Hospital outcomes of older people with cognitive impairment: An integrative review

Objectives To summarise existing knowledge of outcomes of older hospital patients with cognitive impairment, including the type and frequency of outcomes reported, and the additional risk experienced by this patient group. Methods Integrative literature review. Health care literature databases, reports, and policy documents on key websites were systematically searched. Papers describing the outcomes of older people with cognitive impairment during hospitalisation and at discharge were analysed and summarised using integrative methods. Results One hundred four articles were included. A range of outcomes were identified, including those occurring during hospitalisation and at discharge. Older people with a dementia diagnosis were at higher risk from death in hospital, nursing home admission, long lengths of stay, as well as intermediate outcomes such as delirium, falls, dehydration, reduction in nutritional status, decline in physical and cognitive function, and new infections in hospital. Fewer studies examined the relationship of all‐cause cognitive impairment with outcomes. Patient and carer experiences of hospital admission were often poor. Few studies collected data relating to hospital environment, eg, ward type or staffing levels, and acuity of illness was rarely described. Conclusions Older people with cognitive impairment have a higher risk of a variety of negative outcomes in hospital. Prevalent intermediate outcomes suggest that changes in care processes are required to ensure maintenance of fundamental care provision and greater attention to patient safety in this vulnerable group. More research is required to understand the most appropriate ways of doing this and how changes in these care processes are best implemented to improve hospital outcomes.

reviewer, and decisions checked with a second reviewer in case of uncertainty. The relevance of all included studies was verified by 3 reviewers. As one of the purposes of this review was to understand which outcomes are being measured for this population in hospital, no formal quality assessment was performed to maintain inclusivity.
Methodological issues, eg, the potential for bias, are indicated in text or tables where appropriate.

| RESULTS
One thousand sixty-two records were identified from database searches, reference lists, and website searches. Following review of abstracts and full papers against eligibility criteria, 104 articles were included in the review (Figure 1). The median number of participants was 498 (range 4-3 000 000), mostly of people aged ≥50. Participant cohorts included general inpatients, specific conditions, eg, heart failure or fractures, or with specific clinical interventions, eg, catheterisation. CI was defined in several ways, eg, of dementia diagnosis, cognitive spectrum disorder (delirium, dementia, or Abbreviated Mental Test <8), or other assessments, eg, Short Blessed Test.
The articles encompass a range of methodologies, eg, observational studies comparing patients with/without CI, studies in which cognitive status or dementia were evaluated as risk factors for specific outcomes, and qualitative studies and audits. A variety of outcomes were explored, not only in patients with dementia compared to those without but also in patients with measurable CI regardless of diagnosis. Associations between CI and outcomes were assessed using a variety of covariates, reflecting the study context and data sources available. Articles with more than 1 outcome are presented in the appropriate tables.
3.1 | Clinical and patient-centred outcomes during hospitalisation

| Patients' experiences of hospital admission
An integrative review summarising 24 papers on patient and carer experience concluded that people with dementia are stigmatised in hospitals, and acute care needs and tasks are prioritised over personalised care 14 (Table 1). The UK National Audit of Dementia Care found that 17% of comments about patient care (collected via a carer questionnaire) described care negatively, and 9% expressed that patient did not receive care appropriate to their needs. 15 Surveys estimate that around 60% of people with dementia are not treated with dignity or understanding whilst hospitalised, and the majority are frightened by the hospital environment. 3 Reporting of negative experiences has been observed to follow a model, the "cycle of discontent", in which poor communication and relationship building between staff and patients/carers lead to expectations not being met, subsequent cycles of identification of poor care and challenge to staff, further deterioration in the relationship, and ultimately reporting of poor experiences. 16 It has been observed that there are many missed opportunities in hospitals to provide person-centred care and enable a person with dementia to sustain personhood. 17 No studies were found that discussed experiences of older patients with any cause of CI.

| Behavioural and psychological symptoms of dementia
The prevalence of behavioural and psychological symptoms of dementia (BPSD) symptoms in people with dementia in hospital rises during admission, likely because of unmet needs and distress, and a higher overall Behavioural Pathology in Alzheimer Disease Scale (BEHAVE-AD score) (incorporating BPSD) associated with increased mortality. 18 Behavioural and psychological symptoms of dementia have been identified as a frequent cause of complications in an Alzheimer Special Acute Care inpatient unit, with agitation and aggressiveness representing 60% of BPSD events. 19 A qualitative study identified disruption in routine, eg, admission to hospital, triggering negative changes in behaviour as the person with dementia attempts to gain control over an unfamiliar environment. 20

