Table 2.

Hierarchical Multiple Regression (step 1 - predictors found in literature, step 2 – type of intervention, step 3 - exploratory predictors that had a significance level of p < 0.2).

Model	B	SE B	β	95%-CI β	p
Step 1 - R2 = 0.385 (p < 0.001)
Constant	30.08	5.035			<.001
Cochrane	43.1	9.78	.475	[.259; .691]	<.001
JIF	5.85	2.17	.291	[.075; .507]	.009
Step 2 - ΔR2 = 0.001 (p = 0.721)
Constant	28.8	6.2			<.001
Cochrane	43.36	9.88	.478	[.260; .696]	<.001
JIF	6.03	2.24	.300	[.077; .523]	.009
Intervention	1.76	4.91	.039	[-.179; .257]	.721
Step 3 - ΔR2 = 0.078 (p = 0.007)
Constant	21.45	6.4			.001
Cochrane	39.22	9.43	.432	[.224; .640]	<.001
JIF	5.33	2.13	.266	[.054; .479]	.015
Intervention	.149	4,66	.003	[-.185; .191]	0.975
RCT vs. NRS	14.15	5.01	.287	[.083; .491]	.007