Which variables are associated with pain intensity and treatment response in advanced cancer patients?— Implications for a future classification system for cancer pain

Authors

  • Anne Kari Knudsenl,

    Corresponding author
    1. European Palliative Care Research Centre, Faculty of Medicine, NTNU, NO-7006 Trondheim, Norway
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  • Cinzia Brunellil,

    1. Palliative Care Unit, Fondazione IRCCS, Istituto Nazionale Dei Tumori, IT-20123 Milan, Italy
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  • Stein Kaasal,

    1. European Palliative Care Research Centre, Faculty of Medicine, NTNU, NO-7006 Trondheim, Norway
    2. Palliative Medicine Unit, Dept. of Oncology, Trondheim University Hospital, NO-7006 Trondheim, Norway
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  • Giovanni Apolonel,

    1. Center for the Evaluation and Research on Pain (CERP), Dept. of Oncology, Instituto di Ricerche Farmacologiche ‘Mario Negri’, IT-20156 Milan, Italy
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  • Oscar Corlil,

    1. Center for the Evaluation and Research on Pain (CERP), Dept. of Oncology, Instituto di Ricerche Farmacologiche ‘Mario Negri’, IT-20156 Milan, Italy
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  • Mauro Montanaril,

    1. Center for the Evaluation and Research on Pain (CERP), Dept. of Oncology, Instituto di Ricerche Farmacologiche ‘Mario Negri’, IT-20156 Milan, Italy
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  • Robin Fainsingerl,

    1. Division of Palliative Care Medicine, University of Alberta, 217 — Health Services Centre, 1090 Youville Drive West, Room Edmonton, Edmonton, AB, Canada T6L 5X8
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  • Nina Aassl,

    1. Faculty of Medicine, University of Oslo, NO-3015 Oslo, Norway
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  • Peter Fayersl,

    1. European Palliative Care Research Centre, Faculty of Medicine, NTNU, NO-7006 Trondheim, Norway
    2. Section of Population Health, Institute of Applied Health Sciences, University of Aberdeen, Polwarth Building, Foresterhill, Aberdeen AB25 2ZD, UK
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  • Augusto Caracenil,

    1. Palliative Care Unit, Fondazione IRCCS, Istituto Nazionale Dei Tumori, IT-20123 Milan, Italy
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  • Pål Klepstadl,

    1. European Palliative Care Research Centre, Faculty of Medicine, NTNU, NO-7006 Trondheim, Norway
    2. Dept. of Anesthesiology and Emergency Medicine, Intensive Care Unit, Trondheim University Hospital, NO-7006 Trondheim, Norway
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  • On behalf of the European Palliative Care Research Collaborative (EPCRC) and the European Pharmacogenetic Study (EPOS)

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    • Please see Appendix A for details.


Dept. of Cancer Research and Molecular Medicine, Faculty of Medicine, NTNU, 3. Floor Bevegelse, Trondheim University Hospital, NO-7006 Trondheim, Norway. Tel.: +47 72 82 62 96/+47 92 28 03 64; fax: +47 72 82 60 28 anne.k.knudsen@ntnu.no.

Abstract

Background: This study is part of a research program to reach consensus on an international cancer pain classification system. A confirmative and explorative approach was applied to investigate which of the variables identified in the literature, by experts and patients that are associated with pain.

Methods: Data from an international, multicentre, cross-sectional study of cancer patients treated with opioids were investigated. Dependent variables were: average pain, worst pain, and pain relief (11-point Numerical Rating Scales). Forty-six independent variables were chosen based upon previous studies. Bivariate analyses identified independent variables associated with at least one of the dependent ones; 21 were included in multivariate linear regression analyses.

Results: Two thousand two hundred and seventy-eight patients were investigated; 52% males, mean age 62 years, mean Karnofsky Performance Status 59%, mean daily opioid oral equivalent dose 341 mg. Fifty-eight percent had breakthrough pain. Mean pain scores were: average pain 3.5, worst pain 5.3 and pain relief 74%. Variables most strongly associated with these three dependent variables were: breakthrough pain, psychological distress, sleep, and opioid dose.

Conclusions: Breakthrough pain and psychological distress were confirmed as key variables of a future classification system. Candidate variables were: sleep, opioid dose, pain mechanism, use of non-opioids, pain localisation, cancer diagnosis, location of metastases, and addiction.

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