Lucia Chinnappa-Quinn et al.’s recent carefully conducted systematic review and meta-analysis provided preliminary evidence of higher risk of cognitive decline following hospitalization for acute physical illnesses in older adults without preexisting clinical dementia, while taking into consideration a wide range of potential risk factors involving both patient and hospitalization factors (Chinnappa-Quinn et al., Reference Chinnappa-Quinn2020). Despite the heterogeneity in patient characteristics and cognitive outcome measures of different studies, a significant result is still identified, suggesting that the risk of post-hospitalization cognitive decline (PHCD) might be present regardless of the type of illness and does not limit only to specific medical conditions (such as delirium) or treatments (such as the need for intensive care and emergency surgical operations, in particular those involving the use of general anesthesia) which have all been well recognized to be associated with higher risk of cognitive impairment. This review study adds to our existing knowledge by reframing the conceptual model of PHCD, with their findings suggesting that a potentially higher order construct exists, and highlights the need for better understanding of how different specific inpatient contexts might model the observed phenomenon. To our knowledge, no prior study has used computational methods to examine PHCD. Such anticipated findings will be of great clinical and public health impact in finding ways to modify the risk of PHCD, especially since our populations are ageing rapidly, hospitalization rates are higher in the older populations and older adults are at a greater risk of developing dementia.
With hospitalization being a potential risk factor for cognitive decline, it would be important for the medical professionals to reflect on how we should translate the present finding to the at-risk populations. While outpatient treatments or home treatments offered by community outreach teams are an alternative to hospitalization, they are likely applicable only to older adults with relatively mild acute illnesses. Hospitalization might still be the most appropriate treatment option for those whose illnesses are so severe that can no longer be further managed in the outpatient community setting. Failure to investigate quickly and to receive timely treatment in the hospital could potentially cause harm to older adults as well, such as missing or delaying diagnoses, lengthening duration of hospitalization, and increasing the risks of morbidities and mortality. Having less access to health care services has been postulated to account for the increased risk of dementia in older adults without history of general anesthesia exposure (Yip et al., Reference Yip, Brayne and Matthews2006), and a recent finding published by Velkers et al. showed that elective surgeries involving the use of general anesthesia were not associated with higher risk of incident dementia (Velkers, Reference Velkers2021); these suggest that some inpatient treatments, especially those that can improve older adults’ health and well-being, might be beneficial rather than detrimental to cognition in the long run. So the question is how we could minimize the risk of PHCD in these older adults who do require inpatient stay?
To date, evidence to support the use of pharmacological treatment in preventing PHCD is not available. Existing literature mainly focuses on the prevention and treatment of delirium, a known risk factor for cognitive impairment. However, no clear benefit has been found in the use of cholinesterase inhibitors in preventing and improving outcomes of delirium (Yu, Reference Yu2018). Also, given the limited benefit and potential harm of antipsychotics and benzodiazepines, it is widely accepted that they should only be used as the last resort for managing hyperactive delirium with severe agitation that poses a significant risk to patient’s life or staff’s safety (Oh et al., Reference Oh, Fong, Hshieh and Inouye2017). More research is needed to establish the safety and effectiveness of pharmacological treatment in modulating the risk of PHCD.
Nevertheless, from the perspective of psychogeriatricians, we believe that many things can still be done to prevent or lower the risk of PHCD. Evidence from meta-analysis shows that various simple but cost-effective multicomponent nonpharmacological strategies can prevent delirium in hospitalized older adults (Burton et al., Reference Burton2021). On the same track, we propose that multilevel nonpharmacological approaches including primary, secondary, and tertiary preventions might apply in PHCD risk reduction. In brief, health promotion and disease prevention through education, lifestyle modification, vaccination, optimization of risk factors for acute illnesses, strengthening cognitive resilience, and improving mental health are some examples of primary prevention activities that might attenuate the likelihood of acute illness from developing and reduce the need for hospitalization services in the first place (World Health Organization, 2017). Secondary prevention strategies might include early identification and treatment of acute illnesses or exacerbation of chronic conditions, preferably in the outpatient or home setting as mentioned above, when the disease severity is still relatively mild. For older adults with acute illness that requires inpatient management, tertiary prevention strategies, such as the Acute Care for Elders (ACE) model that focuses on not only timely treatment but more importantly an older adult friendly environment, early rehabilitation, enhanced discharge planning, and patient-centered care with the aim to reduce functional decline in acutely ill older adults (Wong et al., Reference Wong, Vollbrecht, Pagel, Malone, Capezuti and Palmer2014), are potentially useful in minimizing further complications and comorbidities including PHCD. Prior studies show that the ACE programs help older adults with acute medical illnesses improve clinical and functional outcomes in the long run, reduce delirium risk, and shorten length of stay and thus lower hospital cost (Baztán et al., Reference Baztán, Suárez-García, López-Arrieta, Rodríguez-Mañas and Rodríguez-Artalejo2009; Fox, Reference Fox2012). Further examination of the effectiveness of these nonpharmacological approaches in preventing PHCD will be invaluable in enabling older adults to achieve cognitive maintenance and healthy ageing.
With the present generation of older adults living longer than their previous counterparts, identifying strategies that can maximize healthy lifespan and compress morbidities including PHCD is of great clinical and public health importance to the growing number of older people, their family members, and the society as a whole. For better or worse, some older individuals will need inpatient treatment in their lives. This commentary recommends using a computational approach to disentangle the complex relationships between different specific inpatient contexts and the observed larger phenomenon of PHCD and, more importantly, proposes comprehensive multilevel nonpharmacological interventions as a potential effective strategy to prevent or minimize the risk of PHCD in older adults.
