Impact case study database

Impact on policy for identification and treatment of delirium

The 4AT has a substantial presence in guidelines and care pathways, both national (11) and international (14). The 4AT is the assessment tool of choice in 18 guidelines, including the 2020 Royal College of Physicians guidelines for standardising the assessment of acute illness severity, NICE-accredited Scottish Intercollegiate Guidelines Network delirium guidelines 2019, New Zealand Delirium Capability Guidelines 2018 and Norwegian guidelines for multidisciplinary treatment of hip fractures 2018. The 4AT is also included amongst the recommended tools in a further 7 guidelines including the European Society of Anaesthesiology guideline for postoperative delirium 2017 and the Australian Delirium Clinical Care Standard 2016. These all cite the original paper [3.2] or the 4AT website [5.1], and emphasise the importance of screening for delirium as a first step in a patient management and treatment plan. All 25 guidelines are listed in [5.2].

Notably, in July 2020, NICE issued an Exceptional Surveillance Report stating that, because the EN-led study demonstrated similar specificity and higher sensitivity of the 4AT compared with the CAM [3.4], their recommendation on delirium assessment would be revised [5.3].

Impact on Covid-19 policy

Because delirium is very common in Covid-19, in March 2020, the British Geriatrics Society, European Delirium Association and Royal College of Psychiatrists authored ‘Coronavirus: Managing delirium in confirmed and suspected cases’. The 4AT is the recommended assessment tool [5.4].

Impact on clinical practice

The 4AT is now the primary tool for delirium assessment in the NHS. In July 2020, replies to a UK-wide Freedom of Information request from 154 NHS acute hospital trusts showed that, of the 146 trusts who had a formal screening process in clinical practice outside the intensive care unit, 80% (117/146) use the 4AT tool to screen for delirium. This equates to 77% of NHS England trusts, 100% of trusts in both Scotland and Wales, and 80% of trusts in Northern Ireland. In most of those hospital trusts, 4AT is the only tool used (77/117), with the remaining trusts using 4AT alongside other tools. Thus, despite the (soon to be reconsidered) 2010 NICE recommendations to use the CAM, the 4AT is now used more in clinical practice than the CAM. The latter is only used in 45% (65/146) of hospital trusts, and the majority of those (39/65) use the CAM alongside other delirium assessment tools [5.5].

Use of the 4AT is particularly common in management of patients with hip fracture. Given that delirium is the most common complication of surgery and anaesthesia in older people, the National Hip Fracture Database has, since 2017, mandated use of the 4AT as part of the Best Practice Tariff for patients undergoing surgery after hip fracture. Their Annual Report 2018 found that delirium assessment with the 4AT was carried out in 90% of all eligible patients (95.3% in England) from 65,958 admissions. The 4AT identified 24.9% (14,781) patients as having ’possible delirium’ [5.6], showing appropriate levels of clinical detection.

International uptake of the 4AT is growing rapidly. An indirect indicator of its reach is the 4AT website, launched in June 2011. Accesses to the site have increased rapidly; from 6,995 users and 20,381 page views in 2014 to 77,629 users and 156,684 views in 2020. The top 5 user countries are the UK, Australia, USA, Ireland and Canada [5.1]. Evidence of international clinical uptake is exemplified by the Australian and New Zealand Hip Fracture Registry Annual Report 2020, which shows that the 4AT is the most common tool used for delirium assessment in hip fracture patients - used by 43% (50/117) hospitals; the CAM by 33% (39/117) [5.7]. The 4AT has been translated into 17 languages with affirmative validation studies published for the French, German, Iranian, Norwegian and Thai versions [all validation studies listed in 5.8]. In addition, Arabic, Chinese, Danish, Dutch, Finnish, Icelandic, Italian, Korean, Polish, Russian, Spanish and Turkish versions have been created by clinicians, after seeking permission from MacLullich [5.1].

