Increasing frailty is associated with higher prevalence and reduced recognition of delirium in older hospitalised inpatients: results of a multi-centre study
Authors:   Geriatric Medicine Research Collaborative, Faheem Waleed , Nandra Taran , Richardson Sarah , Saliu David , Wilson Daisy , Jackson Thomas A. , Magill Laura , McCluskey Lauren , Perry Rita , Welch Carly , Wilson Daisy , Copeland Claire , Cunningham Emma L. , Davis Daniel , Treml Jonathan , Pinkney Thomas , Quinn Terrence , Nightingale Peter , Jelley Benjamin , Gaunt Victoria , Lochlainn Mary Ni , Giridharan Kumudhini , Alsahab Mustafa , Makin Stephen , Torsney Kelli , Masoli Jane , Ronan Lindsay , Burton Jenni K. , Todd Oliver , Taylor Joanne , Willott Ruth , Cox Natalie , Healy Roisin , Haddad Nedaa , Ramakrishna Sharan , Subhan Zahid , Mazzoleni Antonella , Nynaes Olga , Crofts Jodie , McNicholas Emily , Robinson Hannah J. , Thyn Thyn , Baillie Jonathan , McKeown William , Rice Caroline , Sloan Gerrard W. , Williamson Katherine , Hayat Yasmeen , Lim Vee Han , Millichamp Katie , Bazaraa Amr , Chilton Angharad , Harbinson Alexander , Headlam John , Hunter Elisabeth , Hussain Zainab , Mahmood Al Wakkass , Ng Liji , Sundara Srividya , Tan Felicia , Wheeler Alice , Wright Sophie , Baldwin Jack B. G. , O’shea Kate , Hodhody Ghazal , Mayor Kara , Patel Riana , Bhakta Shiv , Goujon Marie , Jakupaj Adriana , Dove James , Kearney Matthew , McCormack Vincent , Moore Kirsty , Pope Leo , Shah Hussun-Ara , Shaw Megan E. , Smith Gemma M. , Love Ryan , Mukundan Maya , Shahid Muhammad , Alareed Ahmad , Beharry Karen , Bhat Ganapathy , Bremakumar Sanojan , Caines Laurence , Darko Sandra , Rai Nisha , De Mucha Pedro Vila , Adams Phillipa , McDonald Helen , Mills Sam , Parry Frances , Rickard Frances , Winearls Stuart , Farah Rinata , Grange Robert , Herbert Fiona , Lonsdale-Eccles Elizabeth , Ain Qurrat Ul , Watson Hannah , Bultynck Celine , Cavaliere Chiara , Doherty Cal , Evans Sarah , Furmedge Daniel , MacCuish Annabel Hentall , Hindley Esther , Meyer Caitlin , Mullarkey Emma , Pullen Rosamund , Ryan Aidan , Sarma Dhruv , Seymour Elaine , Stambollouian Katharine , Thayabaran Darmiga , Wu Chenxian , Peck George , Raza Mahrukh , Sahnan Kapil , Dhillon Amber , Abiola Oluwatosin O. , Bryant Catherine , Bygate Rachael , Frewen John , Greaves Isabel , Morrow Olivia , Tetlow Simon , Tinson Guy , Yunus Aayenah , Bedi Simran , Evans Olivia , Giet Leeying , Behbahani Abolfazl , Bhattacharya Saurav , Hunt Clare , Mishra Rajeev , Connor Louise , Poynton Jack , Deacon Elizabeth , Durcan Rory , Fisken Emma , Hall Susan A. , Noble Jane , Prendergast Emma L. , Macharouthu Ajay , Macrae Victoria , Murphy-Ackroyd Emily , Rose Emily C. , Watt Nicola , Blair Mairi , Mackenzie Eilidh R. , McCormack Roisin , Irwin Sophie J. , Einarsson Alice , Khor Ming , Alhadadi Baraa , Cameron Ewen , Campbell Angela , Capek Eileen , Christie Lorna , Connell Laura , Cook Alan , Deosaran Jordanna , Elliott Marianne , Evans Elizabeth , Fancourt Sarah , Henderson Sarah , Hussain Ambreen , Jones Karen , Kelly Dominic , McErlean Catherine M. , Miller Hazel , Naeem Fariha , Ostrowski Caroline , Parkinson Megan , Sami Fadi , Shepherd Alison , Whyte Lindsay , Wright Emily , Ferguson Eilidh E. C. , Gallagher Michael , McCluskey Heather J. , Beveridge Louise , Clements Hollie A. , Hart Jasmine , Henderson Neil , Lim Su Kwan , Lucocq James E. , McCulloch Alison , Murray Adam A. , Ngan Esther