The prevalence of and factors associated with inclusion of non-English language studies in Campbell systematic reviews: a survey and meta-epidemiological study

Table 3 Differences in language inclusiveness based on subject area (i.e. Campbell Collaboration Review Group)

Language category	Number of reviews in each subject area (%)
Language category	Crime and Justice^a	International Development^a	Education^a	Social Welfare^a
LOE-restricted	11	0	3	1
LOE-restricted	(24.4)	(0.0)	(10.3)	(1.7)
LOE-open	29	18	20	54
LOE-open	(64.4)	(72.0)	(69.0)	(90.0)
LOE-inclusive	5	7	6	5
LOE-inclusive	(11.1)	(28.0)	(20.7)	(8.3)
Total reviews^b	45 (36.6)	25 (20.3)	29 (23.6)	60 (48.8)
Number of non-English studies included^b	13 (33.3)	21 (53.8)	18 (46.2)	8 (20.5)

^aThe Knowledge Transfer and Implementation group has been dropped from the table as it contains only a single LOE-open review
^bSome reviews, and their included non-English language studies, belong to more than one of the thematic groups and are therefore counted more than once

ISSN: 2046-4053