Table 1.

Details of five meta-analyses (MAs) based on five randomized controlled trials (RCTs) on the value of cardiotocography (CTG) combined with fetal ECG ST interval analysis (CTG+ST) for fetal surveillance in labor

Meta-analysis	Cochrane review Neilson (2012)	European MA Becker et al. (2012)	American MA Potti & Berghella (2012)	Stockholm MA Salmelin et al. (2013)	IPD MA Schuit et al. (2013)
Type of meta-analysis	Aggregate	Aggregate	Aggregate	Aggregate	Individual participant data
Data collection	5 RCTs, principal authors of Swedish and French RCTs contacted for missing data	5 RCTs, principal authors of Swedish, Finnish, French and Dutch RCTs among authors to European and IPD MAs	5 RCTs, only data used in original articles are used	4 RCTs, only data used in original articles are used	4 RCTs, IPD provided by principal investigators: all randomized cases from Swedish and French RCTs included, from Finnish RCT 11 exclusions, from Dutch RCT 14 exclusions
Measures of treatment effect	RR with 95% CI (fixed-/random-effect model as appropriate); fixed-effect when no heterogeneity	RR with 95% CI (fixed-/random-effect model as appropriate); fixed effect when no heterogeneity	RR with 95% CI (fixed-/random-effect models as appropriate); fixed-effect when no heterogeneity	RR with 95%CI; consistently random-effect, although tests for heterogeneity were performed	RR with an RR <1 indicating treatment benefit; random-effect log-binomial model; imputation of missing data
Assessment of heterogeneity (figures indicate substantial heterogeneity)	Tau2 (>0), I2 (>30%), chi-square for heterogeneity (p < 0.10)	Tau2 (>0), I2 (>50%)	I2 (40–84%, if ≥85% no MA), chi-square for heterogeneity (p < 0.10)	Performed, but random-effects MA consistently used	I 2 (0% indicating no heterogeneity, 25% low, 50% moderate, 75% high)

IPD, individual participant data; RR, risk ratio.