| Methods |
Single‐centred randomised controlled trial, 2 arms with individual randomisation. |
| Participants |
Location: Australia, University hospital.
Timeframe: 1963‐1964.
Eligible criteria: pregnant women less than 37 weeks' gestation with preterm labour and; moderate to strong uterine contractions; cervical dilatation not more than 4‐5 cm; intact membranes; minimal antepartum haemorrhage, if present; twins.
Exclusion criteria: advanced cervical dilatation; rupture membranes; accidental antepartum haemorrhage.
Total recruited: 44 women, 22 to isoxsuprine (vs) 22 to placebo. |
| Interventions |
1) Isoxsuprine.
Dose: intramuscular injection every 3 hrs (average 80 mg in first 24 hrs) until contraction ceased for 36 hrs.
Maintenance: 40‐60 mg oral/day.
2) Placebo. |
| Outcomes |
Primary outcomes: perinatal death (7 days).
Secondary outcomes: neonatal death. |
| Notes |
Prenatal corticosteroid use: not stated. |
| Risk of bias |
| Bias |
Authors' judgement |
Support for judgement |
| Random sequence generation (selection bias) |
Unclear risk |
This was described as a double‐blind trial but there was no information on randomisation methods. |
| Allocation concealment (selection bias) |
Unclear risk |
This was a placebo‐controlled double‐blind trial. It was not clear whether study medications were identical. Methods of allocation at the point of randomisation were not described. |
| Blinding of participants and personnel (performance bias)
All outcomes |
Low risk |
This was a described as a double‐blind trial. |
| Blinding of outcome assessment (detection bias)
All outcomes |
Unclear risk |
Not clear whether or not those collecting outcome data were aware of treatment allocation. |
| Incomplete outcome data (attrition bias)
All outcomes |
Unclear risk |
It was not entirely clear how many women were randomised to each group. One table suggests that there were 27 in the intervention group and 24 in the control group, later it said that 48 women were included in the analysis. Women who had not given birth at the end of the trial period were excluded from the analysis (2 in each group). |
| Selective reporting (reporting bias) |
Unclear risk |
It appeared that some analysis may have been carried out retrospectively as outcomes were not set out in the methods. The main outcome (prolongation of pregnancy) was reported as a mean without SD. |
| Other bias |
Unclear risk |
There was very little information on study methods. There were 5 multiple pregnancies in the intervention group and 2 in the control group. |
