Time course of risk factors associated with mortality of 1260 critically ill patients with COVID-19 admitted to 24 Italian intensive care units – Electronic Supplementary Material

(1)

Time course of risk factors associated with mortality of 1260 critically ill patients with COVID-19 admitted to 24 Italian intensive care units –

Electronic Supplementary Material

1. List of the 24 Italian Hospitals participating in the study

2. Additional materials and methods

 Data collection

 Clinical and laboratory parameters

 Multivariable analysis

 Time-course of physiological variables during ICU stay

 Joint models

3. Results

 Univariable analysis

 Table 1s - Intubated patients' characteristics at ICU admission, respiratory and hemodynamic parameters, blood tests and univariate risk factors for outcome.

 Table 2s - Patients' characteristics at ICU admission, respiratory and hemodynamic parameters, blood tests and univariate risk factors for outcome in non-intubated patients.

 Table 3s - Patient’s known comorbidities at ICU admission and univariate risk factors for ICU outcome.



(2)

 Table 5s - Indicators of outcome and univariate risk factors for ICU-mortality outcome.

 Multivariable analysis.

 Multivariable analysis (including SAPS in the model).

 Time-course of physiological variables during ICU stay (model results and figures 1s- 37s).

 Figure 38s - Distribution over time of non-curarized and curarized intubated patients from ICU admission (day 0) up to 30 days or ICU discharge/death.

 Figure 39s - Distribution over time of non-pronated and pronated intubated patients from ICU admission (day 0) up to 30 days or ICU discharge/death.

 Results of joint longitudinal models of PaO

2

/FiO

2

and compliance, adjusting for curarization and pronation in the longitudinal component.

 Table 6s - Median [IQR] days between two consecutive tests on the same patient divided by site.

 Figure 40s - Distribution of ICU mortality according to quartiles of numbers of enrolled patients in each site.

 Time-course of physiological variables during ICU stay in intubated during ICU stay (not at admission) (model results and figures 41s – 44s).

2

(3)

List of the 24 Italian Hospitals of the COVID-19 Italian ICU Network participating in the study

Hospital City

Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico Milan

ASST Grande Ospedale Metropolitano Niguarda Milan

ASST MONZA - Ospedale San Gerardo Monza

AO Carlo Poma Mantova

ASST dei Sette Laghi, Ospedale di Circolo e Fondazione Macchi Varese

Humanitas Research Hospital Milan

Ospedale San Giovanni Molinette Torino

Azienda Ospedaliera – Universitaria di Bologna, Policlinico S. Orsola Malpighi Bologna

ASST Lecco Ospedale di Merate Merate

ASST Lecco - Ospedale 'A. Manzoni' Lecco

ASST Nord Milano - Ospedale Edoardo Bassini - Cinisello Balsamo Cinisello Balsamo

ASST Monza - Ospedale di Desio Desio

AULSS 5 Polesana - Ospedale di Rovigo e Ospedale di Trecenta Rovigo - Trecenta AULSS 9 Scaligera - Ospedale Magalini di Villafranca Verona

Azienda Ospedaliera di Perugia Perugia

ASST Cremona Cremona

Azienda Sanitaria Universitaria Friuli Centrale - Udine Udine

Azienda Ospedaliero - Universitaria di Modena Modena

Azienda Ospedaliera - Universitaria di Sassari Sassari

Policlinico Universitario Fondazione Agostino Gemelli Roma

Azienda Ospedaliera Mater Domini di Catanzaro Catanzaro

Azienda Ospedaliera Universitaria Federico II Napoli

Azienda Ospedaliera - Universitaria di Ferrara Ferrara

(4)

Additional materials and methods Data collection

One or more trained investigators in each Center retrieved daily patient data from the medical record and filled an electronic database (REDCap, Research Electronic Data Capture; Vanderbilt University, Nashville, TN, USA). An anesthesiologist and an anesthesia resident at the

promoting Center reviewed all the data collected; any outliers were regularly screened by an automated quality check and manually verified against the source data (medical chart) by

contacting each Center. Being a retrospective, real-data study, no tests were made specifically for the study purposes only. Therefore some parameters not requested daily for clinical practice may show some pattern of missing data.

This implies some limitations on data collection, including missing data, although maximal efforts have been employed to minimize the amount of missing data and promote data quality.

Clinical and laboratory parameters

SOFA score, temperature, respiratory rate, F

i

O

2

, Positive End Expiratory Pressure (PEEP), PaO

2

/FiO

2

, pH, the arterial partial pressure of oxygen (PaO

2

), the arterial partial pressure of carbon dioxide (PaCO

2

), Tidal Volume on Predicted Body Weight (TV/PBW), plateau pressure, driving pressure (calculated as the difference between plateau pressure and total PEEP),

compliance of respiratory system (C

RS

), ventilatory ratio, lactate, heart rate, mean arterial pressure (MAP), creatinine, urea, white blood cells (WBC), platelets, bilirubin, C-reactive protein, procalcitonin, lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT), international normalized ratio (INR), albumin, glucose, fibrinogen, D- dimer, ferritin, troponin T, pro-brain natriuretic peptide (pro-BNP).

4

(5)

Multivariable analysis

Two multivariable models were developed for demographics and baseline laboratory parameters (Model 1: age, SOFA score, pH, lactate, PaO

2

/FiO

2

, creatinine, WBC, PaCO

2

, platelets, MAP) and for comorbidities (Model 2: cardiovascular diseases, pulmonary diseases, immunologic diseas, diabetes, malignancy, hypertension, chronic kidney disease, smoking, using variables strongly associated with mortality at univariable analysis, known from previous literature to be strongly associated with outcome and not collinear). The final model included independent factors from models 1 and 2, with no further selection. The hazard ratio (HR) along with the 95%

confidence interval (CI) were reported. A sub-analysis was performed considering only the intubated patients; for this subgroup, airway plateau pressure was added to Model 1.

Time-course of physiological variables during ICU stay

Variation of dependent variables over time was modeled according to a polynomial multilevel model (general linear mixed models) with random intercept at patient level and random slope at time (days) level. Eighteen physiological variables were evaluated: (PaO

2

/FiO

2

, C

RS

, driving pressure, tidal volume on predicted body weight [TV/PBW], pH, bilirubin, creatinine, D-dimer, ferritin, lactate, C-reactive protein, urea, PaCO

2

, platelets, fibrinogen, neutrophils, lymphocytes and neutrophils-lymphocytes ratio. Each model included one of the preovious parameters as a dependent variable, while time and patient's clinical outcome were considered the independent variables.

These models are flexible ways for modeling individual differences, for the examination of time-

(6)

was applied since it takes into account the within-patient repeated measurements, differently from the nalysis which only average the daily values over the ICU stay. Statistical analyses were performed as described in a previously published paper (Lanini et al. The Journal of clinical investigation 2015; 125: 4692-4698) and carried out by SAS 9.4 statistical package.

The overall pattern of individual differences in time in the linear mixed models was estimated using restricted maximum likelihood (REML). The significance of new random effects added to the model (intercept and slope) was evaluated using likelihood ratio tests (LRT). The random intercept model was compared to a null model including only the dependent variable (linear regression) and the random intercept was included if the LRT P value was ≤ 0.100. The random intercept model was used as a null model and compared to the random intercept plus the random slope null model. The random slope was included if the LRT P value was ≤ 0.100. The model was implemented with a completely general (unstructured) covariance matrix.

The functional form of association between the dependent variables and time was assessed by polynomial models. The best fit was decided by LRT to assess subsequent polynomial models with increasing exponential power (up to 3rd order) using time as a continuous independent variable. To compare these models with an LRT, maximum likelihood (ML) method was used.

