J Clin Med Res

Journal of Clinical Medicine Research, ISSN 1918-3003 print, 1918-3011 online, Open Access

Article copyright, the authors; Journal compilation copyright, J Clin Med Res and Elmer Press Inc

Journal website https://jocmr.elmerjournals.com

Original Article

Volume 18, Number 3, March 2026, pages 196-204

The MAGENTA Model for Individual Prediction of In-Hospital Mortality in Chronic Obstructive Pulmonary Disease With Acute Exacerbation: An External Validation Study

↓ Figure 1. Study flow diagram of the patient cohort. AECOPD: acute exacerbation of chronic obstructive pulmonary disease; FEV1: forced expiratory volume in 1 second; FVC: forced vital capacity.

↓ Figure 2. Receiver operating characteristic curve for model discrimination of the MAGENTA model in the validation cohort. AUC: area under the curve; CI: confidence interval; ROC: receiver operating characteristic.

↓ Figure 3. Calibration plot of the MAGENTA model in the validation cohort. (a) Original model calibration showed miscalibration, with an expected-to-observed (E:O) ratio of 1.335, calibration-in-the-large (CITL) of –0.439, and slope of 0.536. (b) After recalibration of the intercept, the E:O ratio and CITL improved to 1.000 and 0.000, respectively, although the slope remained < 1, suggesting that the prediction model was overfitting. (c) After recalibration of both the intercept and slope, calibration improved further, with E:O ratio = 1.000, CITL = 0.000, and slope = 1.000, indicating good overall agreement between predicted and observed risks.

↓ **Table 1.** Characteristics of Survived and Non-Survived Admissions With AECOPD (N = 938 Admissions)
Characteristics	Missing data, n (%)	Non-survived admissions, n (%)	Survived admissions, n (%)	P value
AECOPD: acute exacerbation of chronic obstructive pulmonary disease; FEV1: forced expiratory volume in 1 second; FVC: forced vital capacity; IQR: interquartile range; SD: standard deviation.
Total		105 (11.2)	833 (88.8)
Male	0 (0)	87 (82.9)	718 (86.2)	0.370
Age, years, mean ± SD	0 (0)	76.7 ± 10.1	74.6 ± 11.4	0.072
Body mass index, kg/m², mean ± SD	121 (12.9)	12.0 ± 8.0	16.6 ± 7.4	< 0.001
Smoking status				0.110
Never smoker	22 (2.4)	19 (18.1)	109 (13.1)
Ex-smoker	22 (2.4)	64 (61.0)	580 (69.6)
Active smoker	22 (2.4)	21 (20.0)	123 (14.8)
Number of cigarettes smoked
Pack-year, median (IQR)	212 (22.6)	30.0 (10.0, 40.0)	25.0 (15.0, 40.0)	0.690
Underlying diseases
Presence (any)	0 (0)	90 (85.7)	697 (83.7)	0.670
Hypertension	0 (0)	50 (47.6)	394 (47.3)	1.000
Diabetes mellitus	0 (0)	22 (21.0)	133 (16.0)	0.210
Ischemic heart disease	0 (0)	12 (11.4)	70 (8.4)	0.280
Atrial fibrillation	0 (0)	13 (12.4)	52 (6.2)	0.038
Left ventricular dysfunction	0 (0)	1 (1.0)	10 (1.2)	1.000
Chronic kidney disease	0 (0)	14 (13.3)	102 (12.2)	0.750
Cerebrovascular disease	0 (0)	8 (7.6)	82 (9.8)	0.600
Cognitive impairment	0 (0)	3 (2.9)	15 (1.8)	0.440
COPD status
Spirometry performed, n (%)	719 (76.7)	10 (9.5)	209 (25.1)	< 0.001
FEV1/FVC ratio, mean ± SD	719 (76.7)	0.5 ± 0.1	0.5 ± 0.1	0.980
FEV1, % predicted, mean ± SD	719 (76.7)	35.4 ± 11.8	44.7 ± 17.3	0.096
FVC, % predicted, mean ± SD	719 (76.7)	53.3 ± 9.6	66.9 ± 18.2	0.021
Long-term oxygen therapy	0 (0)	3 (2.9)	32 (3.8)	0.790
Cor pulmonale	805 (85.8)	3 (2.9)	25 (3.0)	1.000
Inhaled controller medications
Presence (any)	0 (0)	76 (72.4)	614 (73.7)	0.810
Salmeterol/fluticasone	0 (0)	64 (61.0)	533 (64.0)	0.590
Formoterol/budesonide	0 (0)	1 (1.0)	21 (2.5)	0.500
Tiotropium	0 (0)	18 (17.1)	210 (25.2)	0.071
Budesonide	0 (0)	4 (3.8)	38 (4.6)	1.000
Influenza vaccination	0 (0)	5 (4.8)	56 (6.7)	0.530

