Table S4. shows the variation trend of plasma mtDNA associated with ARDS outcomes.

Variable	Overall	Declined	Elevated	P value
Number	21	14	7
Ventilator-free days	14±10	18±8	6±9	0.03
ICU stay	20±9	20±8	20±11	0.55
Mortality (%)	4 (19.0%)	1 (7.1%)	3 (42.9%)	0.09

Data are presented as mean ± SD or median (interquartile range) if not normally distributed. mtDNA, mitochondria DNA. Decrease Group means patients’ mtDNA levels declined by time (Day 1, Day 3 and Day 7); Increase Group means patients’ mtDNA levels rose by time (Day1, Day3 and Day7). See Table 1 legend for expansion of other abbreviation.