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Neurodevelopment and the effects of a neurobehavioral intervention in very preterm-bornchildrenvan Hus, J.W.P.

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Citation for published version (APA):van Hus, J. W. P. (2014). Neurodevelopment and the effects of a neurobehavioral intervention in very preterm-born children.

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Chapter 2

Reliability, sensitivity and responsiveness

of the Infant Behavioral Assessment in very

preterm infants

Karen Koldewijn, Janeline W.P. Van Hus, Aleid G. Van Wassenaer-Leemhuis,

Martine Jeukens-Visser, Joke H. Kok, Frans Nollet, Marie-Jeanne Wolf

Acta Paediatrica 2012;10:258-263

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28 | Chapter 2

Abstract

Aim. The aim of this study is to investigate the reliability, sensitivity and responsiveness

of the Infant Behavioral Assessment (IBA) to evaluate neurobehavioral organization in

very preterm-born infants.

Methods. Videotaped assessments of very preterm-born infants participating in a recent

trial, served to evaluate a standardized IBA observation. Inter-rater reliability was based

on 40 videos scored by two independent observers, using percentage agreement and

weighted Kappa’s. Sensitivity was evaluated by comparing the IBA results of 169 infants

at 35-38 weeks postmenstrual age, dichotomized according to two developmental risk

factors. For responsiveness, the effect size (ES) was calculated between 0 and 6 months

corrected age in all intervention and control infants and in subgroups of high-risk

intervention and control infants with oxygen-dependency ≥28 days.

Results. Inter-rater agreement was 93% in the total assessment; Kappa agreement was

moderate to good in the behavioral categories. Significant differences were found

between groups with or without risk factors. Larger differences between ESs in the

randomized groups with oxygen-dependency ≥28 days than in the total randomized

groups reflect the responsiveness of the IBA.

Conclusion. In this study, we found satisfactory to good clinimetric characteristics of the

IBA in very preterm-born infants.

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Clinimetric properties of the IBA | 29

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Introduction

The Infant Behavioral Assessment© (IBA)1 is an assessment designed to evaluate the

infant’s neurobehavioral organization to support positive interactions of the infant

with the environment. The IBA was derived from the NIDCAP_ Observation Sheet2, the

‘Naturalistic Observation of Newborn Behavior’ by Als3, but intended for infants from 0–8

months of corrected age (CA). Hedlund and Tatarka further articulated Als’s4 theoretical

construct of the ‘Synactive Model of Newborn Behavioral Organization and Development’

for older infants at developmental risk, as well as infants who are typically developing.

The IBA is primarily intended to be used in a qualitative manner, in conjunction with the

corresponding intervention program: the Infant Behavioral Assessment and Intervention

Program© (IBAIP).5,6 The interventionist continuously observes and interprets the infant’s

behavior and the setting during the interaction with the IBA. This behavioral analysis

results in strengths-based recommendations to support the infant’s sensory approach of

information and neurobehavioral competence, and/or in environmental adaptations to

diminish the infant’s stress or discomfort.

The effectiveness of the IBAIP was evaluated in a randomized controlled trial (RCT),

enrolling infants born <32 weeks gestation and/or 1500 g. We already published that

IBA-guided interventions in this RCT lead to more positive and sensitive mother–

infant interactions at 6 months,7 more improvement of self-regulatory competence

and improved mental, motor and behavioral development in the infants at 6 months,8

improved motor outcome at 24 months,9 and to more independency of the infants at

preschool age.10

For an accurate role in early intervention, the clinimetric characteristics of the IBA

need to be explored. In two pilot studies,11,12 we described the theoretical background,

scoring and interpretation of the IBA. These studies showed that short quantified IBA

observations were able to detect considerable differences between low-risk preterm

and term infants,11 and between infants that received intervention and control infants

at term, 3 and 6 months CA.12 In addition, the IBA showed differences between term,

preterm and preterm intervention infants’ neurobehavioral development over time.11,12

The purpose of this study is to further investigate the clinimetric characteristics of the IBA,

by determining its reliability, sensitivity and responsiveness to evaluate neurobehavioral

organization in very preterm-born infants.