↓ Table 1. Characteristics of Survived and Non-Survived Admissions With AECOPD (N = 938 Admissions)

Characteristics

Missing data, n (%)

Non-survived admissions, n (%)

Survived admissions, n (%)

P value

AECOPD: acute exacerbation of chronic obstructive pulmonary disease; FEV1: forced expiratory volume in 1 second; FVC: forced vital capacity; IQR: interquartile range; SD: standard deviation.

Total

105 (11.2)

833 (88.8)

Male

0 (0)

87 (82.9)

718 (86.2)

0.370

Age, years, mean ± SD

0 (0)

76.7 ± 10.1

74.6 ± 11.4

0.072

Body mass index, kg/m², mean ± SD

121 (12.9)

12.0 ± 8.0

16.6 ± 7.4

< 0.001

Smoking status

0.110

Never smoker

22 (2.4)

19 (18.1)

109 (13.1)

Ex-smoker

22 (2.4)

64 (61.0)

580 (69.6)

Active smoker

22 (2.4)

21 (20.0)

123 (14.8)

Number of cigarettes smoked

Pack-year, median (IQR)

212 (22.6)

30.0 (10.0, 40.0)

25.0 (15.0, 40.0)

0.690

Underlying diseases

Presence (any)

0 (0)

90 (85.7)

697 (83.7)

0.670

Hypertension

0 (0)

50 (47.6)

394 (47.3)

1.000

Diabetes mellitus

0 (0)

22 (21.0)

133 (16.0)

0.210

Ischemic heart disease

0 (0)

12 (11.4)

70 (8.4)

0.280

Atrial fibrillation

0 (0)

13 (12.4)

52 (6.2)

0.038

Left ventricular dysfunction

0 (0)

1 (1.0)

10 (1.2)

1.000

Chronic kidney disease

0 (0)

14 (13.3)

102 (12.2)

0.750

Cerebrovascular disease

0 (0)

8 (7.6)

82 (9.8)

0.600

Cognitive impairment

0 (0)

3 (2.9)

15 (1.8)

0.440

COPD status

Spirometry performed, n (%)

719 (76.7)

10 (9.5)

209 (25.1)

< 0.001

FEV1/FVC ratio, mean ± SD

719 (76.7)

0.5 ± 0.1

0.980

FEV1, % predicted, mean ± SD

719 (76.7)

35.4 ± 11.8

44.7 ± 17.3

0.096

FVC, % predicted, mean ± SD

719 (76.7)

53.3 ± 9.6

66.9 ± 18.2

0.021

Long-term oxygen therapy

0 (0)

3 (2.9)

32 (3.8)

0.790

Cor pulmonale

805 (85.8)

3 (2.9)

25 (3.0)

1.000

Inhaled controller medications

Presence (any)

0 (0)

76 (72.4)

614 (73.7)

0.810

Salmeterol/fluticasone

0 (0)

64 (61.0)

533 (64.0)

0.590

Formoterol/budesonide

0 (0)

1 (1.0)

21 (2.5)

0.500

Tiotropium

0 (0)

