Functional impact of pediatric postthrombotic syndrome.

Background: Postthrombotic syndrome (PTS) is the most common complication of deep vein thrombosis (DVT) in children.

Objectives: We aimed to assess the impact of pediatric PTS on functioning as assessed by movement ability, mobility, functional disability, and physical activity levels in children after diagnosis of limb DVT.

Methods: Patients aged 8-21 years in follow-up care after objectively documented limb DVT were prospectively recruited in this cross-sectional study. Measures of functioning (outcomes) included self-reported questionnaires that assessed: 1) movement ability, measured with the Movement Ability Measure-Computer Adaptive Test version; 2) mobility, evaluated with the Computer Adaptive Test version of the Patient-Reported Outcomes Measurement Information System Pediatric Physical Functioning, Mobility domain; 3) functional disability, evaluated with the Functional Disability Inventory; and 4) physical activity levels, evaluated with the Godin Leisure-Time Exercise Questionnaire. The main predictor was PTS severity, which was assessed using the index for the Clinical Assessment of PTS in children. The association between PTS and outcomes was analyzed using linear models.

Results: Eighty-seven patients (median age, 16 years; 25th-75th percentile, 15-18 years; 56% boys) were enrolled. Adjusted for age, sex, and underlying condition, increasing PTS severity was associated with lower current movement ability, a wider gap between current vs preferred movement ability, lower mobility, and slightly higher functional disability scores. There was a nonsignificant effect of PTS severity on moderate-strenuous physical activity.

Conclusion: In children, increased PTS severity is associated with lower movement ability and impaired mobility. Reducing the gap between the patients' current vs preferred movement ability is a relevant aspect of PTS management in children.