The paper describes a number of methodological problems experienced in a long-term evaluation of hyperbaric treatment for MS. Among the problems discussed are those relating to the locus and logistics of assessment, the reliability of ‘subjective’ assessments, the feasibility of ‘objective’ measurements, the identification of outcome categories and patient drop-out and selectivity.

Taylor, Webster, , , , , , , (1987). Methodological problems in evaluating hyperbaric treatment of multiple sclerosis. A case study. Neuroepidemiology, 1987 ;6(1-2):77-84. https://www.ncbi.nlm.nih.gov/pubmed/3627346