CENTRAL (the Cochrane Library) search strategy

#1 MeSH descriptor: [labour, Obstetric] explode all trees
#2 MeSH descriptor: [labour Pain] explode all trees
#3 MeSH descriptor: [Delivery, Obstetric] explode all trees
#4 MeSH descriptor: [Parturition] explode all trees
#5 (labo?r near (obstetric or pain* or vaginal)) or (labo?r or parturient* or child?birth or obstet* or deliver*):ti,ab
#6 #1 or #2 or #3 or #4 or #5
#7 MeSH descriptor: [Analgesia, Epidural] explode all trees
#8 MeSH descriptor: [Anesthesia, Epidural] explode all trees
#9 MeSH descriptor: [Infusions, Spinal] explode all trees
#10 MeSH descriptor: [Injections, Spinal] explode all trees
#11 epidural*:ti,ab or (spinal near (infusion* or injection*)):ti,ab or (pain near relief) or (bupivacaine or ropivacaine or mepivacaine or fentanyl or sufentanil)
#12 #7 or #8 or #9 or #10 or #11
#13 bolus* or AMB or basal infusion* or BCI or (intermittent or variable?frequency or patient?controlled):ti,ab
#14 #6 and #12 and #13

OVID MEDLINE search strategy

1 bolus*.mp. or AMB.ti,ab. or basal infusion*.mp. or BCI.ti,ab. or (intermittent or variable?frequency or patient?controlled).ti,ab.
2 exp Analgesia, Epidural/ or exp Anesthesia, Epidural/ or exp Infusions, Spinal/ or exp Injections, Spinal/ or epidural*.ti,ab. or (spinal adj3 (infusion* or injection*)).ti,ab. or (pain adj3 relief).mp. or (bupivacaine or ropivacaine or mepivacaine or fentanyl or sufentanil).mp.
3 exp labour, Obstetric/ or exp labour Pain/ or exp Delivery, Obstetric/ or Parturition/ or (labo?r adj3 (obstetric or pain* or vaginal)).mp. or (labo?r or parturient* or child?birth or obstet* or deliver*).ti,ab.
4 ((randomized controlled trial or controlled clinical trial).pt. or randomized.ab. or placebo.ab. or clinical trials as topic.sh. or randomly.ab. or trial.ti.) not (animals not (humans and animals)).sh.
5 1 and 2 and 3 and 4

OVID Embase search strategy

1 bolus*.mp. or AMB.ti,ab. or basal infusion*.mp. or BCI.ti,ab. or (intermittent or variable?frequency or patient?controlled).ti,ab.
2 exp epidural anesthesia/ or exp epidural anesthesia/ or exp intraspinal drug administration/ or epidural*.ti,ab. or (spinal adj3 (infusion* or injection*)).ti,ab. or (pain adj3 relief).mp. or (bupivacaine or ropivacaine or mepivacaine or fentanyl or sufentanil).mp.
3 exp labour/ or exp labour pain/ or exp delivery/ or birth/ or (labo?r adj3 (obstetric or pain* or vaginal)).mp. or (labo?r or parturient* or child?birth or obstet* or deliver*).ti,ab.
4 (randomized‐controlled‐trial/ or randomization/ or controlled‐study/ or multicenter‐study/ or phase‐3‐clinical‐trial/ or phase‐4‐clinical‐trial/ or double‐blind‐procedure/ or single‐blind‐procedure/ or (random* or cross?over* or multicenter* or factorial* or placebo* or volunteer*).mp. or ((singl* or doubl* or trebl* or tripl*) adj3 (blind* or mask*)).ti,ab. or (latin adj square).mp.) not (animals not (humans and animals)).sh.
5 1 and 2 and 3 and 4

WHO‐ICTRP

1 (basal infusion OR analgesia OR bolus) AND labor

ClinTrials.gov

1 labor [DISEASE] AND ( "basal infusion" OR bolus ) [TREATMENT] AND EXACT NOT "Male" [GENDER]

Data collection form

1. General information

2. Study eligibility

DO NOT PROCEED IF STUDY EXCLUDED FROM REVIEW

3. Population and setting

4. Methods

5. 'Risk of bias' assessment

See Chapter 8 of the Cochrane Handbook for Systematic Reviews of Interventions

6. Participants

Provide overall data and, if available, comparative data for each intervention or comparison group.

7. Intervention groups

Copy and paste table for each intervention and comparison group

8. Outcomes

Copy and paste table for each outcome.

9. Results

Copy and paste the appropriate table for each outcome, including additional tables for each time point and subgroup as required.

10. Applicability

11. Other information

1. Random sequence generation (checking for possible selection bias)

We described for each included study the method used to generate the allocation sequence in sufficient detail to allow an assessment of whether it should produce comparable groups.

We assessed the method as being at:

1. low risk of bias (any truly random process, e.g. random number table; computer random number generator);

2. high risk of bias (any non‐random process, e.g. odd or even date of birth; hospital or clinic record number);

3. unclear risk of bias.

2. Allocation concealment (checking for possible selection bias)

We described for each included study the method used to conceal allocation to interventions prior to assignment and will assess whether intervention allocation could have been foreseen in advance of, or during recruitment, or changed after assignment.

We assessed the methods as being at:

1. low risk of bias (e.g. telephone or central randomization; consecutively numbered sealed opaque envelopes);

2. high risk of bias (open random allocation; unsealed or non‐opaque envelopes, alternation; date of birth);

3. unclear risk of bias.

3. Blinding

4. Incomplete outcome data (checking for possible attrition bias due to the amount, nature and handling of incomplete outcome data)

We described for each included study, and for each outcome or class of outcomes, the completeness of data including attrition and exclusions from the analysis. We stated whether attrition and exclusions were reported and the numbers included in the analysis at each stage (compared with the total randomized participants), reasons for attrition or exclusion where reported, and whether missing data were balanced across groups or were related to outcomes. Where sufficient information is reported, or could be supplied by the trial authors, we re‐included missing data in the analyses which we undertook.

We assessed methods as being at:

1. low risk of bias (e.g. no missing outcome data; missing outcome data balanced across groups);

2. high risk of bias (e.g. numbers or reasons for missing data imbalanced across groups; 'as treated' analysis done with substantial departure of intervention received from that assigned at randomization);

3. unclear risk of bias.

5. Selective reporting (checking for reporting bias)

We described for each included study how we investigated the possibility of selective outcome reporting bias and what we found.

We assessed the methods as being at:

1. low risk of bias (where it is clear that all of the study's pre‐specified outcomes and all expected outcomes of interest to the review have been reported);

2. high risk of bias (where not all the study's pre‐specified outcomes have been reported; one or more reported primary outcomes were not pre‐specified; outcomes of interest are reported incompletely and so cannot be used; study fails to include results of a key outcome that would have been expected to have been reported);

3. unclear risk of bias.

6. Other bias (checking for bias due to problems not covered by 1 to 5 above)

We described for each included study any important concerns we had about other possible sources of bias.

7. Overall risk of bias

We made explicit judgements about whether studies are at high risk of bias, according to the criteria given in the Cochrane Handbook for Systematic Reviews of Interventions (Higgins 2011). With reference to items 1 to 6 above, we assessed the likely magnitude and direction of the bias and whether we considered it likely to impact on the findings. We planned to explore the impact of the level of bias through undertaking sensitivity analyses ‐ see Sensitivity analysis.