The effect of secular trends and specialist neurocritical care on mortality for patients with Intracerebral Haemorrhage, Myasthenia Gravis, and Guillain-Barré syndrome admitted to critical care
An analysis of the Intensive Care National Audit & Research Centre (ICNARC) national United Kingdom database
– Supplement Document
Maxwell Damian 1, Yoav Ben-Shlomo 2, Robin Howard 3, Tony Bellotti 4, David Harrison 4, Kathryn Griggs 4, Kathryn Rowan 4.
1 Neurosciences Critical Care Unit and Department of Neurology, Addenbrooke’s Hospital, Cambridge CB2 0QQ and Ipswich Hospital, Ipswich IP5 4PD
2 School of Social and Community Medicine, University of Bristol, Bristol BS8 2PS
3 The National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG and St. Thomas’ Hospital, London SE1 7EH
4 ICNARC, Tavistock House, Tavistock Square, London WC1H 9HR
Table S1. Descriptive statistics for admissions with Myasthenia Gravis by unit group.
NCCU / GICU-FNS / GICU-LNS / AllNumber of admissions / 254 / 308 / 502 / 1,064
Number women (%) / 141 (55.5) / 159 (51.6) / 286 (57.0) / 586 (55.1)
Age, mean (sd) / 62.7 (18.1) / 63.5 (17.3) / 63.0 (20.1) / 63.1 (18.8)
IMD quintile, n (%):
1 (least deprived) / 52 (20.5) / 46 (14.9) / 91 (18.1) / 189 (17.8)
2 / 29 (11.4) / 46 (14.9) / 110 (21.9) / 185 (17.4)
3 / 58 (22.8) / 67 (21.8) / 108 (21.5) / 233 (21.9)
4 / 58 (22.8) / 70 (22.7) / 104 (20.7) / 232 (21.8)
5 (most deprived) / 44 (17.3) / 61 (19.8) / 64 (12.8) / 169 (15.9)
ICNARC score, mean (sd) / 16.1 (7.5) / 15.7 (8.9) / 15.6 (8.1) / 15.8 (8.2)
Lowest Glasgow coma score in first 24 hours *, mean (sd) / 12.4 (3.9) / 13.5 (3.3) / 13.6 (3.2) / 13.3 (3.4)
Number of admissions with 1 or more severe comorbidities,
n (%) / 53 (20.9) / 91 (29.6) / 111 (22.1) / 255 (24.0)
Ventilated in the first 24 hours, n (%) / 167 (65.8) / 177 (57.5) / 314 (62.6) / 658 (61.8)
Source of admission, n (%):
Same hospital: / 221 (87.0) / 265 (86.0) / 430 (85.7) / 916 (86.1)
Other hospital / 33 (13.0) / 43 (14.0) / 72 (14.3) / 148 (13.9)
Admission type, n (%)
Non-surgical (medical) / 245 (96.5) / 281 (91.2) / 466 (92.8) / 992 (93.2)
Emergency surgical / 9 (3.5) / 27 (8.8) / 36 (7.2) / 72 (6.8)
Transferred to other ICU **, n (%) / 14 (6.1) / 37 (13.0) / 56 (12.3) / 107 (11.0)
CCU length of stay
median [IQR]; geometric mean / 6.7 [2.6, 13.5]
6.2 / 3.4 [1.3, 9.0]
3.3 / 4.4 [1.5, 10.2]
3.7 / 4.6 [1.7, 10.8]
4.0
Acute hospital length of stay ***
median [IQR]; geometric mean / 38 [21, 75]
36.3 / 29 [16, 53]
28.5 / 26 [11, 49] 22.5 / 29 [14, 55]
27.0
CCU mortality ***,
n (%) [95%CI] / 22 (9.8)
[6.6, 14.4] / 19 (7.0)
[4.5, 10.6] / 41 (9.2)
[6.9, 12.3] / 82 (8.7)
[7.1 – 10.7]
Acute hospital mortality ***,
n (%) [95%CI] / 41 (19.3)
[14.6, 25.2] / 60 (22.8)
[18.2, 28.3] / 97 (22.8)
[19.0, 27.0] / 198 (22.0)
[19.4 – 24.8]
For readmissions within the same acute hospital stay CCU mortality is calculated as 1 episode.
* Excluding admissions that were sedated or paralysed during the first 24 hours
** Percentage of unit survivors
*** Excluding readmissions to the critical care unit during the hospital stay
GICU-FNS: General ICU with full-time neurological support. GICU-LNS: General ICU with limited neurological support.
Table S2. Descriptive statistics for admissions with Guillain-Barré syndrome by unit group.
