How does informal employment affect health and health equity? Emerging gaps in research from a scoping review and modified e-Delphi survey

INTRODUCTION: This article reports on the results from a scoping review and a modified e-Delphi survey with experts which aimed to synthesize existing knowledge and identify research gaps on the health and health equity implications of informal employment in both low- and middle-income countries (LMICs) and high-income countries (HICs). METHODS: The scoping review included peer-reviewed articles published online between January 2015 and December 2019 in English. Additionally, a modified e-Delphi survey with experts was conducted to validate our findings from the scoping review and receive feedback on additional research and policy gaps. We drew on micro- and macro-level frameworks on employment relations and health inequities developed by the Employment Conditions Knowledge Network to synthesize and analyze existing literature. RESULTS: A total of 540 articles were screened, and 57 met the eligibility criteria for this scoping review study, including 36 on micro-level research, 19 on macro-level research, and 13 on policy intervention research. Most of the included studies were conducted in LMICs while the research interest in informal work and health has increased globally. Findings from existing literature on the health and health equity implications of informal employment are mixed: informal employment does not necessarily lead to poorer health outcomes than formal employment. Although all informal workers share some fundamental vulnerabilities, including harmful working conditions and limited access to health and social protections, the related health implications vary according to the sub-groups of workers (e.g., gender) and the country context (e.g., types of welfare state or labour market). In the modified e-Delphi survey, participants showed a high level of agreement on a lack of consensus on the definition of informal employment, the usefulness of the concept of informal employment, the need for more comparative policy research, qualitative health research, and research on the intersection between gender and informal employment. CONCLUSIONS: Our results clearly identify the need for more research to further understand the various mechanisms through which informal employment affects health in different countries and for different groups of informal workers. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12939-022-01684-7.