Abstract: We included 53 studies primarily describing the experiences of LHWs, programme recipients, and other health workers. LHWs in high income countries mainly offered promotion, counselling and support. In low and middle income countries, LHWs offered similar services but sometimes also distributed supplements, contraceptives and other products, and diagnosed and treated children with common childhood diseases. Some LHWs were trained to manage uncomplicated labour and to refer women with pregnancy or labour complications. Many of the findings were based on studies from multiple settings, but with some methodological limitations. These findings were assessed as being of moderate certainty. Some findings were based on one or two studies and had some methodological limitations. These were assessed have low certainty. Barriers and facilitators were mainly tied to programme acceptability, appropriateness and credibility; and health system constraints. Programme recipients were generally positive to the programmes, appreciating the LHWs’ skills and the similarities they saw between themselves and the LHWs. However, some recipients were concerned about confidentiality when receiving home visits. Others saw LHW services as not relevant or not sufficient, particularly when LHWs only offered promotional services. LHWs and recipients emphasised the importance of trust, respect, kindness and empathy. However, LHWs sometimes found it difficult to manage emotional relationships and boundaries with recipients. Some LHWs feared blame if care was not successful. Others felt demotivated when their services were not appreciated. Support from health systems and community leaders could give LHWs credibility, at least if the health systems and community leaders had authority and respect. Active support from family members was also important. Health professionals often appreciated the LHWs’ contributions in reducing their workload and for their communication skills and commitment. However, some health professionals thought that LHWs added to their workload and feared a loss of authority. LHWs were motivated by factors including altruism, social recognition, knowledge gain and career development. Some unsalaried LHWs wanted regular payment, while others were concerned that payment might threaten their social status or lead recipients to question their motives. Some salaried LHWs were dissatisfied with their pay levels. Others were frustrated when payment differed across regions or institutions. Some LHWs stated that they had few opportunities to voice complaints. LHWs described insufficient, poor quality, irrelevant and inflexible training programmes, calling for more training in counselling and communication and in topics outside their current role, including common health problems and domestic problems. LHWs and supervisors complained about supervisors’ lack of skills, time and transportation. Some LHWs appreciated the opportunity to share experiences with fellow LHWs. In some studies, LHWs were traditional birth attendants who had received additional training. Some health professionals were concerned that these LHWs were over-confident about their ability to manage danger signs. LHWs and recipients pointed to other problems, including women’s reluctance to be referred after bad experiences with health professionals, fear of caesarean sections, lack of transport, and cost. Some LHWs were reluctant to refer women on because of poor co-operation with health professionals. We organised these findings and the outcome measures included in the review of LHW programme effectiveness in a logic model. Here we proposed six chains of events where specific programme components lead to specific intermediate or long-term outcomes, and where specific moderators positively or negatively affect this process. We suggest how future updates of the LHW effectiveness review could explore whether the presence of these components influences programme success. Rather than being seen as a lesser trained health worker, LHWs may represent a different and sometimes preferred type of health worker. The close relationship between LHWs and recipients is a programme strength. However, programme planners must consider how to achieve the benefits of closeness while minimizing the potential drawbacks. Other important facilitators may include the development of services that recipients perceive as relevant; regular and visible support from the health system and the community; and appropriate training, supervision and incentives.

Plain-language summary: A LHW is a lay person who has received some training to deliver healthcare services but is not a health professional. In most of the studies in this review, LHWs offered health care to people who were on low incomes living in wealthy countries or to people living in poor countries. The LHWs in wealthy countries offered health promotion, counselling and support. The LHWs in poor countries offered similar services but they sometimes also distributed food supplements, contraceptives and other products, treated children with common childhood diseases, or managed women in uncomplicated labour. What the research says The studies described the experiences of LHWs, mothers, programme managers, and other health workers with LHW programmes. Many of our findings were based on studies from different settings and had some methodological problems. We judged these findings to have moderate certainty. Some findings were only based on one or two studies that had some methodological problems and were judged to be of low certainty. Mothers were generally positive about the programmes. They appreciated the LHWs’ skills and the similarities they saw between themselves and the LHWs. However, some mothers were concerned about confidentiality when receiving home visits. Others saw LHW services as not relevant or not sufficient, particularly when LHWs only offered promotional services. LHWs and mothers emphasised the importance of trust, respect, kindness and empathy. However, LHWs sometimes found it difficult to manage emotional relationships and boundaries with mothers. Some LHWs feared blame if health care was not successful. Others felt demotivated when their services were not appreciated. Support from health systems and community leaders could give LHWs credibility if these health systems and community leaders had authority and respect. Active support from family members was also important. Health professionals often appreciated the LHWs' contributions to reducing their workload, and their communication skills and commitment. However, some health professionals thought that LHWs added to their own workloads and feared a loss of authority. LHWs were motivated by altruism, social recognition, knowledge gain and career development. Some unsalaried LHWs wanted regular payment. Others were concerned that payment might threaten their social status or lead people to question their motives. Some salaried LHWs were dissatisfied with their pay levels. Others were frustrated when other LHWs had higher salaries. Some LHWs said that they had few opportunities to voice complaints. Some LHWs described insufficient, poor quality and irrelevant training programmes. They called for more training in counselling and communication and in topics outside their current role, including common health problems and domestic problems. LHWs and supervisors complained about supervisors’ lack of skills, time and transportation. Some LHWs appreciated the opportunity to share experiences with other LHWs. Some LHWs were traditional birth attendants who had received additional training. Some health professionals were concerned that these LHWs were over-confident about their ability to manage danger signs. LHWs and mothers identified women’s reluctance to be referred after bad experiences with health professionals, fear of caesarean sections, lack of transport, and costs. Some LHWs were also reluctant to refer women on because of poor co-operation with health professionals. We organized these findings into chains of events where we have proposed how certain LHW programme elements might lead to greater programme success. Authors’ conclusions Rather than being seen as a lesser trained health worker, LHWs represent a different and sometimes preferred type of health worker. The often close relationship between LHWs and their recipients is a strength of such programmes. However, programme planners must consider how to achieve the benefits of closeness while avoiding the problems. It may also be important to offer services that recipients perceive as relevant; to ensure regular and visible support from other health workers and community leaders; and to offer appropriate training, supervision and incentives.