Table 2

Study characteristics

Lead author’s institutional affiliationLowLower middleUpper middleHighLow and lower middleUpper middle and high
No of studies (% total)5 (4)86 (63)1 (1)44 (32)91 (66)45 (33)
Received funding from high/upper middle0141371438
Mean publication year200520102013201120092011
Mean citations47.621.518.027.022.026.8
Mean impact factor1.11.73.25.01.74.9
Mean population size627403 8792983173 376380 15217 025