Table 1. Summary results of Bayesian random-effect and meta-regression models on birth outcomes affected by maternal influenza vaccination.

Birth outcomes	Bayesian random-effect model					Bayesian random-effect meta-regression model
	Study	Odds ratio			P (OR<1)	Odds ratio (vaccination season)			P (OR<1)	Odds ratio (income level)			P (OR<1)
		Posterior median	95% CrI			Posterior median	95% CrI			Posterior median	95% CrI
PTB	SD (τ)	0.094				0.101				0.086
	Overall	0.945	0.736	1.345	0.733	0.837	0.566	1.278	0.844	1.019	0.784	1.364	0.414
	RCT overall	0.954	0.787	1.224	0.707	0.847	0.606	1.201	0.848	1.003	0.816	1.260	0.484
	Cohort overall	0.916	0.859	0.977	0.995	0.798	0.608	1.029	0.960	1.016	0.905	1.143	0.393
	Case-control overall	0.970	0.762	1.439	0.601	0.868	0.593	1.369	0.765	1.039	0.804	1.449	0.359
LBW	SD (τ)	0.107				0.119				0.120
	Overall	0.928	0.432	2.112	0.766	0.508	0.045	4.655	0.714	0.952	0.405	2.335	0.642
	RCT overall	0.926	0.721	1.238	0.800	0.500	0.066	3.669	0.727	0.938	0.714	1.301	0.723
	Cohort overall	0.932	0.864	0.998	0.978	0.521	0.072	3.736	0.715	0.966	0.786	1.165	0.644
SGA	SD (τ)	0.123				0.124				0.125
	Overall	0.971	0.249	4.217	0.633	1.202	0.273	4.783	0.728	0.975	0.205	4.482	0.608
	RCT overall	0.964	0.475	2.010	0.666	1.189	0.538	2.685	0.264	0.965	0.478	2.051	0.653
	Cohort overall	0.976	0.947	1.004	0.955	1.211	0.798	1.892	0.851	0.981	0.927	1.039	0.768
Con-genital mal-formation	SD (τ)	0.100				0.103				0.102
	Overall	1.026	0.687	1.600	0.380	1.383	0.814	2.459	0.086	1.005	0.643	1.577	0.480
	RCT overall	1.032	0.659	1.709	0.390	1.393	0.795	2.576	0.095	1.002	0.610	1.621	0.494
	Cohort overall	1.026	0.955	1.108	0.220	1.384	0.961	2.058	0.040	1.007	0.891	1.173	0.451
	Case-control overall	1.022	0.706	1.499	0.410	1.374	0.827	2.347	0.087	1.004	0.677	1.504	0.487
Fetal death	SD (τ)	0.222				0.191				0.203
	Overall	0.942	0.560	1.954	0.616	0.732	0.372	1.681	0.821	0.977	0.578	1.885	0.550
	RCT overall	1.002	0.686	1.679	0.497	0.767	0.414	1.525	0.791	1.023	0.693	1.673	0.454
	Cohort overall	0.822	0.718	0.931	0.996	0.643	0.391	1.100	0.951	0.857	0.655	1.102	0.919
	Case-control overall	1.077	0.719	1.833	0.385	0.814	0.433	1.672	0.726	1.098	0.724	1.832	0.343

CrI: Credible Interval,

SD (τ): Standard deviation between studies (estimation of heterogeneity between studies)