Children born extremely preterm or extremely low birth weight (ELBW) without major disabilities may present with mild but persistent neurodevelopmental impairments.1–3 In particular, these children are challenged by impairments in gross motor function and postural stability.1,2 Because they have no major impairments, no identified disabilities, and are otherwise healthy, they are often overlooked, with minimal support services.4 Because adverse long-term outcomes are possible, ongoing assessment and possibly intervention should be considered. The role of intervention and measuring its effectiveness, as performance potentially declines, requires investigation.1–3 Exploring this issue among children who are 4 years and extremely preterm (<28 weeks' gestation) or ELBW (<1000 g) is particularly useful, as this is a critical time-point as they are on the cusp of commencing formal education. Teachers and parents report that these children may lack school readiness.5 As gender differences have been reported, consideration of whether male gender predisposes to poorer outcomes should be considered as well.6 Various models of early intervention have been used with children born extremely preterm or ELBW with mixed degrees of success.7 Group-based intervention has been effective with older children but from different populations.8,9
We have investigated the short-term motor, postural, and strength benefits of group-based physical therapy compared with standard care among children who are 4 years old and extremely preterm and/or ELBW children with minimal or mild motor impairments. Standard care was best practice advice, which included bimonthly contact with families and provision of general age-appropriate information. These findings are not the focus of the current study and will be reported elsewhere. However, in summary, at baseline, the group of children had low average motor coordination, poor postural stability, and reduced lower limb strength.10 Both intervention and best practice care led to positive short-term results.
Standardized tests, such as Movement Assessment Battery for Children-Second Edition (MABC-2), were used in reaching these short-term conclusions. However, as clinicians, standardized tests may not be used for a variety of reasons including time constraints or test limitations. Therefore, we shifted our focus to an outcome measure designed with clinicians in mind and achieved this by using Goal Attainment Scaling (GAS).11 GAS provided a means of demonstrating that any gains made at an individual level on goals set in consultation with parents would assist in determining the effectiveness of the program. Goals were oriented to functional tasks that the parents deemed relevant for their child.
GAS can be applied to levels of the International Classification of Functioning Disability and Health (ICF) framework,12 including impairment, activity, and participation. GAS is responsive and sensitive to change and it has acceptable content validity.13,14 GAS, in comparison to milestone attainment, may be more suitable for detecting incremental change.15 In the pediatric context, although evidence supporting the reliability of GAS is lacking, guidelines have been developed that provide an optimal approach for goal setting.16
The purpose of this study is to investigate whether a group of 4-year-old children born extremely preterm and or ELBW, with minimal or mild motor impairments, made short-term individual gains as a result of intervention as measured by GAS. In addition, the study aimed to investigate whether these changes were related to motor coordination, postural stability, and limb strength performance immediately after intervention. The difference between genders on goal attainment was examined, as male gender has been identified as a risk factor for poorer performance among children born ELBW.6
This study was part of a larger study approved by the Mater Health Services Human Research Ethics Committee and the Medical Research Ethics Committee of The University of Queensland and was registered with the Australian New Zealand Clinical Trials Registry (ACTRN12613000950763).
Twenty-four children were randomized to the intervention part of the study. The full demographic details have been previously described10 and summary demographic details are in Table 1. The children were born between May 2005 and November 2008 and were managed in the Neonatal Intensive Care Unit at the Mater Mothers' Hospital, Brisbane, Australia. They were recruited between July 2010 and February 2013. The study included children who were extremely preterm and/or ELBW, but will hereafter be referred to as ELBW. Children lived within 1-hour travel of the testing center. Children were 4 to 4½ years corrected for prematurity when enrolling in the study and had not started formal education. In the case of extreme prematurity, it is usual to continue using corrected age until the child is 5 years of age or until formal school education has commenced.17 Mean corrected age of the children at baseline was 49.6 months (standard deviation [SD] 2.4 months). Children had attended the Mater Mothers' Hospital Growth and Development clinic follow-up assessment at 4 years (corrected age) and had a score from the Neurosensory Motor Developmental Assessment18 of 9 to 12 or less (minimal to mild deviation from normal) and an IQ of more than 70 on the Stanford-Binet Intelligence Scales.19
TABLE 1 -
Perinatal and Social Details of Participants
|Perinatal/Social Factor (n = 24)
|Antenatal steroids, n (%)
|Premature rupture of membranes, n (%)
|Cesarean section, n (%)
|Gestation, wk, median (IQR)
|Birth weight, g, mean (SD)
|Male gender, n (%)
|Apgar at 5 min < 7, n (%)
|Chronic neonatal lung disease, n (%)
|Late-onset infection, n (%)
|Periventricular hemorrhage, n (%)
|Periventricular leukomalacia, n (%)
|Home oxygen program, n (%)
|Maternal age, y, mean (SD)
|Private health insurance, n (%)
Abbreviations: IQR, interquartile range; SD, standard deviation.