| Malnutrition or dehydration
Older people with dementia are more likely to have a low Mini-Nutritional Assessment (MNA) score and laboratory indices indicating malnutrition at hospital admission, with overall MNA score and subscore related to dietary habits (MNA-3) significant predictors of death in hospital. 21 Of admitted patients who are already undernourished, those with CI are less likely to meet their required energy and protein intake, achieving <50% of total energy expenditure requirements. 22 Organisational factors may contribute to decline in nutritional status through lack of availability of adequate nutrition. An audit revealed that only 76% of staff considered people with dementia had their nutritional needs met "always or most of the time", and <75% of staff said that they could obtain snacks between meals for patients with dementia, who were unable to eat full meals at regular times. 15 Fluid intake is also a key indicator of fundamental care in hospital. Assessment of renal FIGURE 1 Selection of articles    a conservation of water in older patients showed concentrated urine in 16% of patients, more commonly in patients with confusion and/or dementia, and was related to higher 30-day mortality. 23

| Functional or cognitive decline
A meta-analysis identified functional decline (measured by activities of daily living (ADL), instrumental ADLs (IADL), Barthel index (BI), mobility, functional independence measure (FIM), or Rankin scale) in hospitalised adults aged ≥65 is independently associated with CI or a dementia diagnosis. 24 Further cognitive decline during hospitalisation is associated with an increased risk of functional decline, defined as a loss of ability to perform 1 or more ADLs without help between admission and discharge. 25

| Incident delirium during hospitalisation
The prevalence of delirium in general hospital patients is around 20%, and approximately half these patients have pre-existing dementia. 6 Although patients with dementia are more likely to have delirium at admission, dementia increases the likelihood of new-onset delirium (or "delirium superimposed on dementia" (DSD)) during hospitalisation. [26][27][28][29] Regardless of a dementia diagnosis, lower cognitive scores are associated with increased occurrence of delirium in hospital, and symptoms of greater severity, eg, disordered attention, orientation, thought organisation, and memory. 27,[30][31][32][33] Cognitive impairment and dementia are predictive of delirium occurring prior to or following surgery for fractures of the hip or proximal femur. [34][35][36][37] Hospital outcomes including mortality, institutionalisation, and length of stay for patients with delirium are worse with pre-existing dementia. [38][39][40][41] Dementia was associated with an increased risk of least 1 episode of delirium during the first 3 days of admission in adults aged ≥65, and increased the odds of unanticipated ICU admission or in-hospital death. 42

| Adverse events and complications occurring in hospital
Events occurring during hospitalisation, eg, urinary tract infections (UTI), pneumonia, or gastroenteritis (hospital-acquired infections (HAI)), pressure ulcers (PU), adverse drug reactions (ADR) falls, and fractures impair recovery by reducing mobility, functional ability, and nutritional status, increase care required, and extend hospitalisation.
Cognitive impairment or dementia leads to an increased risk of falls in hospital, 43,44 including recurrent falls 45 and falls related to impulsive behaviour. 46 In addition, factors identified in >75% of falls in patients with dementia included being in hospital at night, acute disease or symptoms of disease, and/or acute drug side effects. 47 Falls may result in fractures, which delay recovery and lengthen hospitalisation.
Occurrence of fractures in patients with dementia is associated with hypnotic medicines, specifically short-acting benzodiazepine hypnotics, ultrashort-acting nonbenzodiazepine hypnotics, hydroxyzine, risperidone, and perospirone. 48 Both medical and surgical inpatients with dementia are at higher risk of 4 common complications, UTIs, PUs, pneumonia, and delirium, and medical patients are also at increased risk from sepsis and "failure to rescue". 49 Pressure ulcers are also more common in patients with CI. 27 Cognitive impairment was shown to be the most significant risk factor for developing urinary and faecal incontinence, 43  Mild/moderate CI was associated with adverse events defined as "incidents" (eg, following an unintended "accident" in hospital such as a slip or trip, medication error, or staff miscommunication), but not subsequent mortality. 56 Inpatients with dementia have a higher risk of acute organ dysfunction and severe sepsis, particularly patients with comorbidities such as chronic obstructive pulmonary disease (COPD). 57,58 Inpatients with COPD and dementia were less likely to be receiving treatment for COPD and to have their lung function assessed, suggesting that undertreatment could contribute to poorer outcomes. 59 3.2 | Differences in care during hospitalisation

| "Outlying" and bed moves
Pressures on hospital beds lead to older people not always being placed in the most suitable location for their care: known as "outlying" or "boarding". These patients may be moved around the hospital several times until they reach their "home ward". Of patients under an Older Person Evaluation Review and Assessment team, who were more likely to be boarding than general medicine patients, those with pre-existing CI were more likely to be moved 3 or times during their hospital admission (Table 2). 60 In a further study, boarding patients with dementia and/or delirium had higher mortality within 48 hours of admission. 61 Although hospital organisational factors result in night-time bed moves, these were deemed avoidable by 50% of staff surveyed in an audit, and considered detrimental to patient experience. 15

