Aim: Carers may offer valuable insight into the true health status of patients with rheumatoid arthritis (RA). This multinational, multi-stakeholder, exploratory study in Australia, China and Japan aimed to enrich our understanding of the role and potential impact of carers on RA management. Method: This study used a 2-phase sequential mixed methods approach involving 3 key stakeholder groups: rheumatologists, RA patients and carers. The first phase involved an in-depth qualitative exploratory survey (n = 30), which informed the development of the subsequent quantitative validation survey (n = 908). In both phases, patients and carers provided self-assessments of disease and support parameters. Results: In the qualitative phase, patients usually understated the amount of physical support required, compared to carers. Rheumatologists underestimated the amount of physical and emotional care required, compared to carers and patients; however, in the quantitative phase, rheumatologists overestimated the level of support provided by carers. Levels of support provided by carers increased as disease severity increased. Active participation of carers in clinical consultations and treatment decision-making was deemed important by 55% of all patients and 82% of all carers. All stakeholders believed carers’ insights into the physical and emotional conditions of patients were useful and should be considered in clinical decision-making. Over 95% of rheumatologists reported soliciting input from the carer. Conclusion: Carers provide valuable input that can give clinicians greater insight into the patients’ physical and emotional states, and treatment adherence. Development of standardized carer-reported outcomes that correlate with patient-reported outcomes and clinical parameters will ensure clinical meaningfulness and external validity.