Background

Delirium, is a clinical condition characterized by acute and fluctuating deterioration of the cognitive state, generally secondary to an acute pathology. It is a common condition in hospitalized older adults and it develops in 20-30% of patients hospitalized in a general ward and up to 80% of those hospitalized in critical care units. Delirium is associated with negative outcomes in older adults, such as longer hospitalizations, higher mortality, and short and medium-term institutionalization. Randomized clinical trials have shown that delirium is preventable through non-pharmacological prevention measures, decreasing its incidence by 30 to 50%. These interventions include promoting physical activity, facilitating the use of glasses and hearing aids, cognitive stimulation, and providing frequent reorientation of time and space, among others.

These measures are currently seldom applied in hospitals in Chile and around the world for various reasons some of which include the heavy workload of clinical staff, the lack of trained personnel, and, in general, the absence of systematic implementation processes.

The main objective is to evaluate whether cognitive stimulation guided by PREVEDEL software prevents delirium status(full/subsyncromal delirium) in hospitalized older adults.

Method/Design: randomized controlled trial, parallel groups, multicenter.

Participants: patients 65 years or older who have been hospitalized for less than 48 hours in the general ward or in the intermediate care unit of 4 hospitals in Santiago, Chile.

Intervention: participants in the intervention group will use a tablet with cognitive stimulation software for delirium prevention for 5 continuous days versus the control group who will use the tablet without the software.

Evaluations: The incidence of delirium and subsyndromal delirium, duration, density of delirium, cognitive and functional status at discharge, adherence to prevention measures, as well as demographic variables of interest will be evaluated.

Background. Delirium is a clinical condition characterized by acute cognitive impairment, of fluctuating course, generally secondary to an acute pathology, which appears after the interaction between predisposing factors and well described precipitants. It is a very common condition in older adults, observed in 20% to 30% of patients hospitalized in a general ward, and up to 80% of those hospitalized in critical care units. Delirium is associated with negative clinical outcomes which include longer hospitalizations, increased direct and indirect costs, functional impairment, greater risk of mortality, increased risk of institutionalization, and deterioration in long-term cognitive status, among others.

Subsyndromal delirium (SSD) is a milder state characterised by the presence of certain delirium symptoms but without meeting full diagnostic criteria thresholds, is also associated with poor posthospitalization outcomes similar to those associated with delirium. The reported frequency of subsyndromal delirium varies (7-50%) according to the definition applied and the clinical population studied. Its incidence in the general medicine ward is 17%.

The frequency of delirium status (full/subsyndromal delirium) in the general room is approximately 25%.

It is known that delirium in hospitalized older adults is preventable. In multiple randomized clinical trials, non-pharmacological interventions to prevent delirium (nPPD), shown to reduce its incidence by 30-50%7.

Despite the high evidence supporting them, non-pharmacological interventions to prevent delirium are poorly implemented in hospitals in Chile and around the world for several reasons, such as the heavy workload of clinical staff, lack of trained personnel, and, in general, the absence of systematic implementation processes.

Prior to this clinical trial, local pilot studies have shown some progress in this area. On the one hand, it has been reported that the incorporation of software technology through a "PREVEDEL" tablet is feasible and can be implemented on a hospital level, with possible effects on decreasing delirium. On the other hand, the implementation of nPPD following a theoretical model improves the adherence of health personnel.

Therefore, a multicenter randomized clinical trial is proposed, which seeks to evaluate whether cognitive stimulation guided by the PREVEDEL software prevents delirium in hospitalized older adults and whether it is a technology that can be used in others hospital centers.

Centers and place where data is collected. Chile. These are: Hospital Clínico de la Universidad de Chile (HCUCH), Hospital San Juan de Dios (HSJD), Clínica Las Condes (CLC) and Hospital Santiago Oriente Dr. Luis Tisné (HLT). Two are public institutions and two are private institutions.

Intervention.

Interventions to implement a program of non-pharmacological interventions to prevent delirium (nPPD) in the centers that will participate in the RCT.

Three months before the start of the clinical trial, an intervention is carried out in the Internal Medicine, Geriatrics and Intermediate Care Unit services of the 4 participating centers in order to establish a homogeneous plan of nPPD and assess adherence. The implementation methodology in the first stage will be according to the Consolidated Framework for Advancing Implementation Science (CFIR) model, used in a local pilot study

Interventions to perform an RCT where the effect of the use of PREVEDEL versus a placebo (Tablet without PREVEDEL) in the prevention of delirium in older adults is compared.

Standard non-pharmacological prevention measures

According to the recommendations in the literature and those made by local studies, the following standard non-pharmacological delirium prevention measures were defined:

Study groups Control Group: will receive the standard delirium prevention measures outlined above, plus the use of a mobile device without delirium prevention software for 5 days (Control Group: nPPD package, without PREVEDEL).

Experimental Group: will receive the standard delirium prevention measures, plus the use of a mobile device with PREVEDEL software for 5 days (Experimental Group: nPPD package, with PREVEDEL).

