Types of studies

We included all published and unpublished randomized controlled trials and cluster randomised trials that evaluated the efficacy of early labour assessment interventions and any support intervention for women in the latent phase of labour. We included studies published in abstract form only, if the abstract contained sufficient information to assess eligibility and risk of bias, and if the results were described in detail. We did not include quasi‐randomised trials.

Types of participants

We included pregnant women in this review. However, we excluded trials with participants who were high‐risk pregnant women, such as those with mental health conditions (Fenwick 2015; Jesse 2015; Toohill 2014).

Types of interventions

We included trials examining assessment programmes in early labour that aimed to assess physical and emotional well‐being and progress in labour with a view to planning hospital admission, along with support interventions in early labour to optimise outcomes for women and babies.

We included interventions that were provided either by healthcare professionals caring for labouring women (e.g. physicians, nurses, or midwives), or by a trained female companion (e.g. doula). Both individual or group interventions were included. We included interventions that were administered at the maternity unit, the woman's home, over the telephone, online (e.g. websites or social media), or via electronic devices.

Examples of assessment in early labour include:

• home or hospital physical examination by health professional to assess stage of labour;

• home, hospital or telephone assessment of progress in labour (by maternal report);

• home, hospital or telephone assessment of psychological well‐being.

Each of these types of assessment might include advice to women about when to seek hospital admission.

Examples of support that encompass psychosocial interventions in early labour include:

• psychosocial supportive interventions (e.g. emotional support for the labouring woman and her birth companions, advice and guidance about her labour, attention to physical comfort, non‐directive counselling, maintaining conversation, telephone‐based peer support, counselling visits at home);

• cognitive behavioural therapy (CBT), cognitive and behavioural interventions (e.g. mental image training, stress reduction program, relaxation training program);

• exercise therapies (e.g. exercise program, fitness, physical activity);

• non‐pharmacological alternative strategies (e.g. acupuncture, Reiki, hypnosis, guided imagery, meditation);

• comfort measures (e.g. massage, aromatherapy, or music therapy).

Support also encompasses educational interventions. These aim to distribute new knowledge or promote coping skills to pregnant women, such as information about the progress of labour, managing the latent phase, or when to go to the labour ward. Examples of educational interventions include:

• information about relaxation;

• information about coping with labour pain;

• information about labour progress.

Interventions were compared to no intervention, other interventions or usual care. Usual care was defined as the care that might be provided to pregnant women if they were not included in the clinical trial.

We included combined interventions that consisted of two or more types of interventions in this review (for example, interventions including both assessment and support). We excluded studies that included support interventions combined with pharmacological treatments. We excluded any educational interventions that provided women with information without any personal contact and communication, e.g. giving women a booklet. We did not apply any language restrictions.

Types of outcome measures

Electronic searches

We searched the Cochrane Pregnancy and Childbirth's Trials Register by contacting their Information Specialist (31 October 2016).

The Register is a database containing over 23,000 reports of controlled trials in the field of pregnancy and childbirth. For full search methods used to populate Pregnancy and Childbirth’s Trials Register, including the detailed search strategies for CENTRAL, MEDLINE, Embase and CINAHL, the list of handsearched journals and conference proceedings, and the list of journals reviewed via the current awareness service, please follow this link to the editorial information about the Cochrane Pregnancy and Childbirth in the Cochrane Library and select the ‘Specialized Register ’ section from the options on the left side of the screen.

Briefly, the Cochrane Pregnancy and Childbirth's Trials Register is maintained by their Information Specialist and contains trials identified from:

1. monthly searches of the Cochrane Central Register of Controlled Trials (CENTRAL);

2. weekly searches of MEDLINE (Ovid);

3. weekly searches of Embase (Ovid);

4. monthly searches of CINAHL (EBSCO);

5. handsearches of 30 journals and the proceedings of major conferences;

6. weekly current awareness alerts for a further 44 journals, plus monthly BioMed Central email alerts.

Search results are screened by two people and the full text of all relevant trial reports identified through the searching activities described above is reviewed. Based on the intervention described, each trial report is assigned a number that corresponds to a specific Pregnancy and Childbirth review topic (or topics), and is then added to the Register. The Information Specialist searches the Register for each review using this topic number rather than keywords. This results in a more specific search set, which has been fully accounted for in the relevant review sections (Included studies; Excluded studies).

In addition, we searched ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for unpublished, planned and ongoing trial reports (31 Octoer 2016) (see: Appendix 1).

Searching other resources

We contacted key personnel and organisations in the relevant field for published and unpublished references.

