Flow chart of patients of two cohorts.

Flow chart of patients of two cohorts.</p

Incidence of retinopathy of prematurity by birth weight and Cox proportional hazards regression analysis estimated adjusted hazard ratio associated with mechanical ventilation.

Incidence of retinopathy of prematurity by birth weight and Cox proportional hazards regression analysis estimated adjusted hazard ratio associated with mechanical ventilation.</p

Incidence of retinopathy of prematurity by birth weight and Cox proportional hazards regression analysis estimated adjusted hazard ratio associated with of ROP using normal birthweight of singleton as reference.

Incidence of retinopathy of prematurity by birth weight and Cox proportional hazards regression analysis estimated adjusted hazard ratio associated with of ROP using normal birthweight of singleton as reference.</p

Incidence and Cox proportional hazards regression analysis estimated adjusted hazard ratio of retinopathy of prematurity associated with mechanical ventilation use at birth.

Incidence and Cox proportional hazards regression analysis estimated adjusted hazard ratio of retinopathy of prematurity associated with mechanical ventilation use at birth.</p

Incidence of retinopathy of prematurity and Cox proportional hazards regression analysis estimated twin to singleton adjusted hazard ratio by demographic status.

Incidence of retinopathy of prematurity and Cox proportional hazards regression analysis estimated twin to singleton adjusted hazard ratio by demographic status.</p

Demographic status of singleton and twin cohorts.

Demographic status of singleton and twin cohorts.</p