NCCU / GICU-FNS / GICU-LNS / AllNumber of admissions / 372 / 487 / 1,047 / 1,906
Number women (%) / 155 (41.7) / 218 (44.8) / 476 (45.5) / 849 (44.5)
Age, mean (sd) / 57.0 (18.1) / 56.1 (18.4) / 56.8 (18.4) / 56.7 (18.3)
IMD quintile, n (%):
1 (least deprived) / 71 (19.1) / 69 (14.2) / 199 (19.0) / 339 (17.8)
2 / 50 (13.4) / 89 (18.3) / 203 (19.4) / 342 (17.9)
3 / 84 (22.6) / 95 (19.5) / 206 (19.7) / 385 (20.2)
4 / 68 (18.3) / 118 (24.2) / 224 (21.4) / 410 (21.5)
5 (most deprived) / 85 (22.9) / 91 (18.7) / 162 (15.5) / 338 (17.7)
ICNARC score, mean (sd) / 15.5 (7.9) / 14.6 (7.6) / 13.7 (7.5) / 14.3 (7.6)
Lowest Glasgow coma score in first 24 hours *, mean (sd) / 12.1 (4.2) / 13.5 (3.2) / 13.9 (2.6) / 13.4 (3.2)
Number of admissions with 1 or more severe comorbidities,
n (%) / 21 (5.7) / 47 (9.7) / 53 (5.1) / 121 (6.4)
Ventilated in the first 24 hours, n (%) / 245 (65.9) / 295 (60.6) / 574 (54.8) / 1,114 (58.5)
Source of admission, n (%):
Same hospital: / 296 (79.6) / 388 (79.7) / 820 (78.3) / 1,504 (78.9)
Other hospital / 75 (20.2) / 98 (20.1) / 226 (21.6) / 399 (20.9)
Admission type, n (%)
Non-surgical (medical) / 366 (98.4) / 480 (98.6) / 1,035 (98.9) / 1,881 (98.7)
Elective surgical / 2 (0.5) / 4 (0.8) / 6 (0.6) / 12 (0.6)
Emergency surgical / 4 (1.1) / 2 (0.4) / 6 (0.6) / 12 (0.6)
Transferred to other ICU **, n (%) / 72 (20.6) / 108 (24.1) / 146 (15.2) / 326 (18.5)
CCU length of stay (days)
median [IQR]; geometric mean / 10.2 [3.8, 24.4]
8.7 / 7.9 [2.8, 23.1]
7.3 / 7.0 [2.4, 21.7]
6.6 / 8.0 [2.7, 22.8]
7.2
Acute hospital length of stay (days) ***,
median [IQR]; geometric mean / 63 [34, 101]
56.4 / 55 [26, 109]
50.9 / 45 [21, 94]
42.4 / 52 [24 – 99]
46.9
CCU mortality ***,
n (%) [95%CI] / 19 (5.7)
[3.6, 8.7] / 34 (7.7)
[5.5, 10.5] / 82 (8.4)
[6.8, 10.4] / 135 (7.7)
[6.5, 9.0]
Acute hospital mortality ***,
n (%) [95%CI] / 44 (14.6)
[11.0, 19.0] / 75 (18.5)
[15.0, 22.5] / 151 (16.7)
[14.4, 19.3] / 270 (16.8)
[15.0, 18.7]
For readmissions within the same acute hospital stay CCU mortality is calculated as 1 episode.
* Excluding admissions that were sedated or paralysed during the first 24 hours
** Percentage of unit survivors
*** Excluding readmissions to the critical care unit during the hospital stay
GICU-FNS: General ICU with full-time neurological support. GICU-LNS: General ICU with limited neurological support.
Table S3. Descriptive statistics for admissions with Intracerebral Haemorrhage by unit group.
