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Informed Consent in Patients With Frailty Syndrome

Silbert, Brendan S. MB, BS, FANZCA; Scott, David A. MB, BS, PhD, FANZCA, FFPMANZCA

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doi: 10.1213/ANE.0000000000004629
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The clinical condition of frailty is the consequence of deterioration in multiple physiological systems with time, which ultimately results in a vulnerability to minor stressors and a resultant decline in clinical health. Thus, small insults such as minor surgery or infections can lead to a rapid decline in health status, leading to a progressive deterioration in the ability to cope with daily life. In brief, frailty is generally understood to be an increased vulnerability to adverse outcomes among people of the same chronological age.1 It can be considered both as a global and transverse measure that catches the end result of subclinical deterioration in body systems. It is distinct from multimorbidity, which captures clinically relevant and overt disease.


In older patients undergoing surgery, frailty is common, and the majority of studies have found that it is associated with adverse postoperative outcomes. McIsaac et al2,3 found that in 645 individuals older than 65 years of age scheduled for elective noncardiac surgery, the prevalence of preoperative frailty was identified in 36.6% (modified Fried Index) to 42.3% (Clinical Frailty Scale [CFS]) of patients and strongly predicted death and new disability (CFS odds ratio [OR] 2.51, 95% confidence interval, 1.50–4.21).2 In emergency general surgical patients older than 65 years of age, 26% were identified as frail, and this was associated with increased postoperative mortality.3 In contrast, a recent study using similar methods to define frailty in a slightly younger group of patients for noncardiac surgery found an incidence of 23%, but failed to confirm any association with poor outcomes.4

In cardiac surgery, the incidence of frailty is similar to that for noncardiac surgery. In a study of patients older than 65 years of age undergoing elective aortic valve replacement surgery, 25% had frailty as defined by functional indexes; and the presence of frailty was associated with increased 30-day mortality.5 Brown et al6 identified an incidence of 30.9% of frailty in patients before cardiac surgery, and this was associated with an increased incidence of postoperative delirium. Makary et al7 showed that postoperative complications, length of stay, and loss of independence were all associated with frailty. A systematic review in 2016 found that there was strong evidence that frailty in older-old and oldest-old surgical patients predicted postoperative mortality, complications, and prolonged length of stay.8

In 2001, the concept of frailty was operationalized. Fried et al9 defined the phenotype of frailty as a clinical syndrome in which 3 or more of the following criteria were present: unintentional weight loss (10 lbs in the past year); self-reported exhaustion; weakness (low grip strength); slow walking speed; and low physical activity. Three or more characteristics had to be present for frailty, whereas the presence of 1 or 2 qualified an individual as prefrail. Other potentially important factors such as cognitive impairment, a highly prevalent condition associated with functional decline and disability, were not included as part of the phenotype.10

Other methods of describing frailty include the deficit accumulation model11 and the CFS.12 There are now more than 60 iterations of frailty classification using a frailty index or deficit accumulation model.13 Shem Tov and Matot14 reviewed 5 methods of frailty measurement designed for the surgical patient. Some explicitly included assessment of higher cerebral functioning12,15,16 or daily functional ability.15,17 The construct of frailty is primarily physical (and physiological) and does not specifically focus on cognitive ability. However, there is a strong rationale for the inclusion of components such as cognition and mood, which may be affected by the same biological processes that lead to the manifestations of “physical” frailty. This may be important because, unlike other organ systems, brain function impacts all aspects of daily function with the added role of determining an individual’s cognition and reasoning.

Regardless of whether or not frailty assessments specifically include cognitive ability, there is a marked overlap between high frailty scores and cognitive decline. In the 3-city study, cognitive impairment was present in 10%, 12%, and 22% of the nonfrail, prefrail, and frail subjects, respectively.18 Borges et al19 also showed that frail older adults were at higher risk of incident cognitive disorders than nonfrail elders. Physical frailty is associated with incident mild cognitive impairment (MCI) in community-based older persons, and confers added risk of incident neurocognitive disorder.20,21 Furthermore, the rates of progression of frailty and cognitive change are highly correlated, suggesting that they may share a common pathological basis.22,23

Despite the observation that physical frailty and cognitive disorders have been shown to be related in epidemiological studies, their pathophysiology has usually been studied separately.24 In 2013, an international consensus group proposed the definition of “cognitive frailty” in older adults as a heterogeneous clinical manifestation characterized by the simultaneous presence of both physical frailty and cognitive impairment. In particular, the key factors defining such a condition include presence of physical frailty and cognitive impairment (clinical dementia rating >0.5)25 and exclusion of concurrent Alzheimer disease dementia or other dementias.24,26 The term recognizes the parallel links and possible common etiology relating the physical frailty syndrome to cognitive decline.

