Correlation between the PROMIS Pediatric Mobility Instrument and the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS)

Background Patient-reported outcome measures (PROMs) are an important resource for clinicians wishing to provide high-quality, patient-centered care. Finding PROMs to use in a pediatric clinical practice that are reliable, age appropriate, succinct, and not redundant is challenging. Questions/Purposes We sought to determine the degree of correlation between two pediatric PROMs, the Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) and the PROMIS Pediatric Mobility (PROMIS PM) instrument, when administered at patients’ initial visit. We hypothesized that there would be a positive correlation between the two questionnaires because of their focus on physical function. Methods We conducted a retrospective cross-sectional review of 294 pediatric patients (mean age, 13.7 years) with localized lower-extremity joint pathologies at our high-volume urban pediatric sports practice. The patients had been asked to complete both PROMs on a computerized platform. Results We found a positive and statistically significant—albeit modest—correlation between the scores obtained on the HSS Pedi-FABS and the PROMIS PM. Neither instrument significantly correlated with patient age, nor were floor and ceiling effects observed. Conclusion The study shows that although both PROM instruments provide valuable information about pediatric physical function, they are not redundant because they measure slightly different constructs. Future studies should further investigate the correlation between these questionnaires in specific subpopulations of pediatric patients with lower-extremity pathology.