Test–Retest Reliability and Construct Validity of the German Translation of the Gait Outcome Assessment List (GOAL) Questionnaire for Children with Ambulatory Cerebral Palsy

Abstract

The Gait Outcome Assessment List (GOAL) is a patient or caregiver-reported assessment of gait-related function across different domains of the International Classification of Functioning, Disability, and Health (ICF) developed for ambulant children with cerebral palsy (CP). So far, the questionnaire is only available in English. The aim of this study was to translate the GOAL into German and to evaluate its reliability and validity by studying the association between GOAL scores and gross motor function as categorized by the gross motor function classification system (GMFCS) in children with cerebral palsy (CP). The GOAL was administered to primary caregivers of n = 91 children and adolescents with CP (n = 32, GMFCS levels I; n = 27, GMFCS level II; and n = 32, GMFCS level III) and n = 15 patients were capable of independently completing the whole questionnaire (GMFCS level I). For assessing test–retest reliability, the questionnaire was completed for a second time 2 weeks after the first by the caregivers of n = 36 patients. Mean total GOAL scores decreased significantly with increasing GMFCS levels with scores of 71 (95% confidence interval [CI]: 66.90–74.77) for GMFCS level I, 56 (95% CI: 50.98–61.86) for GMFCS level II, and 45 (95% CI: 40.58–48.48) for GMFCS level III, respectively. In three out of seven domains, caregivers rated their children significantly lower than children rated themselves. The test–retest reliability was excellent as was internal consistency given the GOAL total score. The German GOAL may serve as a much needed patient-reported outcome measure of gait-related function in ambulant children and adolescents with CP.

Reliability of the Gait Outcomes Assessment List questionnaire

“…SEMs across GMFCS levels were different for specific domains. Combined with previous relative reliability measures and validity, 13–16 these results provide a more comprehensive evaluation of the GOAL's psychometric properties, particularly the ability to discriminate true change from measurement error. This increases the confidence of clinicians in the ability of the GOAL to provide an accurate and reliable assessment rating of a child's function difficulty, pain and fatigue, and happiness with bracing and self‐esteem over time.…”

“…This is the first study to investigate the absolute reliability of the GOAL and adds an important dimension to the collection of studies that demonstrate its psychometric properties 13–16 . The study provides clinicians with essential information regarding the SEM and MDC necessary to interpret scores at one or more points in time.…”

“…13,14 Reliability has not been fully established. 15,16 Reliability is necessary to distinguish true change from measurement error. 3,4 There are multiple types of reliability, each evaluating different aspects.…”

The Danish child and parent Gait Outcomes Assessment List questionnaires were reliable and valid for cerebral palsy

“…12 A number of studies have validated the GOAL questionnaires to date and these showed that they were able to discriminate between GMFCS levels I-III. 13,14 Moderate positive correlations were found between the GOAL scores and the walking and activities lists in the Functional Mobility Scale and Functional Assessment Questionnaire. 13 A moderate negative correlation was found between the total GOAL scores and the gait profile score derived from the three-dimensional gait analysis.…”

Factor analysis of the Gait Outcomes Assessment List's goal questions: A new method to measure goal prioritization in ambulatory individuals with cerebral palsy

“…Although the psychometric properties of GOAL's total and seven difficulty, frequency, and unhappiness domain scores have been demonstrated across multiple clinical sites, [10][11][12] very little is known about the properties of the goal prioritization items. Making sense of 49 different goals is challenging both from clinical and research perspectives and we sought to address this concern.…”