Table 1 Keywords and boolean terms used in EBSCO

PsycInfo (424), CINAHL (224),

MEDLINE (688)

Ethnic minorities OR Racial minorities OR Ethnic groups

AND

Research OR “Research participation” OR “RESEARCH ENGAGEMENT”

AND

Barriers OR Obstacles OR Challenges

AND

UK OR “United Kingdom” OR ENGLAND OR BRITAIN OR WALES OR SCOTLAND OR “NORTHEN IRELAND”

AND

REVIEW* OR “META ANALYSIS” OR “SYSTEMATIC REVIEW”