Table 3

Use of incentives stratified by recruitment continent (n=300)*

Recruitment continentNUse of incentives, n (%)
YesNoNot reported
Africa263 (11.5)1 (3.8)22 (84.6)
Asia821 (1.2)2 (2.4)79 (96.3)
Australia183 (16.7)0 (0.0)15 (83.3)
Europe542 (3.7)3 (5.6)49 (90.7)
North America11933 (27.7)0 (0.0)86 (72.3)
South America90 (0.0)0 (0.0)9 (100.0)
  • *Some studies recruited participants from more than one continent.