Validating Studies to Assess the Diagnostic Accuracy of a Software Application for Detection and Monitoring of Attentional Deficits in Delirium
- Conditions
- DementiaDelirium
- Interventions
- Other: No intervention given to participants
- Registration Number
- NCT02590796
- Lead Sponsor
- University of Edinburgh
- Brief Summary
The study has two phases: Phase B and Phase C. The purpose of the Phase B study is to determine the performance (sensitivity and specificity) of a smartphone application (DelApp) to identify delirium in the whole inpatient sample. The study also aims to determine the performance (sensitivity and specificity) of the DelApp to discriminate between delirium (with or without dementia) and dementia (without delirium).
The purpose of the Phase C study is to determine the efficacy of the DelApp software application in detecting delirium in unselected patients in an inpatient sample and to determine the performance of the DelApp to discriminate between delirium and dementia. The study also aims to explore the performance of the DelApp in tracking change in cognitive function.
- Detailed Description
The investigators previously developed a new neuropsychological test for the objective measurement of inattention in delirium, which was implemented on a purpose-built computerised device (Delbox). A prototype software application (DelApp) for smartphones has now been developed based on the same test.
The DelApp has many advantages over existing tests, including objectivity, automated scoring and ease-of-use. Studies in 30 hospital patients showed highly comparable performance between the Delbox and DelApp. Further proof-of-principle single-rater studies using the DelApp in more than 200 hospital patients have provided additional evidence of good performance of the DelApp.
Though there are strong positive findings from investigator pilot studies, larger-scale formal studies with blinded raters and more representative patient samples are now required.
The proposed study is part of a larger programme of work funded by the Medical Research Council (grant value £1.01M) on the optimisation and clinical validation of the DelApp, which consists of three stages: Phase A - optimisation of the DelApp and feasibility testing (REC no 15/SC00/19); Phase B - case-control studies in selected patients; and Phase C - validation studies in unselected patients. Ultimately investigators aim to generate a software product which will be fully licensed and commercially available to healthcare organisations.
The proposed Phase B studies will be carried out in hospitalised patients in general and acute medical wards and ICU. The objectives of these studies are (a) to assess diagnostic performance of the DelApp in discrete patient groups and to inform optimal cut-points (Phase B); and (b) to evaluate the diagnostic performance of the DelApp in unselected patients (Phase C). The studies will also contribute to a better understanding of the nature of neuropsychological deficits underlying delirium. At the end of these studies, the DelApp may be modified depending on the study results. Investigators will select the stimuli and subtests that provide the best balance of sensitivity and specificity.
Two case-control studies will be conducted involving patients recruited from general and acute wards (Study B.1) and ICU (Study B.2). Each study will run in two sites, i.e. the Royal Infirmary of Edinburgh (RIE) and the Glasgow Royal Infirmary (GRI). The performance of the DelApp (index test) against reference standard diagnosis will be independently assessed by two trained raters, with one pair of raters on each site. As in our prior case-control studies, convenience samples will be used, where clinicians are asked to identify patients in the target groups.
Hospitalised patients will be asked to undertake a number of tests at their bedside. These tests will be administered to patients once only. Patients will be visited by two different researchers on the same day, with a gap of approximately 15-60 min between assessment visits assuming that consent is provided in the first visit. The first visit will involve assessment of capacity and (in those thought likely to be capable of giving consent) obtaining informed consent, as well as assessment of delirium (reference tests) and cognition. The second visit will involve the DelApp assessment (index test). Thus, the index test and reference tests are administered by independent raters. Where the patient is unable to provide consent for themselves, proxy consent will be sought, and if granted, the same visits as above will occur.
The Phase C formal validation studies have a similar design to the case-control studies. The main difference is that unselected samples of patients will be recruited from general and acute medical wards (Study C.1) and ICU (Study C.2) in the GRI and RIE.
A subset of patients in studies C.1 and C.2 (N=60 combined) will undergo up to 4 repeat assessments (at least one day apart), along with the reference standard, to explore the performance of the DelApp in tracking change in cognitive function.
In the longitudinal assessments, researchers will ask patients able to provide consent at the time of recruitment if they consent to subsequent assessments even if at the time of these subsequent assessments the patient lacks capacity. However, during the subsequent assessments, it will be carefully checked if the patient assents to continue their participation in the study. In patients who initially lack capacity and have been included through consent from a legal proxy, and who are undergoing serial assessments, researchers will seek informed consent from patients at the beginning of each new testing session. If the patient regains capacity after the final assessment, the investigators will seek retrospective consent from the patient where possible.
Recruitment & Eligibility
- Status
- COMPLETED
- Sex
- All
- Target Recruitment
- 907
-
General Wards
- Aged 65 or over
- Capacity to provide written, informed consent or the availability of a suitable relative or welfare guardian/attorney who is able to provide informed consent on behalf of the participant.
ICU
- Aged 18 or over
- Capacity to provide written, informed consent or the availability of a suitable relative or welfare guardian/attorney who is able to provide informed consent on behalf of the patient.
-
General Wards
- Unable to understand spoken task instructions
- Vision or hearing impairment severe enough to preclude testing or interview
- Photosensitive epilepsy
ICU
- Unable to understand spoken task instructions
- Pre-existing, known cognitive impairment including dementia
- Vision or hearing impairment severe enough to preclude testing or interview
- Photosensitive epilepsy
- A score on the Richmond Agitation-Sedation Scale of below -3
Study & Design
- Study Type
- OBSERVATIONAL
- Study Design
- Not specified
- Arm && Interventions
Group Intervention Description Hospitalised patients with dementia/ no delirium No intervention given to participants Hospitalised patients with a diagnosis of dementia who do not have delirium in general wards. Hospitalised patients with no delirium or dementia No intervention given to participants Hospitalised patients with no delirium or dementia in general wards. ICU delirium No intervention given to participants Patients with delirium who are hospitalised in the intensive care units. Outpatients with dementia No intervention given to participants People with a diagnosis of dementia who are living in the community. Healthy volunteers No intervention given to participants Healthy volunteers who are living in the community who do not have a cognitive impairment. ICU no delirium No intervention given to participants Patients who do not have delirium who are hospitalised in intensive care units. Hospitalised patients with delirium No intervention given to participants hospitalised patients with delirium in general wards.
- Primary Outcome Measures
Name Time Method Diagnostic accuracy of the DelApp to discriminate between delirium (with or without dementia) and dementia (without delirium). Baseline DelApp score against delirium diagnosed using DSM-5 criteria in groups with dementia and delirium.
Diagnostic accuracy of the DelApp for diagnosing delirium Baseline DelApp score against delirium diagnosed using DSM-5 criteria in the whole inpatient sample.
- Secondary Outcome Measures
Name Time Method Length of stay up to 3 months length of stay in hospital
Discharge location up to 3 months Where patient is discharged to after hospital. e.g home, care home.
Accuracy of DelApp in measuring delirium severity Baseline DelApp score against score on Delirium Rating Scale revised 98 (DRS-R98).
Mortality 3 months Mortality at three months post assessment
Accuracy of DelApp to measure within-subject change in attentional functioning and delirium status over time 2 weeks Comparision of DelApp scores to DSM-5 criteria for delirium.
Inter-rater agreement of the DelApp Baseline Assessed by comparing researcher assessment scores to the scores of clinical staff who are delirium specialists.
Trial Locations
- Locations (2)
University of Glasgow
🇬🇧Glasgow, United Kingdom
University of Edinburgh
🇬🇧Edinburgh, United Kingdom