Accordingly, the model including highest polynomial power over the simplest one was chosen whenever LRT P ≤ 0.100. Next, patients’ group (discharged from ICU and death in ICU) was added as a binary term (0 discharged from ICU, 1 death in ICU). The interaction between group and time (linear, quadratic and cubic) was assessed by LRT and interaction was included in the model if LRT P value ≤ 0.100. Non-significant (P>0.05) fixed effects were removed from the model. The analysis was performed in 2 ways: 1) temporal trends were modeled from ICU admission (day 0) up to 30 days or ICU discharge/death; 2) the time scale started from ICU

6

(7)

discharge/death (day 0) back to a maximum of 30 days before (e.g., -5 corresponds to 5 days before the ICU discharge/death).

Joint models

Full joint modelling of each longitudinal parameter with the time-to-death endpoint was fit, with Weibull parametric regression; the covariates for the survival components were chosen

according to the result of step 1; for the longitudinal component, only time was used as potential predictor, with the same polynomial order selected in step 2 was chosen; the longitudinal

component was linked to the survival component in time-dependent associations, with daily value, slope, or both (the final model choice was based on the Akaike Information Criterion). For daily value we intended each single day value for each variable along the whole ICU course. We log-transformed some variables to achieve normality before fitting the corresponding model. The stjm routine in Stata was employed (Crowther M.J., Abrams K.R. LPC (2013). Joint modeling of longitudinal and survival data. Stata J 13:165-184). To present effect sizes in a metric familiar to clinicians, we exponentiated the coefficients (and confidence intervals) estimated by the Weibull models, obtaining Hazard Ratios.

P-values <0.05 were statistically significant. Analyses were performed using SAS 9.4 (SAS

Institute Inc., Cary, NC, USA), StataSE 16.0 (StataCorp LLC) and SigmaPlot 12.0 (Systat

Software Inc., San Jose, CA).

(8)

Results

Intubated patients compared to non-intubated patients had higher PaO

2

/FiO

2

(129 [93-180]

versus 111 [81-162] mmHg; P<0.001) and higher PaCO

2

(47 [40-55] versus 37 [33-42] mmHg;

P<0.001).

Univariable analysis

Patients' age was significantly associated with mortality both considering all patients (P<0.001, HR=1.060; Table 1) and the subgroup of intubated patients (P<0.001, HR=1.050; Table 1s).

Temperature, PaO

2

/F

i

O

2

, mean arterial pressure, white blood cells and aspartate aminotransferase resulted associated with mortality only in the overall analysis.

Among intubated patients, FiO

2

and plateau pressure at ICU admission were associated with mortality (P=0.009, HR=1.009 and P=0.03, HR=1.043 respectively) (Table 1s).

Hypertension (P<0.001, HR=1.66), cardiovascular disease (P<0.001, HR=1.61), diabetes (P<0.001, HR=1.84), malignancies (P=0.02, HR=1.46), chronic kidney disease (P=0.002, HR=2.1), chronic respiratory disease (P=0.003, HR=1.57) and smoking (P=0.05, HR=1.41) were associated with increased mortality at univariable analysis (see Table 2s).

8

(9)

Table 1s. Patient’s known comorbidities at ICU admission and univariate risk factors for ICU outcome.

OVERALL

(N=1260, 100%) SURVIVAL

(N=834, 66.19%) DEATH

(N=426, 33.81%) P-value HR (95%CI)

COMORBIDITIES 988 (78.41%) 615 (73.74%) 373 (87.56%) <0.001 2.172 (1.624 – 2.904)

Cardiovascular diseases^§ 197 (15.63%) 105 (12.59%) 92 (21.60%) <0.001 1.610 (1.277 – 2.028)

Hypertension 607 (48.17%) 358 (42.93%) 249 (58.45%) <0.001 1.659 (1.367 – 2.015)

Pulmonary diseases^§ 100 (7.94%) 51 (6.12%) 49 (11.50%) 0.003 1.570 (1.165 – 2.115)

Smoking 83 (6.59%) 48 (5.76%) 35 (8.22%) 0.050 1.414 (1.000 – 1.999)

Hepatic disorders^§ 24 (1.90%) 14 (1.68%) 10 (2.35%) 0.497 1.243 (0.664 – 2.328)

Chronic Kidney Failure 33 (2.62%) 14 (1.68%) 19 (4.46%) 0.001 2.161 (1.364 – 3.424)

Diabetes^§ 228 (18.10%) 120 (14.39%) 108 (25.35%) <0.001 1.840 (1.477 – 2.291)

Malignancy^§ 85 (6.75%) 44 (5.28%) 41 (9.62%) 0.024 1.457 (1.051 – 2.020)

Immunologic diseases^§ 152 (12.06%) 90 (10.79%) 62 (14.55%) 0.067 1.289 (0.982 – 1.692)

Obesity 344 (30.85%) 231 (30.84%) 113 (30.87%) 0.084 1.023 (0.819 – 1.278)

Others^§ 481 (38.17%) 313 (37.53%) 168 (39.44%) 0.351 1.097 (0.903 – 1.333)

NO COMORBIDITY 272 (21.59%) 219 (26.26%) 53 (12.44%) <0.001 0.460 (0.344 – 0.616)

§

Cardiovascular diseases include previous myocardial infarction, congestive heart failure, peripheral vascular and cerebrovascular disease.

Pulmonary diseases include Chronic Obstructive Pulmonary Disease (COPD), Asthma, Bronchiectasis and parenchymal pulmonary disease.

Malignancy includes metastatic or non-metastatic tumor (solid or lymphohematopoietic). Hepatic disorders include mild and moderate- severe. Immunologic diseases include immunodeficiency disorders, immunosuppressive or chronic steroid therapy and autoimmune diseases.

Others include hemiplegia, dementia, gastric ulcer disease, connective tissue diseases and others unspecified.

(10)

Table 2s. Intubated patients' characteristics at ICU admission, respiratory and hemodynamic parameters, blood tests and univariate risk factors for outcome.

OVERALL (N = 707)

SURVIVAL (N = 435, 61.53%)

DEATH

(N = 272, 38.47%) P-value HR (95%CI) DEMOGRAPHICS

Age (years) 63 [54 - 69] (N = 706) 59 [52 - 66] (N = 434) 66 [62 - 72] (N = 272) <0.001 1.050 (1.036 – 1.064)

Male (n) 553 (78.22%) 332 (76.32%) 221 (81.25%) 0.140 1.258 (0.928 – 1.707)

Female (n) 154 (21.78%) 103 (23.68%) 51 (18.75%)

BMI (kg/m²) 28 [25 - 31] (N = 658) 27 [25 - 31] (N = 410) 28 [26 - 31] (N = 248) 0.185 1.013 (0.994 – 1.033) CLINICAL PARAMETERS

SOFA Score 4 [3 - 5] (N = 673) 4 [3 - 4] (N = 419) 4 [3 - 6] (N = 254) <0.001 1.244 (1.157 – 1.337)

Temperature (°C) 36.9 [36.1 - 37.6] (N = 642) 36.9 [36.1 - 37.6] (N = 397) 36.9 [36 - 37.6] (N = 245) 0.350 0.945 (0.839 – 1.064) Respiratory Rate (bpm) 20 [16 - 22] (N = 687) 19 [16 - 22] (N = 429) 20 [18 - 22] (N = 258) 0.324 1.014 (0.986 – 1.043)

FiO2 (%) 70 [60 - 80] (N = 679) 63 [55 - 80] (N = 422) 70 [60 - 90] (N = 257) 0.009 1.009 (1.002 – 1.016)

