Table 1

Number of eligible infants, the number surviving to the first eye check, crude survival rate, and the number of cases of ⩾ stage 3 retinopathy of prematurity (ROP) in each city

City No of infants No of survivors Crude survival rate per 1000 births ⩽1250 g No of cases of
⩾ stage 3 ROP
11229073715
22351697194
365446771
4103646211
595545684
Total62042167925