Abstract: We included 17 RCTs comprising a total of 2264 participants; 13 RCTs included 1954 adult participants, and four RCTs included 310 children. This update included 12 new studies, excluded one previously included study, and excluded five new trials. One trial awaits classification. All trials limited inclusion to inpatients with community-acquired pneumonia (CAP), with or without healthcare-associated pneumonia (HCAP). We assessed the risk of selection bias and attrition bias as low or unclear overall. We assessed performance bias risk as low for nine trials, unclear for one trial, and high for seven trials. We assessed reporting bias risk as low for three trials and high for the remaining 14 trials. Corticosteroids significantly reduced mortality in adults with severe pneumonia (RR 0.58, 95% CI 0.40 to 0.84; moderate-quality evidence), but not in adults with non-severe pneumonia (RR 0.95, 95% CI 0.45 to 2.00). Early clinical failure rates (defined as death from any cause, radiographic progression, or clinical instability at day 5 to 8) were significantly reduced with corticosteroids in people with severe and non-severe pneumonia (RR 0.32, 95% CI 0.15 to 0.7; and RR 0.68, 95% CI 0.56 to 0.83, respectively; high-quality evidence). Corstocosteroids reduced time to clinical cure, length of hospital and intensive care unit stays, development of respiratory failure or shock not present at pneumonia onset, and rates of pneumonia complications. Among children with bacterial pneumonia, corticosteroids reduced early clinical failure rates (defined as for adults, RR 0.41, 95% CI 0.24 to 0.70; high-quality evidence) based on two small, clinically heterogeneous trials, and reduced time to clinical cure. Hyperglycaemia was significantly more common in adults treated with corticosteroids (RR 1.72, 95% CI 1.38 to 2.14). There were no significant differences between corticosteroid-treated people and controls for other adverse events or secondary infections (RR 1.19, 95% CI 0.73 to 1.93). Corticosteroid therapy reduced mortality and morbidity in adults with severe CAP; the number needed to treat for an additional beneficial outcome was 18 patients (95% CI 12 to 49) to prevent one death. Corticosteroid therapy reduced morbidity, but not mortality, for adults and children with non-severe CAP. Corticosteroid therapy was associated with more adverse events, especially hyperglycaemia, but the harms did not seem to outweigh the benefits.

Plain-language summary: We included 17 studies evaluating systemic corticosteroid therapy (given intravenously or by tablets) for people with pneumonia (2264 participants; 1954 adults and 310 children). We included 12 new studies in this update and excluded one previously included study. All included studies evaluated people who had acquired pneumonia in the community (community-acquired pneumonia (CAP)) being treated in the hospital; no studies assessed people who had developed pneumonia while in hospital or who were on breathing machines (mechanically ventilated). Eight trials did not report funding sources; seven were funded by academic sponsors; one was funded by a pharmaceutical company; and one reported receiving no funding. Corticosteroids reduced deaths in adults with severe CAP, but not in people with non-severe CAP. Eighteen adults with severe CAP need to be treated with corticosteroids to prevent one death. People with CAP treated with corticosteroids had lower clinical failure rates (death, worsening of imaging studies, or no clinical improvement), shorter time to cure, a shorter hospital stay, and fewer complications. We found good-quality evidence that corticosteroids reduced clinical failure rates in children with pneumonia, but the data were based on a small number of children with different types of pneumonia. People treated with corticosteroids had higher blood glucose levels (hyperglycaemia) than those not treated with corticosteroids. Corticosteroid treatment was not associated with increased rates of other serious adverse events. Corticosteroids were beneficial for adults with severe CAP. People with non-severe CAP may also benefit from corticosteroid therapy, but with no survival advantage. We downgraded the quality of the evidence due to issues with study design, unclear results, or results that were not similar across studies. For the outcomes of death and clinical failure in adults, we graded the quality of the evidence as moderate. For the outcomes of clinical failure in people with severe CAP, non-severe CAP, and in children, we graded the quality of the evidence as high.