Patients and Methods

Data of a recent multicenter RCT, which evaluated the effect of the IBAIP in very preterm

infants after discharge from hospital, were used.8 Primary outcomes were the Bayley

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30 | Chapter 2

Scales of Infant Development-II (BSID-II)13 at 6 and 24 months CA.8,9 The trial included

176 infants of <32 weeks gestational age (GA) and/or <1500 g, born in one of the seven

Amsterdam hospitals, and with parents living in Amsterdam. GA was determined by

maternal history and ultrasound examination in early pregnancy, or postnatal with the

Dubowitz-score14 if ante-partum information was inconclusive. The infants’ mean (SD)

GA was 29.6 (2.2) weeks in the intervention group and 30 (2.2) weeks in the control

group; the mean (SD) birth weight was 1242 (332) g in the intervention group and 1306

(318) g in the control group.

The interventions consisted of one session shortly before discharge from hospital and

six to eight sessions at home, until 6 months CA. The interventionists used continuous

naturalistic IBA observations to systematically analyse the child’s behavior during

interactions, resulting in immediate strengths based recommendations to support the

infant and the parent. In addition, shortly before discharge, at 3 and 6 months CA,

standardized IBA observations were registered to evaluate the infants’ neurobehavioral

performance for research purposes.8 In this study, these observations are used to

determine the reliability and validity of the IBA. IBA observations of 169 infants were

available at baseline (35–38 weeks postmenstrual age, PMA), and 162 infants at 6 months

CA; data of 157 infants were available at both baseline and 6 months CA. Data loss was

because of technical problems with the video administration or a nonoptimal state of

the infant. A detailed description of perinatal and socio-demographic characteristics and

infant outcomes can be found in Koldewijn et al.8

The Infant Behavioral Assessment

The IBA is based on naturalistic observations, discriminating 113 behaviors in four

systems: 26 items in the autonomic system, 44 items in the motor system, 9 items in

the state system and 34 items in the attention ⁄ interaction system (Appendix 1). The

infant’s behaviors are scored as present (=1) if they are observed at least once during the

observational interval, or as absent (=0). Within each of the four systems, the behaviors

are interpreted as approach (stable / engagement), self-regulatory (utilized by the

infant to concentrate, cope and/or console himself), or stress (unstable ⁄ disengagement)

behaviors. For example, on the IBA score sheet (Appendix 1), the items in the motor

system, subsystem hands, are interpreted as follows: grasp and resting are considered to

communicate approach ⁄ stabile behavior; holding on, hand to midline, hand to mouth,

groping, hand on stomach, self-clasp and hand on head are considered self-regulatory

behavior; finger extension, finger splay and fisting are considered to express stress.1 The

categories approach and self-regulation demonstrate the infant’s unique behavioral

strengths to interact; stress behaviors show the infants’ vulnerabilities and needs.



2

The IBA is intended for use by health professionals who have experience with young

infants. Formal training and certification in the IBA is required; an inter-rater agreement

of at least 85% must be established.1 The IBA does not have normative data for either

term or preterm infants, as the test aims to assess the individual infant’s behavioral

strengths and needs in response to sensory information, to provide the quality and

amount of information or support that is appropriate for that particular infant, at that

particular time.

Data collection

Research use of the IBA requires careful standardization and grading of the challenge

for each specific infant group and/or age. The infant needs to be able to join in an age

appropriate interaction but should also be challenged enough to use self-regulatory

behaviors or show short moments of stress.

At baseline (35–38 PMA), the infant was recorded on video in hospital, during the

changing of a diaper by the mother. The infant was in supine in the bed, and a 2-minute

‘observation window’ was used to score the IBA, starting when the diaper was opened.

