What are the inclusion and exclusion 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)
- 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.