• Public health
• Retina

Health policy is constantly striving to release capacity in overstretched health services, or to improve effectiveness, efficiency and patient experience, while maintaining clinical safety. However, policy implementation may also introduce unintended consequences. This is elegantly highlighted in the paper by Olvera-Barrios et al 1 reporting a large retrospective study on the differential impact of extended diabetic eye screening intervals among persons with diabetes, considered to be at low risk of sight loss.

Understanding disparities in health (inequalities and variations in healthcare) and addressing their underlying factors remains a constant challenge with competing priorities for limited healthcare capacity and resources. Diabetes is no exception. Its prevalence is increasing globally2 and in the UK,3 it is higher among some ethnic communities.4–8 There is growing evidence on the variation in risk of developing significant sight threatening diabetic retinopathy (STDR) by ethnicity and age in UK populations9 10 and elsewhere.11 12 The findings reported by Olvera-Barrios et al make an important contribution to this body of evidence. Consistent with previous studies, they report significantly increased risk of developing STDR among black and South Asian ethnic groups9–12 and in the younger age groups.13 14