Study	Reason for exclusion
Adewole 1993	This study examined breast stimulation and used a cross‐over design. Women were allocated to either breast stimulation versus no stimulation; after 3 days, if labour had not started women crossed over into the other study group.
Damania 1988	Very little information was provided on study methods. It was not clear this was a RCT.
Damania 1992	In this study breast stimulation was compared with an oxytocin infusion. It was not clear that women in the oxytocin group were discharged home.
Di Lieto 1989	This study used a cross‐over design.
Doany 1997	In this study intravaginal PGE₂ with or without membrane sweeping was compared with placebo with or without membrane sweeping. Complex interventions or interventions involving membrane sweeping are not included in this review.
Dorfman 1987	In this study women received a range of homeopathic herbal preparations versus placebo. The intervention was to prepare women for childbirth generally rather than to induce labour.
Elliott 1984	This study focused on breast stimulation and used a cross‐over design.
Evans 1983	It was not clear that this was a RCT: "the assignment [of medication] to patients was by consecutive entry into either of the studies". The paper described findings for 2 separate studies both examining the use of intracervical porcine ovarian relaxin. The first study appeared to be conducted in hospital and women receiving medication were compared with a control group. In the "outpatient study" there was no control group; women received either 2 mg or 4 mg of relaxin 5 to 7 days before scheduled induction; no outcomes were reported relevant for inclusion in the review.
Garry 2000	This study compared castor oil with no treatment, women were alternately allocated to groups; otherwise there was little information on methods.
Griffin 2003	This study was reported in a brief abstract and insufficient information was available on methods and results to include the study. We contacted the study author and further data are not available.
Herabutya 1992	This study examined intracervical prostaglandin. Little information was provided on study methods. Women "randomized" to the intervention group received intracervical PGE₂ and then monitored for 4 h to 6 h, some had a repeat dose after 6 h, some had a repeat dose the next day and if labour did not start on the third day these women were admitted to hospital for amniotomy and oxytocin infusion. It was not clear what happened to women in the control group other than that they had weekly fetal monitoring; these women were not admitted unless there were signs of abnormality or until they reached 44 weeks' gestation. The management of women in the 2 groups was so different that results are difficult to interpret.
Kadar 1990	This study focused on nipple stimulation. Group allocation was by a quasi‐randomised method; there were serious protocol violations and analysis was not by randomisation group making results very difficult to interpret.
Kaul 2004	This study focused on membrane sweeping. This intervention is not included in this review.
Krammer 1995	This study was reported in a very brief abstract. No original data were presented in the results.
Magann 1999	This study compared PGE₂ and membrane sweeping. Membrane sweeping is not included in this review.
Manidakis 1999	This study was reported in a brief abstract. It was not clear that it was a RCT. We were unable to find contact details for the author to obtain further information.
Moghtadaei 2007	This study focused on extra‐amniotic saline infusion, an intervention rarely used nowadays. It was not clear that this intervention was carried out in an outpatient setting.
Ohel 1996	This quasi randomised trial compared women receiving vaginal PGE₂ with expectant management. Analysis was not by randomisation group. Of 96 cases randomised to PGE₂ 26 preferred expectant management and were therefore omitted from the analysis. As there was no intention‐to‐treat analysis results of this study were very difficult to interpret.
Rayburn 1988	In this study some of the women included in the study were admitted to hospital rather that being treated as outpatients. No separate results were available for women in the outpatient group.
Rezk 2014	This RCT was not conducted in outpatient setting.
Salamalekis 2000	In this study membrane sweeping was compared with oxytocin for labour induction. It was not clear that women were discharged home after interventions and membrane sweeping is not included in this review.
Salmon 1986	This study focused on breast stimulation and used a cross‐over design. Women were allocated to either breast stimulation versus no stimulation; after 3 days, if labour had not started women crossed over into the other study group.
Spallicci 2007	The intervention in this trial was an intracervical injection of hyaluronidase. This intervention is no longer used in clinical practice.
Voss 1996	It was not clear that this intervention was carried out in an outpatient setting or that women were discharged home after treatment.
Ziaei 2003	This study compared dexamethasone with oxytocin. it was not clear that the intervention was carried out in an outpatient setting.

h: hour/s
 RCT: randomised controlled trial