18 (17.1)

210 (25.2)

0.071

Budesonide

0 (0)

4 (3.8)

38 (4.6)

1.000

Influenza vaccination

0 (0)

5 (4.8)

56 (6.7)

0.530

↓ **Table 2.** Clinical Parameters During Admission of Survived and Non-Survived Admissions With AECOPD (N = 938 Admissions)
Clinical parameters	Missing data, n (%)	Non-survived admissions, n (%) (n = 105)	Survived admissions, n (%) (n = 833)	P value
AECOPD: acute exacerbation of chronic obstructive pulmonary disease; BP: blood pressure; IQR: interquartile range; SD: standard deviation; WBC: white blood cell count.
Initial vital signs
Body temperature, °C, mean ± SD	0 (0)	37.5 ± 0.9	37.4 ± 1.0	0.220
Heart rate, beats/min, mean ± SD	0 (0)	111.6 ± 30.7	111.4 ± 22.4	0.930
Systolic BP, mm Hg, mean ± SD	0 (0)	129.6 ± 35.9	142.9 ± 29.5	< 0.001
Diastolic BP, mm Hg, mean ± SD	0 (0)	76.7 ± 20.4	84.4 ± 17.3	< 0.001
Mean arterial pressure, mm Hg, mean ± SD	0 (0)	94.4 ± 24.4	103.9 ± 19.8	< 0.001
Respiratory rate, breaths/min, mean ± SD	2 (0.2)	34.3 ± 10.2	34.7 ± 7.4	0.660
Required endotracheal intubation, n (%)	2 (0.2)	100 (95.2)	583 (70.0)	< 0.001
Radiographic consolidation	0 (0)	59 (56.2)	174 (20.9)	< 0.001
Laboratory investigations
Sodium, mmol/L, mean ± SD	8 (0.9)	138.3 ± 5.8	138.6 ± 5.7	0.650
Bicarbonate, mmol/L, mean ± SD	8 (0.9)	23.7 ± 6.8	24.2 ± 5.2	0.380
Blood urea nitrogen, mg/dL, median (IQR)	8 (0.9)	22.5 (14.0, 35.0)	15.0 (11.0, 21.0)	< 0.001
Serum creatinine, mg/dL, median (IQR)	2 (0.2)	1.1 (0.8, 1.5)	0.9 (0.7, 1.2)	< 0.001
Serum albumin, g/dL, mean ± SD	436 (46.5)	3.2 ± 0.6	3.8 ± 0.6	< 0.001
Hemoglobin, g/dL, mean ± SD	5 (0.5)	11.9 ± 2.2	12.6 ± 2.0	< 0.001
WBC, cells/mm³, median (IQR)	5 (0.5)	14,000 (9,400, 19,700)	12,980 (9,850, 16,550)	0.138
Neutrophil percent, mean ± SD	5 (0.5)	83.0 ± 14.0	84.5 ± 12.7	0.240
Eosinophil count, cells/mm³, median (IQR)	5 (0.5)	0.0 (0.0, 101.6)	14.2 (0, 194.8)	0.020
Length of hospital stay, days, median (IQR)	0 (0)	11.0 (3.0, 18.0)	3.0 (2.0, 6.0)	< 0.001

↓ Table 2. Clinical Parameters During Admission of Survived and Non-Survived Admissions With AECOPD (N = 938 Admissions)

Clinical parameters

Missing data, n (%)

Non-survived admissions, n (%) (n = 105)

Survived admissions, n (%) (n = 833)

P value

AECOPD: acute exacerbation of chronic obstructive pulmonary disease; BP: blood pressure; IQR: interquartile range; SD: standard deviation; WBC: white blood cell count.

