Correction for: Goldman MD, LaRocca NG, Rudick RA, Hudson LD, Chin PS, Francis GS, Jacobs A, Kapoor R, Matthews PM, Mowry EM, Balcer LJ, Panzara M, Phillips G, Uitdehaag BMJ, Cohen JA; Multiple Sclerosis Outcome Assessments Consortium. Evaluation of multiple sclerosis disability outcome measures...