Purpose. To determine the psychometric validity of the pediatric quality of life inventory (PedsQL 4.0) in assessing the impact of refractive errors on health-related quality of life (HRQoL) in preschool children in Singapore.
Methods. Parents of toddlers (aged 25 to 48 months) and young children (49 to 72 months) completed the PedsQL 4.0, an HRQoL scale as part of population-based trial in Singapore. The outcome measures were the overall score, and the “physical”; “emotional”; “social”; and “school” functioning subscales. Rasch analysis was used to validate the PedsQL 4.0.
Results. Parents of 939 (48.9%) toddlers and 982 (51.1%) young children completed the PedsQL 4.0 survey. The overall mean (±standard deviation) spherical equivalence for the right eye was 0.47 ± 1.13 diopter (D) for toddlers and 0.74 ± 1.22 D for young children. One hundred forty-nine (15.9%) toddlers and 90 (9.2%) young children were considered myopic (≥−0.50 D). Most participants (n = 1286, 89.6%) had presenting visual acuity 6/9 or better. Rasch analysis showed evidence of disordered category thresholds and poor person-item targeting for both groups. The separation reliability was 0.00 for toddlers and 0.03 for young children, indicating there was no variance in both samples. The PedsQL 4.0 overall and subscale scores displayed substantial multidimensionality as the variance values explained by the measures was <25% in both groups. A minimum value of 60% is usually considering acceptable.
Conclusions. The PedsQL 4.0 in its current state is not a valid psychometric scale to effectively evaluate the impact of refractive errors on HRQoL in preschool children in Singapore.
Centre for Eye Research Australia, The Royal Victorian Eye and Ear Hospital, University of Melbourne, Victoria, Australia (ELL, MM, MD, TYW), Singapore Eye Research Institute, Singapore National Eye Centre, Singapore (ELL, TYW), Jurong Medical Centre, Singapore (BC, AEK-G), Duke-NUS Graduate Medical School, Singapore (TLY), Singapore International Eye Cataract Retina Centre, Mount Elizabeth Medical Centre, Singapore (AEK-G), Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore (AEK-G), Department of Ophthalmology and Visual Sciences, Alexandra Hospital, Singapore (AEK-G), Department of Ophthalmology, Duke University Medical Centre, Durham, North Carolina (TLY, AC), and Community Occupational and Family Medicine, National University of Singapore, Singapore (SMS).
Received April 8, 2010; accepted June 22, 2010.
Ecosse Lamoureux; CERA, Department of Ophthalmology; University of Melbourne; 32 Gisborne Street; East Melbourne, Victoria 3002; Australia; e-mail: firstname.lastname@example.org