Initial vital signs

Body temperature, °C, mean ± SD

0 (0)

37.5 ± 0.9

37.4 ± 1.0

0.220

Heart rate, beats/min, mean ± SD

0 (0)

111.6 ± 30.7

111.4 ± 22.4

0.930

Systolic BP, mm Hg, mean ± SD

0 (0)

129.6 ± 35.9

142.9 ± 29.5

< 0.001

Diastolic BP, mm Hg, mean ± SD

0 (0)

76.7 ± 20.4

84.4 ± 17.3

< 0.001

Mean arterial pressure, mm Hg, mean ± SD

0 (0)

94.4 ± 24.4

103.9 ± 19.8

< 0.001

Respiratory rate, breaths/min, mean ± SD

2 (0.2)

34.3 ± 10.2

34.7 ± 7.4

0.660

Required endotracheal intubation, n (%)

2 (0.2)

100 (95.2)

583 (70.0)

< 0.001

Radiographic consolidation

0 (0)

59 (56.2)

174 (20.9)

< 0.001

Laboratory investigations

Sodium, mmol/L, mean ± SD

8 (0.9)

138.3 ± 5.8

138.6 ± 5.7

0.650

Bicarbonate, mmol/L, mean ± SD

8 (0.9)

23.7 ± 6.8

24.2 ± 5.2

0.380

Blood urea nitrogen, mg/dL, median (IQR)

8 (0.9)

22.5 (14.0, 35.0)

15.0 (11.0, 21.0)

< 0.001

Serum creatinine, mg/dL, median (IQR)

2 (0.2)

1.1 (0.8, 1.5)

0.9 (0.7, 1.2)

< 0.001

Serum albumin, g/dL, mean ± SD

436 (46.5)

3.2 ± 0.6

3.8 ± 0.6

< 0.001

Hemoglobin, g/dL, mean ± SD

5 (0.5)

11.9 ± 2.2

12.6 ± 2.0

< 0.001

WBC, cells/mm³, median (IQR)

5 (0.5)

14,000 (9,400, 19,700)

12,980 (9,850, 16,550)

0.138

Neutrophil percent, mean ± SD

5 (0.5)

83.0 ± 14.0

84.5 ± 12.7

0.240

Eosinophil count, cells/mm³, median (IQR)

5 (0.5)

0.0 (0.0, 101.6)

14.2 (0, 194.8)

0.020

Length of hospital stay, days, median (IQR)

0 (0)

11.0 (3.0, 18.0)

3.0 (2.0, 6.0)

< 0.001

↓ **Table 3.** Clinical Characteristics of the Patients in the Validation Dataset and the Development Dataset
Clinical characteristic	Validation dataset (n = 938)	Development dataset (n = 923)
BT: body temperature; BUN: blood urea nitrogen; IQR: interquartile range; MAP: mean arterial pressure; SCr: serum creatinine; SD: standard deviation; WBC: white blood cell.
Demographic characteristics
Age, years	0 (0)	76.7 ± 10.1	74.6 ± 11.4	0.072	0 (0)	76.8 ± 11.0	74.1 ± 11.0	0.020
Initial assessments
BT, °C	0 (0)	37.5 ± 0.9	37.4 ± 1.0	0.220	1 (0.1)	37.4 ± 0.9	37.1 ± 0.6	< 0.001
MAP, mm Hg	0 (0)	94.4 ± 24.4	103.9 ± 19.8	< 0.001	0 (0)	90.3 ± 20.3	98.3 ± 15.4	< 0.001
Required endotracheal intubation, n (%)	0 (0)	100 (95.2)	583 (70.0)	< 0.001	0 (0)	96 (95.1)	561 (68.3)	< 0.001
Initial investigations
Radiographic consolidation, n (%)	2 (0.2)	59 (56.2)	174 (20.9)	< 0.001	0 (0)	65 (64.4)	304 (37.0)	< 0.001
Complete blood count
WBC count, cells/mm³	5 (0.5)	16,065 ± 10,697	13,767 ± 6,106	0.001	1 (0.1)	15,296 ± 6,978	13,738 ± 6,083	0.017
Eosinophil count, cells/mm³, median (IQR)	5 (0.5)	0 (0, 102)	14.2 (0, 195)	0.020	1 (0.1)	9.5 (0, 172)	40.8 (0, 228)	0.010
Blood chemistry
Sodium, mmol/L	8 (0.9)	138.3 ± 5.8	138.6 ± 5.7	0.650	4 (0.4)	137.5 ± 7.6	138.8 ± 4.6	0.013
BUN, mg/dL, median (IQR)	8 (0.9)	22.5 (14.0, 35.0)	15.0 (11.0, 21.0)	< 0.001	0 (0)	21 (14, 32)	15 (11, 21)	< 0.001
SCr, mg/dL, median (IQR)	2 (0.2)	1.1 (0.8, 1.5)	0.9 (0.7, 1.2)	< 0.001	0 (0)	1.1 (0.8, 1.5)	0.9 (0.8, 1.2)	0.002
Serum albumin, g/dL	436 (46.5)	3.2 ± 0.6	3.8 ± 0.6	< 0.001	323 (35.0)	3.4 ± 0.6	3.9 ± 0.5	< 0.001

