Cross-Cultural Validation of the Tegner Activity Scale for a United Kingdom Paediatric Population

Patient-reported outcome measures (PROMs) commonly incorporate activity scales to assess functional status before and after treatment. The Tegner Activity Scale (TAS) is widely used in adult knee pathology but has a reading age of 18 to 19 years and includes predominantly adult-focused activities, limiting its applicability in children. This pilot study evaluated the understanding and performance of the TAS in a United Kingdom paediatric population and compared it with a newly developed United Kingdom paediatric activity scale. A United Kingdom-specific paediatric activity scale was developed by a panel of paediatric orthopaedic and sports surgeons with a target reading age of 8 years. Children aged ≥ 8 years attending a tertiary paediatric orthopaedic clinic and one parent independently completed the TAS and the new activity scale, alongside demographic and sporting participation data. Activity scores were correlated with reported sporting level, and agreement between child and parent responses was assessed. Subgroup analyses examined the effects of sporting discipline, level of competition, and single- versus multisport participation. Seventy child-parent pairs were recruited (mean age 12.8 years; 38.5% female). Only 53% of children reported understanding the TAS. No significant differences were found between child- and parent-reported TAS scores (6.75 vs. 6.37; p = 0.13), although agreement occurred in only 43.5% of pairs. Correlation between TAS score and reported sporting level was 58.6%. The new United Kingdom activity scale also demonstrated no significant difference between child- and parent-reported scores (4.84 vs. 4.74; p = 0.61) but improved agreement between respondents and showed significantly stronger correlation with sporting level (80.6% vs. 58.6%; p < 0.05). Unlike the TAS, the new scale demonstrated consistent performance across sporting disciplines and competition levels. The TAS demonstrates limited suitability for United Kingdom paediatric patients owing to poor comprehension and weaker correlation with sporting participation. A United Kingdom-specific paediatric activity scale with a lower reading age showed significantly improved agreement and criterion validity. These findings support further development and formal validation of a United Kingdom paediatric activity PROM in accordance with Consensus-based Standards for the selection of health Measurement Instruments (COSMIN) recommendations.