Table 2 Variables and outcome measures

 Passive range of motion: elbow extension, wrist extension (with fingers extended), wrist extension (with fingers flexed), supination

Standardised goniometric measurement; inclinometer for measures of supination;

Goniometric measurements have a high level of intra-rater reliability when measuring passive range of movement in the lower limb in children with CP (ICC >.80) and SEM of 3.5° [44, 45].

Inertial Motion sensors.

Inertial motion sensors (see additional information below) will be used to measure passive wrist extension with fingers extended only.

 Active range of movement: elbow extension, wrist extension (with fingers extended), wrist extension (with fingers flexed), supination

Standardised goniometric measurement and use of inclinometer for measures of supination.

See additional information above.

Inertial Motion sensors

Inertial motion sensors (see additional information below) will be used to measure active wrist extension with fingers extended only.

 Functional range of wrist extension during standardised tasks.

Inertial Motion sensors.

A wireless inertial motion sensor for children has been designed and engineered for this trial to measure wrist flexion/extension movement during functional activity. The sensors use a combination of inertial sensor technologies to provide an accurate estimate of orientation referenced to a fixed frame [46]. Once correctly positioned they wirelessly capture movement with 3° of freedom in a virtual reality environment to provide continuous kinematic data during unrestricted functional movements. The validity and reliability of the newly developed sensor has been assessed with 10 children with CP (aged 4–12 years) against 3DMA, the ‘gold standard’ method to quantify movement. Preliminary data demonstrates the inertial motion sensors have excellent static and dynamic accuracy (+/-0.5 and +/-1.2° respectively).

 Muscle stiffness (finger flexors, wrist flexors, pronators and elbow flexors)

Modified Ashworth Scale [47]

The six point Modified Ashworth Scale has moderate intra-rater reliability when assessing the elbow (ICC 0.66) and wrist flexors (ICC 0.57) in children with CP [48].

 Muscle spasticity (finger flexors, wrist flexors, pronators and elbow flexors)

Modified Tardieu Scale [47]

The Modified Tardieu Scale has moderate to high intra-rater reliability when assessing the elbow (ICC 0.65) and wrist flexors (ICC 0.92) in children with CP [48].

Australian Spasticity Scale [33]

The Australian Spasticity Assessment Scale has demonstrated moderate to high inter-rater agreement (47–100 %) [33]

 Grip strength

Hand held dynamometer (CITEC)

Dynamometery has been shown to have excellent levels of inter-rater (ICC 0.95) and test-re-test reliability (ICC 0.96) when measuring strength in the hand of children with hemiplegic CP [49].

 Hand deformity

Neurological Hand Deformity Classification Scale [50]

The Neurological Hand Deformity Classification has evidence of reliability for children with spastic cerebral palsy with high inter-rater agreement (Kappa 0.87) and intra-rater agreement (Kappa 0.91) [15]

 Thumb position

House Thumb in Palm classification [51]

This measure has been developed for children with CP based on the predictors of surgical success and has been found to be reliable: Kappa = 0.73 (rater agreement) and 0.74 (test-re-test agreement) [49, 52].

 Hand pain

Study specific questionnaire

The study specific questionnaire was developed for this study to document parent perception of domains unable to be captured in existing measures. Questions will be completed by the child where possible or by a parent/carer proxy. Although proxy respondents are known to underestimate pain, parent-reported pain will be required for children who are more severely cognitively impaired or unable to communicate their pain effectively.

 Self-care skills

Pediatric Evaluation of Disability Inventory – Computer Adaptive Test [53]

This is a standardised assessment of how children with impairments function in the context of their daily life. The Pediatric Evaluation of Disability- Computer Aided Test provides an accurate and precise assessment of abilities in four functional domains (ICC 0.99). For this trial only data from the Daily Activities domain will be collected.

 Manual ability

ABILHAND-Kids [54]

This tool has been Rasch analysed and has demonstrated validity and appropriate range and measurement precision for clinical practice and research: reliability: R = 0.94; reproducibility over time: R = 0.91 [54].

 Speed and dexterity

Box and Blocks Test [55]

This test has a high level of intra-rater (ICC 0.99) and test-retest reliability (ICC 0.85) [56].

 Hand function

Modified House Scale [57]

This scale is reliable in children with CP: inter rater reliability (ICC 0.94-0.96); intra rater reliability (ICC 0.93-0.96) [57]. Rasch analysis was performed on the original scale and the items reduced: analysis suggests that the modified version demonstrates good construct validity [58].

 Ease of care-giving

Study specific questionnaire

Parent response to specific questions regarding the child’s ability to use their hands in self-care tasks or, for children with severe forms of cerebral palsy the ease with which parents or carer’s can complete daily tasks of care for them.

 Participation

Participation and Environment Measure-Child & Youth [59]

Designed to measure frequency of participation, involvement during participation and the impact of the environment on participation in children aged 5 to17 years [59]. This measure captures participation outcomes in home, school and community contexts. Reliability of the frequency scales (ICC range 0.58-0.84) and involvement scales (ICC 0.69-0.76 is moderate to high [59].

 Child Health related quality of life and care-giving burden

Cerebral Palsy Quality of Life Questionnaire – Child and Teen versions [60, 61]

Due to the varying ages and abilities of the child-participants, both parent- and self-report versions of the Child or Teen CP Quality of Life will be used to measure quality of life. Test-re-test reliability for the Child version was high (ranged from ICC 0.76 to 0.89 across 7 scales) [61], and moderate to high for the Teen version (ICC 0.57 to 0.88) [60]

 Cost Effectiveness Analysis (CEA)

Study specific questionnaire

Data on type and number of health professional appointments attended by child in preceding 6-month time period will be utilised for calculation of healthcare cost as well as out of pocket costs to families. Net incremental costs expressed as ICER to meaningful clinical and physical outcomes (e.g. selected from body function domains; activity domains; and the clinical quality of life questionnaire).

 Cost Utility Analysis (CUA)

Child Health Utility -9 Dimensions [37]

Net ICER to the quality of life improvement for children and parents/carers expressed as QALY using an economic MAUI. Where possible the Child Health Utility will be completed along with the parent proxy version. The Child Health Utility has 9 items, takes 2-3 min to complete and covers worry, sadness, pain, tiredness, annoyance, school work, sleep, daily routine and ability to join in activities. The Child Health Utility-9D demonstrated good validity and high levels of agreement with a similar instrument (ICC: 0.742) [62]. The parent measure of quality of life, the Assessment of Quality of Life 8 Dimensions has high reliability (ICC 0.89) [36].

Assessment of Quality of Life 8 Dimensions [36]

 Cost Consequences Analysis (CCA)

CEA/CUA reported alongside a broader documentation of child & family relevant outcomes