“…The service recipients of CHWs tend to vary with country income status (Supplemental File 3). In high-income countries, CHWs provide health services to ethnic minority and low-income populations within these countries [ 21 , 23 , 33 , 41 , 42 , 45 , 47 – 50 , 56 – 60 , 62 , 63 , 74 – 80 , 84 – 86 , 97 , 101 , 107 , 108 , 110 , 113 , 115 , 118 – 120 , 123 ]. The service recipients in these settings are usually individuals with non-communicable diseases such as cancers, cardiovascular diseases, chronic respiratory diseases, and diabetes [ 23 , 24 , 31 , 33 , 41 , 47 – 49 , 56 , 58 , 63 , 73 , 77 , 80 , 85 , 96 , 100 , 101 , 106 , 109 , 112 , 113 , 115 – 117 , 120 ].…”