Table 3.

Particular countries and regions referenced in documents included ^a (frequencies of citation) grouped according to 2014 World Bank Country classification

Category	Country/region (frequency of citation)
Low-income countries	Benin (1), Guinea-Bissau (1), Congo (1), Mali (1), Chad (1), Eritrea (1), Ethiopia (2), Gambia (1), Afghanistan (2), Bangladesh (2), Kenya (1), Malawi (1), Morocco (1), Nepal (3), Tanzania (3), Uganda (1), Zimbabwe (1)
Lower-middle-income countries	Bolivia (1), Cameroon (1), Guyana (1), Mongolia (1), Pakistan (1), Philippines (1), Vietnam, (1), Zambia (1), Lesotho (1)
Upper-middle-income countries	South Africa (1), Peru (1), Brazil (3), China (2), Thailand (1), Mexico (1)
High-income countries	Chile (1) b, USA (1) c
Regions	Balkan countries (1), Eastern Europe (2), Africa (1)

^a Citations are made in 50 documents (one document may refer to more than one country) Remaining documents reference LMICs generally

^b Chile was classified as an upper middle-income country up to 2014

^c The USA is used as a comparator in one study