Table 2.

Comparing distributed Cox regression (Dist), pooled Cox regression (pooled), multivariate meta-analysis (MulV), and univariate meta-analysis (UniV) with simulated data of sample size with data generated from unstratified models. Sample sizes from data-contributing sites are provided in the table below. Covariates distributions are different among the data-contributing sites. True log HR value is . Number of replications 10 000

Method	Unstratified			Stratified			Meta-analysis				Unstratified			Stratified			Meta-analysis
	Pooled	Dist		Pooled	Dist		MulV	UniV			Pooled	Dist		Pooled	Dist		MulV	UniV
	; ;										; ;
bias	0.0006	0.0036		0.0002	0.0042		0.0013	0.0016			0.0000	0.0022		0.0004	0.0027		0.0019	0.0001
cr	0.9507	0.9559		0.9498	0.9481		0.9506	0.9473			0.9528	0.9578		0.9511	0.9491		0.9500	0.9510
mae	0.0459	0.0469		0.0653	0.0658		0.0653	0.0818			0.0424	0.0435		0.0550	0.0552		0.0550	0.0617
cios	0.9500	0.9413		0.8434	0.8418		0.8434	0.7740			0.9500	0.9424		0.8764	0.8756		0.8763	0.8419
sse	0.0574	0.0585		0.0821	0.0825		0.0821	0.1030			0.0533	0.0546		0.0689	0.0691		0.0688	0.0773
ese	0.0571	0.0602		0.0813	0.0814		0.0813	0.1028			0.0537	0.0563		0.0692	0.0689		0.0691	0.0769
rse	0.0569	0.0604									0.0535	0.0566

cr: coverage rate; mae: mean absolute error; cios: confidence interval overlap statistics; sse: sample standard error; ese: estimated standard error; rse: robust standard error estimate.