There has been a long-standing debate about how many and what kind of functions a CHW can perform. It is important to consider the effectiveness of CHWs in performing certain clearly defined roles, rather than assigning them tasks that they are not trained to do. Nor should they be overloaded with tasks, making it difficult to work effectively.
Clear job descriptions also assist CHWs in navigating their dual accountability to the community and the healthcare service . Whatever their role, effective integration into the healthcare system is vital to the sustainability of a CHW programme, partly because CHWs are well placed to help patients from vulnerable communities to gain access to facility-based care. 
CHWs perform different roles depending on the programme. They may be generalists, performing a range of tasks, or specialists with a focus on, for example, TB treatment or maternal and child health.
There are few high-quality evaluations to establish the comparative effectiveness of generalist or specialist CHWs and limited evidence on the long term cost-effectiveness of generalist CHWs, who take on responsibilities across a wide range of diseases or conditions. Ordinarily, specialist CHWs are part of NGO-driven programmes and, because CHW programmes have been heavily donor-dependent, many health systems have been left with a fragmented environment, where disease-specific responses dominate. Government programmes, on the other hand, attempt to get more ‛bang for buck’ by using generalist CHWs. However, these programmes frequently are not monitored and evaluated, making it difficult to assess their effectiveness.
What we do know is that some CHW-driven interventions work better than others. A 2006 Cochrane review found that there is:
- Strong evidence of the effectiveness of CHW-driven work in:
- immunisation promotion
- tuberculosis treatment support
- Good evidence for the effectiveness of CHW-driven work in:
- under-five mortality reduction
- Variable evidence for the effectiveness of CHW-driven work in:
- under-five morbidity reduction
- breastfeeding support
- support for mothers of sick children
- parent-child interaction
- child abuse reduction
The evidence for CHW-driven work on high risk pregnancy support suggests that it is not effective.
The Cochrane review assessed studies carried out in high-income countries and its use may therefore be limited for a middle-income country like South Africa but it remains one of the best indications of the available evidence that we have.
A 2011 review of studies from high, middle, and low income countries bore some similar results. It found:
- Moderate quality of evidence of effectiveness for the promotion of:
- immunisation uptake in childhood
- initiation of breastfeeding
- any breastfeeding
- exclusive breastfeeding
- pulmonary tuberculosis cure rates
- Moderate quality evidence or no effect for:
- TB preventive treatment completion
- child morbidity
- neonatal morbidity
- healthcare seeking for childhood illness
The findings of these reviews support the general view that CHW interventions should be focused on HIV, TB and maternal and child health.
The WBPHCOT Policy provides for tasks to be completed by CHWs in the following ‘broad areas’:
- Health promotion and disease prevention
- Conduct community, household- and individual-level health assessments.
- Identify potential and actual health risks and assist the household or individual to seek appropriate care.
- Screen and refer individuals for further assessment and testing, where appropriate.
- Identify pregnant women and conduct home visits during pregnancy and the postnatal period to promote healthy and safe births and identify danger signs needing extra care.
- Provide extra support for healthy behaviours during early childhood, including exclusive breastfeeding.
- Provide screening and health promotion programmes in schools and Early Childhood Development centres.
- Work in partnership with the School Health Team and other healthcare workers, such as Health Promoters.
- Counsel on and provide support for family planning choices.
- Provide follow-up and assistance to persons with health problems, including distribution of medicines according to the Integrated Chronic Disease Model, and help with adherence to treatment and treatment defaulter tracing.
- Promote and work with other sectors and undertake collaborative community-based interventions, such as Early Childhood Development, palliative care, geriatric care.
- Curative services as their scope and training allow
- Rehabilitative care as their scope and training allow
- Palliative care as their scope and training allow
- Psychosocial support
- Establish and manage support groups, e.g., treatment adherence, disease area-specific.
- Administrative tasks
- Comply with all reporting requirements
- Attend supervision meetings
The policy clearly envisages a generalist programme with a range of required functions, albeit limited to preventative functions. There is some evidence to suggest that CHWs are more effective when they are able to perform some curative functions rather than performing only preventative functions. This helps CHWs to be taken seriously by patients and motivates CHWs themselves.
There is argument to say that, particularly if there is a low CHW to population ratio and, given the expectations not only to provide care in homes and in facilities but also to link with School Health Teams and others, plus the social work functions performed by CHWs, the list of functions assigned to CHWs is too long and there should be provision in the WBPHCOTs for the inclusion of social auxiliary workers.
It is clear is that within the scope of CHWs under the WBPHCOT Policy, are functions that have been shown to be effective in the response to HIV and TB and in maternal and child health. The possibility of expansion or refinement of the range of functions of CHWs should be left open, subject to monitoring and evaluation of the CHW programme, but the base functions provided for are a good start and are largely supported by evidence.
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