Effects of Early Intervention on Mental or Neuromusculoskeletal and Movement-Related Functions in Children Born Low Birthweight or Preterm: A Meta-Analysis

Abstract

OBJECTIVE. We conducted a meta-analysis to examine the association between early intervention and mental or neuromusculoskeletal and movement-related functions of children born low birthweight (LBW) or preterm.

METHOD. The meta-analysis included 16 studies that yielded 97 effects. Q and I ² values were used to determine heterogeneity. Publication bias was evaluated using Egger’s regression intercept test and a funnel plot.

RESULTS. The association between early intervention and either mental or neuromusculoskeletal and movement-related functions yielded a significant but small effect size (d = .219, p < .0001). Heterogeneity was statistically insignificant.

CONCLUSION. Participation in early intervention programs addressing mental or neuromusculoskeletal and movement-related functions in children born LBW or preterm results in significant improvements in these areas.

Keywords

early intervention (education)infant,low birth weight mental processes motor skills disorders movement disorders premature birth

Every day in the United States and throughout the world, many children are born low birthweight (LBW) or preterm (World Health Organization [WHO], 2013). Birthweight is the first weight measurement obtained after birth. Newborns who weigh <2,500 g are classified as LBW (WHO, 2013). According to the National Vital Statistics Report of 2010, the U.S. LBW rate was 8.15% of total births (Martin et al., 2012). Preterm birth occurs when a child is born before 37 wk gestation or is fewer than 259 days gestational age (WHO, 2013). An estimated 28% of neonatal deaths are attributable to preterm births (excluding children born with malformations; Beck et al., 2010). Although data are insufficient to estimate the global incidence of preterm birth, some developed countries, such as the United States, the United Kingdom, and the Scandinavian countries, have had a dramatic rise in preterm births over the past 20 yr (Blencowe et al., 2012). Preterm birth is usually associated with LBW.

Children born prematurely have higher rates of mental function deficits and neuromusculoskeletal and movement-related dysfunctions during their first years of life compared with children born at normal birthweight or full term (Beck et al., 2010). Deficits in mental functions and neuromusculoskeletal and movement-related functions in children born LBW or preterm may have important effects on school readiness and academic achievement (Aarnoudse-Moens, Smidts, Oosterlaan, Duivenvoorden, & Weisglas-Kuperus, 2009; Anderson & Doyle, 2003 ; Bora, Pritchard, Moor, Austin, & Woodward, 2011; Gidley Larson et al., 2011). Dysfunctions such as cognitive deficits, learning disabilities, attention problems, behavioral problems, and neuropsychological deficits become evident in approximately 50%–70% of children born prematurely when they reach school age (Sullivan & Hawes, 2007). Cognitive impairments, including difficulties with phonological processing, attention, and executive functions, are associated with lower academic attainment and poorer educational outcomes (Johnson, Wolke, Hennessy, & Marlow, 2011).

The first few years of life are crucial for any child, and it is vitally important that children reach each developmental milestone to prepare them for success in their school-age and adult occupations. Infants and children born LBW or preterm can benefit greatly from early intervention and family education at an early age (Parlakian, 2003). Multidisciplinary team members, such as occupational and physical therapy practitioners, nurses, and physicians, deliver early intervention services and education to infants and children born LBW or preterm, and the families are very much involved in the process (Feldman, Eidelman, Sirota, & Weller, 2002; Gardner, Walker, Powell, & Grantham-McGregor, 2003; Johnson, Ring, Anderson, & Marlow, 2005; Nordhov et al., 2010; Sajaniemi et al., 2001).

Defining early intervention is not an easy task; the term has been defined in many different ways. According to the National Center for Infants, Toddlers, and Families, early intervention consists of identifying that an infant or a child is having developmental problems and other issues that could affect his or her life (Parlakian, 2003). The Individuals With Disabilities Education Improvement Act of 2004 (IDEA 2004) stipulates that infants and toddlers ages 0–3 yr who are eligible should be provided early intervention (Part C) services and an individualized family service plan (IFSP) as soon as their issues have been detected to prevent further problems and help them succeed in life (Opp, 2009). Additionally, the law supports the transition to appropriate services such as special education or preschool services under IDEA Part B for children and youth ages 3–22 yr if the multidisciplinary team finds them still to be eligible for additional services to address cognitive, physical, communication, social or emotional, or adaptive development. The American Occupational Therapy Association has defined early intervention as a group of therapies and services offered to infants and children with developmental delays and their families (Opp, 2009).

It has long been hypothesized that early intervention produces positive outcomes when introduced in the appropriate time frame (Wood, 1981). To understand the effect of early intervention on infants born LBW, Ohgi, Fukuda, Akiyama, and Gima (2004) provided a Neonatal Behavioral Assessment Scale–based intervention combined with developmental support for 12 high-risk LBW infants. The early intervention group had higher scores on the Bayley Mental Developmental Index than the comparison group, who received routine medical nursing care without early intervention (Ohgi et al., 2004).

