Dear editor
We thank Dr İlhan and his colleagues for their interest and comments on the recent published paper, “Association between frailty and delirium in older adult patients discharged from hospital”. The following paragraphs aim to respond to their questions.
A previous published primary study distinguished the impact of delirium on the Mini-Mental State Examination scores, using appropriate statistical analysis methods.1 However, as documented in other papers, delirium is a fluctuant state of attention and consciousness including unpredictable clinical manifestations during a delirium episode.2 Obviously, the assessment of the mental state (Mini-Mental State Examination, Geriatric Depression Scale) could be influenced by the occurrence of a prodromal or a subsyndromal delirium episode.3,4 Nurses must know the clinical and early prodromal signs. However, studies in the hospital environment show that they do not recognize the signs of delirium. To encounter this issue, a threefold strategy was adopted in our study. First, we standardized the mental state assessment procedure. Second, we trained the research nurse in delirium/mental state assessment to minimalize measure bias. Of course to detect prodromal or subsyndromal delirium symptoms, appropriate knowledge and clinical observation skills are needed.4 Consequently, we recruited an experienced research nurse with recognized competencies in geriatric clinical assessment. Nevertheless, it has been documented that depression and dementia are substantial confounders in relationship to the detection of the different types of delirium (hypoactive and subsyndromal delirium), confirmed in well-documented reviews of Inouye et al5 and Siddiqi et al;6 although, the comment of the authors is pertinent. Cognitive impairment is a substantial confounding factor in relationship to the assessment of delirium, but also delirium influences the assessment of cognitive impairment.7 This highlights the importance to integrate comprehensive geriatric assessment at the hospital admission of older inpatients including instrumental activities of daily live (IADL) and the Mini-Mental State Examination.8,9
To respond to the question of the IADL cutoff point dependency versus independency in our study, the following answer is proposed. Since the development of the IADL scale in 1969 by Lawton and Brody,9 multiple linguistic translations and cultural adaptations were realized. These versions are not always corresponding with the cutoff points proposed in the original scale. Our study employed the French-IADL-validated 4-level-Likert ordinal scale for the home-dwelling older adults of Israel and Weintraub.10 The scale presents a score variation from 9 to 36 (1= completely independent versus 36= completely dependent). A receiver operating characteristic analysis revealed 16 points as the optimal cutoff value in our study between independent versus dependent.10,11
In answer to the relationship between delirium and frailty, we propose the following reflections. For more than 20 years, clinical researchers have been trying to progress in the early detection of delirium. Even with well-established delirium guidelines12 proposing multiple delirium detection tools, listing pharmacological and nonpharmacological risk factors, poor progress has been observed in delirium prevention and detection in daily practice.13 The challenge is even worse among home-dwelling older adults after hospitalization. A huge number of hospitalized elderly adults are prematurely discharged and return home. In approximately half of the elderly patients leaving hospital, an episode of delirium is not detected. Undoubtedly, delirium is likely to develop among this frail population, as it is documented in several studies that hospitalization provokes physical and cognitive decline.14,15 To assess the severity of frailty, we used the French version Edmonton Frailty Scale including physical and cognitive dysfunction, considered as a major risk factor for delirium.15 The majority of the frailty instruments do not look for cognitive dysfunction. Despite the association between frailty and cognitive dysfunction, a minority of frailty instruments assesses cognition, and the type of assessment varies substantially. However, some indicators of frailty have been shown to better predict cognitive impairment decline than others. Timed walk and grip strength were significant predictors of subsequent diagnosis of Mild Cognitive Impairment.16,17 O’Halloran et al18 documented the link between frailty and poorer sustained attention. Although, there is significant epidemiological evidence linking elements of frailty and cognitive decline, little work has directly explored the mechanism underlying this link. Several publications have suggested frailty components as mediators or possible pathways for cognitive decline but actually there is a lack of experimental evidence to support these suggestions. However, cognition and frailty are both assessed together more frequently during the last 5 years.19
Dr İlhan and colleagues discussed the variable “poly-medication” and proposed a more exhaustive exploration to document this variable’s impact on delirium. We agree that a more detailed analysis could offer more information; however, three major reasons can be evoked explaining why we limited our analysis. First, our study did not focus on medication risk factors. Second, due to a lack of resources, we were not able to integrate this variable into our study. Third, many medications have been associated with the development of delirium, but the strength of the associations is uncertain and it is unclear which medications should be avoided in people at risk of delirium.20,21 Few studies examined different types of medications together in different doses, and most studies assessed the effects in small heterogeneous samples.
Finally, we apologize for the conflicting data, considered as a typing error in the abstract and we will discuss adapting this error with the journal editor.