↓ Table 3. Clinical Characteristics of the Patients in the Validation Dataset and the Development Dataset

Clinical characteristic

Validation dataset (n = 938)

Development dataset (n = 923)

Missing values

Non-survived admissions (n = 105)

Survived admissions (n = 833)

P value

Missing values

Non-survived admissions (n = 101)

Survived admissions (n = 822)

P value

n (%)

Mean ± SD

n (%)

Mean ± SD

BT: body temperature; BUN: blood urea nitrogen; IQR: interquartile range; MAP: mean arterial pressure; SCr: serum creatinine; SD: standard deviation; WBC: white blood cell.

Demographic characteristics

Age, years

0 (0)

76.7 ± 10.1

74.6 ± 11.4

0.072

0 (0)

76.8 ± 11.0

74.1 ± 11.0

0.020

Initial assessments

BT, °C

0 (0)

37.5 ± 0.9

37.4 ± 1.0

0.220

1 (0.1)

37.4 ± 0.9

37.1 ± 0.6

< 0.001

MAP, mm Hg

0 (0)

94.4 ± 24.4

103.9 ± 19.8

< 0.001

0 (0)

90.3 ± 20.3

98.3 ± 15.4

< 0.001

Required endotracheal intubation, n (%)

0 (0)

100 (95.2)

583 (70.0)

< 0.001

0 (0)

96 (95.1)

561 (68.3)

< 0.001

Initial investigations

Radiographic consolidation, n (%)

2 (0.2)

59 (56.2)

174 (20.9)

< 0.001

0 (0)

65 (64.4)

304 (37.0)

< 0.001

Complete blood count

WBC count, cells/mm³

5 (0.5)

16,065 ± 10,697

13,767 ± 6,106

0.001

1 (0.1)

15,296 ± 6,978

13,738 ± 6,083

0.017

Eosinophil count, cells/mm³, median (IQR)

5 (0.5)

0 (0, 102)

14.2 (0, 195)

0.020

1 (0.1)

9.5 (0, 172)

40.8 (0, 228)

0.010

Blood chemistry

Sodium, mmol/L

8 (0.9)

138.3 ± 5.8

138.6 ± 5.7

0.650

4 (0.4)

137.5 ± 7.6

138.8 ± 4.6

0.013

BUN, mg/dL, median (IQR)

8 (0.9)

22.5 (14.0, 35.0)

15.0 (11.0, 21.0)

< 0.001

0 (0)

21 (14, 32)

15 (11, 21)

< 0.001

SCr, mg/dL, median (IQR)

2 (0.2)

1.1 (0.8, 1.5)

0.9 (0.7, 1.2)

< 0.001

0 (0)

1.1 (0.8, 1.5)

0.9 (0.8, 1.2)

0.002

Serum albumin, g/dL

436 (46.5)

3.2 ± 0.6

3.8 ± 0.6

< 0.001

323 (35.0)

3.4 ± 0.6

3.9 ± 0.5

< 0.001