Exclusion criteria were major congenital anomalies, diagnosed neurological impairments, a visual impairment not corrected by corrective lenses, a hearing impairment not corrected by aids, parents/guardians who did not speak English, and families that could not commit to the study attendance requirements.
Testing took place at the Mater Children's Hospital, Brisbane. Once informed written consent was obtained, experienced pediatric physical therapists performed baseline assessment using a protocol for motor and postural evaluation. The protocol included details regarding how the tests were to be performed and the order of the tests. Assessors completed a series of assessments independently and simultaneously before the study to confirm adherence to the testing protocol. The assessors had no involvement in the intervention or goal setting. Intervention commenced within 1 month of the baseline measures. Goal setting was performed at the first treatment session by an independent pediatric physical therapist and parents. The intervention program was weekly for 6 weeks and occurred in the physical therapy department at the Mater Children's Hospital, Brisbane. The weekly sessions were approximately 60 minutes plus 20 to 30 minutes for explanation of home program and parent discussion. Children were reassessed on baseline measures within 1 month of program completion.
The intervention program was based on a combination of traditional physical therapy and task-oriented approaches (Appendix, Supplemental Digital Content 1, available at: https://links.lww.com/PPT/A155). Traditional physical therapy involves training an individual in essential age-specific gross and fine motors skills, as well as the fundamental sensory and motor abilities necessary to perform those skills. Task-oriented approach emphasizes motor performance and incorporates cognitive approaches with attention directed toward specific aspects of a motor skill. There is evidence supporting the efficacy of both approaches (traditional and task-oriented) among children with motor impairment such as developmental coordination disorder.20
Intervention was group based with 3 to 4 children per group. An experienced pediatric physical therapist led the intervention, with the assistance of a physical therapist student. Parents or caregivers facilitated as needed throughout the program. This may have been in the form of physical or motivational assistance during the sessions or by ensuring compliance with the intervention program. Sessions were structured and included the same key components each week, but activities within these components were progressed on a weekly basis (Appendix, Supplemental Digital Content 1, available at: https://links.lww.com/PPT/A155). Activities could be modified according to a child's needs.
Postural control and stability were addressed by targeting core stability and by incorporating it into functional balance. Core stability activities were progressed by position change, with activities starting in long-sitting, then moving to sitting with feet free, then standing. Functional balance activities included single-leg stance games initially, such as kicking a ball, and then progressed to walking heel toe along an obstacle course. Another key component was sensorimotor, including important aspects of position sense, tactile object recognition, eye follow and eye-hand coordination, and vestibular responses. Specific attention to upper limb strength was a fundamental component and activities became progressively more challenging each week. For example, children initially performed commando crawl activities (abdomen in contact with floor), then progressed to modified push-ups (partial support of body weight), followed by crab walks (further loading of elbow extensors and shoulder muscles to support body weight). Paired activities, such as hand clapping games, and a fine motor element were also included. Emphasis was also placed on an individual component with activities modified to each child's specific needs.
The home program was updated weekly. It replicated each intervention session, with similar components each week that were progressed. Parents were advised to encourage their children to perform 20 to 30 minutes of the home program per day. Frequency was based on what was deemed necessary to support improvements while still being manageable for families.
Parents were not discouraged from allowing their children to access other therapies during the intervention period. Two children had occupational therapy while participating in the study.
Primary Outcome Measure
Goal Attainment Scaling.
GAS measured goal performance and evaluated the effectiveness of the intervention program.11,16 GAS is a criterion-referenced measure of change at the level of the individual16 and is a valid and reliable test suitable for young children with or without motor delays.16,21–23 In terms of its validity, Palisano21 investigated the content validity of GAS and the responsiveness of GAS compared with a behavioral objective in 21 infants with motor delays. Findings from this study support the content validity (77%-88% of the physical therapists' ratings for each of 3 different dimensions examined by the therapists, met the criterion for content validity) and the responsiveness of GAS to change (for 61% of the goals, change that could not be determined by the behavioral objective was determined with the GAS).21 King et al23 explored the utility of GAS for evaluating the effects of therapy services in the school setting for children with physical or communication needs. In this study of 16 children, reliability of GAS ratings was determined by the level of agreement between the GAS therapists and the treating therapists on the amount of improvement the children made on their goals. The level of agreement was found to be moderate (correlation of 0.6).