At 3 months CA, the infant was recorded at home. The infant was in an unsupported

supine position. A 2-minute ‘observation window’ was used to score the IBA, starting at

the moment the mother presented a bell and rattle as used in the BSID-II. At 6 months

CA, the BSID-II assessment at the follow-up clinic was recorded on video; a 2-minute

‘observation window’ during the ‘exploration of the bell’ was used to score the IBA,

again with the infant in an unsupported supine position. An awake state of the infant

was required;1 a full description of the standardizations is available by the author of this

paper.

All IBA fragments were scored from video by an IBAIP certified observer (JvH), who

was blinded for group assignment. The IBA was quantified by counting the occurrence

of ‘approach’ and ‘stress’ behaviors in the autonomic, motor, state and attention

⁄ interaction system, and for the IBA total scores of approach and stress; means were

calculated for each of the four systems and the IBA total score. Self-regulation is not

used as an outcome measure for the infant’s neurobehavioral organization, as self-

regulation has a mediating function that results either in the enhancement of approach

(by concentration) or the prevention⁄reduction of stress (by coping or consoling).

To evaluate the inter-observer reliability of the IBA, video fragments of 40 infants were

scored at the CA of 3 months by two independent certified and experienced observers

(KK and JvH). The age of 3 months was chosen as the IBA incorporates items for the age

of 0–8 months. Three-month old infants are expected to express behaviors throughout

the four systems. At term age, infants may express only few approach behaviors in the

attention ⁄ interaction system and at 6 months only few stress behaviors in the autonomic

system.

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To investigate the sensitivity of the IBA, we evaluated its ability to discriminate

between neurobehavioral outcomes of subgroups of infants with or without the

perinatal risk factors of GA ≤28 weeks and oxygen dependency >28 days at the age

of 35–38 weeks PMA. The IBA responsiveness to change was investigated over the

period from 0 to 6 months. As young infants are expected to make more adaptations

and changes in this period than at any time later in life, we expected large changes.

We therefore focused primarily on the responsiveness of the IBA to show differences in

change after intervention, in the total intervention and control group, and a subgroup

of intervention and control infants with oxygen dependency >28 days. This high-risk

group was chosen because oxygen dependency was found to be significantly associated

with the primary outcomes at 6 months in our RCT. Moreover, at 24 and 44 months, it

became clear that the intervention (IBAIP) benefited the development of infants with

long-term oxygen dependency most.9,10

Statistical analysis

Data were analyzed using the SPSS 15.0 program (SPSS, Chicago, IL, USA).

Percentage agreement for each item was calculated. Item-by-item percentage

agreement was calculated for the total and the three categories of approach, self-

regulation and stress. In addition, agreement between observers was calculated using

weighted Kappa statistics with quadratic weights for these three categories. According

to Landis and Koch,15 a Kappa of >0.80 is very good, 0.61–0.80 good, 0.40– 0.60 moderate

and <0.40 is poor. According to the instructions in the IBA Training Manual,1 the five

items for skin colour were removed, because colour cannot be scored from video.

The sensitivity of the IBA to discriminate between infants dichotomized according to

two developmental risk factors was analyzed with t-tests. An alpha level of 0.05 was

considered significant. For the responsiveness of the IBA, Cohen’s16 effect size (ES) was

used as a measure of change. ES was obtained by dividing the absolute change between

the outcomes at baseline and the outcomes at 6 months by the standard deviation of the

baseline measurement. An ES of ≥0.80 is considered large, an ES of 0.50 is medium and

an ES of 0.20 is considered small.

Results

Inter-observer reliability

Table 1 summarizes the inter-observer agreement on the IBA categories of approach,

self-regulation and stress, and the total item-by-item percentage agreement of the IBA

in 40 infants. Inter-observer agreement was moderate in the category of approach (Kw

= 0.58) and good in the categories self-regulation (Kw = 0.72) and stress (Kw = 0.75).



