Original Report| Volume 12, ISSUE 2, P257-262, February 2011

Download started.


Improving Individual Measurement of Postoperative Pain: The Pain Trajectory

Published:January 18, 2011DOI:


      The purpose of this study was to demonstrate a method for increasing the precision and information yield of postoperative pain assessment. We recorded pain intensity ratings over 6 days after surgery in 502 elective surgery patients and examined individual pain trajectories. A linear fit of an individual patient's scores defines a trajectory with two features: (1) the intercept or initial pain intensity; and (2) the slope, or rate of pain resolution. Three pain trajectory patterns emerged from examination of the pain trajectory slopes. Most patients (63% of the sample) demonstrated a negative slope trajectory characterized by a decline in pain intensity over days after surgery. Other patients (25% of the sample) demonstrated a flat trajectory with no meaningful change over 6 days from pain they reported initially. A third patient group (12% of the sample) had a positive slope trajectory in which pain scores increased over 6 days after surgery. Measures derived from individual pain trajectories yielded much lower standard errors of measurement and therefore had better measurement precision than did conventional pain assessment methods. Pain trajectory measures proved sufficiently precise to characterize pain patterns reliably in individual patients.


      Progress in acute pain management requires effective pain assessment. The acute pain trajectory quantifies rate of pain resolution as well as pain intensity. It affords more precise measurement than conventional pain assessment and can identify abnormal postoperative pain resolution.

      Key words

      To read this article in full you will need to make a payment

      Purchase one-time access:

      Academic & Personal: 24 hour online accessCorporate R&D Professionals: 24 hour online access
      One-time access price info
      • For academic or personal research use, select 'Academic and Personal'
      • For corporate R&D use, select 'Corporate R&D Professionals'


      Subscribe to The Journal of Pain
      Already a print subscriber? Claim online access
      Already an online subscriber? Sign in
      Institutional Access: Sign in to ScienceDirect


        • Apfelbaum J.L.
        • Chen C.
        • Mehta S.S.
        • Gan T.J.
        Postoperative pain experience: Results from a national survey suggest postoperative pain continues to be undermanaged.
        Anesth Analg. 2003; 97: 534-540
        • Donaldson G.
        Patient-reported outcomes and the mandate of measurement.
        Qual Life Res. 2008; 17: 1303-1313
        • Hinrichs-Rocker A.
        • Schulz K.
        • Jarvinen I.
        • Lefering R.
        • Simanski C.
        • Neugebauer E.A.
        Psychosocial predictors and correlates for chronic post-surgical pain (CPSP): A systematic review.
        Eur J Pain. 2009; 13: 719-730
        • Macrae W.A.
        Chronic post-surgical pain: 10 years on.
        Br J Anaesth. 2008; 101: 77-86
        • Perkins F.M.
        • Kehlet H.
        Chronic pain as an outcome of surgery: A review of predictive factors.
        Anesthesiology. 2000; 93: 1123-1133
        • Peters M.L.
        • Sommer M.
        • de Rijke J.M.
        • Kessels F.
        • Heineman E.
        • Patijn J.
        • Marcus M.A.
        • Vlaeyen J.W.
        • van Kleef M.
        Somatic and psychologic predictors of long-term unfavorable outcome after surgical intervention.
        Ann Surg. 2007; 245: 487-494
        • Singer J.D.
        Using SAS PROC MIXED to fir multilevel models, hierarchical models, and individual growth models.
        J Educ Behav Stat. 1998; 23: 323
        • Singer J.D.
        • Willett J.B.
        Applied Longitudinal Data Analysis: Modeling Change and Event Occurrence.
        Oxford University Press, Inc, New York2003
        • Sommer M.
        • de Rijke J.M.
        • van Kleef M.
        • Kessels A.G.
        • Peters M.L.
        • Geurts J.W.
        • Gramke H.F.
        • Marcus M.A.
        The prevalence of postoperative pain in a sample of 1490 surgical inpatients.
        Eur J Anaesth. 2008; 25: 267-274
        • White P.F.
        Multimodal analgesia: Its role in preventing postoperative pain.
        Curr Opin Investig Drugs. 2008; 9: 76-82