Table II.

Summary of studies reporting risk factor analyses for impaired fine or gross motor skills in children born very preterm or with very low birthweight

Study reference [Identifier for Figure 4]	Country and recruitment period	Age of assessment (y:mo)	GA (wks)/birthweight (g)	Design and participants	Exclusion criteria for major disability	Number (%) of survivors assesseda	Outcome measure (continuous (cts) unless otherwise specified)	Significant risk factors for poorer outcome (p<0.05) in final model
Children of all levels of disability
Age of assessment <5 years
Pin et al.32 [M]	Australia 2006–2007	1:6	<30w	PC of infants admitted to four tertiary NICUs in Melbourne.	N/A	54 (76)	Gross motor development. Total score from Alberta Infant Motor Scale (AIMS).85 Blinded assessment.	PN steroids.
Vohr et al.21 [B]	United States 1993–1998	1:6–1:10	<33w and <1000g	PC of infants admitted to the NICU of 12 centres participating in the multicentre NICHD NRN routine FUP.	N/A	3785 (80)	Fine and gross motor skills. PDI score from BSID-II (<70 vs ≥70). Blinded assessment.	Adjusted age, no AN steroids, lower BW, BPD, IVH 3–4, male sex, lower maternal education, multiple pregnancy, PVL, PN steroids, sepsis (early or late).
Stoelhorst et al.33,b [N]	Netherlands 1996–1997	2:0	<32w	PC of all live births in three Dutch health regions comprising 9% of the population.	N/A	144 (61)	Fine and gross motor skills. PDI score from BSID-I.86 Blinded assessment.	PN steroids, SGA.
Messinger et al.34,c [O]	United States 1999–2001	2:6	<1000g	Infants admitted to the NICU of 12 centres participating in the multi-centre NICHD NRN routine FUP and enrolled in a glutamine supplementation RCT.	N/A	539 (47)	Fine and gross motor skills. PDI score from BSID-II.	Lower BRS at 18m, BW ≤750g, male sex, lower maternal education, lower maternal income, lower PDI at 18m.
Age of assessment ≥5 years
Orchinik et al.35,d [R]	United States 2001–2003	5:0	<28w or <1000g	PC of infants admitted to a single centre NICU (Ohio) participating in the multicentre NICHD NRN routine FUP.	N/A	133 (67)	Fine and gross motor skills. T-score from BOT-2 short form version87 <10th centile. Blinded assessment.	Neurosensory disorder and/or MDI<70 at 20m.
Taylor et al.36,e [S]	United States 1992–1995	8:0	<1000g	PC of infants admitted to a single centre NICU (Ohio) participating in the multicentre NICHD NRN routine FUP.	N/A	204 (86)	Fine and gross motor skills. T-score from BOT short form version88 (cts and <1SD below mean of control group). Blinded assessment.	Model 1 (T-score<1SD): BPD, longer neonatal hospital stay. Model 2 (cts T-score): BPD, BW <750g, NEC, PN steroids, NRI>3, longer neonatal hospital stay.
Restricted to children free of major disability
Age of assessment <5 years
Charkaluk et al.37 [P]	France 1997	2:0	<33w	PC of all live births in one French region (Nord-Pas-de-Calais, EPIPAGE Study).	CP or severe neurosensory impairment (n=45).	347 (64)	Fine motor domain of Brunet–Lezine scale (revised).89	Longer intubation, lower parental occupation.
Wood et al.26 [G]	UK and Republic of Ireland 1995	2:6	<26w	PC of all live births in the UK and Republic of Ireland (EPICURE Study).	PDI score <55 from BSID-II or functional motor disability (n=47).	197 (64)	Fine and gross motor skills. PDI score from BSID-II.	Breast milk in hospital, BPD, non-vaginal breech delivery, male sex, multigravida, parenchymal pathology and/or ventriculomegaly
Janssen et al.38 [Q]	Netherlands 1996–2001	2:0–3:0	<33w	PC of infants admitted to a single centre NICU (Nijmegen) and enrolled for the Dutch neonatal routine FUP.	Under multidisciplinary treatment for disability (n=23).	437 (56)	Fine and gross motor skills. PDI score from BSID-II (<85 vs ≥85). Blinded assessment.	BPD, male sex, neonatal convulsions, lower maternal education.
Age of assessment ≥5 years
Hansen et al.27 [H]	Denmark 1994–1995	5:0	<28w or <1000g	PC of all live births in Denmark ascertained from all 18 neonatal care units and the Danish Medical Birth Register (ETFOL Study).	CP or visual disability (n=23)	137 (51)	Motor development. Total score from MABC. Blinded assessment.	Male sex.
Janssen et al.39 [T]	Netherlands1996–2001	5:0	<33w	PC of infants admitted to a single centre NICU (Nijmegen) and enrolled for the Dutch Neonatal routine FUP.	CP, visual disability or under multidisciplinary treatment for disability (n=31).	371 (47)	Motor impairment. Total score <15th centile from MABC. Blinded assessment.	Male sex, GA <30w, IVH, PDI <90 at 30m, BRS motor quality <26 at 30m.
Dewey et al.40 [U]	Canada 1996–2000	5:0	<1000g	PC study of infants admitted to a single centre NICU (Calgary).	CP, IQ<70 or visual impairment (n=44).	103 (52)	Motor development. Total score from MABC.	BPD, higher GA, PN steroids.
Leversen et al.41,f [V]	Norway 1999–2000	5:0	<28w or <1000 g	PC of all live births in Norway.	CP or severe sensory deficit (n=33).	261 (70)	Motor development. Total score from MABC.	Model 1 (GA <28w): no AN steroids, lower GA, male sex, ROP >2, SGA. Model 2 (GA ≥28w): male sex, ROP 1–2.
Goyen and Lui42 [W]	Australia 1992–1995	8:0	<29w or <1000g	Infants admitted to a tertiary referral centre (Sydney) receiving high-risk referrals from regional centres and enrolled for the routine FUP.	CP, visual/hearing impairment, IQ<85, not attending mainstream school (n=64).	50 (24)	Motor impairment. Total score <15th centile from MABC.	PROM, ROP.
Davis et al.43 [X]	Australia 1991–1992	8:0	<29w or <1000 g	PC of all live births in the state of Victoria.	CP or IQ>2SD below mean (n=45).	210 (70)	Motor impairment. Total score <5th centile from MABC. Blinded assessment.	Male sex.
Zanudin et al.44 [Y]	Australia 1992–1994	12:0	<1000 g	Retrospective longitudinal study of infants admitted to a single centre NICU (Brisbane).	CP, neurological impairment, cognitive index >2SD below mean at 4 years (n not reported)	48 (<50)	Motor development. Total score from MABC.	BPD, male sex.

