Table 2.

Meta-regression analyses

Variable	Studies, k	β coefficient	s.e.	95% CI	z-score	P
Year of publication	20	0.0511	0.0291	−0.0059 to 0.1082	1.76	0.0791
Percentage of patients with schizophrenia	11	0.0004	0.0109	−0.0210 to 0.0217	0.03	0.9737
Sample size	20	−0.0022	0.0016	−0.0053 to 0.0009	−1.41	0.1572
Mean age	17	−0.1314	0.2488	−0.6190 to 0.3562	−0.53	0.5974
Percentage of males	18	0.0187	0.0219	−0.0242 to 0.0616	0.85	0.3934
Percentage on antipsychotics	7	−0.0021	0.0080	−0.0177 to 0.0136	−0.26	0.7966
Quality of the study	20	−0.0915	0.1386	−0.3631 to 0.1801	−0.66	0.5092