Tsuji T, et al. - The authors performed this study to evaluate whether patients with chronic low back pain (CLBP) with early pain reduction or treatment-related adverse events of special interest (TR-AESIs; nausea, somnolence, constipation) had enhanced responses to duloxetine. This post hoc analysis of a Japanese randomized, placebo-controlled study concluded that early pain reduction or TR-AESIs could predict which CLBP patients were most inclined to respond to duloxetine with improvements in pain and quality of life (QOL).