@article {791, title = {Response to Hays et al and McHorney and Cohen: Practical implications of item response theory and computerized adaptive testing: A brief summary of ongoing studies of widely used headache impact scales}, journal = {Medical Care}, volume = {38}, year = {2000}, pages = {73-82}, author = {Ware, J. E., Jr. and Bjorner, J. B. and Kosinski, M.} }