In another study, Lekskulchai and Cole (2001) investigated motor performance in three groups of infants born preterm: 43 infants in an intervention group, 41 infants in a control group, and 27 low-risk infants in a comparison group. The early developmental intervention program comprised 12 activities, including home-based activities, and motor performance was assessed using the Test of Infant Motor Performance (Campbell, Kolobe, Osten, Lenke, & Girolami, 1995). The preterm infants who received early intervention showed greater motor progression than the preterm infants who did not receive the intervention (Lekskulchai & Cole, 2001).

Studies on early intervention have used different tools and assessments, making it difficult to categorize specific treatment activities or interventions as early intervention (Gianní et al., 2006; Kaaresen et al., 2008; McCormick et al., 2006; Melnyk et al., 2001; Olafsen et al., 2006; Tessier et al., 2003; Teti et al., 2009; Westrup, Böhm, Lagercrantz, & Stjernqvist, 2004). To investigate the association between early intervention and improvement in mental or neuromusculoskeletal and movement-related functions in children born LBW or preterm, a meta-analysis is ideal because the analyses account for variability in intervention by standardizing scores. Therefore, the purpose of this study was to perform a meta-analysis to investigate whether an association exists between early intervention and improvement in mental or neuromuscular and movement scores in children born LBW or preterm.

A recent exhaustive magnetic resonance imaging study of 137 participants ages 13–22 yr showed that both LBW and preterm birth are associated with reduced gray matter density bilaterally in the temporal lobe structures and cerebellum (Spencer et al., 2008). The study concluded that these brain anomalies persist into adolescence. Additionally, in a separate but related meta-analysis, we found that both preterm birth and LBW were associated with deficits in mental and neuromuscular and movement-related functions in a similar way (Spittle, Orton, Doyle, & Boyd, 2007). Thus, in the current study, we pooled scores from children born LBW or preterm to form a single group to increase the number of effects.

Method

Independent and Dependent Variables

The independent variable for this meta-analysis was whether the children were participating in an early intervention program. Early intervention programs used in the studies included the Newborn Individualized Developmental Care and Assessment Program (Als et al., 2003; Westrup et al., 2004); the kangaroo care intervention (Feldman et al., 2002; Tessier et al., 2003); the Mother–Infant Transaction Program (Gianní et al., 2006; Kaaresen et al., 2008; Nordhov et al., 2010); Creating Opportunities for Parent Empowerment (Melnyk et al., 2001); the Avon Premature Infant Project (Johnson et al., 2005); the Infant Behavioral Assessment and Intervention Program (Koldewijn et al., 2009; Verkerk et al., 2012); a modified version of the Vermont Intervention Program (Olafsen et al., 2006); and other motor, behavioral, and cognitive programs (Gardner et al., 2003; McCormick et al., 2006; Sajaniemi et al., 2001; Teti et al., 2009; Table 1).

Table 1.

Summary of Studies of Early Intervention for Children Born Low Birthweight or Preterm