PEEP (cmH2O) 12 [10 - 15] (N = 680) 12 [10 - 14] (N = 424) 12 [10 - 15] (N = 256) 0.968 0.999 (0.953 – 1.047) PaO2/FiO2 (mmHg) 129 [93 - 180] (N = 665) 137 [100 - 188] (N = 415) 115 [89 - 164] (N = 250) 0.055 0.998 (0.996 – 1.000) TV/PBW (ml/kg) 7.1 [6.4 - 7.9] (N = 592) 7.1 [6.4 - 8.0] (N = 367) 7.0 [6.3 - 7.8] (N = 225) 0.645 0.975 (0.876 – 1.086) Plateau Pressure (cmH2O) 24 [22 - 27] (N = 463) 24 [22 - 27] (N = 283) 25 [22 - 28] (N = 180) 0.035 1.043 (1.003 – 1.084) Driving Pressure (cmH2O) 12 [9 - 14] (N = 463) 12 [10 - 13] (N = 283) 12 [9 - 14] (N = 180) 0.294 1.022 (0.981 – 1.065) CRS (ml/cmH2O) 41 [33 - 51] (N = 461) 42 [34 - 50] (N = 281) 39 [32 - 53] (N = 180) 0.781 1.001 (0.994 – 1.008) Ventilatory Ratio 1.71 [1.36 - 2.1] (N = 578) 1.67 [1.35 - 1.96] (N = 360) 1.8 [1.4 - 2.21] (N = 218) 0.427 1.082 (0.891 – 1.315) pH 7.36 [7.29 - 7.42] (N = 670) 7.38 [7.31 - 7.43] (N = 418) 7.33 [7.26 - 7.39] (N = 252) <0.001 0.043 (0.012 – 0.146) PaO2 (mmHg) 84 [70 - 105] (N = 674) 85 [70 - 105] (N = 420) 82 [67 - 107] (N = 254) 0.686 0.999 (0.996 – 1.003) PaCO2 (mmHg) 47 [40 - 55] (N = 669) 45 [40 - 53] (N = 418) 49 [42 - 58] (N = 251) 0.017 1.012 (1.002 – 1.022) Lactate (mEq/L) 1.2 [0.9 - 1.5] (N = 528) 1.1 [0.9 - 1.4] (N = 321) 1.3 [1 - 1.7] (N = 207) <0.001 1.131 (1.061 – 1.205) Heart Rate (bpm) 80 [70 - 95] (N = 645) 80 [70 - 92] (N = 399) 84 [70 - 96] (N = 246) 0.525 1.002 (0.996 – 1.008) Mean Arterial Pressure

(mmHg) 81 [71 - 93] (N = 649) 83 [73 - 93] (N = 399) 80 [70 - 92] (N = 250) 0.090 0.993 (0.984 – 1.001)

Creatinine (mg/dL) 0.89 [0.7 - 1.16] (N = 632) 0.84 [0.66 - 1.08] (N = 391) 0.94 [0.75 - 1.36] (N = 241) <0.001 1.165 (1.073 – 1.265) Urea (mg/dL) 49 [34 - 70] (N = 586) 43 [30 - 64] (N = 362) 57 [41 - 91] (N = 224) <0.001 1.008 (1.005 – 1.011) White Blood Cells (10³/μL) 9.2 [6.4 - 12.8] (N = 635) 9.1 [6.3 - 12.6] (N = 395) 9.6 [6.7 - 13.1] (N = 240) 0.580 1.004 (0.990 – 1.018)

10

(11)

Table 2s. Intubated patients' characteristics at ICU admission, respiratory and hemodynamic parameters, blood tests and univariate risk factors for outcome.

OVERALL

(N = 707) SURVIVAL

(N = 435, 61.53%) DEATH

(N = 272, 38.47%) P-value HR (95%CI) Neutrophils (10³/μL) 7.8 [5.2 – 11.2] (N=513) 7.5 [5.1 – 10.7] (N=322) 8.1 [5.4 – 12.0] (N=191) 0.852 1.003 (0.972 – 1.036) Lymphocytes (10³/μL) 0.7 [0.4 – 1.0] (N=468) 0.7 [0.5 – 1.0] (N=295) 0.7 [0.4 – 1.0] (N=173) 0.677 0.938 (0.695 – 1.266) Neutrophil-Lymphocyte

Ratio 11.3 [6.9 – 19.3] (N=466) 10.5 [6.9 – 18.0] (N=294) 12.8 [7.1 – 22.4] (N=172) 0.891 1.000 (0.996 – 1.003) Platelets (10³/mm³) 231 [174 - 308] (N = 635) 248 [188 - 314] (N = 394) 218 [152 - 294] (N = 241) 0.006 0.998 (0.997 – 0.999) Bilirubin tot (mg/dL) 0.7 [0.5 - 1.1] (N = 588) 0.7 [0.5 - 1.1] (N = 366) 0.7 [0.5 - 1.2] (N = 222) 0.002 1.184 (1.062 – 1.319) C-reactive Protein (mg/L) 14.6 [6.7 - 23.1] (N = 588) 14.5 [7.1 - 22.1] (N = 365) 14.8 [6.3 - 25.7] (N = 223) 0.915 1.000 (0.995 – 1.004) Procalcitonin (ng/mL) 0.4 [0.2 - 1.2] (N = 382) 0.3 [0.2 - 1.1] (N = 239) 0.5 [0.2 - 1.7] (N = 143) 0.004 1.060 (1.018 – 1.104) LDH (U/L) 467 [348 - 624] (N = 527) 450 [339 - 600] (N = 329) 502 [378 - 687] (N = 198) 0.002 1.001 (1.000 – 1.001)

AST (U/L) 45 [31 - 67] (N = 375) 45 [32 - 70] (N = 233) 45 [29 - 65] (N = 142) 0.308 1.002 (0.999 – 1.004)

ALT (U/L) 40 [26 - 64] (N = 449) 41 [27 - 68] (N = 279) 39 [24 - 58] (N = 170) 0.940 1.000 (0.997 – 1.003)

INR 1.2 [1.1 - 1.3] (N = 434) 1.2 [1.1 - 1.3] (N = 269) 1.2 [1.1 - 1.3] (N = 165) <0.001 2.316 (1.446 – 3.710) Albumin (g/dL) 2.8 [2.5 - 3.1] (N = 275) 2.9 [2.6 - 3.1] (N = 178) 2.7 [2.4 - 3] (N = 97) 0.062 0.663 (0.431 – 1.020) Glucose (mg/dL) 136 [112 - 179] (N = 411) 128 [110 - 168] (N = 257) 150 [118 - 199] (N = 154) 0.010 1.003 (1.001 – 1.005) Fibrinogen (mg/dL) 625 [491 - 735] (N = 291) 628 [508 - 735] (N = 189) 607 [429 - 726] (N = 102) 0.335 1.000 (0.999 – 1.000) D-dimer (ng/mL) 1798 [720 - 6147] (N = 468) 1385 [613 - 4667] (N = 307) 2660 [1119 - 8120] (N = 161) 0.688 1.000 (1.000 – 1.000) Ferritin (ng/mL) 1490 [985 - 2455] (N = 199) 1516 [932 - 2465] (N = 130) 1444 [1054 - 2453] (N = 69) 0.311 1.000 (1.000 – 1.000) Troponin T (ng/L) 9 [0 - 21] (N = 182) 8 [0 - 14] (N = 117) 12 [0 - 39] (N = 65) 0.030 1.000 (1.000 – 1.001) Pro-BNP (ng/L) 277 [90 - 857] (N = 42) 243 [90 - 554] (N = 30) 788 [99 - 1809] (N = 12) 0.011 1.000 (1.000 – 1.000)

Abbreviations: HR hazard ratio, CI confidence interval, BMI body mass index, SOFA sequential organ failure assessment, FiO2 fractional inspired oxygen, PEEP positive end expiratory pressure, PaO2/FiO2 ratio of arterial oxygen partial pressure, PaO2 arterial oxygen partial pressure, PaCO2 arterial carbon dioxide partial pressure, LDH lactate dehydrogenase, AST aspartate transaminase, ALT alanine transaminase, INR international normalized ratio, BNP brain natriuretic peptide.

(12)

Table 3s. Patients' characteristics at ICU admission, respiratory and hemodynamic parameters, blood tests and univariate risk factors for outcome in non-intubated patients.

