Nordstrom 1997

Methods	2‐arm placebo‐controlled randomised trial.
Participants	Between 16th December 1993 and 6th October 1994, 1000 parturients were randomised in a hospital setting in Sweden. The population comprised women of unspecified parity, a singleton pregnancy, at both high and low risk for PPH, who delivered by vaginal delivery. Exclusion criteria were not specified.
Interventions	10 IU of oxytocin administered by an intravenous bolus (n = 513) versus placebo or control (n = 487).
Outcomes	The study recorded the following outcomes: PPH at 500, PPH at 1000, additional uterotonics, transfusion, manual removal of placenta, blood loss (mL), third‐stage duration (min).
Notes	Contact with study authors for additional information: no. Additional data from authors: no.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	The randomisation was computer‐generated.
Allocation concealment (selection bias)	Low risk	Ampoules were prepared at the hospital pharmacy and consecutively‐numbered.
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"The content of the ampullas was unknown to mothers, midwives and doctors until the study was completed."
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Assessors were blinded to treatment allocations.
Objective assessment of blood loss	High risk	Investigators evaluated blood loss "by measuring collected blood and adding what was estimated to have been absorbed by surgical cloths and tissues."
Incomplete outcome data (attrition bias) All outcomes	Low risk	Data were collected completely from all randomised study participants.
Selective reporting (reporting bias)	Unclear risk	The protocol of the study was unavailable for verification.
Intention to treat analysis	Low risk	All those who were enrolled and randomly allocated to treatment were included in the analysis, in the groups to which they were randomised.
Funding source	Low risk	The study was supported by funding from the County Council and County Health Authority Research and Development Foundation in the County of Jämtland, Sweden (public funding).