The validity of the SRS-22 instrument in an adult spinal deformity population compared with the Oswestry and SF-12: a study of response distribution, concurrent validity, internal consistency, and reliability. - Bridwell KH; Cats-Baril W; Harrast J; Berven S; Glassman S; Farcy JP; Horton WC; Lenke LG; Baldus C; Radake T (Spine, 2005)