| Pain and end of life or palliative care
Pain may indicate a new infection, injury, or worsening in condition.
The prevalence of pain amongst inpatients with CI is estimated at 39 and is associated with increases in the BEHAVE-AD score, and increased aggression, phobia, and anxiety. 62 Dementia reduces a patient's ability to describe pain characteristics and changes, thus delaying diagnosis of infections or overtreating with analgesics like opioids, contributing to complications, eg, delirium, bowel problems, and lengthened stay. 63 There is no current evidence as to whether patients with CI experience more pain during hospitalisation, probably because of difficulties in assessment.  99 However, similar LOS was described in 1 article, and comorbidities found more predictive of longer hospital stays in another study. 76,82 Discharge after the patient is "medically fit", because of delays in discharge planning or difficulties in organising   include considering the patient's wishes and using multidisciplinaryinformed standards for discharge from hospital to a care home, although in an audit, consent to a change in residence was not recorded in >30% of patients, nor evidence of "best interests" decision making where patients lacked capacity. 15,106,111 Fifty-four per cent of carers' comments regarding discharge/care transfer said that discharge was unsafe and poorly planned, which may lead to readmissions because of lack of available support in the discharge location.

| DISCUSSION
It appears that the presence of cognitive impairment (particularly dementia) in older hospitalised patients influences a variety of clinical and health service outcomes. This is replicated globally, within different health care systems and patient populations. Although most studies focus on patients with diagnosed dementia rather than all-cause CI, an increased risk of poor outcomes, eg, in-hospital mortality, delirium, longer LOS, and institutionalisation at discharge was common. Higher mortality rates may partly reflect lack of available suitable care at end of life, lack of end-of-life care plans, eg, "do-not-hospitalise" advance directives, or unnecessary transfers from nursing homes. 70,[112][113][114][115] Delays in organising appropriate discharge contribute to lengthened hospital stays, highlighting that administrative management and linked services required by these patients may impact on final hospital outcome, as more days in hospital may lead to deconditioning, and policy changes to health and social care infrastructure have unforeseen impacts. 116 Patients with CI are at increased risk of new infections in hospital, decline in functional and nutritional status, behavioural symptoms, and incontinence. These may be considered "intermediate" outcomes, precipitating patient deterioration, for example, CI was associated with mortality only in patients who had at least 1 adverse event in hospital, and dementia associated with mortality only if delirium had occurred. 41,79 Such adverse clinical events could indicate a "failure to maintain" patients' basic health needs, leading to further deterioration. 117 A better understanding of how CI precipitates these events, and what can be done to prevent, detect, and reduce their risk, would enable development of better care models and improved patient outcomes. The multifactorial nature of these events requires a multilevel approach at 7 levels of care-patient, task, staff, team, environment, organisation, and institution-to make improvements, and outcomes for hospital dementia care should reflect changes at each of these levels. 118      functional scores were more significant in predicting mortality than dementia in older patients, but few studies investigating the relationship between CI and mortality adjusted for patient function, suggesting residual confounding. The current trend for including frailty assessments in acute hospital care will provide key information, although it will become difficult to disentangle the relative contributions of frailty and CI, as CI comprises part of commonly used frailty assessments. The majority of studies explored associations between patient characteristics at the beginning of hospital admission with a binary outcome during hospitalisation or outcomes at discharge, not accounting for time-varying covariates, eg, staffing levels and changes in illness acuity or function. Availability of longitudinal data representing day-to-day care, or outcomes reflecting care processes, is essential to understand more about modifiable risk factors contributing to poor outcomes.
Staffing levels, knowledge, and skills are a barrier to provision of best-practice care for people with CI in hospital. 15,123 However, studies in this review neither included detailed descriptions of staffing levels and skill mix, staff continuity, training and knowledge, and the general hospital environment, nor took account of these in analyses.
Outcomes of value in capturing aspects of care, eg, patient experience, may require specific questionnaires or assessments, and are not commonly available. For example, the person-centred care of older people with CI in acute care scale (POPAC) measures nursing staff best-practice care processes to identify CI and employment of nursing interventions to meet associated needs, and could be useful in evaluating routine care and service developments such as training, as well as an outcome in research. 124 No single study included a wide range of care, clinical, and wellbeing outcomes. Given the role of intermediate outcomes in influencing catastrophic events such as mortality, a core outcome set for CI focussed on hospital care is required. This could be used to standardise outcomes for interventional and observational studies, improving comparability of studies, and in routine care to improve care quality and enable evaluation of care innovations. Dementia care audits provide a good starting place to develop outcome sets, as they focus on fundamental care that should be in place to prevent negative outcomes.
Examples include delirium screening, mobility assessment, nutritional status, pressure ulcers, pain, continence, and functioning, 15   National audit Over one third of patients did not have their consent to a change in residence after discharge, or evidence that a best interests decision making process had taken place, in the case that they lacked capacity. 54% of carer's comments regarding discharge/care transfer said that discharge was unsafe and poorly planned, which may lead to readmissions to hospital because of lack of readiness of support in the discharge location. a Papers reporting on 1 outcome are repeated as necessary in the other tables of this paper.
Although selective publication of significant results is possible, there would have to be several large unpublished studies to substantially change the overview of findings.