Block 1977.

Study characteristics
Methods	Type of study: RCT Method of treatment allocation: computer‐generated randomisation sequence. Coded drug boxes were provided. Stratification: none stated Placebo: yes, normal saline Sample size calculation: no Intention‐to‐treat analyses: no
Participants	Location: Department of Gynecology and Obstetrics at the University of Oklahoma College of Medicine, Oklahoma City, Oklahoma, USA Eligibility criteria: women with preterm labour and PROM Gestational age range: not stated Exclusion criteria: not stated Total recruited: 167 women randomised (14 delivered elsewhere and were lost to follow‐up). Data are available on 169 infants (60 infants in the betamethasone arm, 41 infants in the methylprednisolone arm, and 54 infants in the control arm).
Interventions	Group A: 12 mg betamethasone IM repeated after 24 hours if delivery had not occurred Group B: 125 mg methylprednisolone IM repeated after 24 hours if delivery had not occurred GRoup C: Control group received 1 mL normal saline IM repeated after 24 hours if delivery had not occurred. If there was evidence of progressive cervical dilatation an alcohol infusion was given in order to attempt to delay delivery for at least 48 hours. In women with PROM delivery was induced if serial white blood cell counts or temperatures became elevated regardless of time elapsed since drug administration.
Outcomes	Fetal/neonatal outcomes reported (fetal death, neonatal death, RDS, need for mechanical ventilation/CPAP)
Notes	Further information was requested from the study authors but there was no reply. Dates of the study: not stated in manuscript, the study is coded as 1970s for the review Funding sources: quote: "supported in part by a grant from Schering Corporation, Kenilworth, New Jersey, USA; and The Upjohn Company, Kalamazoo, Michigan, USA" Declarations of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Quote:"Computer generated randomisation sequence."
Allocation concealment (selection bias)	Low risk	Quote:"Consecutively numbered boxes containing randomly selected study drug or placebo."
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Clinicians were never aware of the contents of the coded box. Placeob was saline so it is likely that participants were blinded.
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Blinding of outcome assessors was not described.
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	14 (10%) women delivered elsewhere and were lost to follow‐up. 6 (4%) women were excluded from analyses as they failed to complete the protocol (1 in the betamethasone group, 2 in the methylprednisolone group, and 3 in the control group).
Selective reporting (reporting bias)	Low risk	Study protocol not available, but appears to report on all pre‐specified outcomes.
Other bias	Low risk	Nothing to indicate any other sources of bias.