Ethnic Variations in the Prevalence of Diabetic Retinopathy in People with Diabetes Attending Screening in the United Kingdom (DRIVE UK) Sobha Sivaprasad 1 *, Bhaskar Gupta 1 , Martin C. Gulliford 2 , Hiten Dodhia 3 , Moin Mohamed 4 , Dinesh Nagi 5 , Jennifer R. Evans 6 1 King’s College Hospital NHS Foundation Trust, London, United Kingdom, 2 Division of Health and Social Care Research, King’s College London, London, United Kingdom, 3 Lambeth NHS Primary Care Trust, London, United Kingdom, 4 St Thomas Hospital NHS Foundation Trust, London, United Kingdom, 5 Mid Yorkshire NHS Trust, Wakefield, West Yorkshire, United Kingdom, 6 London School of Hygiene and Tropical Medicine, London, United Kingdom Abstract Aims: To compare the prevalence of diabetic retinopathy (DR) in people of various ethnic groups with diabetes in the United Kingdom (UK). Methods: The Diabetic Retinopathy In Various Ethnic groups in UK (DRIVE UK) Study is a cross-sectional study on the ethnic variations of the prevalence of DR and visual impairment in two multi-racial cohorts in the UK. People on the diabetes register in West Yorkshire and South East London who were screened, treated or monitored between April 2008 to July 2009 (London) or August 2009 (West Yorkshire) were included in the study. Data included age, sex, ethnic group, type of diabetes, presenting visual acuity and the results of grading of diabetic retinopathy. Prevalence estimates for the ethnic groups were age-standardised to the white European population for comparison purposes. Results: Out of 57,144 people on the two diabetic registers, data were available on 50,285 individuals (88.0%), of these 3,323 had type 1 and 46,962 had type 2 diabetes. In type 2 diabetes, the prevalence of any DR was 38.0% (95% confidence interval(CI) 37.4% to 38.5%) in white Europeans compared to 52.4% (51.2% to 53.6%) in African/Afro-Caribbeans and 42.3% (40.3% to 44.2%) in South Asians. Similarly, sight threatening DR was also significantly more prevalent in Afro-Caribbeans (11.5%, 95% CI 10.7% to 12.3%) and South Asians (10.3%, 9.0% to 11.5%) compared to white Europeans (5.5%, 5.3% to 5.8%). Differences observed in Type 1 diabetes did not achieve conventional levels of statistical significance, but there were lower numbers for these analyses. Conclusions: Minority ethnic communities with type 2 diabetes in the UK are more prone to diabetic retinopathy, including sight-threatening retinopathy and maculopathy compared to white Europeans. Citation: Sivaprasad S, Gupta B, Gulliford MC, Dodhia H, Mohamed M, et al. (2012) Ethnic Variations in the Prevalence of Diabetic Retinopathy in People with Diabetes Attending Screening in the United Kingdom (DRIVE UK). PLoS ONE 7(3): e32182. doi:10.1371/journal.pone.0032182 Editor: Noel Christopher Barengo, Fundacio ´ n para la Prevencio ´ n y el Control de las Enfermedades Cro ´ nicas No Transmisibles en Ame ´rica Latina (FunPRECAL), Argentina Received August 30, 2011; Accepted January 23, 2012; Published March 8, 2012 Copyright: ß 2012 Sivaprasad et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was supported by Guide Dogs For the Blind Association: Grant No: OR-2008-04d. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. Competing Interests: The authors have declared that no competing interests exist. * E-mail: senswathi@aol.com Introduction Diabetic retinopathy (DR) is the most common microvascular complication of diabetes. Visual loss from diabetic retinopathy results primarily from two complications. New vessels grow on the retina; this is known as proliferative retinopathy and accounts for the majority of severe visual loss. In addition, retinal blood vessels can become permeable and cause swelling of the centre of the retina, called diabetic macular oedema. Clinically significant macular oedema is a leading cause of moderate visual loss in diabetes. Proliferative retinopathy, severe non-proliferative reti- nopathy and clinically significant macular oedema can be considered as sight threatening retinopathy. The established risk factors of DR include prolonged exposure to hyperglycaemia and hypertension. However, DR can progress despite optimal control of these risk factors [1]. Ethnicity is considered a complex risk factor of diabetes. Type 2 diabetes is estimated to be three to four times more common in people of Asian and African–Caribbean origin compared to white Europeans [2]. The current population in most metropolitan cities in UK is ethnically diverse [3], but differs in relative proportions of ethnic origins when compared to the US population, where contemporary comparative data on the prevalence of diabetic retinopathy in multiethnic cohorts are available [4,5]. The healthcare system in the UK also differs from that in the US. So it is useful to obtain ethnicity specific estimates of DR in the UK to understand the impact of the changing population trends on the prevalence of DR. PLoS ONE | www.plosone.org 1 March 2012 | Volume 7 | Issue 3 | e32182