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Table 1 Patient characteristics of all patients and comparison between survivors and non-survivors

From: Skeletal muscle quality as assessed by CT-derived skeletal muscle density is associated with 6-month mortality in mechanically ventilated critically ill patients

  All patients
N = 491
Survivors1
(n = 299)
Non-survivors1
(n = 165)
P value survivors vs. non-survivors
  Mean/median/n SD/IQR/% Mean/median/n SD/IQR/% Mean/median/n SD/IQR/%  
Age, years 58 ±18 55 ±18 67 ±14 <0.001
Sex, male, n (%) 305 62% 191 64% 93 56% 0.135
BMI, kg/m2 25.2 ±4.3 25.5 ±4.4 24.6 ±4.3 0.042
 Underweight2, n (%) 19 4.1% 11 3.7% 8 4.8% 0.291
 Normal weight2, n (%) 238 51.3% 145 48.5% 93 56.4%  
 Overweight2, n (%) 158 34.1% 108 36.1% 50 30.3%  
 Obesity2, n (%) 49 10.6% 35 11.7% 14 8.5%  
APACHE II score 24 ±8 22 ±8 27 ±8 <0.001
Admission category, n (%)        0.001
 Medical 248 50.5% 130 43% 102 62%  
 Surgical 243 49.5% 169 57% 63 38%  
Admission diagnosis, n (%)        <0.001
 Cardiovascular 32 6.5% 18a 6.0% 14a 8.5%  
 Metabolic/renal 15 3.1% 8a 2.7% 6a 3.6%  
 Neurologic 41 8.4% 19a 6.4% 16a 9.7%  
 Post-resuscitation 28 5.7% 16a 5.4% 11a 6.7%  
 Post-surgery 149 30.3% 95a 31.8% 50a 30.3%  
 Respiratory insufficiency 68 13.8% 40a 13.4% 25a 15.2%  
 Sepsis 31 6.3% 14a 4.7% 15a 9.1%  
 Trauma 94 19.1% 74a 24.7% 13b 7.9%  
 Other 33 6.7% 15a 5.0% 15a 9.1%  
Length of hospital stay before ICU admission, days 0 0–4 0 0–4 0 0–6 0.166
Time from ICU admission to CT scan, days 0 0–1 0 0–1 0 0–1 0.277
Skeletal muscle area, cm2 136.5 ±39.0 143.5 ±38.9 120.3 ±33.0 <0.001
Skeletal muscle index, cm2/m2 44.8 ±11.0 46.6 ±10.6 40.4 ±9.9 <0.001
Low skeletal muscle area3, n (%) 312 63.5% 163 54.5% 137 83.0% <0.001
SMD, HU 29.9 ±11.7 31.4 ±11.7 25.1 ±9.4 <0.001
IMAT, cm2 13.6 8.4–24.3 13.3 7.9–23.2 17.1 10.5–27.1 0.004
Visceral adipose tissue, cm2 (n = 337) 96.7 49.3–170.6 95.8 50.9–178.1 108.1 54.1–177.5 0.593
Subcutaneous adipose tissue, cm2 (n = 337) 132.7 90.2–182.4 133.7 89.8–189.2 127.7 95.7–176.2 0.440
  1. 1Survivors and non-survivors 6 months after ICU admission
  2. 2WHO categories: underweight, BMI <18.5; normal weight: BMI 18.5–24.9; overweight: BMI 25–29.9; obesity: BMI ≥30 [42]
  3. 3Defined by skeletal muscle area: <170 cm2 for males and <110 cm2 for females [9]
  4. a, bValues in the same row not sharing the same superscript letter are significantly different in a post-hoc Bonferroni analysis
  5. Values in bold indicate statistically significant p values
  6. APACHE Acute Physiological, Age, and Chronic Health Evaluation, BMI, body mass index, CT computed tomography, HU Hounsfield Units, ICU intensive care unit, IMAT intermuscular adipose tissue, IQR interquartile range, SD standard deviation, SMD skeletal muscle density