^aPercentage of children surviving to the age of the intended assessment who were assessed for outcome; not all included in the final model.

^bTwo models for motor skills reported. Model based on 2-year outcome included. Model based on 1.5-year outcome not included.

^cSeveral models for motor skills fitted. Full model adjusting for 18-month PDI and BRS total score included.

^dEach risk factor was fitted separately and adjusted for sex, race, parental SES, and months in school at testing (the article did not report results for the adjustment factors).

^eTwo models for motor skills reported; one based on dichotomous outcome and one based on continuous outcome. Risk factors reported separately for each model in the table. Each risk factor was fitted separately and adjusted for sex, race, parental SES, family stressors, and family resources (the article did not report results for the adjustment factors).

^fTwo models for motor skills reported for each gestational age group (<28wks and ≥28wks). Risk factor considered as significant in Figure 4 if p<0.05 in either model. AN, antenatal; BOT, Bruinincks–Oseretsky Test of Motor Proficiency; BPD, bronchopulmonary dysplasia; BRS, Behaviour Rating Scale from BSID; BSID, Bayley Scales of Infant Development;⁴⁸ BW, birthweight; CP, cerebral palsy; FUP, follow-up; GA, gestational age; IVH, intraventricular haemorrhage; IQ, intelligence quitient; MABC, Movement Assessment Battery for Children;⁴⁹ MDI, Mental Developmental Index from BSID; N/A, not applicable; NEC, necrotizing enterocolitis; NICU, neonatal intensive care unit; NICHD NRN, National Institutes of Child Health and Human Development Neonatal Research Network; NRI, neonatal risk index; PC, prospective cohort; PDI, Psychomotor Developmental Index from BSID; PN, postnatal; PROM, prolonged rupture of membranes; PVL, periventricular leukomalacia; RCT, randomized controlled trial; ROP, retinopathy of prematurity; SD, standard deviation.