We also searched the reference lists of retrieved studies.

We did not apply any language or date restrictions.

Selection of studies

Review authors S Kobayashi (SK) and K Takehara (KT), independently assessed full text of all potential studies identified as a result of the search strategy for inclusion. We resolved any disagreement through discussion or, if required, we consulted the third review author, H Sasaki (HS).

We created a study flow diagram to map out the number of records identified, included and excluded (Figure 1).

Figure 1

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Study flow diagram.

Data extraction and management

We designed a form to extract data. For eligible studies, two review authors extracted data using the agreed form. We resolved discrepancies through discussion or, if required, we consulted the third review author. Data were entered into Review Manager 5.3 software (RevMan 2014), and checked for accuracy.

When information regarding any of the above was unclear, for example only an abstract was available, we attempted to contact the authors of the original reports to ask them to provide further details.

Assessment of risk of bias in included studies

We (SK, KT) independently assessed risk of bias for each study using the criteria outlined in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). Any disagreement was resolved by discussion or by involving a third assessor (HS).

Measures of treatment effect

Unit of analysis issues

Dealing with missing data

We noted the levels of attrition of included studies. In future updates, if more eligible studies are included, we will explore the impact of including studies with high levels of missing data in the overall assessment of treatment effect by using sensitivity analysis.

For all outcomes, we carried out analyses, as far as possible, on an intention‐to‐treat basis, that is, we attempted to include all participants randomized to each group in the analyses. The denominator for each outcome in each trial was the number randomized minus any participants whose outcomes were known to be missing.

Assessment of heterogeneity

We assessed statistical heterogeneity in each meta‐analysis using the Tau², I² and Chi² statistics. We regarded heterogeneity as substantial if I² was greater than 30% and either Tau² was greater than zero, or there was a low P value (less than 0.10) in the Chi² test for heterogeneity. If we identified substantial heterogeneity (above 30%), we planned to explore it by prespecified subgroup analysis.

Assessment of reporting biases

In future updates, if there are 10 or more studies in the meta‐analysis, we will investigate reporting biases (such as publication bias) using funnel plots. We will assess funnel plot asymmetry visually. If asymmetry is suggested by a visual assessment, we will perform exploratory analyses to investigate it.

Data synthesis

We carried out statistical analysis using the Review Manager 5.3 software (RevMan 2014). We used fixed‐effect meta‐analysis for combining data where it was reasonable to assume that studies were estimating the same underlying treatment effect, that is, where trials were examining the same intervention, and the trials’ populations and methods were judged to be sufficiently similar.

If clinical heterogeneity was sufficient to lead us to expect that the underlying treatment effects differed between trials, or if substantial statistical heterogeneity was detected, we used random‐effects meta‐analysis to produce an overall summary, where we considered an average treatment effect across trials to be clinically meaningful. The random‐effects summary was treated as the average range of possible treatment effects, and we have discussed the clinical implications of treatment effects differing between trials. If we considered that the average treatment effect was not clinically meaningful, we planned not to combine trials. When we have used random‐effects analyses, the results have been presented as the average treatment effect with 95% confidence intervals.

Subgroup analysis and investigation of heterogeneity

If we identified substantial heterogeneity, we planned to investigate it using subgroup analyses and sensitivity analyses and to consider whether an overall summary was meaningful. If it was, we planned to use random‐effects analysis to produce it.

We planned the following subgroup analyses:

• the use of epidural or any regional anaesthesia by parity (nulliparity versus multiparity).

We were unable to carry out this planned subgroup analysis due to insufficient data.

In future updates if subgroup analysis is carried out, we will assess subgroup differences using interaction tests available within the current version of Review Manager. We will report the results of subgroup analyses quoting the Chi² statistic and P value, and the interaction test I² value.

Sensitivity analysis

We did not carry out a sensitivity analysis. However, in future updates of this review, we will perform sensitivity analysis to assess the affect of results due to the high risk of bias of some of the included trials. For the purpose of this sensitivity analysis, 'high quality' will be defined as a trial having a low risk of bias for random sequence generation and allocation concealment, and missing less than 20% of the data, given the stated importance of attrition as a quality measure (Tierney 2005). We will include only the primary outcome in the sensitivity analyses. If statistical heterogeneity is evident, we will carry out the sensitivity analysis to explore the effects of fixed‐effect or random‐effects analyses. Furthermore, if we made any assumptions for ICC values used in cluster‐randomised trials, we will perform a sensitivity analysis using a range of ICC values.