly from non-randomized studies, suggests that flexible adult ICU visiting hours are safe policies that can result in benefits such as prevention of delirium and increase in satisfaction with care. Accordingly, the ICU Visits Study was designed to compare the effectiveness and safety of a flexible family visitation model (FFVM) vs. an RFVM on delirium prevention among ICU patients, and also to analyze its potential effects on family members and ICU professionals.

Methods/design: The ICU Visits Study is a cluster-randomized crossover trial which compares an FFVM (12 consecutive ICU visiting hours per day) with an RFVM (< 4.5 ICU visiting hours per day) in 40 Brazilian adult ICUs. Participant ICUs are randomly assigned to either an FFVM or RFVM in a 1:1 ratio. After enrollment and follow-up of 25 patients, each ICU is crossed over to the other visitation model, until 25 more patients per site are enrolled and followed. The primary outcome is the cumulative incidence of delirium measured by the Confusion Assessment Method for the ICU. Secondary and tertiary outcomes include relevant measures of effectiveness and safety of ICU visiting policies among patients, family members, and ICU professionals. Herein, we describe all primary statistical procedures that will be used to evaluate the results and perform exploratory and sensitivity analyses of this study. This pre-specified statistical analysis plan was written and submitted without knowledge of the study data.

Discussion: This a priori statistical analysis plan aims to enhance the transparency of our study, facilitating unbiased analyses of ICU visit study data, and provide guidance for statistical analysis for groups conducting studies in the same field.

Trial registration: ClinicalTrials.gov, NCT02932358 . Registered on 11 October 2016.

Keywords: Anxiety; Burnout; Critical care; Cross infection; Delirium; Depression; Family; Health personnel; Personal satisfaction.

Conflict of interest statement

Ethics approval and consent to participate

This study will be conducted according to Resolution No. 466/12 of the Brazilian National Health Council (http://bvsms.saude.gov.br/bvs/saudelegis/cns/2013/res0466_12_12_2012.html). The present study protocol version (version 3, from 22 February 2017) has been approved by the research ethics committee of the coordinating site (approval No. CAAE 57717516.3.1001.5330) and the research ethics committees of all participating institutions. The need for patients’ written informed consent was waived in 37 of 40 participating ICUs, because the standard of care encompasses both study interventions. In 3 of 40 ICUs informed consent will be required for patients or proxies. Informed consent will be required for family members and ICU professionals in all ICUs.

Consent for publication

Not applicable.

Competing interests

The authors declare that they have no competing interests.

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Figures

Fig. 1

Study design. FFVM flexible family visitation model, ICU intensive care unit, RFVM restrictive family visitation model. All ICUs will have a learning period within the first 15 days of phases 1 and 2. During this period, ICUs will receive the intervention (FFVM or RFVM) but will not recruit subjects. Local investigators will use this period to adapt the ICU staff to the organizational aspects of study interventions