- INTRODUCTION: No studies have examined factors associated with fear in any group of people vulnerable during COVID-19 due to pre-existing medical conditions. OBJECTIVE: To investigate factors associated with fear of consequences of COVID-19 among people living with a pre-existing medical condition, the autoimmune disease systemic sclerosis (SSc; scleroderma), including country. METHODS: Pre-COVID-19 data from the Scleroderma Patient-centered Intervention Network (SPIN) Cohort were linked to COVID-19 data collected in April 2020. Multivariable linear regression was used to assess factors associated with continuous scores of the 10-item COVID-19 Fears Questionnaire for Chronic Medical Conditions, controlling for pre-COVID-19 anxiety symptoms. RESULTS: Compared to France (N = 156), COVID-19 Fear scores among participants from the United Kingdom (N = 50) were 0.12 SD (95% CI 0.03 to 0.21) higher; scores for Canada (N = 97) and the United States (N = 128) were higher, but not statistically significant. Greater interference of breathing problems was associated with higher fears due to COVID-19 (Standardized regression coefficient = 0.12, 95% CI 0.01 to 0.23). Participants with higher financial resources adequacy scores had lower COVID-19 Fear scores (Standardized coefficient = -0.18, 95% CI -0.28 to -0.09). CONCLUSIONS: Fears due to COVID-19 were associated with clinical and functional vulnerabilities in this chronically ill population. This suggests that interventions may benefit from addressing specific clinical issues that apply to specific populations. Financial resources, health policies and political influences may also be important. The needs of people living with chronic illness during a pandemic may differ depending on the social and political context in which they live.