The Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS): Normative Data

Background: Recent data have shown an increase in youth sports participation at younger ages, which may be linked to greater musculoskeletal injury risk. The Hospital for Special Surgery Pediatric Functional Activity Brief Scale (HSS Pedi-FABS) is a validated 8-item instrument designed to quantify the activity of children between 10 and 18 years old. Normative data on pediatric and adolescent activity level are unknown. Purpose: To establish normative activity-level data for American youth and to determine if there is a natural decrease in activity level during adolescence. Study Design: Cross-sectional study; Level of evidence, 3. Methods: A cross-sectional investigation was performed among 2002 US children and adolescents equally split by sex and age and representing census-weighted distributions of state of residency, race/ethnicity, and health insurance status. Respondents completed the HSS Pedi-FABS, as well as survey questions on demographics and sports participation. Normative data were reported with descriptive statistics. Linear regression analysis was performed to determine if there was an effect of age on activity level during adolescence. Results: A total of 2002 respondents completed the survey; the mean age of the respondents at the time of survey completion was 14.0 ± 2.6 years. Mean weekly amount of reported physical activity was 9.3 ± 8.4 hours. HSS Pedi-FABS scores were normally distributed with a mean of 15.4 ± 8.5 points (out of 30 possible points). There was a modest but statistically significant decrease in HSS Pedi-FABS activity scores with increasing age (r = −0.175, P < .001), corresponding to a linear decrease in activity scores by 27% on average from age 10 to 18 years. Conclusion: The current study provides baseline normative data for activity level in a census-weighted representative population sample of 2002 American youth through the use of a validated activity score (HSS Pedi-FABS). There was a modest but statistically significant decrease in activity scores with increasing age. These results will aid future research by providing normative, representative population-level activity data and will help to quantify the natural rate of decreased activity during adolescence.