2

Observers achieved an average of 93% (range 85–97%) item-by-item agreement for the

total assessment. Of a total of 108 items, 97 had good to excellent agreement (>80%)

and 11 had moderate agreement (60–80%). Of the 11 items with moderate agreement,

seven were in the motor system, three in the attention ⁄ interaction system and one was

in the state system.

Table 1. Infant Behavioral Assessment. Inter-observer agreement (n = 40)Categories No of items Weighted Kappa Percentage agreementApproach 22 0.581 92Regulation 42 0.722 90Stress 44 0.754 95Total IBA 108 n.a. 93

n.a.: not applicable

Sensitivity of the IBA at term age

The differences on the IBA subsystem scores and total scores in the two high–risk groups

are shown in Table 2. All outcomes pointed in the expected direction, indicating less

approach and/or more stress in infants at biological risk. Significantly less autonomic

approach, more autonomic stress and less total approach were found in infants with a

GA ≤28 weeks. Infants with oxygen dependency >28 days showed less autonomic and

motor approach, more autonomic and state stress, less total approach and more total

stress.

Responsiveness of the IBA to change over time

Table 3 shows the responsiveness of the IBA subscores and total scores between 35–38

weeks PMA and 6 months CA. Approach in the state system could not be calculated

because of the preterm infants’ limited use of approach behaviors in the state system at

35–38 weeks PMA. As expected, the ESs were large, both in the randomized total groups

and in the oxygen-dependent high-risk groups, except for stress in the state system in the

randomized total groups. Again all outcomes pointed in the expected direction: ESs for

approach showed positive values (more approach over time) and ESs for stress showed

negative values (less stress over time). The ESs in the total intervention group were larger

for approach and stress than in the total control group. Largest changes were found in

intervention infants with oxygen dependency >28 days. In the control infants of this

high-risk subgroup, approach behavior increased to a higher extent (+5.72) than in the

total control group, but to a lesser extent than in the total intervention group. In this

high-risk control group, stress behavior, however, decreased to a lesser extent (-2.73)

than in all other groups.

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34 | Chapter 2

Table 2. Infant Behavioral Assessment (IBA). Differences between infant groups with or

without high-risk at 35-38 weeks postmenstrual age

Gestational age < 28 weeks Oxygen ≥ 28 days

IBA subscoresYes (n=30)Mean (SD)

No (n=139) Mean (SD)

Yes (n=50)Mean (SD)

No (n=119) Mean (SD)

Autonomic approach 0.56 (0.76) 1.02 (0.77)** 0.56 (0.76) 1.02 (0.77)** stress 2.73 (0.74) 2.33 (0.94)** 2.72 (0.88) 2.27 (0.89)**Motor approach 1.93 (1.29) 2.40 (1.29) 2.00 (1.25) 2.45 (1.30)* stress 6.43 (1.55) 6.38 (1.62) 6.58 (1.66) 6.31 (1.58)State approach 0.00 (0.00) 0.01 (0.09) 0.00 (0.00) 0.01 (0.92) stress 0.67 (0.61) 0.47 (0.00) 0.70 (0.61) 0.43 (0.61)**Attention-interaction approach 0.27 (0.52) 0.32 (0.59) 0.26 (0.49) 0.34 (0.61) stress 2.90 (1.90) 2.68 (1.38) 3.00 (1.51) 2.61 (1.46)IBA total scores approach 2.73 (1.48) 3.69 (1.85)** 2.82 (1.69) 3.82 (1.79)** stress 12.73 (3.07) 11.87 (2.87) 13.00(3.02) 11.61 (2.74)**

T-test, *P<0.05, **P<0.01

Table 3. Infant Behavioral Assessment (IBA): Effect Size (ES) of change in all VLBW infants

and in in infants with oxygen dependency ≥28 days, between 0 and 6 months corrected

age

IBA scores

ES all interventionInfants (n=83)

