Outcome: severe‐NPDR/PDR

According to the previously published article on outcomes in the TLGS cohort ²¹ , for each participant, any medical event leading to hospitalization was followed up by a telephone call annually. Individuals were asked about any medical conditions by a trained nurse, and later, a trained physician collected complementary data regarding that event during a home visit and by the acquisition of data from medical files. The collected data were then evaluated by an outcome committee consisting of an internist, endocrinologist, cardiologist, epidemiologist and other experts, if required, to assign a specific outcome for every event. Importantly, the outcome committee is blinded to the status of baseline risk factors. Following the TLGS protocol, severe‐NPDR/PDR was defined as the history of the first pan‐retinal photocoagulation (PRP), which was carried out in the follow‐up period. The recommendation of a trial of PRP for severe NPDR and PDR was addressed in several studies ^{22 , 23} . Furthermore, carrying out PRP at the severe NPDR stage is likely to be cost‐effective compared with delaying photocoagulation until PDR develops ²⁴ .