Bone Abstracts

Objectives: Different versions of the Childhood Health Questionnaire (CHAQ) have been used in Paediatric Rheumatology since 1994 to establish levels of functional disability. To date, use of the CHAQ has not been reported in Osteogenesis Imperfecta (OI). The aim of this study was to establish if disability scores generated from a modified CHAQ (MCHAQ) correlate with OI severity.

Methods: The MCHAQ was developed to reflect the specific needs of children with OI. All main features of the original CHAQ remain, but with a total of 32 questions. A category format was used and disability was graded 0–4 (0= no disability, 4= severe disability). Each patient was clinically categorized as having mild (Type I), moderate (Type IV) or severe OI (Type III), independent of genotype.

Results: The MCHAQ was completed by 100 patients with OI (median age 9.9 years (range 3.1–19.8)), with no age difference between clinical severity groups. MCHAQ scores were significantly higher in severe (2.06 (0.69–3.58); n=12) compared to moderate (0.59 (0–2.38), P=0.002; n=19) and mild OI (0.22 (0–1.61), P<0.001; n=69), and moderate OI tended to have higher scores than mild OI (P=0.051). MCHAQ scores (ρ=−0.291, P=0.003) and the percentage of tasks classified as ‘unable to do’ (ρ=−0.210, P=0.036) and ‘not-applicable’ (ρ=−0.617, P<0.001) were negatively associated with age, suggesting a learning effect. However, across age, children were consistently unable to perform certain skills such as riding a bike or tricycle (19.4% of children), cutting fingernails (14.3%), participating fully in physical education at school (14.3%) and reach up and get down a heavy object (such as a large game or book) from above his/her head (14.1%).

Conclusion: The MCHAQ differentiated the functional level of disability in patients with OI based on clinical severity category and identified specific functional difficulties that can guide therapy intervention. MCHAQ allows monitoring of individual change but the score is also age dependent. Therefore, comparison with healthy children will be required to test the hypothesis whether children with OI acquire skills later than their normal peers.

Disclosure: The authors declared no competing interests.