Background: External fixator treatment (EFT) of lower limb deformities is expected to optimize gait and physical appearance, which might improve the child's health-related quality of life (HRQOL). Although EFT can impose a significant psychologic burden on the children and their families, there is a lack of studies on the HRQOL of children undergoing EFT. The purpose of this paper is to determine the construct validity and the responsiveness of the Pediatric Quality of Life Inventory (PedsQL) generic module in children with lower limb deformities undergoing EFT and to describe the use of other outcome measures in this population.
Methods: Fifty-two children (mean age: 13.0 y, SD: 4.2) who enrolled in the pilot phase of a randomized controlled trial to examine the safety and efficacy of botulinum toxin type A injections in children undergoing EFT of the lower limb were included in this study. Pain and functional mobility were measured at baseline. HRQOL was assessed with the child self-report and parent proxy-report formats of the Pediatric Quality of Life Inventory 4.0 Generic Core Scales (PedsQL) at baseline, at mid-distraction, mid-consolidation, 1-week post-frame removal, and 3 months post-frame removal time points. The known groups method was used to measure the construct validity of the PedsQL; paired t tests, Cohen's d estimate of effect size (ES) and standardized response mean were used to calculate its responsiveness.
Results: Children and parents reported significantly lower HRQOL scores on all PedsQL domains compared with norms. ES and standardized response mean calculations both show largest amounts of change in the Physical Health domain, with children and parents reporting worse HRQOL at mid-distraction than at baseline. The PedsQL shows statistically significant changes only in the emotional functioning score of the child self-report from 3 months post-frame removal compared with baseline.
Conclusions: The PedsQL is able to discriminate HRQOL between children with leg length discrepancy and the normal population. The responsiveness of the PedsQL in children with lower limb deformities was shown through patient change over time as a result of EFT. Our findings indicate the importance of assessing a wide range of domains including physical, psychosocial, and emotional components of health in children with leg length discrepancy undergoing EFT.
Levels of evidence: Level IV. Case series.