The 4 ‘A’s test for detecting delirium in acute medical patients: a diagnostic accuracy study

• DOI: 10.3310/hta23400
• Publication Date: 2019-08-09T10:51:48Z
• Authors: Alasdair MJ MacLu...; Susan D Shenkin; Steve Goodacre; Mary Godfrey; Janet Hanley; Antaine Stíobhairt; Elizabeth Lavender; Julia Boyd; Jacqueline Stephen; Christopher Weir; Allan MacRaild; Jill Steven; Polly Black; Katharina Diernbe...; Peter Hall; Zoë Tieges; Christopher Fox; Atul Anand; John Young; Najma Siddiqi; Alasdair Gray
• Keywords: diagnostic study; Male; INTENSIVE-CARE-UNIT; 610; Sensitivity and Specificity; PALLIATIVE CARE; 03 medical and health sciences; 0302 clinical medicine; SDG 3 - Good Health and Well-being; Double-Blind Method; ACUTE HOSPITALS; Surveys and Questionnaires; delirium detection; Medical technology; Humans; Mass Screening; OLDER-PEOPLE; acute medical patients; 4AT; Prospective Studies; R855-855.5; The 4 'A's test; ELDERLY-PATIENTS; DIAGNOSTIC ACCURACY; Aged; 616.8 Nervous & mental disorders; CAM; Health Policy; DEMENTIA; Delirium, dementia, acute hospitals, 4AT, diagnostic accuracy, CAM; Delirium; HIP FRACTURE; COGNITIVE IMPAIRMENT; CONFUSION ASSESSMENT METHOD; EMERGENCY-DEPARTMENT; United Kingdom; 3. Good health; Health; ABBREVIATED MENTAL TEST; RISK-FACTORS; Mental health; Female; DELIRIUM; Emergency Service, Hospital; RC0321 Neuroscience. Biological psychiatry. Neuropsychiatry

Delirium is a common and serious neuropsychiatric syndrome, usually triggered by illness or drugs. It remains underdetected. One reason for this lack of brief, pragmatic assessment tools. The 4 'A's test (Arousal, Attention, Abbreviated Mental Test - 4, Acute change) (4AT) screening tool designed routine use. This project evaluated its usability, diagnostic accuracy cost.Phase 1 the usability 4AT in practice was measured with two surveys qualitative studies health-care professionals, review current clinical use as well presence guidelines reports. Phase 2 4AT's assessed newly admitted acute medical patients aged ≥ 70 years. Its performance compared that Confusion Assessment Method (CAM; longer tool). individual items related to cognitive status, length stay, new institutionalisation, mortality at 12 weeks outcomes. method used prospective, double-blind study emergency departments general wards three UK sites. Each patient underwent reference standard delirium also randomised receive an either (n = 421) CAM 420). A health economics analysis conducted.Phase found evidence awareness increasing, but there need education on particular. Most users reported useful, it widespread both beyond. No changes were considered necessary. involved 785 individuals who had data analysis; their mean age 81.4 (standard deviation 6.4) years, 45% male, 99% white 9% known dementia diagnosis. 392) area under receiver operating characteristic curve 0.90. positive score (> 3) specificity 95% [95% confidence interval (CI) 92% 97%] sensitivity 76% (95% CI 61% 87%) delirium. 382) 100% 98% 100%) 40% 26% 57%) subset participants whom possible assess using this. Patients scores lengths stay (median 5 days, interquartile range 2.0-14.0 days) than did those negative 1.0-6.0 days), they higher 12-week rate (16.1% 9.2%, respectively). estimated costs initial inpatient more double without (e.g. Scotland, £7559, £7362 £7755, vs. £4215, £4175 £4254). cost false-positive cases £4653, false-negative £8956, missed diagnosis £2067.Patients years soon after admitted, limiting generalisability. treatment accordance limited ability comparative cost-effectiveness.These findings support rapid instrument. has acceptable older > years.Further research should address real-world implementation assessment. be tested other populations.Current Controlled Trials ISRCTN53388093.This funded National Institute Health Research (NIHR) Technology programme will published full Assessment; Vol. 23, No. 40. See NIHR Journals Library website further information. funder specified any against CAM, no role design conduct study.Delirium sudden onset confusion can happen when someone unwell. people go into hospital, upsetting families. important diagnose, because do less without, often treatable. ideal way diagnose specialist, expensive time-consuming. We therefore developed short called ‘A’s (4AT). four stand Arousal, – change. First, we interviewed hospital staff about 4AT. already widely easy then how performed practice. total recently participated, around one eight researcher carried out each different normal reliably ruled An abnormal reasonably effective detecting delirium, still needed follow up such People stayed likely die, expensive. conclude useful rule see if detailed testing required. could help treat correctly quickly. would save money improve