Campbell 2006.
| Methods | RCT | |
| Participants | 600 nulliparous, low‐income, under‐insured pregnant women (300 doula group, 300 control group) booked for delivery at a hospital in New Jersey, USA were enrolled between 12 and 38 weeks' gestation. They were considered low risk, with no contraindications to labour and had a female friend or relative willing to act as their lay doula. The doula was in addition to support people of their own choosing | |
| Interventions | Intervention: continuous support by a female friend or relative who had 2, 2‐hour sessions about labour support. The training sessions were conducted for nearly all of the lay caregivers when the participants were 34 to 36 weeks' gestation. Control group: support people of their own choosing |
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| Outcomes | Labour length, epidural analgesia, oxytocin augmentation, cervical dilation at epidural insertion, length of second stage labour, caesarean birth, 1‐min Apgar score > 6, 5‐min Apgar score > 6, delayed initiation of breastfeeding | |
| Notes | Epidural analgesia was available and EFM was used routinely Dates of study: enrolment took place between 1998 and 2002 Funding: Johnson & Johnson provided a small stipend to complete the data analysis. "Johnson & Johnson did not influence the design and conduct of the study or the analysis and interpretation of the data." Conflicts of interest: not reported. |
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| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Low risk | "Computer generated randomisation scheme" |
| Allocation concealment (selection bias) | Low risk | Consecutively‐numbered, sealed opaque envelopes contained treatment assignments. After obtaining consent, a research assistant opened the next envelope. It was unclear whether the research assistant enrolling the woman was the same one that opened the envelope |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | Labour room staff, participants, and the participant's caregivers were not blinded to group assignment |
| Blinding of outcome assessment (detection bias) All outcomes | High risk | Medical record abstraction was done by the author who was not blinded. The 6‐week questionnaire data collection was not blinded |
| Incomplete outcome data (attrition bias) All outcomes | High risk | Medical record information was completed for 97.7% of the sample (82.3% in the intervention group and 94.3% in the control group). The differential rates are due to withdrawals from the intervention group for doula related reasons (incomplete training and not being present during labour). The 6‐week questionnaire was completed for 82.3% of the sample. Only those women included in the study at delivery had the opportunity to complete the questionnaire and thus the differential completion rate between groups remained (76.3% in the intervention group and 88.3% in the control group). The differential withdrawals could introduce selection bias |
| Selective reporting (reporting bias) | Low risk | All outcomes were reported |
| Other bias | Unclear risk | The training of the doulas giving the intervention was done by the research assistant, who was herself a doula. This same research assistant enrolled all study participants |