E. Y. , Traill Philippa K. , Walter Amy , Wilson Michael S. J. , Wrathall Abigail , Yap Zhi Jiun , Anderson Clementine , Abu-Arafeh Hashem , Gluck Ilan , Mitchell Oliver , Robson Richard , Sampson Elizabeth L. , Annamalai Arunkumar , Bhatti Jamal , Briggs Laura , Fraser Debbie , Gui Jonathan , Leah Eleanor , Matthews Natasha R. , Mithrakumar Pryankaran , Moad Mohammad , Sen Michael , Straughan Jacqui , Taranu Roxana , Usmani Kasim , Aamir Ayesha , Achara Amaka , Akintade Olugbenro , Ellis Elizabeth J. , Gurung Sneha , Iwu Chioma , Khalid Abdullah B. , Koshedo Sejlo , Nagumantry Shonit , Nashed Nader , Nwabufor Philip , Obi Ijeoma T. , Visvaratnam Parrthiepan , Wu Edward , Bertagne Marc , Jackson Peter , Allen James , Brown Harriet , Champion Jennifer , Christodoulides Natasha , Handley Olivia , Macdonald Fiona E. , Beeley Laura J. , Clayton Victoria , Kay Aaron , Marshall John , Morgan Hannah , Naish George , Cleaver Sarah L. , Evans Jenny , Morrow Abbie , Amarnani Raj , Cheah Khai L. , Cushen Claire , Enfield-Bance Amy , Glasser Martin , Govindji Suriti , Mani Shama , Gregory Jemma , Jatti Puja , Khan Asma , Lee Helena , Millner Helen , Naqvi Huma , Williamson Emily , Harkin Teresa , Khizar Bushra , Lewis Anna , Pendleton Hannah , Rutter Steve , Ahmed Rohan , Coffey Farah , Hackett Beth , Holmes Elizabeth A. M. , Khan Ali , Mustafa Zeeshan , Bowman Mark A. , Irvine James , Patterson Katherine , Horner Sarah , Wong Ting W. , Cairns Christopher , Foster Kate , Hornsby Alex , Horton Robbie , Jones Laura , King Rachel , Lyon Emily , Tencheva Ani , Wilson Faye , Young Lesley J. , Dama Sindhoora , Giblin Eleanor , Kunaselan Lleika , Lowes Olivia , Menezes Reema , Taylor Abigail , Timperley Alex , Batho Rachel , Bell Charlotte , Carter Sammy , Croft Paul , Griffiths Eliza , Hall Giles , Hunt William , Jacques Holly , Leishman Felicity , Murthy Seema , Quinn Sinead , Reidm James , Walker Amy , Matthews Stephanie A. , Behbahani Ayoub , Glasser Martin , Ferreira Ana Silva , Ashton Caroline , Byravan Swetha , Cummings Laura , Faruq Sana , Jagdeo Sarah , Thomas Philip , Broadhurst Karen , Wilson Joseph B. , Bowden Helen , Hoffman Katrin , Jones Howell T. , Katz-Summercorn Charles , Khambay Ethan , Porter Lucy , Speed James , Austin Keziah , Bahsoon Farrah , Laud Rose , Ali Jawad , Fergusson Niall , Wilkes Claire , Babb Laura , Gaywood James , Green Jessica , Kantczak Ada , Madden Katy F. , Porter-Bent Sasha , San Moe Su Su , Babar Laxmi , Chamberlain Helen , Cricklow Tamsin , Giles Alexis , Gupta Abhishek , Hughes Clare , Lee Tammy , Cheema Anum , Matheswaran Yathu , Nneamaka Asiodu , Ross Anekea , Vedutla Tarunya , Allain Theresa J. , Bowen Emily , Dovey Julie , Gaskell Natalie , Scott Deborah , Stratton Emma , Thake Miriam , Bullock Stuart , McKay Siobhan , Radoja Stephanie , Abdelbadiee Sherif , Cohen Samuel , Giddings Jane , Miller Christopher J. , Mumtaz Emma , Patel Minal D. , Prasad Vishnu , Satharasinghe Lahiru , Studley Mark , Browne Marylin , Durrant Sabrina K. , Jay Emma , McQuillan Alex , Offer Megan , Varghese Jessel , Baron Alexander , Chourot Christian , Jackson Peter , Kirrane Kimberley , Rayner Helen , Tantam Kate , Tumi Ebrahiem , Venkat Shabnam , Aggarwal Nisha , Astaire Emma , Basker Karthik , Berwick L. , Bilton Edward , Chamboult Aimee-Louise , Chapman George , Chevolleau Jasmine , Fenneley Grace , House Shannelle , Ingamells Nathan , Jewell Emilia , Kalyaani Vickneswaran , Kiani Mahum , Konda