title: The dimensionality of pain: palliative care and chronic pain patients differ in their reports of pain intensity and pain interference.
abstract: The accurate, precise, and consistent assessment of pain is of particular importance in palliative care. The European Palliative Care Research Collaborative is developing a computer-based pain assessment instrument and has been evaluating the content and dimensionality of existing pain questionnaires. The most important dimensions of pain are intensity and interference. However, since pain interference is a consequence of and largely reflects pain intensity, we postulated that it might either provide information to enhance the evaluation of intensity, or that an overall summary measure of pain severity could be constructed by combining the 2 dimensions. Cancer patients in palliative care (n=395) and chronic pain patients (n=168) completed questionnaires that included 23 pain items culled from existing questionnaires. Psychometric analyses confirmed the existence of 2 main dimensions, intensity and interference, and also guided identification of items that contributed most strongly to these dimensions. However, there was strong evidence that the relationship between the intensity and the interference items differs markedly in palliative care patients compared to chronic pain patients. As hypothesized, there was strong correlation between intensity and interference, lending support to the possibility that, for some purposes, these dimensions may be combined to provide a higher-level summary measure of patients' pain experience. We conclude that these dimensions should be kept distinct when assessing patients in general, although for a single type of patient (such as palliative care patients), it may be possible to regard intensity and interference as contributing to an overall measure of pain severity.
authors: Division of Applied Health Sciences, University of Aberdeen, Medical School, Aberdeen, UK Pain and Palliation Research Group, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway Regional Center for Excellence in Palliative Care, Department of Oncology, Oslo University Hospital Ulleval, Norway Department of Anaesthesiology and Acute Medicine, St. Olavs University Hospital, Trondheim, Norway National Resource Center for Late Effecta, Oslo University Hospital, Oslo, Norway Palliative Care, Pain Therapy and Rehabilitation Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy Department of Palliative Medicine, Bristol Oncology Centre, UK Department of Oncology, St. Olavs University Hospital, Trondheim, Norway.
authors: Peter M
authors: PM
authors: Fayers
authors: Marianne J
authors: MJ
authors: Hjermstad
authors: Pål
authors: P
authors: Klepstad
authors: Jon Håvard
authors: JH
authors: Loge
authors: Augusto
authors: A
authors: Caraceni
authors: Geoffrey W
authors: GW
authors: Hanks
authors: Petter
authors: P
authors: Borchgrevink
authors: Stein
authors: S
authors: Kaasa
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002908:Chronic Disease; D003936:Diagnosis, Computer-Assisted; D005060:Europe / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010146:Pain / Q000451:nursing* / Q000503:physiopathology / Q000523:psychology*; D010147:Pain Measurement / Q000379:methods; D058748:Pain Perception; D010166:Palliative Care / Q000379:methods*; D011594:Psychometrics; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires; D055815:Young Adult