GAS involves goal setting and identifying 5 possible outcomes for each goal. GAS enables grading of goal attainment and comparison across goals and children over time.
Three goals were identified for each child before commencing the intervention and in partnership between a physical therapist and parents/carers. Goals were relevant, understandable, measurable, attainable, and time limited.16 A different focus for each goal was used: goal 1 was “action” focused, goal 2 was “function” focused, and goal 3 was “performance” focused. Goals in each focus area were structured around similar types of activities. Group-based evaluation was enhanced by having the same 3 focus areas for all children (action, function, and performance) although goals were individualized to the child. The original 5-point scale developed by Kiresuk et al24 was used (Table 2). The starting point allocates a score of “−2” to current performance, and change is measured from that point. The categorical scale range is from “−2” (much less than expected outcome) to “+2” (much more than expected outcome), with a score of “0” corresponding to expected level of performance. Table 3 includes an example of GAS applied to one of the participants. Up to 3 trials were permitted when testing each goal. Bias was minimized by ensuring that the goals were written and assessed by an experienced physical therapist who was not the physical therapist leading the intervention. This independent physical therapist, in collaboration with parents, performed the goal rating.
TABLE 2 -
Goal Attainment Scaling Levels24
|Much less than expected outcome
||Performance that is expected to occur 7% of the time, ranging from regression to minor/no changes
|Somewhat less than expected outcome
||Performance that is expected to occur 21% of the time and is somewhat less than anticipated for the treatment period
|Expected level of performance by the end of the measurement period
||Performance anticipated at the start of treatment for the designated measurement period and is expected to occur 43% of the time
|Somewhat more than expected outcome
||Performance that is expected to occur 21% of the time and is somewhat more improvement than expected for the treatment period
|Much more than expected outcome
||Performance that is expected to occur 7% of the time and is uncommon as significant more improvement than expected occurred during the measurement period
TABLE 3 -
Example of Goal Attainment Scaling
|Much less than expected outcome
||Stands on 1 leg with light assistance to maintain balance
||Uses palmar grasp to write some letters of name with verbal and visual cueing
||Occasional turn-taking when participating in group activities for 1 h, verbal cueing required
|Somewhat less than expected outcome
||Stands on 1 leg for approximately 2 s with poor stability
||Uses palmar grasp to write all letters of name with verbal and visual cueing
||Turn-taking 25% of the time when participating in group activities for 1 h, verbal cueing required
|Expected performance by the end of the measurement period
||Stands on 1 leg for approximately 4 s with stability
||Uses dynamic tripod to write all letters of name with verbal and visual cueing
||Turn-taking 50% of the time when participating in group activities for 1 h
|Somewhat more than expected outcome
||Stands on 1 leg for approximately 6 s with stability
||Uses dynamic tripod to write all letters of name with visual cueing
||Turn-taking 75% of the time when participating in group activities for 1 h
|Much more than expected outcome
||Stands on 1 leg for approximately 8 s with stability
||Uses dynamic tripod to write all letters of name independently
||Consistently takes turns with other children when participating in group activities for 1 h
Secondary Outcome Measures
Movement Assessment Battery for Children-Second Edition.
Motor coordination of the children was assessed using the MABC-2.25 This is a norm-referenced standardized test and consists of 3 components: manual dexterity, aiming, and catching and balance. Individual component scores have been shown to be reliable and have acceptable correlation with each other and the total test score.25 Although there is evidence to support the reliability and validity of the original MABC, there are fewer studies that have addressed these issues with the MABC-2.25–28 Wuang et al,28 in a study of 144 children (aged 6-12 years) with developmental coordination disorder, stated that the MABC-2 is a reliable test to assess motor performance (intraclass correlation coefficient 0.97). The authors also demonstrated that all subscales of the MABC-2, except balance, had acceptable validity in distinguishing those children whose motor performance had improved versus those children whose motor performance had stayed the same.28 Scoring of the MABC-2 provides a standard score and percentile for each component and overall percentile rank on the basis of a combination of the 3 components. Children are classified as having definite motor difficulties if they have a percentile rank at the fifth percentile or less. A percentile rank between the fifth and 15th percentiles indicates borderline motor difficulties.
The timed single-leg stance (SLS) and lateral reach test were used to assess postural control and balance. Although few measurements of postural stability in children are available that are reliable and valid29 and norms for these tests are lacking, the SLS and lateral reach tests are functional, commonly applied in the clinical setting and have been used in children with Developmental Coordination Disorder, cerebral palsy, and children who are ELBW.1,30–32
A set testing protocol with standard instructions was used for SLS and lateral reach tests. Children were tested barefoot and were given 3 trials per side of the body with best performance recorded.
