in the Beers criteria.41 The fact that common treatments such as oxygen and intravenous fluids should be treated the same way as other drugs is sometimes forgotten, but these are potentially dangerous treatments (particularly for older patients) and should be administered with due caution. The physiological changes associated with normal ageing and the pathological changes associated with disease processes common among older people in the hospital all impact the risks associated with giving medications to this population. These changes have effects on the pharmacokinetics and pharmacodynamics of virtually all medications.
Frail elderly people are rarely included in large pharmaceutical trials, which in turn may result in harm because findings from clinical trials involving younger patients may be incorrectly extrapolated to older patients. The changes that occur with age also have practical implications in terms of drug regimens, administration, and concordance; for example, swallowing difficulties, arthritis, and cognitive or visual impairment need to be taken into consideration when prescribing and administering drugs to these complex patients.
As with all patient‐safety issues in older people, adverse drug events do not occur in isolation – they are closely linked to the geriatric syndromes in both cause and effect. The unique characteristics of the frail elderly again play a part here. Because of the frequently nonspecific ways in which adverse drug events present in these patients (often in the form of the geriatric syndromes described above, particularly delirium or falls), they often go unrecognized — and rather than the causative agents being stopped, more medications are added, causing further adverse effects. This can lead to a vicious circle known as the prescribing cascade.42
Implications
The undoubtedly higher rate of adverse events in older people has obvious implications financially and for service provision. We must also consider the inescapable implications of the ageing population. By 2025, the number of people in the UK over age 85 will increase by two‐thirds; people over 65 account for 60% of acute hospital admissions and 70% of bed days in National Health Service (NHS) hospitals. Ensuring patient safety and high‐quality care for the growing number of older patients in healthcare systems might be seen as a battle against the inevitable consequences of illness and age, combined with the negative outcomes of preventable geriatric syndromes and adverse effects of treatments and interventions.
Box 11.2 Common types of medication‐related problems in older people in the hospital.
Why are older people more susceptible to healthcare‐associated harm than younger patients?
The causes of harm to patients are complex and may lie in individual error, process factors, organizational or cultural issues, or wider system problems. In this section, we address a number of issues that are particularly critical in the care of older people.
The effects of comorbidity and frailty
As major international studies have shown, adverse events are not associated with age alone but rather with comorbidity, complexity, and frailty. Comorbidity is commonplace among the elderly: 98% of people over the age of 65 in one primary care population had multiple chronic medical conditions.43 For patients, this leads to complex care needs, interacting medical conditions, and polypharmacy – all of which make them more vulnerable to poorer outcomes in general, such as increased mortality and length of hospital stays. In this group, acute illness is usually associated with exacerbations of multiple coexisting chronic diseases, which interplay to produce complex physiological, cognitive, and functional consequences. Of course, there is a great deal of inter‐individual heterogeneity in the way in which these complexities manifest themselves. It follows that acute illness leading to hospitalization in such individuals is rarely as straightforward as it might be in a younger, fitter patient, and hence more healthcare‐associated harm can occur. A review of dementia patients in acute hospitals revealed significant adverse events including falls, functional decline, delirium, increased length of stay, and even mortality.44 There were many contributory factors including inadequate assessment and treatment, unnecessary interventions, and limited resources.
Frailty can be, but is not always, associated with the latter stages of chronic illnesses. Definitions vary, but frailty is understood to be a clinical syndrome in its own right, associated with loss of reserve in multiple organs and a clinical phenotype of generalized weakness, weight loss, exhaustion, and immobility.45 This loss of reserve leads to the frail individual being less able to withstand illness and hospitalization than those without the condition.
The interaction between older people with multiple comorbidities, complexity, and frailty with the healthcare system is often complicated by the fact that illness presents in different, often more non‐specific ways in this population and may manifest as one of the geriatric syndromes described earlier.
In addition, cognitive impairment and sensory impairment may make it difficult for these patients to communicate with healthcare staff, which means they are less able to be involved in their own care than younger people, thus increasing their vulnerability to errors.
Decision‐making in the care of older people
Safe, high‐quality care for older people requires staff to make complex decisions about medical and non‐medical matters, with the involvement of the whole multidisciplinary team and with the aim of meeting patients’ best interests. This applies across the entire healthcare system, including decisions relating to the prevention and management of long‐term conditions in primary care, when and whether to refer or admit patients to secondary care, inpatient care, and the complex planning required to maximize patient safety on discharge from the hospital. The challenge is to make these decisions in the safest possible way by anticipating and pre‐empting potential errors or harm and always acting in the patient’s best interests.
Very old people, particularly those who are frail and complex, have in the past often been excluded from the large clinical and pharmaceutical trials46 that have formed the basis of our pharmaceutical approach to treating many common conditions. To a certain extent, this is understandable: the different physiological characteristics, coexisting medical conditions, and therapies associated with old age can lead to a variety of responses to drug therapy, both beneficial and adverse; these responses can be difficult to predict, detect, and adjust for accurately in terms of measured outcomes. As a consequence, optimal therapeutic decision‐making for the individual – for instance, in terms of drug dosing or combinations – may be difficult to achieve because of the lack of an appropriate evidence base. Hence a degree of clinical judgement based on the risks and benefits of treatment in the context of elderly, frail physiology needs to be used to make such decisions. In recent years, it has become more apparent that older people are the target group for many treatments, and trials have increasingly been designed with these patients in mind.47
Commonly used therapeutic guidelines can also be difficult to generalize to older people; particularly when used by those who are not au fait with geriatric medicine (such as relatively inexperienced prescribers or prescribers in settings that are more used to dealing with younger or fitter people), this can result in inappropriate treatments being given to frail older people, with adverse consequences that may include over‐ or under‐treatment, for example with opiate analgesia. Even in conditions where a strong consensus and clear guidelines for management exist, there is evidence that treatment remains inadequate. This is particularly true of conditions such as delirium, where appropriate