Authors	Participants	Intervention	Intervention Provider	Duration	Outcome Measures
Als et al. (2003)	N = 92 (intervention group n = 45, control group n = 47)	Newborn Individualized Developmental Care and Assessment Program (NIDCAP)	Nurse and developmental professional	NA	Assessment of Preterm Infants’ Behavior: motor system
Feldman, Eidelman, Sirota, & Weller (2002)	N = 146 (intervention group n = 73, control group n = 73)	Kangaroo care intervention	Physician–nurse team	1 hr for 14 days	Bayley Scales of Infant Development II (BSID–II): Mental Development Index (MDI) and Psychomotor Developmental Index (PDI)
Gardner, Walker, Powell, & Grantham-McGregor (2003)	N = 222 (intervention group n = 66, control group n = 156)	Home visiting early psychosocial intervention	Community health workers	Weekly 1-hr visits for first 8 wk of life	Cover and support test and behavior ratings
Gianní et al. (2006)	N = 36 (intervention group n = 18, control group n = 18)	Early developmental mother–child intervention program	Psychologist and psychometrician	2×/mo for 3–9 mo	Griffiths Mental Development Scales
Johnson, Ring, Anderson, & Marlow (2005)	N = 134 (intervention group n = 67, control group n = 67)	Avon Premature Infant Project	Psychologist, nurse, and mother	2 yr	British Ability Scales–2nd Edition, Movement Assessment Battery for Children (M–ABC) and Child Behavior Checklist (CBCL) school-age version
Kaaresen et al. (2008)	N = 136 (intervention group n = 69, control group n = 67)	Modified version of the Mother–Infant Transaction Program (MIPT)	Physical therapists and neonatologists	1 hr for 7 days before discharge	BSID–II and CBCL
Koldewijn et al. (2009)	N = 176 (intervention group n = 86, control group n = 90)	Infant Behavioral Assessment and Intervention Program (IBAIP)	Physical therapist	1 session before discharge and 6–8 home interventions	BSID–II: MDI and PDI
McCormick et al. (2006)	N = 377 (intervention group n = 254, control group n = 123)	Infant Health and Development Program	NA	Weekly during 1st yr and every other week during 2nd and 3rd yr of life	Full-scale IQ, Peabody Picture Vocabulary Test (PPVT–III), Woodcock–Johnson Tests of Achievement, and CBCL
Melnyk et al. (2001)	N = 42 (intervention group n = 20, control group n = 22)	Creating Opportunities for Parent Empowerment	NA	2–4 days postbirth through 1 wk following discharge from the NICU	BSID–II: MDI
Nordhov et al. (2010)	N = 146 (intervention group n = 72, control group n = 74)	Modified MIPT	Physiotherapist, coordinating nurse, and psychologist	1 hr for 7 days before discharge	BSID–II
Olafsen et al. (2006)	N = 140 (intervention group n = 71, control group n = 69)	Modified version of the Vermont Intervention Program for Low-Birthweight Infants	Neonatal nurses	1 hr for 7 days before discharge and four 1-hr home visits	Early Social Communication Scales
Sajaniemi et al. (2001)	N = 100 (intervention group n = 49, control group n = 51)	Early occupational therapy intervention	Occupational therapist	1 hr/wk for 20 sessions	Wechsler Preschool and Primary Scale of Intelligence–Revised (WPPSI–R)
Tessier et al. (2003)	N = 336 (intervention group n = 183, control group n = 153)	Kangaroo mother care	Nurse and mother	NA	Griffiths Mental Development Scales and Global IQ test
Teti et al. (2009)	N = 173 (intervention group n = 84, control group n = 89)	Early intervention program	Neonatal Behavioral Assessment Scale examiners	8 sessions over 20 wk	BSID–II: MDI and PDI
Verkerk et al. (2012)	N = 151 (intervention group n = 76, control group n = 75)	IBAIP	Occupational therapist and physical therapist	NA	PPVT, CBCL, and Behavior Rating Inventory of Executive Function–Preschool Version
Westrup, Böhm, Lagercrantz, & Stjernqvist (2004)	N = 26 (intervention group n = 11, control group n = 15)	NIDCAP	Physiotherapist	NA	WPPSI–R, M–ABC, and subtests of the NEPSY test battery

Note. NA = not applicable; NICU = neonatal intensive care unit.

The dependent variable was improvement in performance scores of children born LBW or preterm on mental or neuromusculoskeletal and movement-related function tests. Some of the tests used were the Assessment of Preterm Infants’ Behavior, British Ability Scales, Movement Assessment Battery for Children, Child Behavior Checklist, Peabody Picture Vocabulary Test, Woodcock–Johnson Tests of Achievement, Bayley Scales of Infant Development II, Wechsler Preschool and Primary Scale of Intelligence–Revised, Griffiths Mental Development Scales, Global IQ test, and Early Social Communication Scales (Table 1).

Sample

Data were collected from studies that searched for a correlation between early intervention and the effectiveness of mental or neuromusculoskeletal and movement-related functions in LBW or preterm children. The search was conducted on the Web through Florida International University’s library databases (e.g., EBSCO host, PubMed, ScienceDirect). The following key words and combinations were used to maximize the yield of pertinent studies: preterm, low birthweight, premature effectiveness, early intervention program, early intervention, mental function, cognition, motor function, premature, movement, and neuromusculoskeletal. These key words were chosen on the basis of the aim of this study. The key terms were used to search all aspects of early intervention programs that addressed mental or neuromusculoskeletal and movement-related functions. In addition, the reference lists of obtained studies were scrutinized for other compatible publications.

Inclusion and Exclusion Criteria

We examined the articles to establish whether the studies fulfilled the following inclusion criteria: original research; empirical design with direct observation of children; publication in English between 2000 and 2013; inclusion of children born LBW or preterm who participated in an early intervention program; presence of a comparison group who did not receive early intervention; inclusion of a mental or neuromusculoskeletal and movement-related function component using standardized and nonstandardized testing; and provision of test scores (means and standard deviations) to enable effect-size calculation. Studies were excluded if they assessed parents instead of children who underwent early intervention, if they did not meet the inclusion criteria, or if the outcomes did not allow us to calculate the effect size (Ottenbacher, Heyn, & Abreu, 2009).

Data Extraction and Coding of Studies

To thoroughly analyze each of the studies used, we extracted and coded the following information: authors and year; mental or neuromusculoskeletal and movement-related function components; early intervention treatment; length of treatment; score, time, or error type of test; treatment group (mean, SD, n); comparison group (mean, SD, n); chronological age; and moderators. All relevant data were entered into an Excel spreadsheet. Data were run through Comprehensive Meta-Analysis (CMA) software (Borenstein, Hedges, Higgins, & Rothstein, 2005) to interpret the data. The studies were coded into the following two categories:

Early intervention program and mental function assessments

Early intervention program and neuromusculoskeletal and movement-related function assessments

Data Analysis

Effect Size.

