Serum Cystatin C and Coronavirus Disease 2019: A Potential Inflammatory Biomarker in Predicting Critical Illness and Mortality for Adult Patients

Table 4

Association of cystatin C with mortality and critical illness in COVID-19 patients without chronic kidney disease.

Cystatin C levels, mg/L	Quartile 1; (<0.89)	Quartile 2; (0.89-1.06)	Quartile 3; (1.06-1.31)	Quartile 4; (≥1.31)	ln-transformed Cystatin C, mg/L
No. of death/total	2/110	5/110	7/119	33/116
Crude model	1; (ref.)	2.57; (0.49, 13.55); 0.2652	3.37; (0.69, 16.61); 0.1346	21.47; (5.01, 92.04); <0.0001	17.69; (6.58, 47.52); <0.0001
Model 1	1; (ref.)	2.22; (0.41, 12.01); 0.3560	1.63; (0.32, 8.37); 0.5569	7.67; (1.70, 34.69); 0.0081	5.95; (2.01, 17.63); 0.0013
Model 2	1; (ref.)	2.40; (0.43, 13.56); 0.3204	1.85; (0.35, 9.83); 0.4689	8.40; (1.75, 40.19); 0.0077	5.73; (1.79, 18.32); 0.0032
Model 3	1; (ref.)	5.25; (0.56, 49.57); 0.1474	3.87; (0.43, 34.58); 0.2259	16.77; (1.99, 141.06); 0.0095	6.61; (1.64, 26.70); 0.0080
No. of critical/total	10/110	9/110	16/119	47/116
Crude model	1; (ref.)	0.89; (0.35, 2.29); 0.8104	1.55; (0.67, 3.59); 0.3022	6.81; (3.22, 14.40); <0.0001	18.78; (7.82, 45.08); <0.0001
Model 1	1; (ref.)	0.79; (0.30, 2.05); 0.6220	0.97; (0.40, 2.34); 0.9518	3.60; (1.59, 8.11); 0.0020	10.07; (3.90, 26.05); <0.0001
Model 2	1; (ref.)	0.77; (0.29, 2.02); 0.5918	1.02; (0.42, 2.47); 0.9704	3.51; (1.51, 8.16); 0.0036	8.89; (3.28, 24.13); <0.0001
Model 3	1; (ref.)	0.88; (0.32, 2.37); 0.7969	1.06; (0.42, 2.66); 0.8987	2.96; (1.20, 7.35); 0.0190	6.37; (2.03, 19.93); 0.0015

APACHE II: Acute Physiology and Chronic Health Evaluation II; COVID-19: coronavirus disease 2019. Data are shown as odds ratios (OR) and 95% confidence intervals (CI). Modeled as per unit increase of ln-transformed cystatin C. Model 1 adjusted for age and sex. Model 2 adjusted for model 1 plus chronic pulmonary disease, hypertension, diabetes, cardiovascular disease, and cerebrovascular disease. Model 3 adjusted for model 1 plus model 2 plus blood creatinine and APACHE II score.