@article {1517202,
	title = {Validation of the Retinopathy of Prematurity Activity Scale (ROP-ActS) using retrospective clinical data},
	journal = {Acta Ophthalmol},
	volume = {99},
	number = {2},
	year = {2021},
	month = {2021 Mar},
	pages = {201-206},
	abstract = {PURPOSE: The International Neonatal Consortium recently published a proposed retinopathy of prematurity (ROP) activity scale intended for use in clinical trials after validation. The aim of this study was to validate the ROP activity scale (ROP-ActS) in a ROP screened cohort with protocol based collected data by evaluating the ability of the ROP-Act scores to predict ROP treatment. In addition, we aimed to evaluate the scale{\textquoteright}s sensitivity characteristic of disease severity by studying association with gestational age (GA) in comparison with conventionally used ROP stage and zone. METHODS: A cohort of 535 preterm infants with 3324 ROP examinations with an end-point of ROP treatment or end of screening in Gothenburg, Sweden, was included. Median GA was 28.1\&nbsp;weeks, 47.5\% were girls, and 74 (13.8\%) infants were treated for ROP. The validation was performed by estimating probabilities for ROP treatment, and by applying logistic and linear regression. RESULTS: The original ROP-ActS was overall well-ordered with respect to ability to predict ROP treatment but could be improved by re-ordering score 3 (zone II stage 1) and 5 (zone III stage 3) based on our clinical cohort data. The modified ROP-ActS was superior to ROP stage and zone in the prediction analysis of ROP treatment. Modified ROP-ActS was more strongly related to GA than currently used ROP stage, but not zone. CONCLUSION: In the studied cohort, the modified ROP-ActS could better predict ROP treatment compared to ROP stage and zone. Retinopathy of Prematurity Activity Scale (ROP-ActS) had a superior sensitivity characteristic studied through association to GA than conventionally used ROP stage.},
	issn = {1755-3768},
	doi = {10.1111/aos.14532},
	author = {Pivodic, Aldina and Nilsson, Staffan and Stahl, Andreas and Smith, Lois E H and Hellstr{\"o}m, Ann}
}