To determine the effect sizes, we used CMA software (Borenstein et al., 2005). CMA uses means, standard deviations, and sample sizes to generate the effect size of the association between early intervention and mental function assessment or neuromusculoskeletal and movement-related function assessment. The effect sizes (d) are classified as small (.20), medium (.50), or large (.80; Rosenthal, 1991). For each effect-size estimate, a standardized mean difference and 95% confidence intervals were calculated in a fixed- and random-effects model. A positive effect size indicates that the group of children who received early intervention did better in both mental and neuromusculoskeletal and movement-related functions than the comparison group who did not receive early intervention program, and a negative effect size indicates that the comparison group did better.

Heterogeneity Test.

We used heterogeneity statistics to find the extent of variability among the group of studies, important to consider when performing a meta-analysis. Heterogeneity is tested using Q and I ² values. A significant Q value (p < .10) indicates the presence of heterogeneity between studies. The I ² value indicates the extent of heterogeneity: absent (0), low (25), medium (50), or large (75 or higher; Shiroma, Ferguson, & Pickelsimer, 2010). In the presence of heterogeneity, we used the random effects model, whereas we used the fixed effects model for homogeneity. In the present meta-analysis, we report both fixed and random effects models because they both were generated by the CMA software.

Publication Bias.

In general, researchers tend to report positive results in the literature. Therefore, it is not unusual to find only positive results when conducting a meta-analysis. To test for publication bias, we used a funnel plot and Egger’s regression intercept test (Egger, Smith, Schneider, & Minder, 1997). The funnel plot provides a visual demonstration of publication bias. A symmetrical funnel plot indicates inclusion of both positive and negative results, and an asymmetrical funnel plot (i.e., leaning toward one side) indicates a publication bias. In addition, Egger’s regression intercept test can statistically detect a significant publication bias (p < .05; Egger et al., 1997).

Results

Study Characteristics

A total of 16 studies were included in this meta-analysis. All included studies addressed early intervention comparing an intervention and a comparison group and were published between 2000 and 2013. The total combined number of participants in all studies was 2,094. The number of participants in each study ranged from 26 to 377. The average chronological age of the participants ranged from 1 mo adjusted age to age 5 yr.

Each study provided and assessed an early intervention in two categories: (1) mental functions and (2) neuromusculoskeletal and movement-related functions. Eight studies assessed mental functions only, 1 assessed neuromusculoskeletal and movement-related functions only, and 7 assessed both mental and neuromusculoskeletal and movement-related functions. The studies generated a total of 97 effects for comparison, 74 for mental functions and 23 for neuromusculoskeletal and movement-related functions. The studies used different types of interventions and assessments to address the children’s need or assess their level of development before starting the early intervention.

Effect Size

The effect size for the effectiveness of early intervention in improving performance in mental and neuromusculoskeletal and movement-related functions is small (d = .219). Using fixed effects analysis, the d for mental functions was .250 (p < .0001) and for neuromusculoskeletal and movement-related functions was .118 (p < .0001). The overall Q value was 93.787 (p > .001), and the overall I ² value was 0.000, suggesting no heterogeneity (Table 2).

Table 2.

Fixed and Random Effect Sizes for Each Outcome Measure

Category	No. of Items Extracted From Studies	Effect Size			Heterogeneity
Category	No. of Items Extracted From Studies	d	Z	p	Q	df (Q)	p	I²
Fixed effects analysis
Mental function	74	.250	11.401	.000	66.724	73	.684	.000
Neuromusculoskeletal and movement-related function	23	.118	2.998	.003	18.471	22	.678	.000
Overall	97	.219	11.419	.000	93.787	96	.545	.000
Random effects analysis
Mental function	74	.250	11.401	.000
Neuromusculoskeletal and movement-related function	23	.118	2.998	.003
Overall	97	.219	11.419	.000

Note. Heterogeneity scores are not shown for random effects analysis because they are the same as for the fixed effects analysis.

Publication Bias

The funnel plot of standard error by standard difference in means showed 97 values distributed inside and 3 values outside the funnel. The distribution of data inside and outside the funnel is asymmetrical (Figure 1). In addition, the p value in Egger’s regression intercept test (intercept 1.213, range = 0.636–1.790) is lower than .05, suggesting that the publication bias was significant (Table 3).

Figure 1.

Funnel plot indicating publication bias.

Table 3.

Egger’s Regression Intercept Test Results

Result	Value
Intercept	1.213
Standard error	0.291
95% lower limit (2-tailed)	0.636
95% upper limit (2-tailed)	1.790
t	4.174
df	95
p (1-tailed)	.000
p (2-tailed)	.000

Note. df = degrees of freedom, p < .05.