To evaluate patient adherence and how the tablet is used, both groups will have an application installed in their devices that will allow them to keep track of the time of use and applications used.

Software content

1. Desktop module.
2. The exercise module.
3. Games module.
4. The documentary module.
5. Alert module.
6. Configuration module, allows software customization.
7. Registration system.

OBJECTIVES AND HYPOTHESIS

General To assess whether cognitive stimulation guided by PREVEDEL software prevents delirium status in hospitalized older adults.

Specifics

• Implement a program of nPPD at the centers that will participate in the randomized clinical trial (RCT).
• Conduct a randomized clinical trial (RCT) comparing the effect of the use of PREVEDEL versus placebo (Tablet without PREVEDEL) in the prevention of delirium in older adults.

Hypothesis Cognitive stimulation guided by PREVEDEL software decreases the incidence of delirium status in hospitalized older adults.

Study sample.

For the calculation of the sample size, local and literature data were considered. A delirium status prevalence of 20% is estimated in the Control group and a decrease of this to 8% in the Intervention group. In this way, with a power of 80%, and an alpha of 0.05 bilaterally, 147 patients will be enrolled in each group. If add to this a 10% loss of follow-up, the overall sample size is 320 patients.

Randomization. Randomization was performed with computer-generated random permuted blocks using a centralized, secure Web-based randomization service.

Masking The enrollers, evaluators and healthcare personnel (nurses, physical therapists, physicians, occupational therapists) do not know the assigned group. Both groups receive a tablet of the same dimensions and with the same basic applications. However, blinding the patient is not possible, since when exploring the tablet, he or she will recognize whether or not it has the PREVEDEL program included. To reduce this bias, the staff that delivers the tablet encourages both groups to use its different basic applications (access the Internet) and that any doubts may have participants about its use should be made to the tablet coordinator, so that the evaluators or healthcare personnel remain masked.

The time between assignment and delivery of the tablet is between 4 to 12 hours in all participating centers. This variable will be measured for later analysis.

Statistical Methods For the descriptive analysis of the variables will use the mean (standard deviation), median (25-75 percentiles), or proportions as appropriate to the type and distribution of the data.

Analytical Statistics: For the primary outcome, a comparison of proportions between patients who develop delirium and subsyndromal delirium in both groups will be made, using Fisher's exact test, and as a measure of efficacy, an OR (95% CI) will be estimated. If there is any baseline variable that is not matched by the randomization, efficacy analyses will be carried out by means of logistic regression with the main variable being the treatment, and the adjustment variables those that the randomization would not have been able to match. Additionally, to compare the effect of the intervention over time, a time-to-event analysis will be performed using the Kaplan-Maier procedure and then the Cox regression model to adjust for baseline variables and the presence of the intervention. For the secondary outcomes, the Fisher's exact test or t-Test will be used, as appropriate, for the type and distribution of the data. Linear regression or multivariate logistics will also be performed, as appropriate, to evaluate the impact of the intervention, adjusting for the input covariates. A bilateral p 0.05 significance level will be used for all analyses.

Ethics Committee The research protocol was reviewed and approved by the ethics committee of the Clinical Hospital of the University of Chile and its approval was validated by the ethics committees of the respective participating centers (Registry No. 049, July 31, 2019).

Trial Steering Committee

Committee was formed with 3 international experts in the "Trial Steering Committee" (TSC) area. This committee will watch over the following aspects:

• Supervise and guarantee scientific quality.
• Advise on study protocol, recruitment progress, adherence, follow-up and data quality.
• Review the recommendations of the data analysis and monitoring committee.
• Review the publications in the primary trials.

For the fulfillment of the objectives, the TSC will meet before, in the middle and at the end of the recruitment.

Informed Consent The informed consent will be given by the patient himself and obtained by one of the main investigators.

Inclusion Criteria:

• Patients 65 years or older.
• Hospitalized less than an 48 hours ago in a general ward or in the intermediate care unit. Participating health center: 1) Hospital Clínico de la Universidad de Chile, 2) Hospital San Juan de Dios, 3) Clínica Las Condes, 4) Hospital Santiago Oriente Dr Luis Tisné.

Exclusion Criteria:

• Presence of full or syndromal delirium (CAM+ or presence of one core elements).
• History of dementia (AD8 greater than 2 points).
• Non-Spanish speaking patients.

The enrollers, evaluators and healthcare personnel (nurses, physical therapists, physicians, occupational therapists) do not know the assigned group. Both groups receive a tablet of the same dimensions and with the same basic applications. However, blinding the patient is not possible, since when exploring the tablet, he or she will recognize whether or not it has the PREVEDEL program included. To reduce this bias, the staff that delivers the tablet encourages both groups to use its different basic applications (access the Internet) and that any doubts may have participants about its use should be made to the tablet coordinator, so that the evaluators or healthcare personnel remain masked.

The time between assignment and delivery of the tablet is between 4 to 12 hours in all participating centers. This variable will be measured for later analysis.