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. Author manuscript; available in PMC: 2012 Nov 1.
Published in final edited form as: Qual Life Res. 2011 Mar 16;20(9):1349–1357. doi: 10.1007/s11136-011-9882-y

Table 1.

Overview of the migration from a legacy measure to PROMIS CAT administration

  1. Administer both the PROMIS and legacy (here, the PHQ-9) measures to the same group of participants

  2. Evaluate calibration assumptions
    1. Assess DIF
    2. Establish that they measure the same unidimensional construct

  3. Using both PROMIS and legacy items, estimate the legacy parameters with the PROMIS items fixed to the PROMIS item bank parameters

  4. Use the legacy items and the parameters obtained in step 3 to estimate scores. These scores will be on the PROMIS metric

  5. Create a test characteristic curve to aid in interpretation of the PROMIS and legacy scores

  6. Simulate CAT to determine the number of items needed for the desired level of measurement precision