ES all control Infants (n=74)

ES interventionInfants with

O2 ≥28 days (n=33)

ES controlInfants with

O2 ≥28 days (n=14)

Autonomic approach + 1.85 + 0.62 +2.54 + 1.20 stress - 2.71 - 2.26 - 3.61 - 2.23Motor approach + 4.14 + 3.11 + 4.19 + 2.80 stress - 3.37 - 3.06 - 3.49 - 2.18State approach n.a. n.a. n.a. n.a. stress - 0.80 - 0.67 - 1.10 - 1.03Attention-interaction approach + 6.16 + 5.48 + 7.70 + 6.49 stress - 1.66 - 1.67 - 2.23 - 1.59IBA total scores approach + 6.81 + 5.51 + 7.71 + 5.72 stress - 3.62 - 3.54 - 4.32 - 2.73

n.a. = not applicable.



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Discussion

This study aimed to determine the reliability, sensitivity and responsiveness of the IBA

to evaluate neurobehavioral organization in very preterm-born infants. Our data show

that the reliability of the IBA in the three categories of communication (approach, self-

regulation and stress) is moderate to good, and the item-by-item percentage agreement

of the IBA was good to excellent. Disagreement occurred most often in motor items such

as ‘stilling’, ‘hands resting’, ‘toe grasp’ and ‘squirm’. ‘Stilling’ is defined as the cessation

of movement of the trunk and extremities in anticipation, while the infant expresses

invested attention in an object, person or sound in the environment. ‘Squirm’ is defined as

writhing or wriggling, agitated movements of the trunk and/or extremities. Differences

in scoring may occur when the infant displays the behavior for a very short moment, or

as part of another movement. Adding a time component to the definitions of some of

these items may further enhance inter-observer agreement. Although some refinement

of the IBA definitions may be needed, the scores indicate an acceptable consistency with

which different observers can create the same analyses of infant behavior with the IBA.

The sensitivity of the IBA is demonstrated by clear differentiations in neurobehavioral

organization between very preterm infants with or without perinatal risk factors. In

particular, infants with oxygen dependency >28 days showed less organization, illustrated

by less approach and more stress. Apart from a more fragile autonomic system, these

infants demonstrated less motor control and displayed more negative emotions or hyper-

alertness. Infants born with a GA ≤28 weeks were discriminated by their more fragile

autonomic system (i.e. less respiratory or visceral stability and more tremor or startle)

and overall less approach behavior, indicating a declined ability to process information

or to engage in interactions. It appears that the outcomes of IBA observations regarding

infants with oxygen dependency and young GA reflect those found in studies using

hands-on neonatal neurobehavioral assessments, confirming that engaging a preterm

infant in a normal caregiving interaction (in this case the changing of a diaper) may risk

instability in the autonomic and motor system.17–19

Large responsiveness was found on all scores of the IBA, in both the total groups and

in the subgroups of oxygen dependent infants over a 6-month period, except for state

stress in the total group, which was moderate responsive. This last finding is probably

due to the standardization of the test, which required an awake state at the start of the

observation. The subsystems show that, in all infant groups, the largest changes take place

in the attention⁄interaction system, which is in line with the infant’s early development,

during which the infant gradually interacts with and explores his environment more.

Consistent with the improved developmental outcomes of the intervention infants in

our trial,8 the IBA measured a larger change in the intervention infants’ neurobehavioral

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36 | Chapter 2

competence (as the balance between approach and stress). In our trial, the risk

factor oxygen dependency ≥28 days was found to have a significant influence on the

outcomes.8–10 In line with these findings, the IBA also measured the largest change in

neurobehavioral competence in these high-risk intervention infants compared with

the total randomized groups and the high-risk control group. High-risk control infants

showed more change in approach over time than the total control group. This may point

at neurobehavioral recovery, which is normally particularly the case in infants with most

severe illnesses. However, the high-risk control infants’ resilience was not accompanied

with less stress, which may be at the cost of the infants’ information processing, and/or

their energy and health.