Discussion

The results of this study support the hypothesis that children born LBW or preterm may benefit significantly from early intervention as evidenced by improved development of mental and neuromusculoskeletal and movement-related functions compared with children born with the same conditions who do not receive early intervention. The results show that early intervention programs, in general, significantly improved mental functions of children born LBW or preterm with respect to increased verbal performance, executive functioning, and IQ scores. Additionally, regarding neuromusculoskeletal and movement-related functions, children born LBW or preterm who received early intervention made better behavioral and neurobehavioral improvement than comparison groups who did not receive early intervention.

The results further suggest that early intervention is beneficial in improving functional outcomes of LBW or preterm children by providing them with services needed to support development. The present meta-analysis provides evidence that early intervention may provide important intervention for the development of daily living, learning, academic, emotional, and social skills in children because mental and neuromusculoskeletal and movement-related functions play a great role in the development of children and their functions (Anderson, De Luca, Hutchinson, Roberts, & Doyle, 2010; Bayless & Stevenson, 2007; Bora et al., 2011). Therefore, intervening early in areas of mental and neuromusculoskeletal and movement-related functions may lessen the risk of neurodevelopmental delays during the school years. Early intervention might be helpful in reversing the complex developmental delay and poor school performance of children born LBW or preterm (Aarnoudse-Moens et al., 2009; Oliveira, Magalhães, & Salmela, 2011; van Baar, Vermaas, Knots, de Kleine, & Soons, 2009).

In general, mental and motor development and functions have been studied as separate and independent processes. However, a plethora of research suggests a tight interdependence between mental and neuromusculoskeletal and movement-related functions in terms of global development and functions (Diamond, 2000; Koziol, Budding, & Chidekel, 2012; Wassenberg et al., 2005). Children with mental dysfunctions are likely also to have impairments in movement-related functions (Diamond, 2000). Diamond (2000) further noted that movement problems are common in children with developmental disorders such as dyslexia, specific language impairment, autism spectrum disorder, and attention deficit hyperactivity disorder, indicating a coupling between mental and movement-related functions. Anatomical evidence indicates that this coupling stems from regular coactivation of the dorsolateral prefrontal cortex and contralateral cerebellum (de Zubicaray et al., 1998; Schlösser et al., 1998). Therefore, it is reasonable to assume that mental functions are important for proper movement-related performance. On the basis of the results of this meta-analysis, we suggest that early intervention address both mental and neuromusculoskeletal and movement-related functions.

Missiuna, Gaines, and Pollock (2002) argued that it is important to recognize both mental and movement-related problems in children born LBW or preterm as soon as possible. IDEA 2004 recognized that a well-timed early intervention not only helps children born LBW or preterm maximize their potential for catching up from developmental delay but also reduces special education costs when they reach school age and enhances their capacity for independent living in the community. Therefore, the results of this meta-analysis suggest that clear early intervention strategies should be integrated into early intervention plans to maximize the effectiveness of intervention and should address mutuality between mental development and movement-related development.

Implications for Occupational Therapy Practice

The results of this meta-analysis have the following implications for occupational therapy practice:

Both mental and neuromusculoskeletal and movement-related functions are important components in a child’s development of activities of daily living, academic skills, and social skills that stretch into adolescence.

Early intervention programs are significantly beneficial in improving mental and neuromusculoskeletal and movement-related functions in children born LBW or preterm.

Early information about children who have mental and movement-related dysfunctions could lead to timely early intervention to minimize mental and movement deficits.

Multidisciplinary early intervention teams should integrate both mental and movement-related aspects when designing early intervention program.

Limitations

A possible weakness of this study is the difficulty we had in identifying which among the wide variety of services constituted early intervention services. The terms we used to search the topic of focus were varied because participants are categorized in many ways (e.g., children, infants, toddlers, babies, newborns). Many of the articles we searched and browsed did not include sufficient data (e.g., mean, standard deviation, and sample size) to allow us to determine the program’s effectiveness using meta-analytic techniques and so were not included in the analysis.

Conclusion

The results of this meta-analysis support our hypothesis that an association exists between participation in an early intervention program and improvement in mental and neuromusculoskeletal and movement-related functions for children born LBW or preterm. These findings suggest the need for proper early diagnosis and for implementation of integrated multidisciplinary early intervention. When planning intervention strategy, early intervention providers should identify correlations between mental dysfunctions and movement-related deficits in children born LBW or preterm and include both areas in intervention.

Footnotes

Acknowledgment

This meta-analysis was part of the master’s project development in occupational therapy at Florida International University. We thank Florida International University for providing facilities and software to conduct this study.

Indicates studies that were included in the meta-analysis.