NCCU / GICU-FNS / GICU-LNS / AllNumber of admissions / 3,753 / 1,808 / 4,752 / 10,313
Number women (%) / 1,555 (41.4) / 733 (40.5) / 1,913 (40.3) / 4,201 (40.7)
Age, mean (sd) / 53.7 (15.3) / 55.7 (16.7) / 56.2 (16.4) / 55.2 (16.1)
IMD quintile, n (%):
1 (least deprived) / 507 (13.5) / 269 (14.9) / 723 (15.2) / 1,499 (14.5)
2 / 645 (17.2) / 292 (16.2) / 785 (16.5) / 1,722 (16.7)
3 / 686 (18.3) / 355 (19.6) / 874 (18.4) / 1,915 (18.6)
4 / 745 (19.9) / 355 (19.6) / 897 (18.9) / 1,997 (19.4)
5 (most deprived) / 940 (25.1) / 411 (22.7) / 1,142 (24.0) / 2,493 (24.2)
ICNARC score, mean (sd) / 17.8 (7.6) / 20.7 (9.3) / 20.4 (9.0) / 19.5 (8.6)
Lowest Glasgow coma score in first 24 hours *, mean (sd) / 6.6 (4.0) / 6.0 (4.1) / 5.7 (4.1) / 6.1 (4.1)
Number of admissions with 1 or more severe comorbidities,
n (%) / 251 (6.7) / 154 (8.5) / 282 (5.9) / 687 (6.7)
Ventilated in the first 24 hours, n (%) / 3,328 (88.7) / 1,611 (89.1) / 4,206 (88.5) / 9,145 (88.7)
Source of admission, n (%):
Same hospital: / 2,435 (64.9) / 1,545 (85.5) / 4,120 (86.7) / 8,100 (78.5)
Other hospital / 1,310 (34.9) / 261 (14.4) / 617 (13.0) / 2,188 (21.2)
Admission type, n(%)
Non-surgical (medical) / 2,297 (61.2) / 1,685 (93.2) / 4,605 (96.9) / 8,587 (83.3)
Elective surgical / 120 (3.2) / 19 (1.1) / 25 (0.5) / 164 (1.6)
Emergency surgical / 1,335 (35.6) / 104 (5.8) / 118 (2.5) / 1,557 (15.1)
Transferred to other ICU **, n (%) / 121 (4.8) / 302 (31.0) / 733 (29.9) / 1,156 (19.4)
CCU length of stay (days)
median [IQR]; geometric mean / 3.8 [1.5, 9.0]
3.5 / 1.3 [0.5, 3.5]
1.2 / 1.2 [0.5, 3.2]
1.1 / 1.8 [0.7, 5.2]
1.7
Acute hospital length of stay (days) ***,
median [IQR]; geometric mean / 18 [5, 45]
15.9 / 6 [1, 28]
8.3 / 4 [1, 22]
7.0 / 9 [2, 33]
9.8
CCU mortality ***,
n (%) [95%CI] / 1,192 (32.6)
[31.1, 34.1] / 830 (46.3)
[44.0, 48.7] / 2,288 (48.4)
[47.0, 49.8] / 4,310 (42.4)
[41.4 – 43.3]
Acute hospital mortality ***,
n (%) [95%CI] / 1,694 (49.5)
[47.8, 51.1] / 1,182 (67.9)
[65.6, 70.0] / 3,155 (69.5)
[68.2, 70.8] / 6,031 (62.1)
[61.2, 63.1]
For readmissions within the same acute hospital stay CCU mortality is calculated as 1 episode.
* Excluding admissions that were sedated or paralysed during the first 24 hours
** Percentage of unit survivors
*** Excluding readmissions to the critical care unit during the hospital stay
GICU-FNS: General ICU with full-time neurological support. GICU-LNS: General ICU with limited neurological support.
Table S4. Multi-level models of acute hospital mortality for patients with MG
Model 1OR (p-value)
[95% CI] / Model 2
OR (p-value)
[95% CI]
Sample size / 852 – 901 / 852
Covariates:
Unit type (p-value) / (0.59); (0.34)2 / (0.49); (0.77)2
NCCU ¹ / 1 / 1
GICU-FNS / 1.25 [0.73, 2.13] / 1.26 [0.76, 2.09]
GICU-LNS / 1.29 [0.79, 2.12] / 0.98 [0.61, 1.57]
Age (per 10 years) / 1.71 (<0.001) [1.50, 1.96] / 1.76 (<0.001) [1.51, 2.06]
Sex (p-value) / (0.45) / (0.02)
Male / 0.88 [0.63, 1.22] / 0.64 [0.44, 0.93]
Female¹ / 1 / 1
IMD score (p-value) / (0.41) / (0.60)
Quintile 1 ¹ / 1 / 1
Quintile 2 / 1.37 [0.81, 2.32] / 1.40 [0.79, 2.48]
Quintile 3 / 0.98 [0.58, 1.65] / 0.94 [0.53, 1.66]
Quintile 4 / 0.81 [0.47, 1.41] / 1.14 [0.63, 2.06]
Quintile 5 / 1.03 [0.59, 1.79] / 1.31 [0.71, 2.43]
ICNARC score (per point) / 1.10 (<0.001) [1.07, 1.12] / 1.09 (<0.001) [1.07, 1.12]