Nagarjun , Kumar Anusha , Lai Jo , Large Jamie , Livesey Joanna , Majid Zeinab , McCready Jack , Moorey Hannah , Morgan Bethan , Morrison Kirty , Mosley Alice , Pailing Adam , Pettler Sophie , Rashid Shayan , Rimmer Lucy , Scarlett Danielle , Sehmbi Gurpreet , Smith Abigail , Smith Nina , Sprosen Charles , Taylor Emily , Taylor Jemima , Tse Connie , Turton Sophie , Vardon Henry , Virk Jasmine , Warwicker Sarah , Woodman Hannah , Woodward Beth L. , Wynne Luke , Yule Ollie , Ahmad Asim , Appiah-Odame Paapa , Barlow Ciaran , Kuek Dorothy K. C. , Nicholls Isabelle , Norman Emma , Pyc Wioletta , Vasudev Ashish , Adams Lawrence A. T. , Box Emma , Chai Chung Sien , Wilson Darcy S. , Drozdowska Bogna , Elliott Emma , Stirling Adam , Taylor-Rowan Martin , Webb Hannah , Wong Li , Abras Ahmed , Adam Muhammad , Amin Zarah , Cooper Olivia , Davies Rhianna , Ikhwan Wan Idoracaera C. , Layton Georgia R. , Mohammedseid-Nurhussien Awolkhier , Shakeel Sohail , Waraich Hana , Ahmed Jabed , Ball Katie , Debrah Kwasi , Page Valerie , Bei Zhao Xiao , McCauley Hannah , McShane David , Cooper Freya , Grundmann Natalie , Haley Michael , Le Poideven Andre , McClelland Sarah B. , Moore Emily , Pang Norman , Currie Hannah , Davies-Morris Jayne , Edwards Sarah , Janagal Sureena , Jenkin Rodric , Jones Polly , Kumbun Gary , Parry Sarah , Tyagi Bhavyas , Valentine Janine , Abdullah Saad , Abu Emmy , Ahmad Sarah , Ahmed Bilquis , Ahmed Hamza , Andrusca Ana , Ansell Matthew , Arkle Thomas , Bargaoanu Imola , Chuter Charlotte , Houldershaw Katie , Ibanichuka Jacqueline , Iqbal Shoaib , Kabia Angela , Kadir Ismail , Krishan Anjli , McClean Adam , McGonigal Gerry , Mishra Pranav , Ofoche Gladys , Reay Anna , Stapley Simon M. , Swietoslawski Adam , Syed Nihaad , Velusamy Karthika , Wahballa Afnan , Wilcockson James 
Published: January 2023

Abstract
Purpose
Delirium is a neuropsychiatric disorder delineated by an acute change in cognition, attention, and consciousness. It is common, particularly in older adults, but poorly recognised. Frailty is the accumulation of deficits conferring an increased risk of adverse outcomes. We set out to determine how severity of frailty, as measured using the CFS, affected delirium rates, and recognition in hospitalised older people in the United Kingdom.

Methods
Adults over 65 years were included in an observational multi-centre audit across UK hospitals, two prospective rounds, and one retrospective note review. Clinical Frailty Scale (CFS), delirium status, and 30-day outcomes were recorded.

Results
The overall prevalence of delirium was 16.3% (483). Patients with delirium were more frail than patients without delirium (median CFS 6 vs 4). The risk of delirium was greater with increasing frailty [OR 2.9 (1.8–4.6) in CFS 4 vs 1–3; OR 12.4 (6.2–24.5) in CFS 8 vs 1–3]. Higher CFS was associated with reduced recognition of delirium (OR of 0.7 (0.3–1.9) in CFS 4 compared to 0.2 (0.1–0.7) in CFS 8). These risks were both independent of age and dementia.

Conclusion
We have demonstrated an incremental increase in risk of delirium with increasing frailty. This has important clinical implications, suggesting that frailty may provide a more nuanced measure of vulnerability to delirium and poor outcomes. However, the most frail patients are least likely to have their delirium diagnosed and there is a significant lack of research into the underlying pathophysiology of both of these common geriatric syndromes.