Single-Leg Stance Test.
Timing in seconds commenced when the child lifted the nominated leg. The non-weight-bearing foot was not permitted to touch the other leg/floor. Eyes remained open. Timing stopped when the non-weight-bearing foot touched the floor or when the testing criteria were no longer satisfied.
Lateral Reach Test.
The child stood in front of a wall, with feet shoulder width apart and with 1 arm raised to 90° of abduction. The child reached as far sideways as possible while maintaining balance and a fixed base of support. The child was not allowed to lean against the wall. The distance reached was measured as the difference in centimeters between arm length (at 90° of abduction) and maximal lateral reach of the finger tip of the third finger.33
Functional Measure of Limb Strength
Standing Long Jump Test.
Standing long jump assessed functional lower limb strength and control. There is evidence supporting its reliability as a measure of explosive strength among 4- and 5-year-old children.34 A set testing protocol with standard instructions was used. Three trials were allowed with best performance recorded. The child was tested barefoot and stood with toes behind a marked take-off line, crouched and jumped forward as far as possible. The child had to land 2 feet together. The horizontal distance jumped was measured from the take-off line to the point of the child's body that landed closest to the starting point.34
Analyses were performed using SPSS version 22.0 (IBM Corporation, Armonk, New York). Sample size was predetermined in association with the larger study.10,31 Before this larger study, a pilot study31 was conducted using the same selection criteria, measures, and intervention. The pilot data demonstrated an average increase of 4 points from baseline to postintervention on the primary outcome measure, the MABC-2 standard score. This represents approximately a 20% increase in the MABC-2 standard score from baseline. Therefore, assuming a modest increase in score in the standard care group of 0.5 points, and an average increase of 4 points with a common SD of 4.4, it was determined that 25 participants per group would be required. Because of time constraints in recruitment, 50 participants were recruited (intervention n = 24, standard care n = 26) but only 24 participants per group completed the study.
Changes in GAS were evaluated as per Kiresuk and Sherman.11 An overall GAS score was calculated for each child (sum of the 3 goal scores for each child) and this was converted into a T score using the formula, T = 50 + C(xi), which is based on the original formula developed by Kiresuk et al.24 In this formula, “C” is a constant depending on the number of scales, in the current study C = 3.01 and xi is the summed attainment score for the 3 goals. A GAS mean T score for the group was determined. A score of 50 or more indicates that goals were attained. One SD corresponds to a change in score of 10. Therefore, a change of 10 points would be needed to reach the next higher or lower performance level. Mean aggregate T scores allowed comparisons across children, as well as a global assessment of children's performance.16
T scores enabled GAS to be used in conjunction with standardized outcome measures to determine associations with performances on other measures and the effect of gender on scores. Pearson correlation was used to associate GAS scores and motor coordination, postural stability, and limb strength. Analyses of pre- and postscores on other measures form part of the larger study and are not presented in this study. An independent samples t test was used (http://www.socscistatistics.com, 2016)35 to evaluate the effect of gender on GAS scores and Cohen's d was used to determine effect size.36 Cohen's criteria assisted with interpretation of the true magnitude of the difference, with d = 0.8 considered a large effect size. The α level was set at 0.05 for all analyses.
GAS Scores at Reassessment
Children improved on GAS following intervention. The GAS mean T score of the group was 58.2 (SD = 0.82), which meant that the group increased by almost 1 SD and exceeded the expected goal of “0” score (Figure 1). The range of GAS mean T scores was 40.9 to 77.4, with only one child reaching an improvement of more than 2 SD from the mean (T = 77.4). Two children did not reach the expected GAS mean T score of 50. These children had GAS mean T scores of 40.9 (1 SD below the expected mean) and 45.4.
Correlations Between GAS Scores and Secondary Outcome Measures
Means and SDs for secondary outcome measures, as well as correlations between GAS scores and these measures, are shown in Table 4. GAS T scores correlated moderately with overall MABC-2 percentile at reassessment. There was an association between GAS T scores and the aiming and catching component of the MABC-2. Higher GAS T scores were associated with better MABC-2 outcomes in these domains. There were no significant correlations between GAS T scores and scores on functional measures of postural stability and limb strength.
TABLE 4 -
Correlations Between Goal Attainment Scaling Scores and Secondary Outcome Measures at Reassessment
|Secondary outcome measure (n = 24)
|MABC-2 manual dexterity percentile, %
|MABC-2 aiming and catching percentile, %
|MABC-2 balance percentile, %
|MABC-2 percentile, %
|Single-leg stance—right, s
|Single-leg stance—left, s
|Lateral reach—right (n = 23), cm
|Lateral reach—left, cm
|Standing long jump, cm
Abbreviations: MABC-2, Movement Assessment Battery for Children-Second Edition; SD, standard deviation.
