1. ICNARC Case Mix Programme for Cardiothoracic Intensive Care Units
Stephen T Webb
Papworth Hospital

2. Declarations of interest
CIA Linkman for ICNARC
Co-applicant on current NIHR Health Service & Delivery Research grant application with ICNARC
‘Friend of ICNARC’ offered free delegate registration at the CMP Annual Meeting in London
No financial declarations of interest

3. Outline ICNARC Case Mix Programme The ICNARC (risk prediction) Model
ARCtIC - Assessment of Risk in Cardiothoracic Intensive Care
Risk prediction models for cardiothoracic ICUs
What could your unit get out of the ICNARC CMP?
How could your unit’s ICNARC CMP data be used?
Future developments

4. A question…
How do you know your cardiothoracic ICU is providing ‘high quality care for all, now and for future generations’?

5. A question for your cardiothoracic ICU…?
How do you know your cardiothoracic ICU is providing ‘high quality care for all, now and for future generations’?
Structures - operational policies, staffing and equipment e.g. FICM Core Standards for ICUs, National Cardiac Benchmarking Collaborative (NCBC)
Processes - local procedures and guidance e.g. NICE Quality Standards, CIA Quality Standards
Outcomes - clinical outcomes e.g. National Clinical Audit

6. Faculty of Intensive Care Medicine
Core Standards for Intensive Care Units 2013
4.2 The Intensive Care Unit should participate in a national database for adult critical care
ICUs must publish the nationally agreed dashboard, including the standardised mortality rate

7. Intensive Care National Audit & Research Centre (ICNARC) - Case Mix Programme (CMP)
Comparative audit of patient outcomes from adult critical care units in NHS and independent hospitals in England, Wales & Northern Ireland
Recognised national clinical audit by the National Advisory Group for Clinical Audit & Enquiries (NAGCAE), accepted by the Department of Health Quality Accounts
95% of adult general ICUs/HDUs participate as well as specialist neurosciences and cardiothoracic units
Launched 1994, 1.5 million admissions
Scotland - Scottish Intensive Care Society Audit Group (SICSAG) Database

8. Risk models for comparative clinical audit
Risk models are needed to make ‘fair comparisons’ - taking into account differences in patient characteristics that would be expected to result in differences in outcomes
The probability of mortality is calculated for each patient using the risk prediction model
The probability of mortality for each patient in a group of patients is summed to calculate the ‘expected’ number of deaths
The ‘expected’ number of deaths can then be compared to the ‘observed’ (actual) number of deaths

9. The ICNARC Model - risk factors
Age
CPR within 24 hours prior to admission
Source of admission and surgical urgency
Reason for admission
ICNARC Physiology Score - weightings for derangements in 12 physiological variables
Interactions between reason for admission and physiological variables
An interaction refers to the variation of one variable according to the value of another
Different relationship between physiological variables and acute hospital mortality in certain reasons for admission

10. The ICNARC Model - repeated recalibration of the model over time

11. The ICNARC Model - acute hospital mortality in a single unit over time - EWMA chart

12. The ICNARC Model - acute hospital mortality ratio compared with other units - funnel plot

13. Cardiothoracic ICUs v General ICUs - what’s the difference?
Case mix of most cardiothoracic ICUs is predominantly cardiac surgery patients (although there may be changes over time - cardiology, transplant, ECMO)
Higher number of admissions, shorter length of stay, lower mortality
Cardiac surgery patients were specifically excluded from most risk models (APACHE II, SAPS II)
The ICNARC Model was developed and validated using data from adult general ICUs only
Cardiopulmonary bypass transiently affects postoperative physiological variables
Deranged physiological variables may be masked by supportive therapy (MV, RRT, PMs, IABPs, ECMO, VADs…)

14. ARCtIC - Assessment of Risk in Cardiothoracic Intensive Care
Group of intensivists interested in outcome measurement in cardiothoracic ICUs
Led by ACTA - CIA (Cardiothoracic Intensivists in ACTA)
Hosted by ICNARC
Supported by other professional societies - SCTS, BCIS
Developing potential for data linkage with other national clinical audits hosted by National Institute for Cardiovascular Outcomes Research (NICOR)
National Adult Cardiac Surgery Audit (NACSA)
National Audit of Percutaneous Coronary Intervention (NAPCI)

15. Systematic review - risk prediction models for acute hospital mortality in cardiothoracic ICUs
Systematic electronic search, 8929 citations identified, 12 met inclusion criteria
Variable objectives, risk factors, outcomes and definitions
Risk factor selection and risk modelling strategies not specified
Sample sizes inadequate to obtain reliable estimates
Minimal data for specific risk prediction models for cardiothoracic ICUs

16. The ICNARC Model (Cardio 2013)
Aim - recalibration of the current ICNARC Model to admissions to cardiothoracic ICUs
5 cardiothoracic ICUs participating in CMP
12303 admissions
Jan Dec 2012 (2 years)
Same risk factors in the ICNARC Model (Cardio 2013) as in the standard ICNARC Model
New coefficients were calculated for existing risk factors
New interactions between reason for admission and physiological variables

17. Specific risk prediction model for cardiothoracic ICUs
Aim - development of a specific risk prediction model for cardiothoracic ICUs
5 cardiothoracic ICUs participating in CMP
17002 admissions
Jan Dec 2012 (3 years)

