Representativeness of the Patient-Reported Outcomes Measurement Information System Internet panel

To evaluate the Patient-Reported Outcomes Measurement Information System (PROMIS), which collected data from an Internet polling panel, and to compare PROMIS with national norms.We compared demographics and self-rated health of the PROMIS general Internet sample (N=11,796) and one of its subsamples (n=2,196) selected to approximate the joint distribution of demographics from the 2000 U.S. Census, with three national surveys and U.S. Census data....