Outcome Measures in Childhood Idiopathic Thrombocytopenic Purpura: Relationship of Bleeding Severity, Quality of Life, and Platelet Count.
Authors: Neunert Cindy E. , Buchanan George R. , Blanchette Victor S. , Barnard Dorothy R. , Young Nancy L. , Curtis Christine , Klaassen Robert J. 
Published: April 2020

Abstract
Idiopathic thrombocytopenic purpura (ITP) is one of the most common disorders requiring the attention of a pediatric hematologist. The most feared outcome of ITP is intracranial hemorrhage (ICH), which fortunately is a rare occurrence in children. Although a rise in platelet count and presumed reduction in risk of ICH are stated therapeutic aims, it is equally important to identify and understand additional outcome measures which are subject to change in this population. These include health-related quality of life (QoL), treatment side effects, cost, and bleeding severity. A QoL questionnaire for pediatric acute and chronic ITP has recently been developed and validated. During the validation study (Pediatr Blood Cancer, 46:692, 2006), grading of hemorrhage and platelet count were also assessed. This report describes the results of a secondary data analysis using the validation study database. Our purpose was to assess the relationship between bleeding severity and QoL, previously not reported. Ninety children (mean age 9.7 yrs.) with ITP (41 acute, 49 chronic) were prospectively enrolled at six North American centers. Platelet count and bleeding severity were measured at baseline. Bleeding severity was assessed using a modification of a previously published grading instrument (J Pediatr, 141:683–8, 2002) where each patient was assigned a grade of 0 (no bleeding) to 5 (life-threatening bleeding) based on the overall amount of hemorrhage in the previous twenty-four hours. QoL scores were obtained by proxy-report by parents on behalf of their child and self-report by children age seven and older. Parents also reported their own QoL. Using a two- tailed Pearson correlation, the bleeding severity grade was weakly correlated with the platelet count in the children with chronic ITP (r= 0.20, p&lt;0.001), but this relationship did not reach significance for children with acute ITP (r= 0.07, p= 0.09). The severity of bleeding did not correlate with the child’s self-reported QoL in either acute (r= 0.005) or chronic ITP (r=0.03). Parents’ self-assessed QoL did not reflect bleeding severity when their children had either acute (r= 0.03) or chronic ITP (r= 0.006). The parents’ perception of the child’s QoL using a proxy score was also poorly correlated with bleeding severity in acute (r= 0.02) and chronic ITP (r= 0.01). In summary, the bleeding severity score did not correlate with the QoL experienced by either the patient or the family in any setting. These results indicate that many factors in addition to bleeding signs may impact the children and parents, such as anxiety about the disease, length of hospital stay, frequency of visits to the physicians’ office, and medication side effects. These findings suggest that the inclusion of multiple outcome measures enhances the scope of our knowledge and should be used in clinical care and research study design in order to understand the full spectrum of disease impact.