OVERALL (N = 553)

SURVIVAL (N = 399, 72%)

DEATH

(N = 154, 28%) P-value HR (95% CI) DEMOGRAPHICS

Age (years) 63 [55 - 70] (N = 553) 60 [53 - 67] (N = 399) 70 [63 - 75] (N = 154) <0.001 1.081 (1.060 – 1.102)

Male (n) 426 (77.3%) 308 (77.19%) 118 (76.62%) 0.468 0.869 (0.595-1.269)

Female (n) 127 (22.97%) 91 (22.81%) 36 (23.38%)

BMI (kg/m2) 28 [25 - 31] (N = 457) 28 [25 - 31] (N = 339) 27 [24 - 30] (N = 118) 0.627 0.990 (0.952 – 1.03)

CLINICAL PARAMETERS

SOFA Score 4 [3 - 4] (N = 519) 4 [3 - 4] (N = 375) 4 [4 - 5] (N = 144) <0.001 1.287 (1.162 – 1.424)

Temperature (°C) 37.0 [36.5 - 37.8] (N=490) 37.0 [36.5 - 37.8] (N = 357) 37.0 [36.5 - 37.6] (N = 133) 0.003 0.748 (0.619 – 0.904)

FiO2 (%) 70 [50 - 90] (N = 524) 60 [50 - 90] (N = 382) 70 [60 - 90] (N = 142) 0.681 1.002 (0.993 – 1.010)

Respiratory Rate (bpm) 26 [22 - 30] (N = 493) 26 [22 - 30] (N = 360) 27 [22 - 30] (N = 133) 0.025 0.972 (0.949 – 0.997)

PEEP (cmH2O) 10 [10 - 12] (N = 367) 10 [10 - 10] (N = 275) 10 [10 - 14] (N = 92) 0.449 1.034 (0.948 – 1.127)

PaO2/FiO2 (mmHg) 111 [81 - 162] (N = 501) 119 [86 - 180] (N = 365) 98 [76 - 133] (N = 136) 0.007 0.996 (0.993 – 0.999) pH 7.45 [7.41 - 7.48] (N = 511) 7.45 [7.42 - 7.49] (N = 373) 7.44 [7.38 - 7.47] (N = 138) <0.001 0.034 (0.006 – 0.209)

PaO2 (mmHg) 75 [61 - 95] (N = 513) 76 [62 - 99] (N = 375) 70 [58 - 87] (N = 138) 0.009 0.993 (0.988 – 0.998)

PaCO2 (mmHg) 37 [33 - 42] (N = 507) 37 [33 - 42] (N = 370) 37 [33 - 43] (N = 137) 0.201 1.009 (0.995 – 1.022)

Lactate (mEq/L) 1.2 [1.0 - 1.7] (N = 337) 1.2 [0.9 - 1.5] (N = 245) 1.6 [1.1 – 2.2] (N = 92) <0.001 1.566 (1.311 – 1.872) Heart Rate (bpm) 85 [74 - 96] (N = 495) 84 [74 - 95] (N = 360) 90 [75 - 97] (N = 135) 0.479 1.004 (0.993 – 1.014) Mean Arterial Pressure (mmHg) 90 [80 - 97] (N = 495) 90 [80 - 98] (N = 360) 87 [75 - 97] (N = 135) 0.002 0.984 (0.973 – 0.994) Creatinine (mg/dL) 0.89 [0.70 - 1.11] (N = 523) 0.84 [0.67 - 1.01] (N = 380) 1.00 [0.77 - 1.39] (N = 143) <0.001 1.152 (1.072 – 1.237) Urea (mg/dL) 42 [30 - 67] (N = 490) 38 [28 - 56] (N = 358) 61 [41 - 90] (N = 132) <0.001 1.011 (1.007 – 1.014) White Blood Cells (10³/μL) 8.1 [6.0 – 11.1] (N = 526) 7.9 [5.9 – 10.8] (N = 385) 9.1 [6.2 - 12] (N = 141) 0.012 1.014 (1.003 – 1.025) Neutrophils (10³/μL) 6.7 [4.8 – 9.4] (N=424) 6.4 [4.7 – 9.0] (N=310) 7.9 [5.1 – 11.0] (N=114) 0.074 1.039 (0.996 – 1.083) Lymphocytes (10³/μL) 0.7 [0.5 – 0.9] (N=400) 0.7 [0.5 – 1.0] (N=291) 0.6 [0.5 – 0.9] (N=109) 0.022 0.500 (0.276 – 0.906) Neutrophil-Lymphocyte Ratio 10.4 [6.4 – 17.1] (N=388) 9.2 [6.0 – 15.0] (N=282) 14.6 [7.3 – 21.1] (N=106) 0.007 1.013 (1.004 – 1.023) Platelets (10³/mm³) 238 [179 - 311] (N = 527) 246 [182 - 321] (N = 385) 219 [169 - 284] (N = 142) 0.014 0.998 (0.996 – 1.000) Bilirubin tot (mg/dL) 0.7 [0.5 – 1.0] (N = 483) 0.7 [0.5 – 1.0] (N = 357) 0.7 [0.5 - 1.0] (N = 126) 0.630 0.931 (0.695 – 1.246)

12

(13)

Table 3s. Patients' characteristics at ICU admission, respiratory and hemodynamic parameters, blood tests and univariate risk factors for outcome in non-intubated patients.

OVERALL

(N = 553) SURVIVAL

(N = 399, 72%) DEATH

(N = 154, 28%) P-value HR (95% CI) C-reactive Protein (mg/L) 11.6 [4.0 - 20.6] (N = 445) 11.6 [3.9 - 19.9] (N = 328) 11.4 [4.1 - 23.0] (N = 117) 0.434 0.993 (0.977 – 1.010) Procalcitonin (ng/mL) 0.3 [0.1 - 1.1] (N = 279) 0.3 [0.1 – 0.8] (N = 200) 0.5 [0.2 - 1.8] (N = 79) 0.448 1.009 (0.985 – 1.034) LDH (U/L) 485 [376 - 651] (N = 437) 467 [359 - 636] (N = 322) 523 [403 - 725] (N = 115) 0.053 1.001 (1.000 – 1.001)

AST (U/L) 43 [28 - 63] (N = 244) 43 [28 - 60] (N = 176) 44 [27 - 77] (N = 68) 0.001 1.006 (1.002 – 1.009)

ALT (U/L) 38 [25 - 61] (N = 314) 38 [26 - 64] (N = 227) 33 [21 - 52] (N = 87) 0.661 0.999 (0.997 – 1.002)

INR 1.2 [1.1 - 1.3] (N = 295) 1.1 [1.1 - 1.3] (N = 214) 1.2 [1.1 - 1.3] (N = 81) 0.650 1.220 (0.516 – 2.884)

Albumin (g/dL) 3.0 [2.6 - 3.2] (N = 213) 3.0 [2.6 - 3.2] (N = 159) 2.8 [2.6 – 3.2] (N = 54) 0.311 0.718 (0.379 – 1.362) Glucose (mg/dL) 120 [101 - 154] (N = 283) 119 [100 - 145] (N = 200) 126 [102 - 178] (N = 83) 0.740 1.001 (0.997 – 1.004) Fibrinogen (mg/dL) 635 [478 - 769] (N = 242) 640 [499 - 776] (N = 180) 613 [417 - 740] (N = 62) 0.021 0.999 (0.997 – 1.000) D-dimer (ng/mL) 1005 [435 - 3022] (N = 364) 894 [399 - 2380] (N = 275) 1486 [568 - 3668] (N = 89) 0.009 1.000 (1.000 – 1.000) Ferritin (ng/mL) 1204 [624 - 1852] (N = 86) 1102 [586 - 1903] (N = 69) 1470 [1000 - 1703] (N = 17) 0.106 1.000 (0.999 – 1.000)

Troponin T (ng/L) 0 [0 - 12] (N = 119) 1 [0 - 12] (N = 87) 0 [0 - 12] (N = 32) 0.076 1.001 (1.000 – 1.002)

Pro-BNP (ng/L) 462 [140 - 1080] (N = 6) 173 [140 - 750] (N = 5) 1193 [1193 - 1193] (N = 1) 1.000 1.226 (0.000 – NA) Abbreviations: HR hazard ratio, CI confidence interval, BMI body mass index, SOFA sequential organ failure assessment, FiO2 fractional inspired oxygen,

PEEP positive end expiratory pressure, PaO2/FiO2 ratio of arterial oxygen partial pressure, PaO2 arterial oxygen partial pressure, PaCO2 arterial carbon dioxide partial pressure, LDH lactate dehydrogenase, AST aspartate transaminase, ALT alanine transaminase, INR international normalized ratio, BNP brain natriuretic peptide.