References

Aarnoudse-Moens

C. S. H.

Smidts

D. P.

Oosterlaan

Duivenvoorden

H. J.

, & Weisglas-Kuperus

(2009). Executive function in very preterm children at early school age. Journal of Abnormal Child Psychology, 37, 981–993. http://dx.doi.org/10.1007/s10802-009-9327-z

Als

Gilkerson

Duffy

F. H.

McAnulty

G. B.

Buehler

D. M.

Vandenberg

, … Jones

K. J.

(2003). A three-center, randomized, controlled trial of individualized developmental care for very low birth weight preterm infants: Medical, neurodevelopmental, parenting, and caregiving effects. Journal of Developmental and Behavioral Pediatrics, 24, 399–408. http://dx.doi.org/10.1097/00004703-200312000-00001

Anderson

P. J.

De Luca

C. R.

Hutchinson

Roberts

Doyle

L. W.

; Victorian Infant Collaborative Group. (2010). Underestimation of developmental delay by the new Bayley–III Scale. Archives of Pediatrics and Adolescent Medicine, 164, 352–356. http://dx.doi.org/10.1001/archpediatrics.2010.20

Anderson

P. J.

Doyle

L. W.

; Victorian Infant Collaborative Study Group. (2003). Neurobehavioral outcomes of school-age children born extremely low birth weight or very preterm in the 1990s. JAMA, 289, 3264–3272. http://dx.doi.org/10.1001/jama.289.24.3264

Bayless

, & Stevenson

(2007). Executive functions in school-age children born very prematurely. Early Human Development, 83, 247–254. http://dx.doi.org/10.1016/j.earlhumdev.2006.05.021

Beck

Wojdyla

Say

Betran

A. P.

Merialdi

Requejo

J. H.

, … Van Look

P. F.

(2010). The worldwide incidence of preterm birth: a systematic review of maternal mortality and morbidity. Bulletin of the World Health Organization, 88, 31–38. http://dx.doi.org/10.2471/BLT.08.062554

Blencowe

Cousens

Oestergaard

M. Z.

Chou

Moller

A. B.

Narwal

, … Lawn

J. E.

(2012). National, regional, and worldwide estimates of preterm birth rates in the year 2010 with time trends since 1990 for selected countries: A systematic analysis and implications. Lancet, 379, 2162–2172. http://dx.doi.org/10.1016/S0140-6736(12)60820-4

Bora

Pritchard

V. E.

Moor

Austin

N. C.

, & Woodward

L. J.

(2011). Emotional and behavioural adjustment of children born very preterm at early school age. Journal of Paediatrics and Child Health, 47, 863–869. http://dx.doi.org/10.1111/j.1440-1754.2011.02105.x

Borenstein

Hedges

Higgins

, & Rothstein

(2005). Comprehensive Meta-Analysis version 2. Englewood, NJ: Biostat.

10.

Campbell

S. K.

Kolobe

T. H. A.

Osten

E. T.

Lenke

, & Girolami

G. L.

(1995). Construct validity of the test of infant motor performance. Physical Therapy, 75, 585–596.

11.

de Zubicaray

G. I.

Williams

S. C. R.

Wilson

S. J.

Rose

S. E.

Brammer

M. J.

Bullmore

E. T.

, … Doddrell

D. M.

(1998). Prefrontal cortex involvement in selective letter generation: A functional magnetic resonance imaging study. Cortex, 34, 389–401. http://dx.doi.org/10.1016/S0010-452(08)70762-7

12.

Diamond

(2000). Close interrelation of motor development and cognitive development and of the cerebellum and prefrontal cortex. Child Development, 71, 44–56. http://dx.doi.org/10.1111/1467-8624.00117

13.

Egger

Smith

G. D.

Schneider

, & Minder

(1997). Bias in meta-analysis detected by a simple, graphical test. British Medical Journal, 315, 629–634. http://dx.doi.org/10.1136/bmj.315.7109.629

14.

Feldman

Eidelman

A. I.

Sirota

, & Weller

(2002). Comparison of skin-to-skin (kangaroo) and traditional care: Parenting outcomes and preterm infant development. Pediatrics, 110, 16–26. http://dx.doi.org/10.1542/peds.110.1.16

15.

Gardner

J. M.

Walker

S. P.

Powell

C. A.

, & Grantham-McGregor

(2003). A randomized controlled trial of a home-visiting intervention on cognition and behavior in term low birth weight infants. Journal of Pediatrics, 143, 634–639. http://dx.doi.org/10.1067/S0022-3476(03)00455-4

16.

Gianní

M. L.

Picciolini

Ravasi

Gardon

Vegni

Fumagalli

, & Mosca

(2006). The effects of an early developmental mother–child intervention program on neurodevelopment outcome in very low birth weight infants: A pilot study. Early Human Development, 82, 691–695. http://dx.doi.org/10.1016/j.earlhumdev.2006.01.011

17.