The concept of frailty has gained traction within the medical community for its potential to flag the vulnerable older patient, predict poor outcomes, and offer the opportunity for early interventions to delay further deterioration. Missing from this scholarship is careful attention to unique ethical considerations that should accompany thinking about frailty. McNally27 points out that “as with many innovations in health, an understanding of the ethical implications often lags behind their introduction.” With reference to anesthesia and surgery, the ethical considerations impact particularly on the process of informed consent.


Informed consent is a fundamental part of clinical medical practice encompassing ethical and legal imperatives in which the physician explains the planned procedures, possible alternatives, and attendant benefits and risks. Current legal standards demand that all material risks be explained to the patient (patient-based standard).28 It is the authorization of an activity based on understanding of what that activity entails and in the absence of control by others.29 Such consent should ensure that the individual voluntarily consents, free from outside influences or force, has capacity and competence to comprehend the relevant information, and authorize such consent. Competence is defined as the capacity to understand the general nature and effect of the proposed treatment.30 Obtaining a signature on a consent form is not an end in itself, and is not a guarantee that a meaningful consent process has occurred.

The process of involving the patient in a collaborative decision-making process is known as shared decision-making, and extends to many aspects of medical management besides informed consent. Specifically, when applied to the informed consent process for anesthesia, the aim is to strike a consensus between the patient’s preferences and the anesthetist’s understanding of the available options, and how these best match the patient’s preferences.31 It is not simply providing a laundry list of available options from which the patient can choose,32 but highlighting the advantages and disadvantages and how these may best suit the individual.

Barron et al33 divide the process of consent into information presentation, comprehension, voluntary decision, and authorization. Each of these presents special challenges and an ethical dilemma when frail older persons are involved.33

Appelbaum and Grisso34 have refined the requirements of competence into 4 major categories:

  1. Communicating choices: The inability to make a choice is a self-evident indication that the individual is unable to make informed consent.
  2. Understanding relevant information: Beyond the mere reception, storage and retrieval of information, patients must be able to understand the fundamental meaning of information. To test understanding, it is better that patients paraphrase the information.
  3. Appreciating the situation and its consequences: Patients must not only understand the information, but must grasp what it means for them.
  4. Manipulating information rationally: Rationally manipulating information involves the ability to reach conclusions that are logically consistent with the starting premises; this may be tested by asking patients appropriate questions.

There is no general agreement on how to measure any of these categories, although there have been several attempts to design assessment tools.35 To understand and appreciate a procedure, a patient must encode, retain, and process information that involves multiple cognitive domains such as attention, memory, and cognition.36 As part of the consent process, incorporating feedback from patients on their level of understanding (beyond simple recall) will help to confirm competence. To test understanding, it is best that patients paraphrase the information; to test appreciation of the situation requires eliciting the conception of their illness, need for treatment, and likely outcomes; to test rational manipulation of information, one must ask patients for recognizable reasons for their choices.34

For those elderly adults who require medical procedures, particularly anesthesia and surgery, the label “frail” raises important issues with regard to the informed consent process.


The frail elderly have decreased physiological reserve, which is not necessarily manifested as defined morbidities. Unfortunately, there is no gold standard for measurement, with the presence of many measurement tools and definitions. However, regardless of how it is assessed, the presence of frailty implies a poor response to stressors, of which hospitalization for anesthesia and surgery must surely be at the forefront. Consequently, frailty is an identified risk factor for falls, disability, long-term care, and death.9 Using a modified frailty index, which increased in score as deficits accumulated, Velanovich et al15 showed that there was a stepwise increase in risk of both mortality and morbidity for each unit increase in frailty index for each surgical specialty and each level of operation complexity. Other studies have confirmed that the modified frailty index score is associated with increased postoperative complications, increased length of stay in hospital, and mortality.37–41 O’Neill et al16 assessed frailty purely on “initial clinical impression,” representing a “gut instinct” based on the clinician’s experience. Those classified as frail were more than twice as likely to die, and this effect was maintained when adjusted for comorbidity and surgery. Furthermore, the risk of death was maintained in those classified as frail who did not undergo surgery.

