An examination of adolescent bone tumor patient responses on the Activities Scale for Kids (ASK)

This study provides an examination of responses on the Activities Scale for Kids, performance version (ASKp), for evaluating physical function in adolescents with malignant lower extremity bone tumors. Twenty-one participants (ages 10.4 to 17.9 years), who had tumor resection surgery, completed the ASKp on two occasions. ASKp data were examined for ceiling and/or floor effects, item distributions, and Not Applicable (NA) responses, as well as textual comments. Ceiling effects were 12.5% and 19%, and 0% demonstrated floor effects. The extreme response options were chosen most frequently, and approximately one third of respondents used NA more than 10% of the time. Overall, this population demonstrated moderately high NA rates and higher than anticipated ceiling effects on the ASKp. These data suggest that caution should be taken when interpreting item-level data in this population and further studies guiding the scoring and interpretation of NA responses are recommended.