The influence of diabetic retinopathy on quality of life: interviews to guide the design of a condition-specific, individualised questionnaire: the RetDQoL.

An individualised measure of the impact of diabetic retinopathy on quality of life (QoL) was developed, using a four-phase iterative approach, incorporating qualitative and quantitative methods. In semi-structured interviews, eleven people with diabetic retinopathy in each of two UK and two German hospitals described how QoL would be different without diabetic retinopathy. They completed and commented on the latest Retinopathy Dependent QoL (RetDQoL) draft. Interviews were content analysed before questionnaire revision and translation for the next centre. Twenty-six men and 18 women were interviewed: median age 60.5 (28-82) years; severity ranged from untreated background diabetic retinopathy to proliferative diabetic retinopathy requiring photocoagulation in both eyes, and vitrectomy. The resulting 26-domain RetDQoL asks about the impact of 'diabetic eye problems'. Iterative methodology ensured good understanding, face and content validity. It can be self- or interviewer-completed. Visual impairment, worries and movement restrictions impaired many aspects of QoL, with impacts before vision loss. Practice implications relate to using the RetDQoL and improving practitioner-patient communication.