For Researchers

What is the purpose of this study?

The purpose of this study is to:

  1. Evaluate the efficacy of the START-Play intervention program in sitting, reaching, and motor based problem solving skills to produce a positive impact on global development and readiness to learn in infants with motor delays
  2. Explore the fidelity of the implementation of the START-Play program and procedures needed to attain a sufficient level of fidelity in various intervention settings
  3. Identify mediating and moderating factors that influence the longer term outcome of global development and cognition from the START-Play intervention program, and thus describe trajectories of change over time related to the development of pre-school readiness in infants with motor delays

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What is the research design?

This randomized controlled trial uses a longitudinal, multisite design. To determine the efficacy of the START-Play intervention program we are randomizing children into two groups; one group will receive the START-Play intervention, and will be compared to a control group receiving their usual early intervention services. Infants who are between 7 and 16 months of age and are able to sit propping on their arms for at least 3 seconds but not yet able to get in and out of sitting by him/herself will be enrolled in this study.

We will recruit 140 infants from four clinical sites, including Pittsburgh, PA; Richmond, VA; Seattle, WA; and Newark, DE. Infants who are assigned to the START-Play intervention group will receive START-Play intervention in addition to their usual early intervention service for 12 weeks. The other group will continue to receive their usual early intervention service; both groups will report all services and therapies received. Data collection (assessment) will be conducted at baseline, after 6 weeks, after 12 weeks, after 6 months and after 12 months. Both the family and the therapist will receive surveys to describe the amount and types of service and intervention the child receives.

What are the inclusion and exclusion criteria?

Inclusion criteria:

  • Infants enter the study between 7 and 16 months of age, when they are able to prop sit for 3 seconds and maintain their head at least to the level of neutral alignment with their trunk.
  • Gross motor delay as reflected in the Bayley III motor subtest >1.0 SD below the mean.
  • Neuromotor disorder such as cerebral palsy (CP), or at risk for CP because of extreme prematurity or brain damage that occurred at or around birth, or infants with motor delay of an unspecified origin (no clear diagnosis, but delayed as defined above)

Exclusion criteria:

  • Medical complications that severely limit participation in assessments and intervention such as severe visual and congenital/genetic anomalies or uncontrolled seizure disorder.
  • Diagnosis other than an unchanging neuromotor disorder (examples: autism, Down syndrome, spinal cord injury, acquired head injury, muscle disorder).
  • A child will be excluded if the parents report any of following:
    • The child has a disability of a progressive nature such as muscular dystrophy;
    • The child’s family plans to move out of the local area within one year from the start of the study;
    • The child has major surgery planned that might affect physical performance.

What are our outcome measures?

The Bayley developmental test (cognitive, motor, and language) is the final primary outcome measure. Other primary measures are the Gross Motor Function Measure, the Early Problem Solving Indicator, and a Reaching Measure. Secondary measures include a modified Parent Child Interaction observation, an object permanence measure, a means-end skill measure, sitting kinematics, and the HOME-AHEMD. See the figure below for our theoretical model of change expected in this study.

How are we addressing fidelity of intervention in this study?

All intervention therapists are trained to achieve at least 80% fidelity of the START-Play intervention as the study begins. Each child in the study will have a video-taped fidelity analysis 3 times during the study, including the children in the control group. This is to assure that the START-Play key ingredients are, in fact, being provided only to the children in the intervention group. We code therapist behaviors minute by minute to quantify the degree of fidelity overall for each child in the study.

Four key ingredients of cognitive opportunities are measured through fidelity check: object permanence, means ends, body-object or object-object affordance, and joint attention. Opportunities are provided through motor activities which require the infant to be active during the practice of the cognitive skills. The video fidelity checks are coded by a single assessor to maintain consistency of coding, and this assessor is a pediatric PT who has achieved 95% agreement on repeated measures of practice videos prior to the study start.



Bayley Scale of Infant and Toddler Development III
Gross Motor Function Measure (GMFM)
Early Problem Solving Indicator


The U.S. Department of Education, Institute of Education Sciences is funding this study. This study falls under the National Center for Special Education Research, and the program is Early Intervention and Early Learning in Special Education. This grant started July 1, 2015, and will end June 30, 2019.