TY - JOUR AU - Macedo L. AU - Herbert Rob AU - McAuley J. AU - Kamper S. AU - Maher C. BT - Journal of Clinical Epidemiology CN - Y LA - eng LB - MSjournal M1 - 3 PY - 2008 SP - 256 EP - 260. T2 - Journal of Clinical Epidemiology TI - Trial methodology and patient characteristics do not influence the size of placebo effects on pain. Meta-regression of trial-level factors VL - 61 ER -