Pain Intensity Threshold

Self-reported pain ≥4 on the 0-10 numeric rating scale (NRS) pain scale.

Note: this scale is a component of the PEG and BPI.

Description of Instrument

Pain Intensity Threshold: In surveys of patients with chronic pain, pain intensity is described as a critically important dimension of the pain experience and a crucial target of pain treatments (Turk et al., 2008). Moreover, panels of pain experts (such as the Initiative on Methods, Measurement, and Pain Assessment in Clinical Trials: IMMPACT) have suggested that “For most clinical trials of chronic pain treatments, a measure of pain intensity will provide the primary outcome measure” (Dworkin et al., 2005). Further IMMPACT recommendations suggest applying a minimum baseline pain intensity score of 4/10 on a numeric pain rating scale as a reasonable inclusion criterion for trials of pain treatments, in order to limit “floor effects” and ensure that participants have sufficient pain levels to show treatment-related improvements (Dworkin et al., 2012).


Identifying important outcome domains for chronic pain clinical trials: an IMMPACT survey of people with pain. Turk DC, Dworkin RH, Revicki D, Harding G, Burke LB, Cella D, Cleeland CS, Cowan P, Farrar JT, Hertz S, Max MB, Rappaport BA. Pain. 2008 Jul 15;137(2):276-285. PMID: 17937976

Core outcome measures for chronic pain clinical trials: IMMPACT recommendations.Dworkin RH, Turk DC, Farrar JT, Haythornthwaite JA, Jensen MP, Katz NP, Kerns RD, Stucki G, Allen RR, Bellamy N, Carr DB, Chandler J, Cowan P, Dionne R, Galer BS, Hertz S, Jadad AR, Kramer LD, Manning DC, Martin S, McCormick CG, McDermott MP, McGrath P, Quessy S, Rappaport BA, Robbins W, Robinson JP, Rothman M, Royal MA, Simon L, Stauffer JW, Stein W, Tollett J, Wernicke J, Witter J; IMMPACT. Pain. 2005 Jan;113(1-2):9-19. PMID: 15621359

Considerations for improving assay sensitivity in chronic pain clinical trials: IMMPACT recommendations. Dworkin RH, Turk DC, Peirce-Sandner S, Burke LB, Farrar JT, Gilron I, Jensen MP, Katz NP, Raja SN, Rappaport BA, Rowbotham MC, Backonja MM, Baron R, Bellamy N, Bhagwagar Z, Costello A, Cowan P, Fang WC, Hertz S, Jay GW, Junor R, Kerns RD, Kerwin R, Kopecky EA, Lissin D, Malamut R, Markman JD, McDermott MP, Munera C, Porter L, Rauschkolb C, Rice ASC, Sampaio C, Skljarevski V, Sommerville K, Stacey BR, Steigerwald I, Tobias J, Trentacosti AM, Wasan AD, Wells GA, Williams J, Witter J, Ziegler D. Pain. 2012 Jun;153(6):1148-1158. PMID: 22494920