TABLE 3.

Design characteristics of the 10 studies describing external validation of BPD prediction models.

Study	Country	Study design	Years of data	Study population	Timing of BPD	Intended moment of model use	Model validated
El Faleh et al. (17)	Switzerland	Registry	2014–2015	BW < 1,501 g and/or GA between 23 0/7 and 31 6/7 weeks	DOL28 or PMA36	1 day	El Faleh et al. (17)
Shim et al. (15)	Korea	Registry	2017	BW < 1,500 g and GA ≥ 22 weeks	PMA36	1 h	Shim et al. (15)
Bhattacharjee et al. (18)	United States	Retrospective cohort	2012–2013	BW < 1,500 g	PMA36	3 day	RSS
Lee et al. (20)	Korea	Registry	2013–2016	BW < 1,500 g and GA 22–32 weeks	PMA36	1 h	CRIB II; CRIB II-BE
Sullivan et al. (23)	United States	Retrospective cohort	2004–2014	BW < 1,500 g	PMA36	12 h, 1 day, 7 day	aHRC-24h, aHRC-7d, SNAP-II, CRIB-II
Gursoy et al. (24)	Turkey	Prospective cohort	2012	GA ≤ 32 weeks and BW ≤ 1,500 g	DOL28	3 day	BPD-TM score
May et al. (28)	United Kingdom	Retrospective cohort	1995–1998	BW < 1,500 g and GA < 33 weeks	DOL28 or PMA36	2 day	Simple pulmonary score
Henderson-Smart et al. (29)	Australia, New Zealand	Registry	2000–2001	GA 22–31 weeks	PMA36	At birth	Henderson-Smart et al. (29)
Kim et al. (30)	Korea	Prospective cohort	2000–2001	BW < 1,500 g	PMA36	4 day, 7 day, 10 day	SMUMRV; Yoder model (55)
Chien et al. (31)	Canada	Registry	1996–1997	GA ≤ 32 weeks	PMA36	12 h	SNAP-II + GA, SGA, sex, low Apgar score, and outborn status

BPD, bronchopulmonary dysplasia; BPD-TM, bronchopulmonary dysplasia test measure; BW, birth weight; CRIB, Clinical Risk Indicator fores; CRIB II-BE, Clinical Risk Indicator fores omitting base excess; DOL, days of life; GA, gestational age; HRC, heart rate characteristics; aHRC-24h, average first day HRC index; aHRC-7d, average first week HRC index within 7 days of birth; PMA, postmenstrual age; RSS, respiratory severity score; SGA, small for gestational age; SMUMRV, modified respiratory variables; SNAP-II, Score for Neonatal Acute Physiology-II.