Objective The Epworth Sleepiness Scale (ESS) was designed to be self-completed by the patient. However, it may not be understood by all, and unrecognised problems with literacy can impair the process. The ESS has been translated into a pictorial version for use in those with normal or diminished literacy skills.

Methods An evaluation of the patients' ability to self-complete the ESS was undertaken in sleep and non-sleep respiratory clinics. Errors or problems encountered were recorded on a standard questionnaire. With the aid of a medical artist, pictorial representations of the eight ESS questions were developed and the new pictorial ESS was offered to patients alongside the traditional ESS. The two scales were compared for agreement with a kappa statistic, and patients were asked to record a preference for either the written or the pictorial scale.

Results Evaluation of the traditional ESS showed that 33.8% (27/80) of ESS-naive patients made errors and 22.5% (18/80) needed help completing the questionnaire. The translated pictorial ESS showed good agreement with the traditional ESS on most questions; median kappa score 0.63, IQR 0.04. Fifty-five per cent reported a preference for the pictorial scale compared with the standard written ESS. Despite the fact that errors were frequently made on the traditional ESS, 96.8% of participants in the second study reported both scales to be easy to complete. More people (75.6%) reported the pictorial ESS to be very easy, in comparison with (64.6%) the worded ESS questionnaire.

Conclusion Errors are common when patients self-complete the traditional written ESS. Pictures with words have been shown to enhance the understanding and translation of medical information, and a pictorial translation of the ESS produces scores comparable with the traditional ESS and may be a suitable alternative for those with normal or diminished literacy.