The results from this study support the validity of the IBA to monitor and guide

very preterm infants’ neurobehavioral organization and to evaluate intervention

to provide a more holistic picture of the infant.20–22 The ability of the IBA to support

the infant’s neurobehavioral organization during interactions from minute to minute

distinguishes the instrument from other neurobehavioral assessments at infant age that

provide us with a score but are not directly related to the actual situation in which

the caregiver or interventionist can do something for the child. Supporting the infant’s

self-regulatory competence to approach and respond to environmental information and

to diminish stress is currently seen as an important element in early intervention for

infants at biological and/or social risk.23–25 A behavioral analysis of the child’s individual

expectations, like the IBA, might be basic for effective neurobehavioral intervention.

Moreover, the IBA may have been crucial for the positive results we found in our RCT

in very preterm infants.7–10 It gives the interventionist a better insight in the infant’s

proximal developmental goals or underlying problem areas and may contribute to the

professionals’ understanding and valuation of the self-regulatory and adaptive processes

that precede skills or needs.5,6 This strengthens the confidence that the interventionist

can timely target areas that need specific support, but also what the infant does well

and needs less support and/or more challenge. The ability of the IBA to incorporate the

infants’ behaviors to approach information and to regulate themselves has the potential

to focus the intervention more positively on ways parents can support and foster their

child’s strengths, which may contribute to a satisfying parent-infant relationship.26,27

Also some limitations of this study should be noted. Research use of the IBA requires a

careful creation of the sample interaction for each specific infant group and/or age, and

our results may not be representative for other groups, ages or circumstances. We found

in preparatory studies that a 2-min interaction shows enough variability in behavior if

the challenge is well chosen. If the interaction takes 5 minutes, the child often shows a

continuation of the same behaviors or the infant may give up. However, the standardized

IBA ‘observation windows’ we used for this study provide a relatively short impression of



2

the infant’s neurobehavioral organization, which may not be representative of the total

interaction. Therefore, IBA observations should not be used as a level of performance, in

isolation from other measures.

We conclude that the IBA is a reliable and valid tool to evaluate and support

neurobehavioral organization in very preterm infants. Additional validation of the IBA

in different infant populations at different ages is warranted.

Acknowledgements

We sincerely thank Rodd Hedlund for the inspiring training sessions and his support.

The study was supported by grants from the Innovatiefonds Zorgverzekeraars (project

no. 576) and ZonMw (Zorg Onderzoek Nederland, project no. 62200032). The trial

from which the data for this study are drawn is registered with controlled-trials.com

ISRCTN65503576.

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References

1. Hedlund R, Tatarka M. (1986) The Infant Behavioral Assessment. Available at: http://www.ibaip.org. Accessed on July 10, 2011.

2. Als H. NIDCAP-observation sheet. Boston, MA: NIDCAP Federation International, 2001, 2006, 1981.

3. Als H. Manual for the naturalistic observation of newborn behavior. Boston, MA: NIDCAP Federation International, 2001, 2006, 1981, 1984, 1995.

4. Als H. Toward a synactive theory of development: promise for the assessment of Infant individuality. Infant Ment Health J 1982;3:229–243.

5. Hedlund R. (1998) The Infant Behavioral Assessment and Intervention Program. Available at: http://www.ibaip.org. Accessed on July 10, 2011.

6. Hedlund R. (1998).The neurobehavioral curriculum for early intervention. Available at: http://www.ibaip.org. Accessed on July 10, 2011.

7. Meijssen D, Wolf M-J, Koldewijn K, et al. The effect of the Infant Behavioral Assessment and Intervention Program on mother-infant interaction after very preterm birth. J Child Psychol Psychiatry 2010; 51:1287–1295.

