Cochrane systematic reviews and co-publication: dissemination of evidence on interventions for ophthalmic conditions

Table 1 Characteristics of 22 co-publications matched to 19 Cochrane Eyes and Vision Group systematic reviews

Study characteristics	N	(%)
Co-publication content compared to the CEVG review
Identical^a	3	(14 %)
Similar but not identical^a	14	(64 %)
Abridged^a	3	(13 %)
Other^b	2	(9 %)
Journal of co-publication
Ophthalmology journal	12	(55 %)
Indexed in Web of Science or Scopus as of publication date	11/12
General or other medical journal	10	(45 %)
Indexed in Web of Science or Scopus as of publication date	7/10
Authorship of co-publication
Identical to CEVG review	11	(50 %)
Same authors, different order	3	(14 %)
One author added or removed	8	(36 %)
Co-publication timing
Before the CEVG review^c	5	(23 %)
Within 2 years after CEVG review	14	(63 %)
More than 2 years after CEVG review	3	(14 %)
Co-publication based on
Original review	15	(68 %)
Updated review	7	(32 %)
Citation of the CEVG review by the co-publication
Cited	12	(55 %)
Not cited, but CEVG review mentioned in the text	4	(18 %)
Not cited or mentioned	6	(27 %)
Country of affiliation of co-publication first author
UK	16	(73 %)
USA	6	(27 %)
Number of included studies ^d
Same as CEVG review	16	(73 %)
Some overlap with CEVG review	6	(27 %)

^aIdentical is exact copy of CSR, Similar would be applied, for example, when the co-publication has a shorter methods section, and Abridged would be applied, for example, when the co-publication is a summary of the major findings from CSR
^bOf two co-publications classified as “Other”, one co-publication-CSR pair had no included studies and the authors discussed the characteristics of the condition; the second co-publication reported a subset of the interventions described in the CEVG review
^cFive CEVG reviews were published after the co-publications
^dNumber of included studies in co-publication: 4 had 0 studies, 6 had 1–4 studies, 6 had 5–9 studies, and 6 had ≥10