John Hilton: Hello, I'm John Hilton, editor in the Cochrane Editorial and Methods department.  As well as the problems with blood sugar control that are caused by diabetes, the condition can lead to a variety of other problems. One of these is an eye problem called diabetic retinopathy and it’s important that people with diabetes are checked for this. A January 2018 Cochrane Review looks at how to increase attendance at these screening visits and lead author, John Lawrenson from the City University of London in the UK, tells us more in this podcast.

John Lawrenson: Diabetic retinopathy is the most common microvascular complication of diabetes and is a leading cause of blindness and visual impairment throughout the world. There is good evidence to support annual or biennial screening to reduce the risk of sight loss in people with diabetes, but screening uptake is less than it should be in many screening programmes; and some of the factors associated with lower levels of screening attendance are living in an area of high social deprivation, being under 40, having a longer duration of diabetes and belonging to a Black Asian and Ethnic minority group.
Our new Cochrane Review drew on 66 randomised trials, with a total of more than 350,000 participants, to investigate interventions intended to increase attendance for diabetic retinopathy screening in people with type 1 and type 2 diabetes mellitus. These interventions are typically complex and multi-dimensional, with one or more targets including patients themselves, healthcare professionals or the healthcare system.
Two thirds of the trials were done in North America and none were from low or middle-income countries. Most of the trials compared the intervention to usual care, while a minority compared a more to a less intense strategy. 
Overall, we found that the interventions led to a 12% absolute increase in screening attendance compared to usual care. There was a smaller improvement (approximately 5%) when a more intensive intervention was compared to a less intensive one. However, our confidence in the certainty of these figures is low because of the wide variation in the results across the studies.
There was some evidence for larger effects in populations with lower baseline screening attendance and another important finding was that interventions aimed at improving the general quality of diabetes care worked as well as those that were specifically aimed at improving retinopathy screening. 
In summary, our review provides evidence that interventions to improve diabetic retinopathy screening are effective, whether they are specifically designed to improve retinopathy screening or are part of a general strategy for improving diabetes care. This is important because of the additional benefits of general quality improvement interventions for people with diabetes, such as improving glycaemic control, vascular risk management and screening for other microvascular complications.

John Hilton: If you would like to learn more about the various screening and more general strategies, you could find the full details in the Cochrane Review. Just go to Cochrane Library dot com and run a search for ‘diabetic retinopathy screening’ to find it.