8. Koldewijn K, Wolf MJ, van Wassenaer A, et al. The Infant Behavioral Assessment and Intervention Program for very low birth weight infants at 6 months corrected age. J Pediatr 2009;154:33–38.

9. Koldewijn K, van Wassenaer A, Wolf MJ, et al. A neurobehavioral intervention and assessment program in very low birth weight infants: outcome at 24 months. J Pediatr 2010;156:359–365.

10. Verkerk G, Jeukens-Visser M, Koldewijn K, et al. The Infant Behavioral Assessment and Intervention Program in very low birth weight infants improves independency in mobility in daily activities at preschool age. J Pediatr 2011;159:933-938.

11. Wolf MJ, Koldewijn K, Beelen A, Smit B, Hedlund R, de Groot IJ. Neurobehavioral and developmental profile of very low birth weight preterm infants in early infancy. Acta Paediatr 2002;91:930–938.

12. Koldewijn K, Wolf MJ, van Wassenaer A, Beelen A, de Groot IJ, Hedlund R. The Infant Behavioral Assessment and Intervention Program to support preterm infants after hospital discharge: a pilot study. Dev Med Child Neuro 2005;47:105–112.

13. Van der Meulen BF, Ruiter SAJ, Lutje Spelberg HC, Smrkovsky M. Bayley scales of Infant Development-II, Netherlands version. Lisse: Swets Test Publishers, 2002.

14. Dubowitz L, Mercuri E, Dubowitz V. An optimal score for the neurological examination of the term infant. J Pediatr 1998;133:406–416.

15. Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics 1977; 33:159–174.

16. Cohen J. Statistical power analyses for the behavioral sciences. 2nd ed. New York: Academic Press, 1977.

17. Brown N, Doyle L, Bear M, Inder T. Alterations in neurobehavior at term reflect differing perinatal exposures in very preterm infants. Pediatrics 2006;118:2461–2471.

18. Mouradian L, Als H, Coster W. Neurobehavioral functioning of healthy preterm infants of varying gestational ages. J Dev Behav Pediatr 2000;21:408–416.

19. Huppi PS, Schuknecht B, Boesch C, Bossi E, Felblinger J, Fusch C, et al. Structural and neurobehavioural delay in postnatal brain development of preterm infants. Pediatr Res 1996;39:895–901.



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20. Saigal S, Rosenbaum P. What matters in the long term: reflections on the context of adult outcomes versus detailed measures in childhood. Semin Fetal Neonatal Med 2007;12:415–422.

21. Msall ME, Park JJ. The spectrum of behavioral outcomes after extreme prematurity: regulatory, attention, social, and adaptive dimensions. Semin Perinatol 2008;32:42–50.

22. Robertson CMT, Watt M-J, Dinu IA. Outcomes for the extremely premature infant: what is new? and where are we going? Pediatr Neurol 2009;40:189–196.

23. Shonkoff JP, Phillips DA. Acquiring self-regulation. In: Shonkhoff JP, Phillips DA, editors. From neurons to neighbourhoods: the science of early childhood development. 2nd ed. Washington, DC: National Academy Press, 2001:93–123.

24. Shonkoff JP, Boyce WT, McEwan BS. Neuroscience, molecular biology, and the childhood roots of health disparities: building a new framework for health promotion and disease prevention. JAMA 2009;301:2252–2259.

25. Msall ME. Optimizing early development and understanding trajectories of resiliency after extreme prematurity. Pediatrics 2009;124:387–390.

26. Dunst CJ. Revisiting ‘Rethinking Early Intervention’. Topics Early Child Spec Educ 2000;20:95–104.

27. Spittle AJ, Orton J, Doyle LW, Boyd RN. Early developmental intervention programs post hospital discharge to prevent motor and cognitive impairments in preterm infants. Cochrane Database Syst Rev 2007;2: CD005495.

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