Key references: Interpreting the number needed to treat for analgesia

Finnerup NB, Sindrup SH, Jensen TS. The evidence for pharmacological treatment of neuropathic pain. Pain 2010;150(3):573–81. https://www.ncbi.nlm.nih.gov/pubmed/20705215
Finnerup NB, Attal N, Haroutounian S, McNicol E, Baron R, Dworkin RH, et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol 2015;14(2):162–73. https://www.ncbi.nlm.nih.gov/pubmed/25575710
Joshi GP, Group PW, Schug SA, Bonnet F, Fischer HB, Neugebauer EA, et al. Postoperative pain management: number-needed-to-treat approach versus procedure-specific pain management approach. Pain 2013;154(1):178–9. https://www.ncbi.nlm.nih.gov/pubmed/23159575
Katz N, Paillard FC, Van , Inwegen R. A review of the use of the number needed to treat to evaluate the efficacy of analgesics. J Pain 2015;16(2):116–23. https://www.ncbi.nlm.nih.gov/pubmed/25419989
Parsons B, Argoff CE, Clair A, Emir B. Improvement in pain severity category in clinical trials of pregabalin. J Pain Res 2016;9:779–85. https://www.ncbi.nlm.nih.gov/pubmed/27785092
Walsh BT, Seidman SN, Sysko R, Gould M. Placebo response in studies of major depression: variable, substantial, and growing. JAMA 2002;287(14):1840–7. https://www.ncbi.nlm.nih.gov/pubmed/11939870