In summary, regardless of the method used to identify it, frailty has been shown to increase postoperative complications, length of hospital stay, and mortality. These added risks are not contained in usual risk predictors, such as the American Society of Anesthesiologists (ASA) score and American College of Surgeons National Surgical Quality Improvement Program (NSQIP). It is therefore important that these added risks are fully disclosed during the informed consent process and incorporated into the decision-making process.

A material risk particularly pertinent to the frail patient is the risk of further cognitive decline after anesthesia and surgery. The group of cognitive disorders, known as perioperative neurocognitive disorders,42 encompasses postoperative delirium, delayed neurocognitive recovery, and neurocognitive disorders (mild and major). Most previous studies into cognitive disorders after anesthesia and surgery have used the purely research-based term postoperative cognitive dysfunction (POCD), which has now been superseded by more appropriate terminology for clinical practice.43 Both delirium and cognitive decline are common adverse events after anesthesia and surgery in the elderly. The incidence of delirium occurs in 5%–50% of older patients after surgery, and is recognized as the most common surgical complication in older adults.44 POCD may be as high as 40% in the immediate postoperative period after cardiac surgery and approximately 17% in the following 3 months for both cardiac and noncardiac surgery.45 These incidences far exceed other adverse events after anesthesia and surgery, and are of material consequence to patients. Beyond the early problems resulting from impaired cognition, the risk of longer-term complications, including further decline in cognition, are known to follow both delirium46,47 and early cognitive decline.48 Hogan et al28 argue that by any standard, a 3- to 4-fold increase in the risk for new-onset memory and problem-solving deficits after surgery is material. Clearly, the default must be to disclose the risk of Perioperative Neurocognitive Disorder (POCD).28


Every person is presumed to have the capacity to consent or refuse treatment unless or until that presumption is rebutted.49 Currently, in law, there is a presumption of capacity in anyone over a specified age, usually 18 years, which can be refuted by overt evidence. Specifically, the law regards capacity to be assessed in the context of a person’s cognitive abilities in relation to the decision being made. For example, in legal matters, a person with diminished cognition may be competent to make a will but not to sign a contract. Consent requires that the anesthesiologist (and surgeon) accept that the individual has the capacity to make an informed decision; this is known as medical decision-making capacity. It should be noted that there are clear exceptions in cases of extreme acute impairment, such as a patient with an obtunded conscious state requiring emergency surgery.

The high prevalence of cognitive impairment in frail patients14 should increase concerns regarding the obtaining of informed consent from a frail individual who may not have the capacity to provide such consent. Informed consent presumes an individual fully understands and comprehends the information presented to them and is competent to make an appropriate decision to accept the risks and benefits so explained. Any decrement in cognitive ability has the potential to interfere with the informed consent process. Informed consent can only be taken from an individual who has both competence and capacity. In general, it has been assumed that normal doctor–patient interactions should expose any deficiency on the part of the patient to provide informed consent. The definition of a person incapable of giving consent has been defined as “incapable of understanding the general nature and effect (ie, consequences) of the prosed treatment or procedure.”30 Such inability to consent is apparent in overt cases of neurological injury, dementia, delirium, psychosis, or intellectual disability. These disorders are usually self-evident. In these circumstances, most hospitals and jurisdictions have a well-defined process for obtaining informed consent from a legally appointed representative (LAR) for the individual, whether the surrogate is a family member, hospital administrator, or legal appointee. Even when a proxy decision is thought to be appropriate, it is good practice to also attain assent from the individual.33

Although competency is a dichotomous concept according to the law, individuals may have capacity to make some decisions but not others. Frail adults are often marginally competent and perhaps unable to be fully responsible for complex decisions, but they may still be able to make more simple and straightforward decisions.33 When cognitive ability is subtly decreased, individuals appear overtly capable of giving consent but may harbor MCI or compromised capacity, which, in fact, makes informed consent questionable. Understanding should be assessed by asking patients to restate the issues in their own words. Failure to comprehend may suggest a lack of decision-making capacity. Clinicians should be vigilant because individuals with cognitive impairment are often practiced in concealing their deficits.