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Lucia Chinnappa-Quinn et al.’s recent carefully conducted systematic review and meta-analysis provided preliminary evidence of higher risk of cognitive decline following hospitalization for acute physical illnesses in older adults without preexisting clinical dementia, while taking into consideration a wide range of potential risk factors involving both patient and hospitalization factors (Chinnappa-Quinn et al., Reference Chinnappa-Quinn2020). Despite the heterogeneity in patient characteristics and cognitive outcome measures of different studies, a significant result is still identified, suggesting that the risk of post-hospitalization cognitive decline (PHCD) might be present regardless of the type of illness and does not limit only to specific medical conditions (such as delirium) or treatments (such as the need for intensive care and emergency surgical operations, in particular those involving the use of general anesthesia) which have all been well recognized to be associated with higher risk of cognitive impairment. This review study adds to our existing knowledge by reframing the conceptual model of PHCD, with their findings suggesting that a potentially higher order construct exists, and highlights the need for better understanding of how different specific inpatient contexts might model the observed phenomenon. To our knowledge, no prior study has used computational methods to examine PHCD. Such anticipated findings will be of great clinical and public health impact in finding ways to modify the risk of PHCD, especially since our populations are ageing rapidly, hospitalization rates are higher in the older populations and older adults are at a greater risk of developing dementia.
With hospitalization being a potential risk factor for cognitive decline, it would be important for the medical professionals to reflect on how we should translate the present finding to the at-risk populations. While outpatient treatments or home treatments offered by community outreach teams are an alternative to hospitalization, they are likely applicable only to older adults with relatively mild acute illnesses. Hospitalization might still be the most appropriate treatment option for those whose illnesses are so severe that can no longer be further managed in the outpatient community setting. Failure to investigate quickly and to receive timely treatment in the hospital could potentially cause harm to older adults as well, such as missing or delaying diagnoses, lengthening duration of hospitalization, and increasing the risks of morbidities and mortality. Having less access to health care services has been postulated to account for the increased risk of dementia in older adults without history of general anesthesia exposure (Yip et al., Reference Yip, Brayne and Matthews2006), and a recent finding published by Velkers et al. showed that elective surgeries involving the use of general anesthesia were not associated with higher risk of incident dementia (Velkers, Reference Velkers2021); these suggest that some inpatient treatments, especially those that can improve older adults’ health and well-being, might be beneficial rather than detrimental to cognition in the long run. So the question is how we could minimize the risk of PHCD in these older adults who do require inpatient stay?
To date, evidence to support the use of pharmacological treatment in preventing PHCD is not available. Existing literature mainly focuses on the prevention and treatment of delirium, a known risk factor for cognitive impairment. However, no clear benefit has been found in the use of cholinesterase inhibitors in preventing and improving outcomes of delirium (Yu, Reference Yu2018). Also, given the limited benefit and potential harm of antipsychotics and benzodiazepines, it is widely accepted that they should only be used as the last resort for managing hyperactive delirium with severe agitation that poses a significant risk to patient’s life or staff’s safety (Oh et al., Reference Oh, Fong, Hshieh and Inouye2017). More research is needed to establish the safety and effectiveness of pharmacological treatment in modulating the risk of PHCD.
Nevertheless, from the perspective of psychogeriatricians, we believe that many things can still be done to prevent or lower the risk of PHCD. Evidence from meta-analysis shows that various simple but cost-effective multicomponent nonpharmacological strategies can prevent delirium in hospitalized older adults (Burton et al., Reference Burton2021). On the same track, we propose that multilevel nonpharmacological approaches including primary, secondary, and tertiary preventions might apply in PHCD risk reduction. In brief, health promotion and disease prevention through education, lifestyle modification, vaccination, optimization of risk factors for acute illnesses, strengthening cognitive resilience, and improving mental health are some examples of primary prevention activities that might attenuate the likelihood of acute illness from developing and reduce the need for hospitalization services in the first place (World Health Organization, 2017). Secondary prevention strategies might include early identification and treatment of acute illnesses or exacerbation of chronic conditions, preferably in the outpatient or home setting as mentioned above, when the disease severity is still relatively mild. For older adults with acute illness that requires inpatient management, tertiary prevention strategies, such as the Acute Care for Elders (ACE) model that focuses on not only timely treatment but more importantly an older adult friendly environment, early rehabilitation, enhanced discharge planning, and patient-centered care with the aim to reduce functional decline in acutely ill older adults (Wong et al., Reference Wong, Vollbrecht, Pagel, Malone, Capezuti and Palmer2014), are potentially useful in minimizing further complications and comorbidities including PHCD. Prior studies show that the ACE programs help older adults with acute medical illnesses improve clinical and functional outcomes in the long run, reduce delirium risk, and shorten length of stay and thus lower hospital cost (Baztán et al., Reference Baztán, Suárez-García, López-Arrieta, Rodríguez-Mañas and Rodríguez-Artalejo2009; Fox, Reference Fox2012). Further examination of the effectiveness of these nonpharmacological approaches in preventing PHCD will be invaluable in enabling older adults to achieve cognitive maintenance and healthy ageing.
With the present generation of older adults living longer than their previous counterparts, identifying strategies that can maximize healthy lifespan and compress morbidities including PHCD is of great clinical and public health importance to the growing number of older people, their family members, and the society as a whole. For better or worse, some older individuals will need inpatient treatment in their lives. This commentary recommends using a computational approach to disentangle the complex relationships between different specific inpatient contexts and the observed larger phenomenon of PHCD and, more importantly, proposes comprehensive multilevel nonpharmacological interventions as a potential effective strategy to prevent or minimize the risk of PHCD in older adults.
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