Human factors/ergonomics recognises work as embedded in and shaped by levels of social, physical and organisational context. This study investigates the contextual or macroergonomic factors present in the health-related work performed by patients. We performed a secondary content analysis of findings from three studies of the work of chronically ill patients and their informal caregivers. Our resulting consolidated macroergonomic patient work system model identified 17 factors across physical, social and organisational domains and household and community levels. These factors are illustrated with examples from the three studies and discussed as having positive, negative or varying effects on health and health behaviour. We present three brief case studies to illustrate how macroergonomic factors combine across domains and levels to shape performance in expected and unexpected ways. Findings demonstrate not only the importance of context for patients' health-related activities but also specific factors to consider in future research, design and policy efforts. Practitioner Summary: Health-related activities of patients are embedded in and shaped by levels of social, physical and organisational context. This paper combined findings from three studies to specify 17 contextual or macroergonomic factors in home- and community-based work systems of chronically ill patients. These factors have research, design and policy implications.