As noted, it is possible that an individual may have capacity in relation to one decision but not in relation to another more complex issue. A pertinent example of this is demonstrated in a case report by Marcucci et al.50 They describe 2 cases in which individuals were able to understand and consent to the surgical procedure, which involved simple concepts of surgery and removal of a tumor because surgery is a tangible process. However, the patients were not able to understand the more abstract concepts of anesthesia. The situation was resolved by allowing the patients to consent to the surgery and obtaining surrogate (LAR) consent for the anesthesia. In both cases, rudimentary cognitive testing demonstrated cognitive deficits that were not overtly apparent. Simple concrete anesthetic concepts may be more accessible than more abstract concepts, such as being unconscious or postoperative pain relief.

Clinicians need to know how to detect the possibility of lack of capacity. The provision of suitable psychological tools may help the simple test of repeating back in patients’ own words.51 Joint decision or shared-decision making approaches that support existing capacity of each patient but involve family and carers have been recommended because, in reality, many of these decisions are made together.52 When capacity is decreased, there is room for simplifying explanations to better fit the patient’s understanding. It goes without saying that many older people require eyeglasses and hearing aids, and these must be used before commencing communication. Further, allowances must be made for linguistic and cultural diversity. Basic elements of communicating with the elderly and frail, such as speaking clearly, in simple language, and in a quiet environment, should be used.53 Finally, it should be recognized that cognitive capacity may fluctuate with time or even the time of day.


The term “frailty” itself, when used in a scientific sense, may identify health concerns and allow early interventions and prognostications. However, from a sociological point of view, it has the connotation of feebleness, passivity, and the temptation to treat such an individual paternalistically. A similar problem (among others) was confronted by the authors of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), when they chose to exclude the term dementia, which also has negative connotations, in favor of the less intimidating term neurocognitive disorder (major).54 It should also be recognized that frailty, like many other medical conditions, represents a continuum. Because concepts such as “mild” or “early” frailty are not yet developed, our language in communicating such concepts to patients and caregivers is imprecise and tends to be binary (ie, frail or not).

The label “frailty” as a biophysical attribute has the potential to encourage validation and objectivity to ageism,55 and may engender paternalistic behavior from carers and family. If such paternalistic behavior encroaches on the self-determination of an individual, it may deny them the basic right of autonomy. There is already a natural tendency to treat the elderly in a paternalistic manner, and it is likely that the label of frailty may enhance this tendency. In such circumstances, even well-meaning carers and family may usurp the individual’s right to make informed consent. Clinicians, in particular, must not impose undue coercion, regarding what they think is “best” for the patient, because this denies the individual of an informed choice. In the extreme, forceful paternalistic behavior by either clinician or family may verge on coercion. When an individual is dependent on a caregiver, there is a tendency for that individual to look to the caregiver for informed consent, even though the individual may have full decision-making capacity.56 This may be augmented by the clinician conveying more information to the caregiver or family members than to elderly individuals themselves.57

It is important to stress that if an individual has the capacity to make informed decisions, including informed consent, one must be wary of appropriating this right by being overprotective. Such behavior robs the individual of autonomy, a basic element of ethical decision making.58 The authentic wishes of the frail should be respected and not overruled in the interests of what the family, carers, or medical staff feel is best for them.

On the other hand, there is a philosophical argument that autonomy should not be the overriding moral value by which we manage patients. In her book, Against Autonomy, Conly59 argues that coercive paternalism may have precedence over autonomy when the good of the individual is concerned. She further distinguishes between the ethical value of soft and hard paternalism,59 depending on the forcefulness or otherwise in which clinicians or family offer advice.

From a pragmatic point of view, especially in time-pressured clinical environments, the legal and bioethical model of consent, which places heavy emphasis on disclosure of risk and benefits, are not always consistent with day to day practice. There is a gap between legal and ethical theory and the patients’ needs and attention to medical information. Patients often have meager comprehension of the risks and benefits, and their decision is driven more by trust in the doctor or by deference to authority than by the information provided.29 McKneally and Martin60 suggest a conceptual model of consent from the patient’s perspective, which contains cultural belief in surgery, enhancement of trust, idealization of specialists, belief in expertise rather than medical information, resignation to the risks of treatment, and acceptance of an expert recommendation.

In reality, many patients delegate responsibility for assessing medical information and making medical decisions to their physicians. Statements in response to treatment choices such as “whatever you think is best” are not uncommon. The exercise of “second-order autonomy” (ie, making an autonomous choice to delegate decision-making authority) may be applied to the physician–patient relationship.61 We suspect that this process is far more common in the elderly and frail, and deserves greater recognition, particularly because it does not satisfy the legal definitions of informed consent.

