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

Year Number of Results
1984 1
1987 1
1989 1
1991 5
1992 5
1993 4
1994 3
1995 5
1996 1
1997 2
1998 1
1999 4
2000 3
2001 4
2002 3
2003 3
2004 1
2005 4
2006 6
2007 2
2008 3
2009 2
2010 4
2011 3
2012 3
2013 3
2014 1
2015 1
2016 2
2017 1
2018 3
2021 1
2024 0

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80 results

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Page 1
The qualification period.
Knipschild P, Leffers P, Feinstein AR. Knipschild P, et al. Among authors: leffers p. J Clin Epidemiol. 1991;44(6):461-4. doi: 10.1016/0895-4356(91)90208-q. J Clin Epidemiol. 1991. PMID: 2037850
Rehabilitation after lumbar disc surgery.
Ostelo RW, de Vet HC, Waddell G, Kerckhoffs MR, Leffers P, van Tulder MW. Ostelo RW, et al. Among authors: leffers p. Cochrane Database Syst Rev. 2002;(2):CD003007. doi: 10.1002/14651858.CD003007. Cochrane Database Syst Rev. 2002. PMID: 12076465 Updated. Review.
Index event bias-a numerical example.
Smits LJ, van Kuijk SM, Leffers P, Peeters LL, Prins MH, Sep SJ. Smits LJ, et al. Among authors: leffers p. J Clin Epidemiol. 2013 Feb;66(2):192-6. doi: 10.1016/j.jclinepi.2012.06.023. J Clin Epidemiol. 2013. PMID: 23257150 Free article.
80 results