The Gait Outcomes Assessment List for Children with Lower Limb Difference (GOAL-LD) : Assessment of reliability and validity

Background:
The Gait Outcomes Assessment List for children with Lower Limb Difference (GOAL-LD) is a patient and parent-reported outcome measure that incorporates the framework of the International Classification of Functioning, Disability, and Health. This prospective multicenter cohort study evaluates the validity and reliability of the GOAL-LD and the differences between parent and adolescent report.

Method:
One hundred thirty-seven pediatric patients aged over 5 years attending limb reconstruction clinics at the participating sites were assessed at baseline, and a self-selected cohort also completed an assessment 2 to 6 weeks later. Construct and criterion validity were assessed by comparing GOAL-LD scores with a measure of limb deformity complexity (LLRS-AIM) and the Pediatric Outcomes Data Collection Instrument, using Spearman correlation coefficients. Face and content validity were determined through ratings of item importance. Test-retest reliability was reported as an intraclass correlation coefficient and internal consistency using Cronbach α. Adolescent reports were compared with their parents using paired t tests.

Results:
The GOAL-LD demonstrated a moderate negative correlation with the LLRS-AIM (r=−0.40, P<0.001) and was able to discriminate between deformity complexity groups as defined by the LLRS-AIM (χ2=11.43, P=0.022). Internal consistency was high across all domains (α≥0.68 to 0.97). Like domains of the Pediatric Outcomes Data Collection Instrument and the GOAL-LD were well correlated. Parents reported a lower total GOAL-LD score when compared with adolescents (mean difference 3.04; SE 1.06; 95% confidence interval, 0.92-5.16; P<0.01); however this difference was only significant for body image and self-esteem (Domain F) and gait appearance (Domain D). Test-retest reliability remained high over the study period (intraclass correlation coefficient 0.85; SE 0.03; 95% confidence interval, 0.77-0.91).

Conclusions:
The GOAL-LD is a valid and reliable self and parent-reported outcome measure for children with lower limb difference. Parents report a lower level of function and attribute a higher importance to items when compared with their children. The GOAL-LD helps to communicate parent and child perspectives on their function and priorities and therefore has the capacity to facilitate family centered treatment planning and care.

Level of Evidence:
Level II—diagnostic. Prospective cross-sectional and a longitudinal cohort design.