Using the PedsQL™ 3.0 Asthma Module to Obtain Scores Comparable with Those of the PROMIS Pediatric Asthma Impact Scale (PAIS)

BACKGROUND: The National Institutes of Health's Patient-Reported Outcomes Measurement Information System (PROMIS) has developed several scales measuring symptoms and function for use by the clinical research community. One advantage of PROMIS is the ability to link other scales to the PROMIS metric. OBJECTIVES: The objectives of this research are to provide evidence of validity for one of the PROMIS measures, the Pediatric Asthma Impact Scale (PAIS), and to link the PedsQL™ Asthma Symptoms Scale with the metric of the PAIS. METHODS: Descriptive statistics were computed describing the relationships among scores on the PAIS, the PedsQL™ Asthma Symptoms, Treatment, Worry, and Communication Scales, and the DISABKIDS Asthma Impact and Worry Scales for approximately 300 children ages 8–17. A novel linkage method based on item response theory (IRT), calibrated projection, was used to link scores on the PedsQL™ Asthma Symptoms Scale with the metric of the PAIS. RESULTS: The PAIS exhibited strong convergent validity with the PedsQL™ Asthma Symptoms Scale, and less strong relations with the other five scales. The linkage system uses scores on the PedsQL™ Asthma Symptoms Scale to produce relatively precise score estimates on the metric of the PAIS. CONCLUSIONS: Results of this study provide evidence for the validity of the PAIS, and a method to use scores on the PedsQL™ Asthma Symptoms Scale to estimate scores on the metric of the PAIS, in partial fulfillment of the PROMIS goal to provide a lingua franca for health-related quality of life.