(14)

Table 4s. Indicators of outcome and univariate risk factors for intensive care unit (ICU) mortality outcome

OVERALL SURVIVAL DEATH P-value

All patients (N = 1260) (N = 834, 66.2%) (N = 426, 33.8%)

ICU length of stay (day) 13 [7 - 22] (N = 1256) 14 [8 - 25] (N = 832) 11 [6 - 19] (N = 424) <0.001 Days from hospital to ICU admission 3 [1 - 5] (N = 1255) 3 [1 - 6] (N = 831) 3 [1 - 5] (N = 424) 0.084 Mechanically ventilated patients (N = 707) (N = 435, 61.53%) (N = 272, 38.47%)

ICU length of stay (day) 14 [8 - 24] (N = 705) 15 [9 - 27] (N = 434) 11 [6 - 18] (N = 271) <0.001 Days from hospital to ICU admission 3 [1 - 5] (N = 704) 3 [1 - 5] (N = 433) 2 [1 - 5] (N = 271) 0.295 Length of mechanical ventilation (day) 10 [3 - 19] (N = 699) 10 [4 - 21] (N = 430) 8 [2 - 16] (N = 269) 0.010 Days from symptom to intubation 9 [6 - 12] (N = 671) 9 [6 - 12] (N = 411) 8 [5 - 12] (N = 260) 0.009 Days from hospital admission to

intubation 2 [1 - 5] (N = 696) 2 [1 - 5] (N = 428) 2 [0 - 5] (N = 268) 0.386

14 Table 5s. Therapies used at least once in intensive care unit (ICU).

OVERALL

(N = 1260) SURVIVAL

(N = 834, 66.2%) DEATH

(N = 426, 33.8%) Neuromuscolar blocking agents

Antiviral 634 (84.31%) (N=752)

716 (62.97%) (N=1137) 394 (84.43%) (N=478)

481 (62.96%) (N=764) 240 (87.59%) (N=274) 235 (63.00%) (N=373) Lopinavir/Ritonavir 513 (45.12%) (N=1137) 346 (45.29%) (N=764) 167 (44.77%) (N=373)

Remdesivir 111 (9.76%) (N=1137) 86 (11.26%) (N=764) 25 (6.70%) (N=373)

Hydroxychloroquine 921 (81.00%) (N=1137) 626 (81.94%) (N=764) 295 (79.09%) (N=373)

Steroids 444 (39.05%) (N=1137) 290 (37.96%) (N=764) 154 (41.29%) (N=373)

ACE inhibitors 94 (8.27%) (N=1137) 75 (9.82%) (N=764) 19 (5.09%) (N=373)

ARB 50 (4.40%) (N=1137) 37 (4.84%) (N=764) 13 (3.49%) (N=373)

Off-Label Therapies

Anti-IL-1 (Anakinra) 80 (7.04%) (N=1137) 62 (8.12%) (N=764) 18 (4.83%) (N=373)

Anti-IL-6 (Tocilizumab) 196 (17.24%) (N=1137) 138 (18.06%) (N=764) 58 (15.55%) (N=373)

Hyperimmune Plasma 6 (0.53%) (N=1137) 3 (0.39%) (N=764) 3 (0.80%) (N=373)

Vitamin C 107 (9.41%) (N=1137) 79 (10.34%) (N=764) 28 (7.51%) (N=373)

N-Acetyilcyistein 53 (4.66%) (N=1137) 43 (5.63%) (N=764) 10 (2.68%) (N=373)

Others* 70 (6.16%) (N=1137) 53 (6.94%) (N=764) 17 (4.56%) (N=373)

Anticoagulants 902 (79.33%) (N=1137) 626 (81.94%) (N=764) 276 (73.99%) (N=373)

Antibiotics 709 (62.36%) (N=1137) 466 (60.99%) (N=764) 243 (65.15%) (N=373)

Extracorporeal Therapies

CRRT 107 (9.41%) (N=1137) 52 (6.81%) (N=764) 55 (14.75%) (N=373)

ECMO V-A 6 (0.53%) (N=1137) 3 (0.39%) (N=764) 3 (0.80%) (N=373)

ECMO V-V 24 (2.11%) (N=1137) 13 (1.70%) (N=764) 11 (2.95%) (N=373)

ECCO2R 5 (0.44%) (N=1137) 1 (0.13%) (N=764) 4 (1.07%) (N=373)

Prone Positioning 471 (41.42%) (N=1137) 279 (36.52%) (N=764) 192 (51.47%) (N=373)

Inhaled Nitric Oxid 90 (7.92%) (N=1137) 37 (4.84%) (N=764) 53 (14.21%) (N=373)

(15)

CRRT denotes continuous renal replacement therapy; ECMO, extra-corporeal membrane oxygenation;V-A, venous-arterial; V-V, veno-venous; ECCO2R extracorporeal carbon dioxed removal; *Others off-label therapies: interferon 1a, ozone, sarilumab, not defined.

(16)

Multivariable analysis

At multivariable analysis, age (P<0.0001, HR=1.046), SOFA score (P<0.0001, HR=1.257), pH (P<0.0001, HR=0.074) and lactate (P<0.0001, HR=1.226) at ICU admission were significantly associated with mortality. Among comorbidities, only diabetes (P=0.002, HR=1.609) showed an association with mortality.

Model 1

Number of observations: 1260 Number of used observations: 758

Parameter DF Estimation Standard

error Chi-square P-value HR 95% CI

Age 1 0.04827 0.00691 48.8725 <.0001 1.049 1.035 1.064

Sofa Score 1 0.22902 0.03804 36.2410 <.0001 1.257 1.167 1.355

pH 1 -2.25453 0.60075 14.0840 0.0002 0.105 0.032 0.341

Lactate 1 0.18571 0.04044 21.0859 <.0001 1.204 1.112 1.303

Elimination

Step Removed DF No. in Chi-square P-value

1

^PaO2/FiO2

1 9 0.0058 0.9394

2 Creatinine 1 8 0.0862 0.7690

3 WBC 1 7 0.1561 0.6928

4

^PaCO²

1 6 0.8008 0.3708

5 Platelets 1 5 1.6017 0.2057

6 MAP 1 4 2.1247 0.1449

PaO

2

arterial partial pressure of oxygen; WBC white blood cells; MAP, mean arterial pressure 5 unit change in age

Description Estimation CI 95% (Wald)

Age Unit=5 1.273 1.190 1.362

0.1 unit change in Lactate

Description Estimation CI 95% (Wald)

Lactate Unit=0.1 1.019 1.011 1.027

16

(17)

Model 2

Number of observations: 1260 Number of used observations: 1256

Effect DF Chi-square P-value

Cardiovascular diseases 1 4.2909 0.0383

Pulmonary diseases 1 6.5705 0.0104

Diabetes 1 13.5616 0.0002

Malignancy 1 4.0726 0.0436

Hypertension 1 14.7026 0.0001

Chronic Kidney Failure 1 4.3193 0.0377

Parameter D

F

Estimatio n

Standard error

Chi- square

P- value

HR 95% CI

Cardiovascolar diseases

1 0.25675 0.12395 4.2909 0.0383 1.293 1.01

4 1.64 8 Pulmonary

diseases 1 0.39070 0.15242 6.5705 0.0104 1.478 1.09

6 1.99

3 Diabetes 1 0.43214 0.11735 13.5616 0.0002 1.541 1.22

4 1.93

9 Malignancy 1 0.34103 0.16899 4.0726 0.0436 1.406 1.01

0 1.95 9

Hypertension 1 0.39153 0.10211 14.7026 0.0001 1.479 1.21

1 1.80 7 Chronic Kidney

Failure

1 0.49941 0.24030 4.3193 0.0377 1.648 1.02

9 2.63 9

Step Removed DF No. in Chi-square P-value

1 Immunologic diseases

1 7 0.0050 0.9436

2 Smoking 1 6 1.3900 0.2384

Complete model

Number of observations: 1260 Number of used observations: 777

Effect DF Chi-square P-value

Age 1 38.0160 <.0001

SOFA Score 1 32.5202 <.0001

(18)