Impact on health and welfare

Detection of delirium using 4AT in the acute clinical setting is the critical first step in unlocking a delirium management pathway, for example the TIME bundle (Think Investigate Manage Engage; detailed in [5.2r]). 12 published clinical audits, undertaken between October 2013 and 2020 from diverse clinical settings, have all demonstrated that adoption of the 4AT significantly increases rates of delirium screening [all audits listed in 5.9]. For example, a 2018 quality improvement study in York Teaching Hospital acute medical unit introduced the 4AT to ensure that patients with delirium were being identified. Assessment of delirium increased from 0% to 64%, with a subsequent shift increase in diagnoses [5.9a]. 7 of these 12 audits specified that a diagnosis of delirium using the 4AT triggered the use of a delirium management pathway, the most common being TIME.

This increasing attention to delirium screening is leading to increasing rates of delirium detection in the UK. Data from Public Health Scotland show increased rates of formal coding of delirium in hospital administrative records, reflecting increased clinical detection rates, between 2013 and 2020. For example, in the 85-89 age group, delirium was coded in 2.8% of cases in 2012-2013, compared with 10.5% cases in 2019-2020, with steady increments in between. Similarly, Public Health England data shows that in the 85+ age group, delirium was coded in 2.1% in 2012-2013, rising to 8.3% in 2019-2020. The parallel increase in UK 4AT use (as evidenced by the Freedom Of Information report and website accesses as above) suggests that 4AT implementation is likely to have been a factor in these improvements [5.10].

Triggering a formal delirium management pathway results in clear clinical benefits for patients. The TIME pathway, for example, includes explicit instructions to clinically assess and treat potential underlying causes of delirium, such as sepsis or drug intoxication, as well as delirium symptoms (such as unmanageable agitation), thereby reducing associated adverse outcomes.

These improved patient outcomes are exemplified in a 2016 report ‘Improving Older Peoples’ Acute Care’, where rapid identification of delirium was a focus to improve care. This revealed that when 4AT assessment on admission was introduced in an acute ward in NHS Glasgow, a 50% reduction in falls was seen over a year compared with the baseline median [5.9b].

Another example of better patient outcomes following the rapid detection of delirium using 4AT is seen in a 2019 Australian study, where the tool was introduced to improve recognition and management of delirium in high-risk wards. Over a 3-month period, 88% of patients were screened, resulting in delirium diagnosis increasing from 8.2% to 19.4%. This was accompanied by a 48% reduction in behavioural response calls, reduced severity of falls, and length of stay was reduced by 0.8 days [5.9c].

Importantly, increased rates of delirium detection, enabled by adoption of the 4AT, are improving older people’s experience of care as a whole; several case studies published in a 2015 Health Improvement Scotland impact report describe not only better management of delirium, but also increased attention to other elements of the TIME pathway, including pain management and nutrition [5.9j]. Similarly, the 4AT was incorporated into a falls care bundle in NHS Glasgow, allowing staff to target patients at greater risk of falls [5.9j], and a project undertaken by NHS Highland demonstrated that quicker diagnosis of delirium, achieved following implementation of the 4AT, led to more timely treatment and referral to the older adult mental health team where necessary [5.9j].

The transformative impact of the 4AT on the health and welfare of delirium patients is summarised by comments made by a prominent Professor of Old Age Psychiatry and a Trustee of Alzheimer’s Research UK: “ The 4’A’s Test is already considered the gold standard in practice for the detection of delirium, and rightly so […] The consequence of missed delirium – both for individual patients and the NHS – are serious and expensive. Anything that increases delirium awareness and improves detection will have clear benefits” [5.11].

Economic Impact

Health economic modelling quantified the savings associated with the use of the 4AT and the consequent reductions in missed diagnoses. This suggests a conservatively estimated saving of approximately GBP100 for each patient aged over 70 admitted to an emergency acute medical or geriatric department, assessed for delirium using the 4AT rather than clinical judgement alone [5.12]. With 731,000 emergency admissions of 72 hours or more for patients over the age of 75 per year in NHS England alone (2018/19), there is ample opportunity to make this saving [5.12]. With 4AT currently used in 77% of NHS England acute hospital trusts [5.5], this would translate to NHS savings of GBP56,000,000 every year.