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 NCBI Filters

Results by year

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

Year Number of Results
1913 1
1936 1
1945 10
1946 66
1947 68
1948 81
1949 85
1950 135
1951 172
1952 187
1953 187
1954 178
1955 179
1956 229
1957 225
1958 238
1959 261
1960 239
1961 266
1962 296
1963 363
1964 481
1965 739
1966 1592
1967 2107
1968 2387
1969 2666
1970 2899
1971 3370
1972 3844
1973 4714
1974 5506
1975 5166
1976 5090
1977 5301
1978 5743
1979 6179
1980 6238
1981 6746
1982 7823
1983 8954
1984 10682
1985 12010
1986 13260
1987 14349
1988 16802
1989 21342
1990 22860
1991 24912
1992 26579
1993 29941
1994 33481
1995 37463
1996 39449
1997 42688
1998 44530
1999 46516
2000 47907
2001 50272
2002 53969
2003 60377
2004 66058
2005 75335
2006 80562
2007 88338
2008 97913
2009 102027
2010 111699
2011 127797
2012 140023
2013 153128
2014 163040
2015 169423
2016 173001
2017 178840
2018 189594
2019 199281
2020 219291
2021 231796
2022 209603
2023 185830
2024 96732
2025 2

Search Results

3,313,786 results

Results by year

Filters applied: . Clear all
Page 1
Introduction to Epidemiological Studies.
Belbasis L, Bellou V. Belbasis L, et al. Methods Mol Biol. 2018;1793:1-6. doi: 10.1007/978-1-4939-7868-7_1. Methods Mol Biol. 2018. PMID: 29876887 Review.
Observational studies: cohort and case-control studies.
Song JW, Chung KC. Song JW, et al. Plast Reconstr Surg. 2010 Dec;126(6):2234-2242. doi: 10.1097/PRS.0b013e3181f44abc. Plast Reconstr Surg. 2010. PMID: 20697313 Free PMC article. Review.
3,313,786 results
You have reached the last available page of results. Please see the User Guide for more information.