Diabetes 1 9.4974 0.0021

Parameter D F

Estimation Standard error Chi-square P-value HR 95% CI

Age 1 0.04543 0.00737 38.0160 <.0001 1.04

6 1.03 1

1.062 SOFA

Score

1 0.22860 0.04009 32.5202 <.0001 1.25

7 1.16 2

1.360 pH 1 -2.61045 0.63697 16.7954 <.0001 0.07

4 0.02

1 0.256

Lactate 1 0.20347 0.04445 20.9496 <.0001 1.22

6 1.12

3 1.337

Diabetes 1 0.47581 0.15439 9.4974 0.0021 1.60

9 1.18 9

2.178 Step Remove DF No. in Chi-square P-value

1 Cardiovascular diseases 1 9 0.2706 0.6029

2 Chronic kidney 1 8 0.8517 0.3561

3 Pulmonary diseases 1 7 0.7960 0.3723

4 Hypertension 1 6 2.2055 0.1375

5 Malignancy 1 5 2.4723 0.1159

5 unit change in age

Description Estimation 95% CI (Wald)

Age Unit=5 1.255 1.168 1.349

0.1 unit change in Lactate

Lactate Unit=0.1 1.021 1.012 1.029

Considering the subgroup of intubated patients, age (P<0.0001, HR=1.046), lower pH (P=0.004, HR=0.082), lactate (P<0.0001, HR=1.228), creatinine (P<0.0001, HR=1.333), diabetes (P<0.001, HR=1.939), malignancies (P=0.003, HR=2.182), and smoking (P=0.005, HR=1.976) were significantly associated with mortality.

Model 1

18

(19)

Number of observations: 707 Number of used observations: 358 Paramete

r D

F Estimatio

n Standard error Chi-

square P-value HR 95% CI (Wald)

Age 1 0.04773 0.00938 25.9107 <.0001 1.04

9 1.030 1.068

pH 1 -2.11228 0.96072 4.8341 0.0279 0.12

1 0.018 0.795

Lactate 1 0.35127 0.09244 14.4406 0.0001 1.42

1 1.185 1.703

Creatinine 1 0.28628 0.05800 24.3582 <.0001 1.33

1 1.188 1.492

Step Removed DF No. in Chi-square P-value

1 Platelets 1 10 0.0045 0.9465

2

^PaCO2

1 9 0.2948 0.5871

3 MAP 1 8 0.8749 0.3496

4 WBC 1 7 2.2953 0.1298

5

^PaO²^/FiO²

1 6 2.1774 0.1401

6 Airway Plateau Pressure 1 5 1.8065 0.1789

7 SOFA Score 1 4 2.5727 0.1087

PaO

2

arterial partial pressure of oxygen; WBC white blood cells; MAP, mean arterial pressure 5 unit change in age:

Age Unit=5 1.270 1.158 1.392

0.1 unit change in Lactate:

Lactate Unit=0.1 1.036 1.017 1.055

Model 2

Number of observations: 707 Number of used observations: 705

Effect DF Chi-square P-value

Diabetes 1 13.1918 0.0003

Malignancy 1 4.3068 0.0380

Hypertension 1 11.3557 0.0008

(20)

F n error square value

Diabetes 1 0.52817 0.14542 13.1918 0.0003 1.696 1.27

5 2.25 5

Malignancy 1 0.42626 0.20540 4.3068 0.0380 1.532 1.02

4 2.29 1

Hypertension 1 0.43481 0.12903 11.3557 0.0008 1.545 1.20

0 1.98 9

Smoking 1 0.48923 0.20087 5.9320 0.0149 1.631 1.10

0 2.41 8

Step Removed

DF

^{No. in} ^Chi-square ^P-value

1 Immunologic diseases 1 7 0.2071 0.6490

2 Chronick Kidney Failure 1 6 0.6149 0.4329

3 Pulmonary 1 5 0.9488 0.3300

4 Cardiovascular diseases 1 4 1.4758 0.2244

Complete model

Number of observations: 707 Number of used observations: 463

Effect DF Chi-square P-value

Age 1 25.7466 <.0001

pH 1 8.4213 0.0037

Lactate 1 19.0127 <.0001

Creatinine 1 24.8705 <.0001

Diabetes 1 13.1309 0.0003

Malignancy 1 9.1293 0.0025

Smoking 1 7.9687 0.0048

Parameter DF Estimation Standard error

Chi-square P- value

HR 95% CI

Age 1 0.04494 0.00886 25.7466 <.0001 1.046 1.028 1.064

pH 1 -2.50085 0.86178 8.4213 0.0037 0.082 0.015 0.444

Lactate 1 0.20564 0.04716 19.0127 <.0001 1.228 1.120 1.347

Creatinine 1 0.28744 0.05764 24.8705 <.0001 1.333 1.191 1.492

Diabetes 1 0.66233 0.18278 13.1309 0.0003 1.939 1.355 2.775

Malignancy 1 0.78032 0.25826 9.1293 0.0025 2.182 1.315 3.620

Smoking 1 0.68122 0.24132 7.9687 0.0048 1.976 1.232 3.171

Step Removed DF No. in Chi-square P-value

1 Hypertension 1 7 1.5704 0.2102

5 unit change in Age

Description Estimation 95% CI

Age Unit=5 1.252 1.148 1.365

20

(21)

0.1 unit change in Lactate

Lactate Unit=0.1 1.021 1.011 1.030

Multivariable analysis (including SAPS in the model)

Model 1 (Overall population) Number of observations: 1260 Number of used observations: 758

Parameter DF Estimation Standard

error Chi-square P-value HR 95% CI

Age 1 0.03768 0.00766 24.2057 <.0001 1.038 1.023 1.054

SOFA 1 0.19254 0.03983 23.3742 <.0001 1.212 1.121 1.311

SAPS 1 0.02622 0.00818 10.2652 0.0014 1.027 1.010 1.043

pH 1 -2.06454 0.60680 11.5759 0.0007 0.127 0.039 0.417

lactate 1 0.17299 0.04081 17.9679 <.0001 1.189 1.097 1.288

Elimination

Step Removed DF No. in Chi-square P-value

1 WBC 1 10 0.0018 0.9659

2 PaO2/FiO2 1 9 0.0147 0.9035

3 Creatinine 1 8 0.1227 0.7261

4 MAP 1 7 0.5069 0.4765

5 PaCO2 1 6 0.9012 0.3425

6 Platelets 1 5 1.2035 0.2726

5 unit change in age

Description Estimation CI 95% (Wald)

(22)

0.1 unit change in Lactate

Description Estimation CI 95% (Wald)

Lactate Unit=0.1

^1.017 ^1.009 ^1.026

Complete model (Overall population) Number of observations: 1260

Number of used observations: 777 Parameter D

F

Estimation Standard error

Chi- square

P- value

HR 95% CI

Age 1 0.03661 0.00805 20.6960 <.0001 1.03

7 1.02 1

1.054 SOFA Score 1 0.19158 0.04270 20.1287 <.0001 1.21

1 1.11 4

1.317 SAPS score 1 0.02162 0.00809 7.1407 0.0075 1.02

2 1.00 6

1.038 pH 1 -2.49566 0.63871 15.2673 <.0001 0.08

2 0.02

4 0.288

Lactate 1 0.18645 0.04517 17.0415 <.0001 1.20

5 1.10

3 1.316

Diabetes 1 0.46525 0.15441 9.0782 0.0026 1.59

2 1.17 7

2.155 Step Remove DF No. in Chi-square P-value

1 Cardiovascular diseases 1 9 0.1058 0.7450

2 Chronic kidney 1 8 0.5225 0.4698

3 Pulmonary diseases 1 7 0.9916 0.3194

4 Hypertension 1 6 2.1822 0.1396

5 Malignancy 1 5 2.1442 0.1431

5 unit change in age

Age Unit=5 1.201 1.110 1.299

0.1 unit change in Lactate

Lactate Unit=0.1 1.019 1.010 1.028

Model 1 (intubated patients) Number of observations: 707 Number of used observations: 358

