PD03: Development of a validated self-report questionnaire of facial photoprotection in xeroderma pigmentosum

R. Sarkany,¹ M. Canfield,² J. Walburn² and J. Weinman²

¹St John’s Institute of Dermatology and ²King’s College London, London, UK

Ultraviolet (UV) protection is vital in xeroderma pigmentosum (XP); it is the only means of preventing skin cancer. As 80% of XP skin cancers are on the face, it would be useful for clinicians to have a short validated questionnaire to assess facial photoprotection in patients with XP. We studied 36 patients with XP over 21 days in the summer. The seven-question questionnaire asked how often the patient had worn or used seven different items of facial photoprotection on cloudy and on sunny days, over the previous 7 days, using a 5-point scale from 1 (never) to 5 (always). From the questionnaire responses, a ‘face protection’ score was calculated using an algorithm that accounted for the complex relationships between different protective items and that divided the face and forehead into five areas. For validation of the questionnaire, we used a face photoprotection activity diary completed by the patient every 15 min for 21 days, detailing what they were doing and what face protection they were using when outside during daylight hours. A mean face protection figure was calculated from these diary data. The short questionnaire and the activity diary were both completed by adult patients themselves, and by the main carer for children and for adults with cognitive impairment. The face photoprotection calculated from the questionnaire was compared for each patient to that calculated from the 21-day activity diary data. The correlation coefficients between the two were 0·66 for face photoprotection on cloudy days and 0·51 for protection on sunny days. UV dosimeter data from each patient also provided a calculated value for the mean daily dose of UV reaching the face (methodology described elsewhere). There was poor correlation between photoprotection, as estimated from the questionnaire, and the mean daily dose of UV reaching the face. The correlation factors were –0·14 for cloudy days and –0·25 for sunny days. This was as expected. The mean UV dose to the face depends not only on photoprotection measures taken when outside, but also on the length of time spent outside. Although self-reported questionnaires have been developed to assess photoprotection in many different populations, few have been validated against a more objective measure of photoprotective behaviour. This short, validated questionnaire is a practical tool for clinicians to assess adherence of patients with XP to face photoprotective measures when they are outside.