Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation

Search Page

Filters

My Custom Filters

Results by year

Table representation of search results timeline featuring number of search results per year.

Year Number of Results
1960 1
1962 1
1967 4
1968 1
1974 5
1979 2
1983 2
1986 3
1987 10
1988 30
1989 1138
1990 2315
1991 313
1992 475
1993 707
1994 1300
1995 1497
1996 1411
1997 1674
1998 2049
1999 2493
2000 2987
2001 3739
2002 4324
2003 4871
2004 5348
2005 5437
2006 5876
2007 5614
2008 6353
2009 7023
2010 7356
2011 7536
2012 7652
2013 8006
2014 7714
2015 8008
2016 8385
2017 8782
2018 9905
2019 11142
2020 11495
2021 9951
2022 8315
2023 7980
2024 11950
2025 7263

Publication date

Text availability

Article attribute

Article type

Additional filters

Article Language

Species

Sex

Age

Other

Search Results

189,456 results

Results by year

Filters applied: . Clear all
Page 1
Randomized Controlled Trials.
Zabor EC, Kaizer AM, Hobbs BP. Zabor EC, et al. Chest. 2020 Jul;158(1S):S79-S87. doi: 10.1016/j.chest.2020.03.013. Chest. 2020. PMID: 32658656 Free PMC article. Review.
Key concepts of clinical trials: a narrative review.
Umscheid CA, Margolis DJ, Grossman CE. Umscheid CA, et al. Postgrad Med. 2011 Sep;123(5):194-204. doi: 10.3810/pgm.2011.09.2475. Postgrad Med. 2011. PMID: 21904102 Free PMC article. Review.
Randomized controlled trials.
McCarthy CM. McCarthy CM. Plast Reconstr Surg. 2011 Apr;127(4):1707-1712. doi: 10.1097/PRS.0b013e31820da3eb. Plast Reconstr Surg. 2011. PMID: 21460678
189,456 results
You have reached the last available page of results. Please see the User Guide for more information.