22

(23)

Parameter D F

Estimation Standard error Chi- square

P- value

HR 95% CI

(Wald)

Age 1 0.03593 0.01051 11.6991 0.0006 1.037 1.015 1.058

SAPS score 1 0.02757 0.01148 5.7674 0.0163 1.028 1.005 1.051

pH 1 -2.02535 0.97643 4.3025 0.0381 0.132 0.019 0.894

Lactate 1 0.32326 0.09593 11.3544 0.0008 1.382 1.145 1.667

Creatinine 1 0.25123 0.05960 17.7699 <.0001 1.286 1.144 1.445

Step Removed DF No. in Chi-square P-value

1 Platelets 1 11 0.2158 0.6423

2

^PaCO2

1 10 0.6757 0.4111

3 MAP 1 9 0.6424 0.4228

4 WBC 1 8 2.1921 0.1387

5 SOFA score 1 7 2.4309 0.1190

6

^PaO²^/FiO²

1 6 2.4850 0.1149

7 Airway Plateau Pressure 1 5 1.6574 0.1980

PaO

2

arterial partial pressure of oxygen; WBC white blood cells; MAP, mean arterial pressure 5 unit change in age:

Age Unit=5 1.197 1.080 1.327

0.1 unit change in Lactate:

Lactate Unit=0.1 1.033 1.014 1.052

Complete model (Intubated patients) Number of observations: 707

Number of used observations: 463

Parameter DF Estimation Standard error

Chi-square P- value

HR 95% CI

Age 1 0.04494 0.00886 25.7466 <.0001 1.046 1.028 1.064

pH 1 -2.50085 0.86178 8.4213 0.0037 0.082 0.015 0.444

Lactate 1 0.20564 0.04716 19.0127 <.0001 1.228 1.120 1.347

Creatinine 1 0.28744 0.05764 24.8705 <.0001 1.333 1.191 1.492

Diabetes 1 0.66233 0.18278 13.1309 0.0003 1.939 1.355 2.775

Malignancy 1 0.78032 0.25826 9.1293 0.0025 2.182 1.315 3.620

Smoking 1 0.68122 0.24132 7.9687 0.0048 1.976 1.232 3.171

Step Removed DF No. in Chi-square P-value

1 Hypertension

1 8 1.3431 0.2465

2 SAPS score

1 7 2.8067 0.0939

(24)

Age Unit=5 1.252 1.148 1.365

0.1 unit change in Lactate

Lactate Unit=0.1 1.021 1.011 1.030

24

(25)

Time-course of physiological variables during ICU stay

PaO

2

/FiO

2

at ICU admission (intercept of the model) was higher in survivors than in non-survivors (166 versus 145 mmHg, respectively: difference 21 mmHg (95% CI 14 – 29 mmHg, P<0.0001). In survivors, PaO

2

/FiO

2

progressively increased throughout ICU stay while, on the contrary, it decreased in non-survivors (P<0.0001), thus the difference increased up to 142 mmHg (95% CI 132 – 152 mmHg) at ICU discharge/death (254 versus 112 mmHg). See figure 1.

C

RS

at ICU admission was higher in survivors than in non-survivors (45.3 versus 42.7 mL/cmH

2

O, respectively; difference 2.6 mL/cmH

2

O, 95% CI 0.1 – 5.0 mL/cmH

2

O, P=0.040). In survivors, C

RS

slightly decreased after ICU admission while it slightly increased before ICU discharge. In non- survivors, compliance markedly decreased over the days (P=0.0004). At discharge/death values were 46.5 and 35.4 mL/cmH

2

O in survivors and non-survivors, respectively (difference 11.1 mL/cmH

2

O, 95% CI 8.1 – 14.2 mL/cmH

2

O, P<.0001). See figure 2.

Driving pressure at ICU admission was higher in non-survivors than in survivors (11.9 versus 11.1 cmH

2

O, difference 0.8 cmH

2

O, 95% CI 0.2 – 1.4 cmH

2

O, P=0.010) and increased during the days, while it remained stable in survivors (P<.0001).

Values of pH at ICU admission were higher in survivors than in non-survivors (7.403 versus 7.354 respectively; difference 0.049, 95% CI 0.043 – 0.056, P<.0001). In survivors, pH increased over the days while in non-survivors it decreased, particularly in the last 5 days (P<.0001). At discharge/death, values were 7.461 and 7.319 in survivors and non-survivors, respectively (difference 0.142, 95% CI 0.133 - 0.152, P<.0001). See figure 3.

Lactate at ICU admission was lower in survivors than in non-survivors (1.27 vs 1.79 mEq/L

respectively; difference 0.52 mEq/L, 95% CI 0.40 - 0.63 mEq/L, P<.0001). In survivors, the value was

almost stable during the days while in non-survivors it increased, particularly in the last 5 days

(26)

(P<.0001). At ICU discharge/death values were 1.11 and 2.57 mEq/L in survivors and non-survivors, respectively (difference 1.46 mEq/L, 95% CI 1.28 - 1.64 mEq/L, P<.0001).See figure 4.

Creatinine at ICU admission was lower in survivors than in non-survivors (1.01 vs 1.41 mg/dL

respectively; difference 0.40 mg/dL, 95% CI 0.26 - 0.54 mg/dL, P<.0001). In survivors, the value was constant during the days while in non-survivors it increased (P<.0001). At discharge/death values were 0.93 and 1.82 mg/dL in survivors and non-survivors, respectively (difference 0.89 mg/dL, 95% CI 0.69 - 1.09 mg/dL, P<.0001). Urea showed a trend similar to creatinine, both in survivors and non-survivors.

See figures 5.

Bilirubin at ICU admission was higher in non-survivors (P=0.014) than in survivors and increased during the days, while it remained stable in survivors (P<.0001).

D-dimer at ICU admission was lower in survivors than in non-survivors (P<.0001), then decreased in both groups.

Ferritin and C-reactive Protein at ICU admission were equal between survivors and non-survivors.

Ferritin in survivors continuously decreased over the days while in non-survivors, after an initial decrease, increased, mainly in the last 10 days (P<.0001). C-reactive Protein decreased during the days in survivors, while in non-survivors it was stable (P=0.003).

Arterial PCO

2

at ICU admission was higher in non-survivors than in survivors (47.5 versus 43.9 mmHg, difference 3.6 mmHg, 95% CI 2.4 - 4.8 mmHg, P<.0001) and increased during the days, while it decreased in survivors (P=0.001).

Neutrophil-lymphocyte ratio was higher in non-survivors at ICU admission and increased in non- survivors during the ICU stay. Both daily value and slope were associated with survival.