Gidley Larson

J. C.

Baron

I. S.

Erickson

Ahronovich

M. D.

Baker

, & Litman

F. R.

(2011). Neuromotor outcomes at school age after extremely low birth weight: Early detection of subtle signs. Neuropsychology, 25, 66–75. http://dx.doi.org/10.1037/a0020478

18.

Individuals With Disabilities Education Improvement Act of 2004, Pub. L. 108–466, 20 U.S.C. § 1400 et seq.

19.

Johnson

Ring

Anderson

, & Marlow

(2005). Randomised trial of parental support for families with very preterm children: Outcome at 5 years. Archives of Disease in Childhood, 90, 909–915. http://dx.doi.org/10.1136/adc.2004.057620

20.

Johnson

Wolke

Hennessy

, & Marlow

(2011). Educational outcomes in extremely preterm children: Neuropsychological correlates and predictors of attainment. Developmental Neuropsychology, 36, 74–95. http://dx.doi.org/10.1080/87565641.2011.540541

21.

Kaaresen

P. I.

Rønning

J. A.

Tunby

Nordhov

S. M.

Ulvund

S. E.

, & Dahl

L. B.

(2008). A randomized controlled trial of an early intervention program in low birth weight children: Outcome at 2 years. Early Human Development, 84, 201–209. http://dx.doi.org/10.1016/j.earlhumdev.2007.07.003

22.

Koldewijn

Wolf

M. J.

van Wassenaer

Meijssen

van Sonderen

van Baar

, … Kok

(2009). The Infant Behavioral Assessment and Intervention Program for very low birth weight infants at 6 months corrected age. Journal of Pediatrics, 154, 33–38, e2. http://dx.doi.org/10.1016/j.jpeds.2008.07.039

23.

Koziol

L. F.

Budding

D. E.

, & Chidekel

(2012). From movement to thought: Executive function, embodied cognition, and the cerebellum. Cerebellum (London, England), 11, 505–525. http://dx.doi.org/10.1007/s12311-011-0321-y

24.

Lekskulchai

, & Cole

(2001). Effect of a developmental program on motor performance in infants born preterm. Australian Journal of Physiotherapy, 47, 169–176.

25.

Martin

J. A.

Hamilton

B. E.

Ventura

S. J.

Osterman

M. J. K.

Wilson

E. C.

, & Mathew

T. J.

(2012). Births: Final data for 2010. National Vital Statistics Reports, 61, 1–71.

26.

McCormick

M. C.

Brooks-Gunn

Buka

S. L.

Goldman

Salganik

, … Casey

P. H.

(2006). Early intervention in low birth weight premature infants: Results at 18 years of age for the Infant Health and Development Program. Pediatrics, 117, 771–780. http://dx.doi.org/10.1542/peds.2005-1316

27.

Melnyk

B. M.

Alpert-Gillis

Feinstein

N. F.

Fairbanks

Schultz-Czarniak

Hust

, … Sinkin

R. A.

(2001). Improving cognitive development of low-birth-weight premature infants with the COPE program: A pilot study of the benefit of early NICU intervention with mothers. Research in Nursing and Health, 24, 373–389. http://dx.doi.org/10.1002/nur.1038

28.

Missiuna

Gaines

B. R.

, & Pollock

(2002). Recognizing and referring children at risk for developmental coordination disorder: Role of the speech–language pathologist. Journal of Speech–Language Pathology and Audiology, 26, 172–179.

29.

Nordhov

S. M.

Rønning

J. A.

Dahl

L. B.

Ulvund

S. E.

Tunby

, & Kaaresen

P. I.

(2010). Early intervention improves cognitive outcomes for preterm infants: Randomized controlled trial. Pediatrics, 126, e1088–e1094. http://dx.doi.org/10.1542/peds.2010-0778

30.

Ohgi

Fukuda

Akiyama

, & Gima

(2004). Effect of an early intervention programme on low birthweight infants with cerebral injuries. Journal of Paediatrics and Child Health, 40, 689–695. http://dx.doi.org/10.1111/j.1440-1754.2004.00512.x

31.

Olafsen

K. S.

Rønning

J. A.

Kaaresen

P. I.

Ulvund

S. E.

Handegård

B. H.

, & Dahl

L. B.

(2006). Joint attention in term and preterm infants at 12 months corrected age: The significance of gender and intervention based on a randomized controlled trial. Infant Behavior and Development, 29, 554–563. http://dx.doi.org/10.1016/j.infbeh.2006.07.004

32.

Oliveira

G. E.

Magalhães

L. C.

, & Salmela

L. F. T.

(2011). Relationship between very low birth weight, environmental factors, and motor and cognitive development of children of 5 and 6 years old. Revista Brasileira de Fisioterapia, 15, 138–145.

33.

Opp

(2009). Occupational therapy in early intervention: Helping children succeed. Retrieved from http://www.aota.org/en/About-Occupational-Therapy/Professionals/CY/Articles/Early-Intervention.aspx

34.