Another issue that arises with the involvement of caregivers and family is privacy. Privacy is generally taken to be an essential element of medical management. With the loss of independence, patients’ privacy must be necessarily diminished. It would seem that when surrogate or joint decision making is necessary, individual privacy must also of necessity be compromised.


If the issue of autonomy and capacity presents problems for clinical consent, these are further magnified in seeking informed consent for research purposes. Subjects who may benefit from an intervention, such as the frail, should not be excluded from clinical research simply because their participation would be inconvenient for the investigators. Furthermore, exclusion of such patients may limit the applicability of research findings to this vulnerable segment of the population.

Many of the concepts involved in clinical research are difficult to understand. Furthermore, informed consent for research is more tightly regulated and detailed than clinical treatment consent (in which some benefit is implicit). Consequently, research consents are lengthy and complex, sometimes requiring multiple components (eg, genetic studies, consent to withdraw, etc). Beyond a certain length, these documents may be overwhelming.62

Research subjects need to understand the distinction between treatment and research. Frail older patients often expect that contact with the health system is always intended to provide therapeutic benefit. To allow this misunderstanding, not only violates research ethics but also introduces potential bias into the results because continued participation will depend on patient response.33 Subjects may need to understand that they may be randomized to a particular treatment that may be of no benefit. Appelbaum et al63 have labeled the misconception that research subjects believe that decisions are being made for their therapeutic benefit “the therapeutic misconception.”

Informed consent for research with individuals with cognitive impairment offers unique challenges above that for clinical treatment. These include distinct issues from those of other vulnerable populations because of the variability in competence.64 The use of an LAR for the individual must not lose sight of the individual’s agency. A fine balance between the researcher, the subject, and the LAR is required to navigate the subtleties of consent for research, and there has been a variety of methods addressing these issues.65 Consensus recommendations for research and international data sharing involving persons with dementia have been recently documented.66 These recommendations further highlight that decision making should be made in a manner appropriate to the level of capacity in conjunction with the LAR. Consent should be broad and should take into account specific issues of research relating to data sharing, privacy, and consent for the future in case of further cognitive deterioration.


Undertaking the legal and ethical requirements of informed consent in a busy daily anesthesiology practice is a challenging issue. Even then, the gap between the theoretical goals of informed consent and actual practice is well recognized.29,67 Ankuda et al68 found that more than a third of patients consented at a preoperative assessment center did not meet ethical and legal requirements for informed consent.

The assessment of frailty and cognition requires time, training, and resources. The ideal tools may not yet be at our disposal to achieve this in a busy preoperative anesthesia/surgery assessment clinic environment; however, there are preliminary studies that suggest this may be feasible.69

It is important to acknowledge that seeking informed consent from the elderly frail poses additional and uniquely complex obstacles. These include an appreciation of the patient’s autonomy to make informed choices free from coercion, but also to allow for shared decision-making or delegation of decision making authority to an LAR when appropriate. To make the wrong call in either direction is to deny the patient’s legal and ethical rights. In addition, the patient’s capacity must be evaluated for the 4 major elements of competence and a judgment made to consider alternative avenues when appropriate. Material risks are greatly increased for the frail (indeed, this is the sine qua non for the construct of frailty), and these risks must be aired for discussion. Language and cultural issues must also be addressed.

The end result is that seeking informed consent from the older frail patient requires a great deal more time, effort, and thought, including evaluating the risk of the frailty itself, as well as the possibility of concurrent cognitive impairment. To assume that the informed consent process can be undertaken in the frail elderly as a quick adjunct to a thorough medical appraisal is inconsistent with best practice. If the anesthesiologist is unable to satisfy these requirements, then the process of informed consent is likely to be invalid. As these concepts are better developed, there is room for discussion about modifying the informed consent process to be more pragmatic in nature, even at the expense of foregoing some ethical issues. This would raise several legal issues, but the practicalities of consenting the frail elderly at present are very challenging for a busy daily practice.


Parts of this manuscript are reprinted with permission from “Informed Consent and Cognitive Impairment” in The Perioperative Neurocognitive Disorders, Roderick G. Eckenhoff and Nicolo Terrando, eds. Cambridge, UK: Cambridge University Press, 2019.


Name: Brendan S. Silbert, MB, BS, FANZCA.

Contribution: This author helped with the literature search and to generate and revise the manuscript.

Name: David A. Scott, MB, BS, PhD, FANZCA, FFPMANZCA.

Contribution: This author helped write and revise the manuscript.

This manuscript was handled by: Robert Whittington, MD.



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