TY - CONF T1 - Using item response theory to construct a health classification system and select health states for valuation for the Preference-Based Index from the Recovering Quality of Life (ReQoL) outcome measure JO - QUALITY OF LIFE RESEARCH PY - 2019/10/01 AU - Keetharuth A AU - Bjorner JB AU - Rowen D AU - Brazier J ED - VL - 28 SP - S68 EP - S68 Y2 - 2025/05/24 ER -