1. PREVALENCE AND INCIDENCE OF DIABETIC RETINOPATHY IN THE UK Rohini Mathur LSHTM RNIB Research Day 2015 Improving health worldwidewww.lshtm.ac.uk

2. Background Diabetic Retinopathy (DR) is caused by the presence of diabetes which results in damage to the retina. Within 20 years of diabetes diagnosis nearly all people with type 1 and almost two thirds of people with type 2 diabetes have some degree of retinopathy. In the UK, the risk of developing type two diabetes has been shown to be 2-6 times higher in South Asian communities compared to the White British population. If untreated, diabetic retinopathy leads to blindness, and is one of the most common causes of sight loss in people of working age.

3. Aims Though diabetic retinopathy is thought to be one of the leading causes of visual impairment and blindness in the UK, population-wide measures of incidence and prevalence have not been determined The aims of this study were to: 1.G enerate nationally representative estimates of the incidence and prevalence of diabetic retinopathy in the United Kingdom 2.Examine trends according to age, sex, ethnicity, socio-economic deprivation, calendar period, and region.

4. Methods A prospective cohort study was conducted to examine the prevalence and incidence of diabetic retinopathy in all patients aged 12 and over between January 2004 and December 2014. The study used data from the Clinical Practice Research Datalink: – A database containing the anonymised medical records of 5.5 million patients – From 601 general practices across the UK – The CPRD is representative of the UK population with respect to age, gender and ethnic group. Retinopathy Screening was introduced as a payment indicator in 2004 as part of the Quality and Outcomes Framework, thus coding is likely to be complete and accurate over the study period

5. Results 7,707,475 patients in the CPRD aged 12+ 4% with type 1 diabetes (338,390) 28% with diabetic retinopathy (95,807) 0.4% with type 1 diabetes (30,657) 48% with diabetic retinopathy (18,846)

6. Prevalence in CPRD over time N=7,707,475

7. Prevalence in CPRD by Region N=7,707,475

8. Trends by gender Hazard RatioCI 95%p.val T1DMMale (ref)1 Female1.05(1.01-1.11)0.030 T2DMMale (ref)1 Female0.92(0.91-0.93)<0.001 Relative risk of incident Retinopathy The prevalence of retinopathy is comparable between males and females The risk of incident retinopathy is lower in females relative to males

9. Trends by ethnic group Hazard Ratio CI 95%p.val T1DMWhite (ref)1 South Asian0.87(0.68-1.10)0.237 Black0.79(0.59-1.04)0.091 T2DMWhite (ref)1 South Asian1.14(1.10-1.19)<0.001 Black1.08(1.02-1.15)0.014 Relative risk of incident Retinopathy Large ethnic differences in prevalence for patients with T1DM Risk of retinopathy is raised for South Asian and Black groups with type 2 diabetes relative to White groups

10. Trends by deprivation quintile Hazard Ratio CI 95%p.val T1DMMost affluent1 Least affluent0.94(0.87-1.02)0.128 T2DMMost affluent1 Least affluent1.08(1.05-1.11)<0.001 Relative risk of incident Retinopathy Prevalence of retinopathy increases with deprivation till Q4 Risk of retinopathy is higher for the least affluent compared to most affluent in patients with type 2 diabetes

11. Conclusions The study has shown that the overall prevalence of retinopathy has been increasing steadily over the last 10 years in parallel to that of type 2 diabetes. Increases in prevalence of retinopathy are likely to be related to increasing prevalence of T2DM and potentially increased ascertainment through national screening programs. Prevalence of retinopathy is similar between males and females, but incidence is lower for females with T2DM. Increasing levels of deprivation are associated with higher prevalence of retinopathy in all diabetics, and with higher incidence amongst T2DM only. Amongst patients with type 2 diabetes, prevalence and incidence of retinopathy is highest in the South Asian group relative to the White group.

12. Strengths This study constitutes the largest ever sample size to examine trends in the burden of diabetes and diabetic retinopathy in the UK. Currently, this is the only national study to examine ethnicity and deprivation in relation to the prevalence and incidence of diabetic retinopathy. The advantage of routine electronic health databases is that they are regularly updated and can be used to provide timely information on the demographic makeup of the general population and on areas of growing healthcare need.

13. Policy implications Given that the CPRD is representative of the UK population structure, we estimate that the absolute number of people with any form of diabetic retinopathy in the UK is approximately 1.5 million. In 2014, attendance at diabetic retinopathy screening was removed from the Quality and Outcomes Framework. Not only will this impact on future research into retinopathy, it is likely to have serious negative implications on service planning for diabetic patients unless the indicator is reinstated. The national diabetic retinopathy screening programme needs to improve access to screening and support around self-management of diabetes for deprived and ethnic minority populations to avoid increasing inequalities.

14. Thank you! I’d like to thank the team at LSHTM: Ian Douglas, Krishnan Bhaskaran, Nish Chaturvedi, Liam Smeeth And at the RNIB Emma Edwards, Helen Lee, John Slade Any Questions? (Full Results will be published on the RNIB website in 2016)

15. PREVALENCE AND INCIDENCE OF DIABETIC RETINOPATHY IN THE UK Rohini Mathur LSHTM RNIB Research Day 2015 Improving health worldwidewww.lshtm.ac.uk