Table 3 Summary of the catchment area covered by the CHWs

 < 50 patients (n = 7) [27, 36,37,38,39, 42, 43]

• CHWs had one or two responsibilities for disease prevention programme (specialist CHWs) [27, 36,37,38,39, 42, 43]

• Most population had positive outcomes, namely, decreased child morbidity and mortality to improved blood glucose and weight control and increased access to acute malnutrition treatment in remote communities, reduced risk of repealed birth among teenagers 2 years) [27, 37,38,39, 42]

• One study showed that high workload affected the CHWs duties and rendered distress, but did not specifically affect certain outcomes [36]

• A study in Haiti suggested that the ideal ratio of CHW to patient is 1:4 with full-time work (40 hours per week) to address HIV and TB, and the ideal distance to walk from home to the patient was one hour round trip [43].

15—100 households (n = 9) [17, 26, 29, 30, 32, 40, 41, 44, 45]

• Most CHWs have more than three responsibilities for disease prevention programme (generalist CHWs) [17, 26, 30, 32, 40, 41, 44, 45]

• Some households had positive outcomes, namely, community satisfaction of CHWs performance and improvement of antenatal care attendance [17, 29, 40, 41]

• One study reported negatives outcomes, such as improved systolic blood pressure in hypertension, inconclusive effects on fasting blood glucose in diabetes, and no demonstrable effect on smoking (120 people per CHW, 40–60 working hours a month) [42, 44]

• Some studies showed that public health programmes did not work optimally due to vague national policies and rushed implementation plans, and insufficient support for CHWs (transportation, remuneration, and supervision) [26, 32]

100—250 households (n = 11) [22, 31,32,33, 46,47,48,49,50,51,52]

• Most CHWs had more than two responsibilities for disease prevention programme (generalist CHWs) [22, 31,32,33, 46, 47, 50, 52]

• All of them had a similar role to address mother and child health issues and communicable diseases [22, 31,32,33, 46,47,48,49,50,51,52]

• Several articles mentioned that CHWs were overburdened due to excessive role, no training, weak supervision, and inappropriate incentive or compensation [22, 32, 47, 48, 51]

• Those receiving positive outcomes facilitate CHWs with monthly salaries and essential support [33, 46, 49, 52]

More than 10.000 people (n = 3) [14, 34, 35]

• Two studies showed that CHWs experienced burnout and stress despite handling only one disease (malaria). It was attributed to the sizeable targets paired with inadequate and unsustainable support for training, compensation, supervision, access to equipment, and recognition [14, 34]

• One study cited CHWs' success in 40,213 household visits, 127,011 health education sessions, and caring for 19,387 children under five. Their achievements were bolstered by in kind incentives like t-shirts, boots, umbrellas, solar power kits, training for coordinators, and three motorbikes [35].