Gender Differences on GAS Scores After Intervention
Females (n = 14, mean = 60.8, SD = 6.35) scored significantly better on GAS after intervention than males (n = 10, mean = 54.6, SD = 8.04) (t = −2.108, df = 22, P = .047). The effect between gender t-test scores was Cohen's d = 0.85.
Group-based physical therapy intervention facilitated goal achievement for children born ELBW with minimal or mild motor impairments. The GAS was an effective means of overall program evaluation. Significant individual gains were made and directly correlated with motor performance after intervention, indicating that improvements in motor skills may have promoted achievement of goals. Goal attainment was not significantly related to functional postural stability and limb strength outcomes. Perhaps this was due to the goals being personalized to the individual and relating to more general motor performance and skills, and therefore having a greater likelihood of being reflected in MABC-2 performance, whereas the functional measures of SLS, lateral reach and standing long jump, were more task-specific tests. The goals and the outcome measures must be well aligned to demonstrate change. Females not only scored significantly better than males on GAS but performed more than 1 SD above the expected mean of 0. This gender effect aligns with another report6 and supports the current study. Male gender is a risk factor for less favorable outcomes and males may need to be monitored more closely.
This study reinforces findings from other studies that have used GAS. Similar to these studies,13,15 the GAS was responsive and sensitive to incremental change among children. It is difficult to compare the current study with previous research in relation to the combination of the model of intervention that was used and the primary outcome measure. Other studies that have used group-based intervention in the pediatric setting have not included GAS and samples of these studies are too heterogeneous.8,9,32
Strengths of this study include the use of a primary outcome measure that is functional and meaningful to children and families, thus reinforcing child and family-centered care. Further benefits of using GAS include progress related to expected results. GAS is realistic, and goal setting may facilitate goal attainment through heightened motivation.37 Care was taken to minimize limitations associated with GAS, including the potential for bias in goal setting, the level of training of the person designing goals, the assessor, or rating process.16 Furthermore, GAS is closely aligned with all levels of the ICF. In this study, GAS emulates the ICF at the individual level, as it incorporates the “health”38 of the child through the 3 GAS focus areas (action, function, and performance), as well as contextual factors. The GAS was used in association with other outcome measures, which added depth to this study but demonstrated where there may be some common bases for both goal attainment and motor performance, as GAS was found to be related to motor outcomes. Results from this study reinforce the clinical value of GAS. It is useful for clinicians who may have limited access to standardized tests, or when standardized measures cannot be repeated within a short time frame.
This study has several limitations. The intervention group was small, the intervention period was brief, and the program may not have had sufficient intensity. Unfortunately, it was not possible to extend the intervention period or prolong the time between GAS baseline assessment and reassessment. The GAS was a short-term measure of change and not a reflection of longer term effects of intervention. Changes in GAS scores may have been due to the therapists' abilities to accurately predict the developmental trajectory and thus the performance levels of the participants at various time points, rather than change attributed to an intervention effect. Although the therapist took into account the effect of intervention and the effect of maturation with the goal-setting process, it is not possible to determine how much of the improvement the children made was due to intervention versus maturation. Compliance with home programs was not measured. This could have provided valuable information, particularly if correlated with GAS scores. Furthermore, the current study was not specifically designed to address reliability associated with using GAS, although every attempt was made to follow published guidelines. This could be considered as part of future research in this area. Research is needed on the reliability and validity of postural stability measures used in this study.
Mild neurodevelopmental impairments are common among 4-year-old children born extremely preterm and/or ELBW who escape major disabilities; therefore, the role of intervention requires ongoing exploration. Group-based physical therapy intervention does have short-term benefits. Most of the children in this study improved as a result of intervention and reached their expected level of performance or better on specific goals using GAS. Therefore, GAS appears to be a suitable tool to use among 4-year-old children with minimal or mild impairments. In addition, this study demonstrated that goals were related to motor coordination and that male gender is a risk factor for less favorable outcomes. Consideration of the effect of group-based physical therapy intervention on other neurodevelopmental outcomes will provide further management direction for the children similar to these participants.
We would like to thank the children and their parents who participated in this study. We acknowledge Leith Poulsen for assisting with recruitment and retrieval of demographic information of eligible children. We also thank all of the physical therapists who contributed to this research, especially Marcella Danks, Bronagh McAlinden, and Kristy Nicola.
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