Okafor 2015.

Methods	Identification of subsequent full‐length publications Searched electronic database PubMed up to December 2014 Person completing the search not reported Searched by all authors, and title Matching criteria not reported
Data	Included 321 abstracts presented at the 2007 to 2011 Cervical Spine Research Society meetings Included all abstracts presented orally
Comparisons	Proportion of abstracts published, overall and by meeting Award‐winning versus not
Outcomes	211 of 321 abstracts published 42/54 abstracts presented at the 2007 meeting, 37/54 at the 2008 meeting, 38/65 at the 2009 meeting, 46/78 at the 2010 meeting, and 48/70 at the 2011 meeting published Proportion of abstracts published by time not reported Factors related to proportion of abstracts published included 35/45 award‐winning abstracts versus 176/276 non award‐winning abstracts published
Notes	Orthopedics/orthopedic surgery ‐ cervical spine Reporting having received no funding
Risk of bias
Item	Authors' judgement	Description
Sampling method?	Yes	Included all abstracts presented orally.
Search for publications?	No	Searched only 1 database.
Follow‐up time?	Yes	The 2011 meeting only had 36 months follow‐up. All other meetings had at least 48 months follow‐up.
Matching?	Unclear	Matching criteria not reported.
Adjustment for confounding?	No	Examined association of meeting year and award winning status with publication using stratified analysis and t tests.