Feasibility study of a smartphone app to monitor systemic sclerosis-related digital ulcers-a potential new tool for remote clinical monitoring.

Objectives: To assess the feasibility, in a clinical setting, of using a smartphone app that allows 'tracking' of SSc-related digital ulcers/lesions over time and to gauge patient opinion of the app's benefits, including a newly added lesion feedback function for patients. Methods: Patients with SSc with active digital ulcers/lesions were recruited and assessed twice: on study entry and at the point of lesion healing. Participants photographed their lesions and recorded patient-reported outcome measures (PROMs) with the app twice weekly. The lesion feedback function showed lesion size (measured from the photographs) over time. Ways in which feasibility was assessed included the number of photographs and PROMS recorded via the app, data from patient questionnaires and verbal feedback. Results: A total of 10 patients were recruited: 9 (90%) female, median age 55 years, median disease duration 12 years. Nine (90%) completed the study. The median duration of study participation per 'lesion episode' was 39 days (range 18-140). A total of 210 images were returned, with a median of 12 (range 4-87) per episode, and 99 sets of visual analogue scale/pain scores were returned, with a median of 7 (range 3-24) per episode. On a scale of 1 (very easy/helpful) to 10 (very difficult/not helpful), the median score for ease of sending photographs was 1 (range 1-3) and for helpfulness of feedback it was 1.5 (range 1-8). All patients were keen to use the app again. Conclusion: The feasibility and benefits of using the smartphone app, including the feedback function, lend support to possible wider use of the app in routine clinical practice.