Summary of findings 1. All‐cause mortality within 30 days.

Estimate of effects, confidence intervals, and certainty of the evidence for prevention of mortality for paediatric patients undergoing surgery for congenital heart disease
Population: paediatric patients undergoing surgery for congenital heart disease Interventions: levosimendan, milrinone, dobutamine, placebo, levosimendan + milrinone + dopamine, milrinone + dopamine, levosimendan + dobutamine, milrinone + dobutamine Comparator (reference): placebo or combination of milrinone + dopamine or combination of milrinone + dobutamine Outcome: prevention of mortality Setting: inpatient								Figure 1
Total studies: 9 Total participants: 557 Total events: 14	Relative effect (95% CI)	Anticipated absolute effect (95% CI)			No. of participants (studies)	Certainty of the evidence	Ranking (SUCRA*)	Comments
		Without intervention	With intervention	Difference
Levosimendan	RR 0.57 (0.15 to 2.13) Network estimate	43 per 1000a	25 per 1000	18 fewer per 1000 (37 fewer to 49 more)	216 (7 RCTs)	Moderate Due to imprecision	0.76	Levosimendan likely results in a large reduction in mortality compared to placebo
Milrinone	RR 0.97 (0.11 to 8.49) Network estimate	43 per 1000a	42 per 1000	1 fewer per 1000 (38 fewer to 322 more)	147 (6 RCTs)	Moderate Due to imprecision	0.39	Milrinone likely results in no difference in mortality compared to placebo
Dobutamine	Excluded due to absence of events	‐	‐	‐	51 (2 RCTs)	‐	Excluded due to absence of events	‐
Placebo	RR 1	Not estimable	Not estimable	Not estimable	143 (3 RCTs)	Reference comparator	0.35	‐
Heterogeneity: tau2 = 0; I2 = 0% (95% CI 0% to 89.6%) Q total 0.86 (df = 2; P = 0.65) Q within designs 0.86 (df = 2; P = 0.65) Q between designs 0 (df = 0)

*SUCRA: surface under the cumulative ranking curve, calculated with R package netmeta

GRADE Working Group grades of evidence (or certainty in the evidence)

High certainty: we are very confident that the true effect lies close to that of the estimate of the effect.

Moderate certainty: we are moderately confident in the effect estimate; the true effect is likely to be close to the estimate of the effect, but there is a possibility that it is substantially different.

Low certainty: our confidence in the effect estimate is limited; the true effect may be substantially different from the estimate of the effect.

Very low certainty: we have very little confidence in the effect estimate; the true effect is likely to be substantially different from the estimate of effect.

Explanatory footnotes

^aBaseline risk (assumed control risk) obtained from Wang 2019, placebo group.

Certainty of the evidence for each intervention was downgraded one step to 'Moderate' due to imprecision.

Abbreviation(s)
CI: confidence interval; df: degrees of freedom; No.: number; RCT: randomised controlled trial; RR: risk ratio; SUCRA: surface under the cumulative ranking curve.