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. Author manuscript; available in PMC: 2012 Jun 14.

Published in final edited form as: Ann Intern Med. 2010 Aug 3;153(3):158–166. doi: 10.1059/0003-4819-153-3-201008030-00006

Table 2.

Record Characteristics for Drug Trials Registered in ClinicalTrials.gov

Characteristic and Category	Total, % (n/N)	Primary Funding Source, % (n/N)			Chi-Square P Value
Characteristic and Category	Total, % (n/N)	Industry	Government	Nonprofit or Nonfederal	Chi-Square P Value
Time of trial registration
Before study start date	9.5 (52/546)	8.7 (30/346)	25.7 (19/74)	2.4 (3/126)	<0.001
Before study completion date^*	48.7 (237/487)	45.9 (134/292)	75.3 (55/73)	34.3 (48/122)	<0.001
Before publication date	79.6 (288/362)	72.6 (167/230)	95.1 (39/41)	90.1 (82/91)	<0.001
Inclusion of primary outcome Primary outcome explicitly described in record^† Provision of study results	66.6 (158/237)	72.4 (97/134)	30.9 (17/55)	91.7 (44/48)	<0.001
Link to published results available in record	35.6 (129/362)	33.9 (78/230)	39.0 (16/41)	38.5 (35/91)	0.66
Link to unpublished results available in record	21.2 (39/184)	33.6 (39/116)	0	0	NA
Trial results reported in record	0.9 (5/546)	1.4 (5/346)	0	0	NA

NA = not applicable.

^*

Completion date not reported for 59 trials.

^†

Analysis performed for trials registered before study completion date.