26

(27)

1. PaO

2

/FiO

2

- Full model parameters Kinetics of PaO

2

/FiO

2

(from ICU admission):

 random intercept at patient level;

 random slope at time level;

 PaO

2

/FiO

2

(dependent variable)

 time as a continuous linear, quadratic and cubic term (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 linear term interaction between the 2 independent variables

Overall model parameters Number of observations used/

Number of observations read 13390/

15228

Missing Values 12%

Random intercept group variable: patients 1260 Random slope variable: time

Observations per patients: (max) 30

Model selection P

Random effect (assessed on null model)

Random intercept vs. standard linear regression model <.0001 Random slope vs. random intercept model <.0001 Functional form of association between time and PF

Linear vs. quadratic <.0001

Quadratic vs. cubic <.0001

Interaction between time and group vs. no interaction <.0001

Fixed effect parameters Coeff. std err. 95% CI P

time: linear 6.042 0.502 5.059 7.026 <.0001

time: quadratic -0.218 0.045 -0.307 -0.130 <.0001

time: cubic 0.006 0.001 0.004 0.009 <.0001

Group: binary (1 death in ICU , 0 discharged from ICU) -21.212 3.851 -28.767 -13.657 <.0001 Interaction

time (linear) and group -6.404 0.392 -7.174 -5.634 <.0001

time (quadratic) and group removed

time (cubic) and group removed

Constant: Intercept at time = 0 166.210 2.343 161.610 170.800 <.0001

Random effect parameters Coeff. std err. 95% CI P

Random intercept 2923.250 160.040 2609.570 3236.930 <.0001

Unstructured covariance -119.480 12.803 -144.570 -94.380 <.0001

Random slope 16.836 1.459 13.980 19.700 <.0001

Residual variance 2932.020 38.997 2855.590 3008.450 <.0001

(28)

Figure 1s. Kinetics of PaO

2

/FiO

2

along 30 days from ICU admission in patients discharged from ICU (left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

28

(29)

Kinetics of PaO

2

/FiO

2

(from ICU discharge):

 random intercept at patient level;

 random slope at time level;

 PaO

2

/FiO

2

(dependent variable)

 time as a continuous linear and quadratic term (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 Linear and quadratic interaction between the 2 independent variables

14807

Missing Values (%) 14%

Linear vs. quadratic 0.0004

Quadratic vs. cubic 0.2783

time: linear 6.369 0.339 5.704 7.034 <.0001

time: quadratic 0.086 0.012 0.062 0.110 <.0001

time: cubic

Group: binary (1 death in ICU , 0 discharged from ICU) -141.850 4.947 -151.550 -132.140 <.0001 Interaction

time (linear) and group -10.556 0.608 -11.747 -9.364 <.0001

time (quadratic) and group -0.173 0.024 -0.220 -0.127 <.0001

time (cubic) and group

Unstructured covariance 144.950 13.881 117.750 172.160 <.0001

Random slope 13.392 1.187 11.060 15.720 <.0001

(30)

Figure 2s. Kinetics of PaO

2

/FiO

2

along 30 days from ICU discharge in patients discharged from ICU (left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

30

(31)

2. Bilirubin - Full model parameters Kinetics of Bilirubin (from ICU admission):

 random intercept at patient level;

 random slope at time level;

 Bilirubin (dependent variable)

 time as a continuous linear, quadratic and cubic term (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 linear term interaction between the 2 independent variables

15228

Missing Values (%) 24.3%

Random intercept group variable: patients 1260

Random slope variable: time

Quadratic vs. cubic <.0001

time: linear 0.102 0.008 0.086 0.119 <.0001

time: quadratic -0.011 0.001 -0.012 -0.009 <.0001

time: cubic 0.000 0.000 0.000 0.000 <.0001

Group: binary (1 death in ICU , 0 discharged from ICU) 0.185 0.075 0.038 0.332 0.014 Interaction

time (linear) and group 0.057 0.008 0.041 0.074 <.0001

time (quadratic) and group removed

time (cubic) and group removed

Unstructured covariance -0.028 0.004 -0.037 -0.020 <.0001

Random slope 0.008 0.001 0.007 0.010 <.0001

(32)

Figure 3s. Kinetics of Bilirubin along 30 days from ICU admission in patients discharged from ICU

(left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

32

(33)

Kinetics of Bilirubin (from ICU discharge):

 random intercept at patient level;

 random slope at time level;

 Bilirubin (dependent variable)

 time as a continuous linear term (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 linear interaction between the 2 independent variables

14807

Quadratic vs. cubic

time: linear -0.015 0.005 -0.024 -0.005 0.003

time: quadratic time: cubic

Group: binary (1 death in ICU , 0 discharged from ICU) 0.933 0.095 0.747 1.119 <.0001 Interaction

time (quadratic) and group time (cubic) and group

Random slope 0.012 0.001 0.011 0.014 <.0001

(34)

Figure 4s. Kinetics of Bilirubin along 30 days from ICU discharge in patients discharged from ICU

(left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

34

(35)

3. Creatinine - Full model parameters Kinetics of Creatinine (from ICU admission):

 random intercept at patient level;

 random slope at time level;

 Creatinine (dependent variable)

 time as independent variable

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 Linear and quadratic term interaction between the 2 independent variables

15228

Interaction between time and group vs. no interaction 0.0011

time: linear remove

d

time: quadratic remove

d time: cubic

time (quadratic) and group -0.001 0.001 -0.002 0.000 0.015

Unstructured covariance 0.012 0.004 0.005 0.019 0.001

Random slope 0.003 0.001 0.002 0.004 <.0001

(36)

Figure 5s. Kinetics of Creatinine along 30 days from ICU admission in patients discharged from ICU

(left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

36

(37)

Kinetics of Creatinine (from ICU discharge):

 random intercept at patient level;

 random slope at time level;

 Creatinine (dependent variable)

 time as a continuous linear term (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 linear term interaction between the 2 independent variables

14807

Quadratic vs. cubic

time: linear -0.008 0.003 -0.014 -0.001 0.019

time: quadratic time: cubic

time (quadratic) and group time (cubic) and group

Random slope 0.002 0.000 0.001 0.002 <.0001

(38)

Figure 6s. Kinetics of Creatinine along 30 days from ICU discharge in patients discharged from ICU

(left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

38

(39)

4. D-dimer - Full model parameters Kinetics of D-dimer (from ICU admission):

 random intercept at patient level;

 random slope at time level;

 D-dimer (dependent variable)

 time as a continuous linear, quadratic and cubic terms (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 Quadratic and cubic terms interaction between the 2 independent variables

15228

time: linear -715.95 89.70 -891.80 -540.10 <.0001

time: quadratic 50.734 8.667 33.745 67.724 <.0001

time: cubic -0.984 0.223 -1.421 -0.547 <.0001

time (linear) and group remove

d

time (quadratic) and group -34.541 6.888 -48.049 -21.033 <.0001

time (cubic) and group 1.246 0.243 0.770 1.722 <.0001

Random intercept 1.07E+08 5929386 9.5E+07 1E+08 <.0001

Unstructured covariance ^-6189181 ³⁹⁰²⁴² ^-6954055 ^-5E+06 ^<.0001

Random slope 380115 29150 322982 437249 <.0001

Residual variance ^49507889 ^1013241 ^4.8E+07 ^5E+07 ^<.0001

(40)

Figure 7s. Kinetics of D-dimer along 30 days from ICU admission in patients discharged from ICU

(left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.

40

(41)

Kinetics of D-dimer (from ICU discharge):

 random intercept at patient level;

 random slope at time level;

 D-dimer (dependent variable)

 time as a continuous quadratic term (independent variable)

 Subject group (death in ICU and discharged from ICU) as a binary term (independent variable)

 quadratic term interaction between the 2 independent variables

14807

Interaction between time and group vs. no interaction 0.0205

time: linear remove

d

time: quadratic 5.61 1.32 3.01 8.21 <.0001

time: cubic

time (linear) and group remove

d

time (quadratic) and group 6.26 2.69 0.98 11.54 0.02

Random intercept 5911291

3 460627

7 5E+07 7E+07 <.0001

Unstructured covariance 1949842 486291 996712 3E+06 <.0001

Random slope 678267 56018 568472 788062 <.0001

Residual variance 2339341

5 524290 2.2E+07 2E+07 <.0001

(42)

Figure 8s. Kinetics of D-dimer along 30 days from ICU discharge in patients discharged from ICU

(left panel) and in patients died in ICU (right panel). Grey dots represent actual data points, blue/red points and lines represent results of linear mixed model with associated 95% confidence interval.