Table 2.

Multiple linear regression analyses for mean grant and maximum grant relative citation ratios.

	Mean grant relative citation ratioa				Maximum grant relative citation ratiob
	β	P value	[95% confidence interval]		β	P value	[95% confidence interval]
Recruitment policy1	1.984	0.005**	1.232	3.196	1.581	0.246	0.726	3.440
Grantee size2
x < $200,000,000USD	REF	REF	REF	REF	REF	REF	REF	REF
$200,000,000USD ≤ x < $400,000,000	1.000	0.998	0.767	1.304	1.051	0.821	0.682	1.618
x ≥ $400,000,000USD	0.884	0.340	0.686	1.140	0.909	0.650	0.601	1.376
Total award cost	1.000	0.361	1.000	1.000	1.000	0.403	1.000	1.000
Planned sample size	1.000	0.360	1.000	1.000	1.000	0.896	1.000	1.000
Fiscal year	0.738	0.006**	0.595	0.917	0.753	0.114	0.529	1.072
Funding mechanism3
R01	REF	REF	REF	REF	REF	REF	REF	REF
K (Career development)	1.625	0.203	0.767	3.442	2.665	0.115	0.784	9.063
R15	0.843	0.698	0.353	2.014	0.443	0.258	0.107	1.831
R21	0.471	0.206	0.146	1.522	0.257	0.162	0.038	1.740
R34	1.667	0.053	0.993	2.799	0.867	0.739	0.373	2.019
R43	0.158	0.002**	0.049	0.512	0.061	0.005**	0.009	0.414
U01	1.208	0.290	0.849	1.720	0.890	0.689	0.500	1.582
U10	0.564	0.104	0.282	1.127	0.777	0.659	0.251	2.402
Clinical trial design
RCT3	REF	REF	REF	REF	REF	REF	REF	REF
Cluster RCT4	0.831	0.441	0.518	1.334	0.807	0.584	0.373	1.746
Pre/post trial	0.583	0.229	0.241	1.410	0.292	0.093	0.069	1.233

^aMean Relative Citation Ratio of all publications for each grant

^bHighest Relative Citation Ratio of any publication for each grant

¹NIMH Recruitment Milestone Reporting Policy;

²Grantee’s total NIH funding in FY2006;

³Individually-randomized control trial;

⁴Cluster-randomized control trial.

^**:0.001 ≤ P ≤ 0.01