Exploring the heterogeneity of effects of corticosteroids on acute respiratory distress syndrome: a systematic review and meta-analysis.
BACKGROUND
The effectiveness of corticosteroid therapy on the mortality of acute respiratory distress syndrome (ARDS) remains under debate. We aimed to explore the grounds for the inconsistent results in previous studies and update the evidence.


METHODS
We searched MEDLINE, Cochrane Central Register of Controlled Trials and Web of Science up to December 2013. Eligible studies included randomized clinical trials (RCTs) and cohort studies that reported mortality and that had corticosteroid nonusers for comparison. The effect of corticosteroids on ARDS mortality was assessed by relative risk (RR) and risk difference (RD) for ICU, hospital, and 60-day mortality using a random-effects model.


RESULTS
Eight RCTs and 10 cohort studies were included for analysis. In RCTs, corticosteroids had a possible but statistically insignificant effect on ICU mortality (RD, -0.28; 95% confidence interval (CI), -0.53 to -0.03 and RR, 0.55; 95% CI, 0.24 to 1.25) but no effect on 60-day mortality (RD, -0.01; 95% CI, -0.12 to 0.10 and RR, 0.97; 95% CI, 0.75 to 1.26). In cohort studies, corticosteroids had no effect on ICU mortality (RR, 1.05; 95% CI, 0.74 to 1.49) but non-significantly increased 60-day mortality (RR, 1.30; 95% CI, 0.96 to 1.78). In the subgroup analysis by ARDS etiology, corticosteroids significantly increased mortality in influenza-related ARDS (three cohort studies, RR, 2.45, 95% CI, 1.40 to 4.27).


CONCLUSIONS
The effects of corticosteroids on the mortality of ARDS differed by duration of outcome measures and etiologies. Corticosteroids did not improve longer-term outcomes and may cause harm in certain subgroups. Current data do not support routine use of corticosteroids in ARDS. More clinical trials are needed to specify the favorable and unfavorable subgroups for corticosteroid therapy.
Sheng-Yuan
SY
Ruan
Hsien-Ho
HH
Lin
Chun-Ta
CT
Huang
Ping-Hung
PH
Kuo
Huey-Dong
HD
Wu
Chong-Jen
CJ
Yu
D000305:Adrenal Cortex Hormones / Q000627:therapeutic use*; D018849:Controlled Clinical Trials as Topic / Q000379:methods / Q000401:mortality; D006801:Humans; D009026:Mortality / Q000639:trends; D012128:Respiratory Distress Syndrome / Q000175:diagnosis* / Q000188:drug therapy* / Q000401:mortality; D016896:Treatment Outcome
D000305:Adrenal Cortex Hormones