References
-
1.Verloo H, Goulet C, Morin D, von Gunten A. Effect estimation of an innovative nursing intervention to improve delirium among home-dwelling older adults: a randomized controlled pilot trial. Dement Geriatr Cogn Dis Extra. 2015;5(1):176–190. doi: 10.1159/000375444. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
2.Nussbaum AM. The Pocket Guide to the DSM-5 Diagnostic Examen. Washington DC: American Psychiatric Publishing; 2013. [Google Scholar]
-
3.Duppils GS, Wikblad K. Delirium: behavioural changes before and during the prodromal phase. J Clin Nurs. 2004;13(5):609–616. doi: 10.1111/j.1365-2702.2004.00898.x. [DOI] [PubMed] [Google Scholar]
-
4.Cole M, Ciampi A, Belzile E, Dubuc-Sarrasin M. Subsyndromal delirium in older people: a systematic review of frequency, risk factors, course and outcomes. Int J Geriatr Psychiatry. 2013;28(8):771–780. doi: 10.1002/gps.3891. [DOI] [PubMed] [Google Scholar]
-
5.Inouye SK, Westendorp RG, Saczynski JS. Delirium in elderly people. Lancet. 2014;383(9920):911–922. doi: 10.1016/S0140-6736(13)60688-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
6.Siddiqi N, Harrison JK, Clegg A, et al. Interventions for preventing delirium in hospitalised non-ICU patients. Cochrane Database Syst Rev. 2016(3):CD005563. doi: 10.1002/14651858.CD005563.pub3. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
7.Leonard M, McInerney S, McFarland J, et al. Comparison of cognitive and neuropsychiatric profiles in hospitalised elderly medical patients with delirium, dementia and comorbid delirium–dementia. BMJ Open. 2016;6(3):e009212. doi: 10.1136/bmjopen-2015-009212. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
8.Folstein MF, Folstein SE, McHugh PR. “Mini-mental state”. A practical method for grading the cognitive state of patients for the clinician. J Psychiatr Res. 1975;12(3):189–198. doi: 10.1016/0022-3956(75)90026-6. [DOI] [PubMed] [Google Scholar]
-
9.Lawton MP, Brody EM. Assessment of older people: self-maintaining and instrumental activities of daily living. Gerontologist. 1969;9(3):179–186. [PubMed] [Google Scholar]
-
10.Israel L, Weintraub L. Methods of psychometric evaluation in geriatrics. Choice of an instrument and its reliability criteria. Presse Med. 1983;12(48):3124–3128. [PubMed] [Google Scholar]
-
11.Hajian-Tilaki K. Receiver operating characteristic (ROC) curve analysis for medical diagnostic test evaluation. Caspian J Intern Med. 2013;4(2):627–635. [PMC free article] [PubMed] [Google Scholar]
-
12.National Guideline C. Screening for Delirium, Dementia and Depression in Older Adults. 2012. [Accessed October 25, 2012]. Available from: http://guidelines.gov/content.aspx?f=rss&id=32417.
-
13.Teale EA, Young JR. Multicomponent delirium prevention interventions: not as effective as NICE suggest? Age Ageing. 2015;44(6):915–917. doi: 10.1093/ageing/afv120. [DOI] [PubMed] [Google Scholar]
-
14.Quinlan N, Marcantonio ER, Inouye SK, Gill TM, Kamholz B, Rudolph JL. Vulnerability: the crossroads of frailty and delirium. J Am Geriatr Soc. 2011;59(Suppl 2):S262–S268. doi: 10.1111/j.1532-5415.2011.03674.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
15.Buurman BM, Hoogerduijn JG, van Gemert EA, de Haan RJ, Schuurmans MJ, de Rooij SE. Clinical characteristics and outcomes of hospitalized older patients with distinct risk profiles for functional decline: a prospective cohort study. PLoS One. 2012;7(1):e29621. doi: 10.1371/journal.pone.0029621. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
16.Auyeung TW, Lee TSW, Kwok T, Woo J. Physical frailty predicts future cognitive decline – a four year prospective study in 2737 cognitively normal older adults. The Journal of Nutrition, Health and Aging. 2011;15:690–694. doi: 10.1007/s12603-011-0110-9. [DOI] [PubMed] [Google Scholar]
-
17.Boyle PA, Buchanan AS, Wilson RS, Leurgans SE, Bennett DA. Physical frailty is associated with incident mild cognitive impairment in community-based older persons. Journal of the American Geriatrics Society. 2010;58:248–255. doi: 10.1111/j.1532-5415.2009.02671.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
-
18.O’Halloran AM, Fan CW, Kenny RA, Penard N, Galli A, Robertson IH. Variability in sustained attention and risk of frailty. Journal of the American Geriatrics Society. 2011;59:2390–2392. doi: 10.1111/j.1532-5415.2011.03706.x. [DOI] [PubMed] [Google Scholar]
-
19.De Vries N, Staal J, Van Ravensberg C, Hobbelen J, Rikkert MO, Nijhuis-Van der Sanden M. Outcome instruments to measure frailty: a systematic review. Ageing Res Rev. 2011;10(1):104–114. doi: 10.1016/j.arr.2010.09.001. [DOI] [PubMed] [Google Scholar]
-
20.Clegg A, Young JB. Which medications to avoid in people at risk of delirium: a systematic review. Age Ageing. 2011;40(1):23–29. doi: 10.1093/ageing/afq140. [DOI] [PubMed] [Google Scholar]
-
21.Resnick B, Pascala JT. American Geriatrics Society updated Beers Criteria for potentially inappropriate medication use in older adults. J Am Geriatr Soc. 2012;60:616–631. doi: 10.1111/j.1532-5415.2012.03923.x. [DOI] [PMC free article] [PubMed] [Google Scholar]