Feasibility study of mobile phone photography as a possible outcome measure of systemic sclerosis-related digital lesions

Objective Clinical trials assessing systemic sclerosis (SSc)-related digital ulcers have been hampered by a lack of reliable outcome measures of healing. Our objective was to assess the feasibility of patients collecting high-quality mobile phone images of their digital lesions as a first step in developing a smartphone-based outcome measure. Methods Patients with SSc-related digital (finger) lesions photographed one or more lesions each day for 30 days using their smartphone and uploaded the images to a secure Dropbox folder. Image quality was assessed using six criteria: blurriness, shadow, uniformity of lighting, dot location, dot angle and central positioning of the lesion. Patients completed a feedback questionnaire. Results Twelve patients returned 332 photographs of 18 lesions. Each patient sent a median of 29.5 photographs [interquartile range (IQR) 15-33.5], with a median of 15 photographs per lesion (IQR 6-32). Twenty-two photographs were duplicates. Of the remaining 310 images, 256 (77%) were sufficiently in focus; 268 (81%) had some shadow; lighting was even in 56 (17%); dot location was acceptable in 233 (70%); dot angle was ideal in 107 (32%); and the lesion was centred in 255 (77%). Patient feedback suggested that 6 of 10 would be willing to record images daily in future studies, and 9 of 10 at least one to three times per week. Conclusion Taking smartphone photographs of digital lesions was feasible for most patients, with most lesions in focus and central in the image. These promising results will inform the next research phase (to develop a smartphone monitoring application incorporating photographs and symptom tracking). Lay Summary What does this mean for patients? Patients with systemic sclerosis (also called scleroderma) are at high risk of developing breaks in the skin of their fingers or toes, called digital ulcers (or lesions), which can be very painful and slow to heal. Monitoring the progress of an ulcer/lesion is challenging, and this makes it difficult to evaluate the effects of new treatments. To overcome this difficulty, photographic monitoring using smartphones can be used. Taking daily photographs is an ideal way to assess how ulcers/lesions change over time. We recruited 12 patients to photograph their ulcer/lesion daily with their smartphones over a 30-day period. We inspected all photographs visually to assess quality. Seventy-seven per cent of photographs were in focus, with the ulcer/lesion in the centre of the image, although patients often found it difficult to obtain good/even lighting. Ten patients completed a post-study feedback questionnaire. Although some patients noted difficulty in handling their smartphone while taking a photograph, most would be willing to record images daily in future studies. The study therefore found that taking photographs of digital ulcers/lesions with a smartphone was possible for most patients. Smartphone photography has potential as an outcome measure in clinical trials of new treatments.