Table 2.

Mixed effect regression analysis of effect sizes

		Model 1 (N = 182)		Model 2 (N = 182)		Model 3 (N = 149)		Model 4 (N = 149)
		Estimate	P value	Estimate	P value	Estimate	P value	Estimate	P value
Number of arms		0.070	0.102	0.055	0.208	0.073	0.282	0.077	0.241
Sample size		-0.001	0.007***	-0.001	0.008***	-0.001	0.002***	-0.001	0.000***
Length of trial		0.004	0.495	0.002	0.697	0.003	0.593	0.000	0.957
Flexible dosing schedule		-0.072	0.190	-0.070	0.205	-0.098	0.062*	-0.112	0.030**
Approval year		0.007	0.028**	0.004	0.307	0.005	0.166	0.000	0.979
Mean number of subjects per site		0.009	0.147	0.007	0.219	0.011	0.065*	0.008	0.171
Type of endpoint (Objective endpointa)	Subjective endpoint (assessment score)	-0.138	0.022**	-0.119	0.048**	-0.090	0.136	-0.067	0.263
	Subjective endpoint (Clinical Global Improvement)	-0.115	0.033**	-0.094	0.081*	-0.076	0.190	-0.049	0.395
Statistical purpose (Othersa)	Superiority	0.245	0.002***	0.215	0.009***	0.287	0.000***	0.229	0.005***
	Noninferiority and equivalence	-0.005	0.933	-0.028	0.700	0.012	0.853	-0.055	0.447
	Dose response	0.133	0.269	0.124	0.304	-	-	-	-
Primary endpoint		0.095	0.018**	0.086	0.032**	0.061	0.152	0.050	0.234
Comparator with the same mode of action of the test drug		-0.127	0.018**	-0.143	0.006***	-0.083	0.124	-0.129	0.020**
Phase2		-0.067	0.384	-0.059	0.447	-	-	-	-
Mean age of subjects		0.006	0.142	0.008	0.075*	0.013	0.004***	0.015	0.001***
Proportion of female subjects		-0.417	0.053*	-0.453	0.037**	-0.752	0.002***	-0.682	0.004***
Precedent foreign clinical trial data		-	-	0.073	0.329	-	-	0.167	0.029**
Companies‘ domestic development experience with similar drugs		-	-	0.079	0.078*	-	-	0.086	0.051*
Constant		-0.148	0.565	-0.098	0.706	-0.200	0.510	-0.168	0.572

^aReference category, *p < 0.1, **p < 0.05, ***p < 0.01.