P230 Feasibility study of mobile phone photography as a possible outcome measure of systemic sclerosis-related digital ulcers
Authors: Davison Adrian K , Patrick Helen , New Paul , Dinsdale Graham , Taxiarchi Vicky P , Dixon William G , Vail Andy , Murray Andrea K , Dickinson Mark , Taylor Christopher , Herrick Ariane L 
Published: April 2022

Abstract

Background/Aims
Digital ulcers cause pain and disability in patients with systemic sclerosis (SSc). They are often used as outcome measures in clinical trials; however, trials have been hampered by a lack of reliable outcome measures of healing. Photographic monitoring of digital ulcers using smartphones could overcome this difficulty. Our objective was to assess the feasibility of patients collecting mobile-phone images of their digital ‘lesions’ as a first step in a programme of research to develop a smartphone-based outcome measure.

Methods
An imaging protocol was developed with input from a patient representative group. Patients with SSc-related digital lesions were recruited and instructed to photograph one or more finger lesions each day over 30 days using their smartphone, at the same time each day. Instructions on how to take the photographs were given either face-to-face or remotely. An adhesive dot, placed adjacent to the lesion(s), provided a 1cm reference scale to help extract accurate measurements. Images were uploaded by each patient to a secure Dropbox folder. Image quality was assessed using six criteria: blurriness, shadow, uniform lighting, dot location, dot angle, and central positioning of the lesion. After image collection, patients were asked to complete a feedback questionnaire, with most questions on a scale of 1 (very easy) to 10 (very difficult).

Results
Twelve patients (10 female, age 37 to 72 years, disease duration 1 to 27 years) returned 331 photographs of 19 lesions (maximum three lesions per patient). Each patient sent a median of 30 photographs (IQR 14 to 33), with a median of 15 photographs per lesion (IQR 2 to 31). Of the 331 photographs, 24 were ‘duplicates’ taken on the same day, meaning that there were 263 ‘missing’ photographs (i.e., 570 photographs would have been taken if 19 lesions had been photographed every day). Image quality results included the following: 255 (77%) of photographs were sufficiently in focus; 268 (81%) had some shadow; lighting was even in 55 (17%); dot location was acceptable in 231 (70%); dot angle was ideal in 107 (32%); the lesion was centred in 254 (77%). Patient feedback showed 9/10 responses would be willing to record images at least 1-3 times per week, and the overall patient experience taking photographs was good, with a median rating of 3 (IQR 3 to 4).

Conclusion
Capturing photographs of digital lesions with a smartphone was feasible for most patients. They were able to take photographs in focus and with lesions central in the image. Support will be required to improve lighting, shadow, and dot positioning while minimising discomfort. These encouraging results will inform the next research phase to develop a smartphone app for monitoring finger lesions.

Disclosure
A.K. Davison: None. H. Patrick: None. P. New: None. G. Dinsdale: None. V.P. Taxiarchi: None. W.G. Dixon: None. A. Vail: None. A.K. Murray: None. M. Dickinson: None. C. Taylor: None. A.L. Herrick: None.