Diagnostic test accuracy of a novel smartphone application for the assessment of attention deficits in delirium in older hospitalised patients: a prospective cohort study protocol

Abstract

BackgroundDelirium is a common and serious clinical syndrome which is often missed in routine clinical care. The core cognitive feature is inattention. We developed a novel bedside neuropsychological test for assessing inattention in delirium implemented on a smartphone platform (DelApp). We aim to evaluate the diagnostic performance of the DelApp in a representative cohort of older hospitalised patients.MethodsThis is a prospective study of older non-scheduled hospitalised patients (target n = 500, age ≥ 65), recruited from elderly care and acute orthopaedic wards. Exclusion criteria are: non-English speakers; severe vision or hearing impairment; photosensitive epilepsy.A structured reference standard delirium assessment based on DSM-5 criteria will be used, which includes a cognitive test battery administered by a trained assessor (Orientation-Memory-Concentration Test, Abbreviated Mental Test-10, Delirium Rating Severity Scale-Revised-98, digit span, months and days backwards, Vigilance A’ test) and assessment of arousal (Observational Scale of Level of Arousal, Richmond Agitation Sedation Scale). Prior change in cognition will be documented using the Informant Questionnaire on Cognitive Decline in the Elderly. Patients will be categorized as delirium (with/without dementia), possible delirium, dementia, no cognitive impairment, or undetermined.A separate assessor (blinded to diagnosis and assessments) will administer the DelApp index test within 3 h of the reference standard assessment. The DelApp comprises assessment of arousal (score 0-4) and sustained attention (score 0-6), yielding a total score between 0 and 10 (higher score = better performance). Outcomes (length of stay, mortality and discharge location) will be collected at 12 weeks.We will evaluate a priori cutpoints derived from a previous case-control study. Measures of the accuracy of DelApp will include sensitivity, specificity, positive and negative predictive values, and area under the ROC curve. We plan repeat assessments on up to 4 occasions in a purposive subsample of 30 patients (15 delirium, 15 no delirium) to examine changes over time.DiscussionThis study evaluates the diagnostic test accuracy of a novel smartphone test for delirium in a representative cohort of older hospitalised patients, including those with dementia. DelApp has the potential to be a convenient, objective method of improving delirium assessment for older people in acute care.Trial registrationClinical trials.gov, NCT02590796. Registered on 29 Oct 2015. Protocol version 5, dated 25 July 2016.Electronic supplementary materialThe online version of this article (10.1186/s12877-018-0901-5) contains supplementary material, which is available to authorized users.

A roadmap to advance delirium research: Recommendations from the NIDUS Scientific Think Tank

“…Such an approach will increase the consistency of case ascertainment and improve the generalizability and comparability of research findings across studies. 7,8…”

A smartphone-based test for the assessment of attention deficits in delirium: A case-control diagnostic test accuracy study in older hospitalised patients

“…DelApp. The DelApp has been described in detail in Rutter et al [26]. It is a smartphonebased test comprising a brief arousal assessment followed by a sustained attention task.…”

“…Reference standard assessment. The reference standard assessment has been described elsewhere [26]. In summary, the following assessment tools were used: the short Orientation-Memory-Concentration test (OMCT), a six-item cognitive test focused on orientation and working memory (score range 0-28, score of 20 or below indicates cognitive impairment) [28]; attention tests including digit span forwards and backwards, days of the week and months of the year backwards [29]; and the Delirium Rating Scale-Revised-98 (DRS-R98 [30]) to aid delirium assessment, supplemented by the Observational Scale of Level of Arousal (OSLA [24]) and the Richmond Agitation-Sedation Scale (RASS [31,32]) for measuring level of arousal.…”

“…Delirium was ascertained according to DSM-5 diagnostic criteria, informed by results from the reference standard assessment alongside observational and medical information to determine group allocation (described in [26]). Where initial grouping based on information provided by the patient's clinical team and medical notes was not consistent with the outcomes from the reference standard assessment, the most appropriate grouping for these cases was decided blind to DelApp results by a consultant geriatrician (AMJM or DJS) based on all the other available information (i.e.…”

Biosensors for Personal Mobile Health: A System Architecture Perspective

“…Based on their ability to delineate shapes, the application produces a score. Rutter et al developed DelApp, a smartphone application for the assessment of attention deficit disorder in older hospitalized patients . The application serves to be an objective assessment tool that is easily administered at the bedside setting.…”