PedsQL™ Sickle Cell Disease Module: Feasibility, Reliability and Validity

Sickle cell disease (SCD) is an inherited chronic disease characterized by complications such as recurrent painful vaso-occlusive events that can require hospitalizations and contribute to early and increased mortality. Prior work using generic health-related quality of life (HRQL) instruments has demonstrated that patients with SCD experience significantly impaired HRQL in their baseline state of health that worsens during acute complications of the disease. To better understand differences in health status in children with SCD, we developed the PedsQL™ SCD Module to measure SCD-specific HRQL. The goal of this study was to determine the measurement properties for the child self- and parent-proxy reports for the newly developed PedsQL™ SCD Module. We hypothesized that the PedsQL™ SCD Module would be feasible and reliable and that children with more severe SCD would have worse HRQL than those with mild disease as measured by the PedsQL™ SCD Module.

This was a cross-sectional study conducted at 5 sites across the United States. Study participants were children with SCD ages 2–18 years who presented to clinic for a routine visit. HRQL was the main outcome measured with the newly developed 43-item PedsQL™ SCD Module which includes nine scales: Pain/Hurt (PH, 9 items), Pain Impact (PI, 10 items), Pain Management/Control (PMC, 2 items), Worry I (WO1, 5 items), Worry II (WO2, 2 items), Emotions (EM, 2 items), Treatment (TR, 7 items), Communication I (CO1, 3 items), Communication II (CO2, 3 items). Higher scores indicate better HRQL and lower SCD symptoms. Missing items were used to determine feasibility and Cronbach's alpha was used to determine reliability. HRQL of children with mild and severe disease were compared using an independent t-test to determine construct validity. Severe disease was defined as patients with 3 or more hospitalizations for pain in the 3 years prior, history of stroke and/or prior acute chest syndrome.

A total of 321 families (313 parents, 243 children ages 5–18 years) completed questionnaires. The average age of the children (46.7% boys) was 9.62 years (SD = 4.88). Feasibility was established, with 3% or less missing data for the module. The PedsQL™ SCD Module was reliable and distinguished between children with mild and severe SCD (Table 1).

The PedsQL™ SCD Module performed well and demonstrated strong measurement properties in patients with SCD. Overall, both the parent-proxy report and child self-report differentiated between patients with severe and mild SCD supporting construct validity of the module. Although these are the first results using the PedsQL™ SCD Module, it has shown great potential as being a strong measure of HRQL for patients with SCD. Future studies incorporating the PedsQL™ SCD Module will benefit from the measure's disease-specific scales and overall ability to distinguish between mild and severe symptoms. Continually, these studies will help further define its' measurement properties and advance our knowledge of the HRQL in patients with SCD.

Off Label Use: Hydroxyurea is approved for use in sickle cell disease in adults but not children. Varni:Mapi Research Trust: Dr. Varni holds the copyright and the trademark for the PedsQL™ and receives financial compensation from the Mapi Research Trust, which is a nonprofit research institute that charges distribution fees to for-profit companies that use the Pediatric Quality Other, PedsQL™, PedsQL™ Patents & Royalties.