No. comorbidities (p-value) / (0.68) / (0.031)
0¹ / 1 / 1
1 / 0.98 [0.65, 1.47] / 1.28 [0.82, 2.00]
2 / 1.64 [0.74, 3.64] / 4.25 [1.59, 11.38]
3+ / 0.00 [-] / 0.00 [-]
Source of admission (p-value) / (0.04) / (0.07)
Same hospital / 0.63 [0.41, 0.97] / 0.63 [0.38, 1.03]
Other hospital ¹ / 1 / 1
Surgical status (p-value) / (0.26) / (0.50)
Non-surgical (medical)¹ / 1 / 1
Emergency surgical / 0.68 [0.34, 1.34] / 0.76 [0.35, 1.67]
Calendar period (per year) / 0.96 (0.15) [0.92, 1.01] / 0.96 (0.19) [0.91, 1.02]
Unit length of stay (p-value) / (0.23) / -
Quintile 1(<1 day) / 0.81 [0.49, 1.33] / -
Quintile 2 (1 day) / 0.93 [0.52, 1.65] / -
Quintile 3 ¹ (2 days) / 1 / -
Quintile 4 (3-6 days) / 1.16 [0.67, 1.99] / -
Quintile 5 (≥7 days) / 1.38 [0.81, 2.32] / -
Within-unit rho 2 / - / 0.00 (0.50)
Model 1= each variable alone with no adjustment; Model 2= mutually adjusted for all variables
¹ Reference categories
2 p-values for test of heterogeneity and test for trend, respectively
GICU-FNS: General ICU with full-time neurological support; GICU-LNS: General ICU with limited neurological support
Table S5. Multi-level models of acute hospital mortality for patients with GBS
Model 1OR (p-value)
[95% CI] / Model 2
OR (p-value)
[95% CI]
Sample size / 1,535 – 1,611 / 1,532
Covariates:
Unit type (p-value) / (0.39); (0.59)2 / (0.32); (0.53)2
NCCU ¹ / 1 / 1
GICU-FNS / 1.33 [0.88, 1.99] / 1.44 [0.90, 2.30]
GICU-LNS / 1.18 [0.82, 1.69] / 1.23 [0.81, 1.87]
Age (per 10 years) / 1.90 (<0.001) [1.70, 2.13] / 1.88 (<0.001) [1.66, 2.14]
Sex (p-value) / (0.67) / (0.75)
Male / 1.06 [0.81, 1.38] / 0.95 [0.70, 1.30]
Female¹ / 1 / 1
IMD score (p-value) / (0.72) / (0.93)
Quintile 1 ¹ / 1 / 1
Quintile 2 / 1.11 [0.72, 1.71] / 1.06 [0.65, 1.75]
Quintile 3 / 0.94 [0.61, 1.45] / 1.05 [0.64, 1.72]
Quintile 4 / 1.14 [0.76, 1.73] / 1.23 [0.76, 1.99]
Quintile 5 / 0.88 [0.56, 1.39] / 1.11 [0.66, 1.89]
ICNARC score (per point) / 1.12 (<0.001) [1.10, 1.14] / 1.09 (<0.001) [1.07, 1.12]
No. comorbidities (p-value) / (<0.001) / (<0.001)
0¹ / 1 / 1
1 / 2.52 [1.51, 4.21] / 1.88 [1.02, 3.44]
2 / 9.08 [3.72, 22.16] / 27.41 [8.28, 90.75]
3+ / 13.97 [2.69, 72.46] / 48.89 [6.83, 349.84]
Source of admission (p-value) / (0.76) / (0.77)
Same hospital / 0.95 [0.69, 1.30] / 0.95 [0.65, 1.38]
Other hospital ¹ / 1 / 1
Surgical status (p-value) / (0.34) / (0.53)
Non-surgical (medical)¹ / 1 / 1
Elective surgical3 / - / -
Emergency surgical / 2.48 [0.74, 8.31] / 2.09 [0.57, 7.62]
Calendar period (per year) / 0.98 (0.22) [0.94, 1.01] / 1.00 (0.83) [0.95, 1.04]
Unit length of stay (p-value) / (0.43) / -
Quintile 1(<1 day) / 0.86 [0.57, 1.31] / -
Quintile 2 (1 day) / 0.80 [0.53, 1.21] / -
Quintile 3 ¹ (2 days) / 1 / -
Quintile 4 (3-6 days) / 0.78 [0.50, 1.21] / -
Quintile 5 (≥7 days) / 1.09 [0.72, 1.64] / -
Within-unit rho 2 / - / 0.00 (0.50)
Model 1= each variable alone with no adjustment; Model 2= mutually adjusted for all variables
¹ Reference categories
2 p-values for test of heterogeneity and test for trend, respectively
3 Excluded from model due to small numbers
GICU-FNS: General ICU with full-time neurological support; GICU-LNS: General ICU with limited neurological support
Adjusting for length of stay had little effect on associations with unit type (NCCU 1, GICU-FNS 1.46 [0.91, 2.35], GICU-LNS 1.22 [0.80, 1.86], p value for trend 0.58)