Ottenbacher

K. J.

Heyn

, & Abreu

B. C.

(2009). Meta-analysis. In Portney

& Watkins

(Eds.), Foundations of clinical research: Applications to clinical practice (pp. 281–298). Upper Saddle River, NJ: Prentice Hall.

35.

Parlakian

(2003). Before the ABCs: Promoting school readiness in infants and toddlers. Herndon, VA: Zero to Three.

36.

Rosenthal

(1991). Meta-analytic procedures for social research. Thousand Oaks, CA: Sage.

37.

Sajaniemi

Mäkelä

Salokorpi

von Wendt

Hämäläinen

, & Hakamies-Blomqvist

(2001). Cognitive performance and attachment patterns at four years of age in extremely low birth weight infants after early intervention. European Child and Adolescent Psychiatry, 10, 122–129. http://dx.doi.org/10.1007/s007870170035

38.

Schlösser

Hutchinson

Joseffer

Rusinek

Saarimaki

Stevenson

, … Brodie

J. D.

(1998). Functional magnetic resonance imaging of human brain activity in a verbal fluency task. Journal of Neurology, Neurosurgery, and Psychiatry, 64, 492–498. http://dx.doi.org/10.1136/jnnp.64.4.492

39.

Shiroma

E. J.

Ferguson

P. L.

, & Pickelsimer

E. E.

(2010). Prevalence of traumatic brain injury in an offender population: A meta-analysis. Journal of Correctional Health Care, 16, 147–159. http://dx.doi.org/10.1177/1078345809356538

40.

Spencer

M. D.

Moorhead

T. W. J.

Gibson

R. J.

McIntosh

A. M.

Sussmann

J. E. D.

Owens

D. G. C.

, … Johnstone

E. C.

(2008). Low birthweight and preterm birth in young people with special educational needs: A magnetic resonance imaging analysis. BMC Medicine, 6, 1–11. http://dx.doi.org/10.1186/1741-7015-6-1

41.

Spittle

A. J.

Orton

Doyle

L. W.

, & Boyd

(2007). Early developmental intervention programs post hospital discharge to prevent motor and cognitive impairments in preterm infants. Cochrane Database of Systematic Reviews (Online), 2, CD005495.

42.

Sullivan

M. C.

, & Hawes

(2007). A decade comparison of preterm motor performance at age 4. Research in Nursing and Health, 30, 641–654. http://dx.doi.org/10.1002/nur.20220

43.

Tessier

Cristo

M. B.

Velez

Giron

Nadeau

de Calume

Z. F.

, … Charpak

(2003). Kangaroo mother care: A method for protecting high-risk low-birth-weight and premature infants against developmental delay. Infant Behavior and Development, 26, 384–397. http://dx.doi.org/10.1016/S0163-6383(03)00037-7

44.

Teti

D. M.

Black

M. M.

Viscardi

Glass

O’Connell

M. A.

Baker

, … Hess

C. R.

(2009). Intervention with African American premature infants: Four-month results of an early intervention program. Journal of Early Intervention, 31, 146–166. http://dx.doi.org/10.1177/1053815109331864

45.

van Baar

A. L.

Vermaas

Knots

de Kleine

M. J. K.

, & Soons

(2009). Functioning at school age of moderately preterm children born at 32 to 36 weeks’ gestational age. Pediatrics, 124, 251–257. http://dx.doi.org/10.1542/peds.2008-2315

46.

Verkerk

Jeukens-Visser

Houtzager

Koldewijn

van Wassenaer

Nollet

, & Kok

(2012). The infant behavioral assessment and intervention program in very low birth weight infants: Outcome on executive functioning, behaviour and cognition at preschool age. Early Human Development, 88, 699–705. http://dx.doi.org/10.1016/j.earlhumdev.2012.02.004

47.

Wassenberg

Feron

F. J. M.

Kessels

A. G. H.

Hendriksen

J. G. M.

Kalff

A. C.

Kroes

, … Vles

J. S. H.

(2005). Relation between cognitive and motor performance in 5- to 6-year-old children: Results from a large-scale cross-sectional study. Child Development, 76, 1092–1103. http://dx.doi.org/10.1111/j.1467-8624.2005.00899.x

48.

Westrup

Böhm

Lagercrantz

, & Stjernqvist

(2004). Preschool outcome in children born very prematurely and cared for according to the Newborn Individualized Developmental Care and Assessment Program (NIDCAP). Acta Paediatrica (Oslo, Norway), 93, 498–507. http://dx.doi.org/10.1080/08035250410023548

49.

Wood

M. E.

. (1981). Costs of intervention programs. In Garland

(Ed.), Early intervention for children with special needs and their families: Findings and recommendations (Westar Series Paper No.11). Seattle: University of Washington.

50.

World Health Organization. (2013). Health status statistics: Morbidity. Geneva: Author. Retrieved from http://www.who.int/healthinfo/statistics/indlowbirthweight/en/index.html