UK PICOS
United Kingdom Paediatric
Intensive Care Outcome Study
Outcomes at 6 months post-admission to paediatric intensive
care: report of a national study of paediatric intensive care
units in the United Kingdom
Contact details: sam.jones@sheffield.ac.uk
1
S Jones*, K Rantell*, K Stevens*,
K Rowan#, C McCabe*, GJ Parry*
*University of Sheffield, #ICNARC
2
What is UK PICOS?
 A nationwide multi-centre study funded by the MRC
in 2001 to undertake a comprehensive study of the
outcomes (mortality and morbidity) of children
receiving paediatric intensive care in the United
Kingdom
 The aim was to measure the health status of children
using the Health Utilities Index (HUI2), 6 months
after admission to a paediatric intensive care unit
(PICU) and to assess the relationship between this
and measures of illness severity at admission
3
Study participants
 Twenty nine PICUs identified in
the UK
 Twenty three PICUs participated
 One year data collection period
 Over 12,000 admissions
4
Data collected
 Admission data, including medical history, reason for
admission and illness severity as measured by PIM,
PRISM & PRISM III
 PICU outcome (died/survived)
 Hospital outcome (died/survived)
 Health status at 6 months as measured by HUI2
PIM:
PRISM:
Paediatric Index of Mortality
Paediatric Risk of Mortality
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Health Utilities Index (HUI2)
 A parent/guardian completed 15 item questionnaire
providing measures on six dimensions of health:
– Sensation (sight, hearing and speech)
– Mobility (ability to move around without help)
– Emotion (anxious or suffering from nightmares)
– Cognition (ability to learn and remember)
– Self-care (ability to wash, dress and bathe)
– Pain (extent to which pain interferes with usual activities)
6
Children included
 All children who survived to PICU discharge were
eligible (n = 10,533, 6% unit mortality)
 Consent was obtained from 3842 admissions, of which
3042 survived to 6 months
 HUI2 questionnaires sent to 2895 and returned from
2044
 Uncertainty of the validity of HUI2 in children <1 year
of age led to their exclusion from this analysis
 Final sample included 1246 children
7
Characteristics of children with HUI2 data
 54% male
 54% unplanned admissions
 61% received mechanical ventilation
 Median (quartiles) age at admission was 5.4 (2.1, 10.3)
years
 Median (quartiles) length of stay was 1.2 (0.8, 3.0) days
Characteristics were similar for those who survived PICU, those who consented,
those who returned a HUI2 and those who did not return a HUI2, e.g. the
probability of mortality as measured using PIM was 0.026, 0.027, 0.025 & 0.026
respectively.
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Risk adjustment models
 Used ordinal logistic regression models with a
proportional odds assumption
 Each dimension of the HUI2 was used as an
outcome
 Explanatory variables: probability of mortality as
calculated using PIM, PRISM and PRISM III
 Used the index of concordance (c-index) to assess
model discriminatory power (analogous to the ROC
area in binary outcomes)
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HUI2 Sensation
0.08
Prob. of mortality
80
60
% 40
20
0.06
PIM
PRISM
0.04
PRISM III
0.02
0
1
2
3
4
0
1
Sensation level
2
3
4
Sensation level
C-index
Regression P-value
PIM
0.56
<0.001
PRISM
0.53
0.030
PRISM III
0.51
0.215
10
HUI2 Mobility
0.1
Prob. of mortality
80
60
% 40
20
0
1
2
3
4
5
0.08
PIM
0.06
PRISM
PRISM III
0.04
0.02
0
1
Mobility level
2
3
4
5
Mobility level
C-index
Regression P-value
PIM
0.58
<0.001
PRISM
0.53
0.491
PRISM III
0.55
0.004
11
HUI2 Emotion
Prob. of mortality
80
60
% 40
20
0
1
2
3
4
Emotion level
5
0.16
0.14
0.12
0.1
PIM
PRISM
0.08
0.06
0.04
PRISM III
0.02
0
1
2
3
4
5
Emotion level
C-index
Regression P-value
PIM
0.53
0.003
PRISM
0.52
0.368
PRISM III
0.54
0.034
12
HUI2 Cognition
0.08
Prob. of mortality
80
60
% 40
20
0.06
PIM
PRISM
0.04
PRISM III
0.02
0
1
2
3
4
0
1
Cognition level
2
3
4
Cognition level
C-index
Regression P-value
PIM
0.55
<0.001
PRISM
0.50
0.366
PRISM III
0.52
0.254
13
HUI2 Self-care
0.1
Prob. of mortality
80
60
% 40
20
0.08
PIM
0.06
PRISM
PRISM III
0.04
0.02
0
1
2
3
Self-care level
4
0
1
2
3
4
Self-care level
C-index
Regression P-value
PIM
0.57
<0.001
PRISM
0.50
0.433
PRISM III
0.52
0.302
14
HUI2 Pain
0.08
Prob. of mortality
80
60
% 40
20
0.06
PIM
PRISM
0.04
PRISM III
0.02
0
1
2
3
4
5
0
1
Pain level
2
3
4
5
Pain level
C-index
Regression P-value
PIM
0.52
0.007
PRISM
0.50
0.841
PRISM III
0.54
0.026
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Summary of results
 Overall, 28% of children were in full health 6 months
post admission to paediatric intensive care
 PIM is associated with all HUI2 dimensions but has
limited discriminatory power
 PRISM and PRISM III are associated with some
dimensions but also have limited discriminatory
power
 Additional potential explanatory variables are
needed to develop adequate risk adjustments models
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Conclusions
 Mortality following paediatric intensive care is
currently around 6% in the UK
 In determining the quality and performance of
PICUs, it is important to take into account
variations in the health status of survivors post
discharge
 Morbidity appears to be related to initial illness
severity, however this information alone is
insufficient to predict long term outcomes
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Conclusions
 In attempting to develop policies to improve
longer-term outcomes of children post paediatric
intensive care, it may be important to also take
into account factors such as co-morbidities,
socioeconomic status and the quality of care
received by children following discharge from
intensive care
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