18. Dataset - Patient characteristics
Age, median (iqr)
65 (58, 75)
Male, n (%)
11,736 (69.0) 
Severe co-morbidities, n (%)
Any severe co-morbidity
2,535 (14.9)
Very severe cardiovascular disease
1,470 (8.6)
Severe respiratory disease
517 (3.0)
Chronic renal replacement therapy
175 (1.0)
Chronic liver disease
44 ( 0.3)
Hematologic malignancy
95 ( 0.6)
Metastatic disease
172 (1.0)
Immunocompromise
394 (2.3)
Activities of daily living, n (%)
No assistance
13,986 (82.3)
Partial assistance
2,994 (17.6)
Total assistance
22 (0.1)
CPR prior to admission, n (%)
701 (4.1)
ICNARC Physiology Score, median (iqr)
13 (10,18)

19. Dataset - Source of admission & Reason for admission
Location prior to admission, n (%)
Theatre – elective/scheduled surgery
11,779 (69.4)
Theatre – urgent/emergency surgery
1,186 (7.0)
Ward or intermediate care
2,099 (12.4)
Other critical care unit
1,242 (7.3)
ED, other hospital or not in hospital
677 (4.0)
Primary reason for admission, n (%)
Surgical
12,970 (76.3) 
Cardiothoracic surgery
11,774 (90.8) 
Other
1,196 (9.2)
Non-surgical
 4,032 (23.7)
Cardiovascular
1,926 (47.8) 
Respiratory
 1,548 (38.4)
558 (13.8) 

20. Dataset - Length of stay & Mortality
Length of stay (days), median (iqr)
Cardiothoracic ICUs
Other units in CMP
Critical care unit stay
1 (1, 3)
2 (1,5)
Hospital stay
10 (7, 19)
12 (5,25)
Mortality, n (%)
Critical care unit mortality
1,251 (7.4)
61,472 (14.5)
Acute hospital mortality
1,881 (11.1)
92,844 (22.0)

21. Specific risk prediction model for cardiothoracic ICUs
Aim - development of a specific risk prediction model for cardiothoracic ICUs
5 cardiothoracic ICUs participating in CMP
17002 admissions
Jan Dec 2012 (3 years)
New risk factors based on admission data and physiological variables
New interactions between cardiothoracic surgery as reason for admission and physiological variables
Acceptable statistical performance

22. New risk prediction model for all units
Aim - development of a new risk prediction model which performs well for all types of adult critical care unit
232 units, including all types of unit
admissions
Jan Dec 2012 (1 year)
New approach to missing data, new statistical methods for modelling physiology, new data fields, new coding method for reason for admission, new interactions

23. New risk prediction model for all units
Aim - development of a new risk prediction model which performs well for all types of adult critical care unit
232 units, including all types of unit
admissions
Jan Dec 2012 (1 year)
New approach to missing data, new statistical methods for modelling physiology, new data fields, new coding method for reason for admission, new interactions
All types of unit - improved statistical performance compared to current ICNARC Model
Cardiothoracic ICUs - similar statistical performance compared to ICNARC Model (Cardio 2013)

24. Which risk prediction model for cardiothoracic ICUs?
Currently - ICNARC Model (Cardio 2013)
Future - specific model for cardiothoracic ICUs or new model for all types of unit?
Specific model for cardiothoracic ICUs - small number of units and relatively small number of admissions in dataset, less up-to- date dataset
New model for all types of unit - large number of units and admissions in dataset (including cardiothoracic ICUs), more up- to-date dataset, allows comparison across different types of units

25. What could your cardiothoracic unit get out of the ICNARC CMP?

26. What could your cardiothoracic unit get out of the ICNARC CMP?

27. What could your cardiothoracic unit get out of the ICNARC CMP?

28. What could your cardiothoracic unit get out of the ICNARC CMP?

29. What could your cardiothoracic unit get out of the ICNARC CMP?

30. How could your cardiothoracic ICU’s ICNARC CMP data be used?
Local reporting
National reporting
Data Analysis Report
CMP Annual Quality Report
Regional reporting
NHS England Specialised Commissioning - Adult Critical Care Quality Dashboard
Operational Delivery Network
Department of Health Quality Account
Care Quality Commission - Acute Hospital Inspections

34. Summary
ICNARC CMP is a national clinical audit which cardiothoracic ICUs can participate in
The ICNARC Model (Cardio 2013) is used for cardiothoracic ICUs in the CMP
New risk prediction models are being developed
CMP data can be used for local quality improvement, compared with other cardiothoracic ICUs and shared with other organisations
CIA and ICNARC are keen to work together in the future - your cardiothoracic ICU can get involved…

35. Acknowledgements
ICNARC: Kathy Rowan, David Harrison, Lucy Lloyd-Scott, Paloma Ferrando, Jason Shahin
Funding: NIHR Health Services & Delivery Research Programme (Project Number 09/2000/65)
ACTA & CIA: Alistair Macfie, Nick Fletcher, Ruth Hurley, Kamen Valchanov, Mahesh Prabhu, Nick Schofield
8 cardiothoracic ICUs currently participating in CMP: Newcastle, Middlesborough, Hull, Sheffield, Liverpool, Leicester, Papworth, St George’s

36. Thanks
…..Questions