Interviewer-Versus Self-Administration of PROMIS® Measures for Adults With Traumatic Injury

Objective: To assess differential item functioning and observed mean differences across two modes of administration for PROMIS (R) measure scores in a sample of adults with traumatic injury. Method: Items from 7 PROMIS (R) adult measures (v1.0 Physical Function, Fatigue, Pain Interference, Anger, Anxiety, and Depression and v2.0 Social Health-Emotional Support) were administered as fixed-length short forms in random order to a cross-sectional sample. Participants were randomly assigned to interviewer-administered (phone or in-person) or self-administered (via the Assessment Center website) conditions. The research was conducted at 5 medical rehabilitation institutions across the U.S. Participants included 277 adults with spinal cord injury (n = 148) or traumatic brain injury (n = 129). Results: DIF analyses indicated that all items were invariant to mode of administration. There was no significant effect of mode of administration for the majority of PROMIS (R) measures tested. Regarding observed scores, there were small but significant effects of mode of administration on the Emotional Support and Depression measures, with participants in the interview condition reporting better support/fewer symptoms. Conclusions: PROMIS (R) instruments demonstrated measurement equivalence across interviewer-administered and self-administered conditions. These findings are particularly important for research or clinical applications where administration of PROMIS (R) measures by independent web- or tablet-based administration is not ideal, for example with individuals with physical or cognitive disabilities or with individuals who lack computer and/or Internet access. PROMIS (R) v1.0 Depression and PROMIS (R) v2.0 Emotional Support scores displayed a tendency toward social desirability that should be considered when these measures are interviewer-administered.