The assessment and treatment of long-term, non-specific spinal pain : behavioural medicine, a cognitive-behavioural perspective

Background: Matching treatment specifically to the needs of long-term, non-specific spinal pain (LTSP) patients might greatly enhance treatment efficacy, but the heterogeneity of patients has hindered this development. There is a wide array of treatments for LTSP. The scientific support for many treatments is, however, limited.

Aims: The aims of this thesis were to: (a) evaluate a method for the assessment of psychosocial and behavioural factors in patients suffering from LTSP (studies I and II), (b) to evaluate whether reliable and valid patient groups could be identified among these patients (study III), (c) to evaluate the predictive validity of these subgroups regarding the outcome of a vocational rehabilitation programme (study IV) and, (b) to evaluate a behavioural medicine rehabilitation (BM) programme as a whole and divided into its two main components, behaviour-oriented physical therapy (PT) and cognitive behavioural therapy (CBT) (study V).

Materials and Methods: Three samples of patients (sample 1, n = 682; sample 2, n = 235; sample 3, n = 273) suffering from LTSP were used. The Multidimensional Pain Inventory (MPI) was translated into Swedish (MPI-S) and used as a measure of psychosocial and behavioural factors in the patients' adjustment to pain. In the component analysis, patients were randomised to one of four alternatives (BM, PT, C13T or a "treatment-as-usual" control group (CG)).

Results: The analyses showed that the factor structure, reliability, generalisability and construct validity of sections I and 2 of the MPI-S were acceptable between genders. However, section 3 was excluded from the MPI-S due to its weak validity. Subsequently, the MPI-S was used to identify three reliable and valid subgroups of patients across two of the patient samples. These subgroups were similar to the "dysfunctional" (DYS), "interpersonally distressed" (ID) and "adaptive coper" (AC) patient types described in earlier research.

The MPI-S subgroup classification was shown to be predictive of total absence from work (sick-listing plus early retirement), utilisation of health care, and health-related quality of life over the 18-month follow-up period. However, subgroup affiliation was not predictive of the percentage of improved patients in the three patient groups.

It was found in the component analysis that the active treatment conditions were superior to the CG condition in one or two of the three primary endpoints at the 18-month follow-up and that the positive effects were restricted to women. The results did not support the superiority of the complete BM programme over its main components, PT and C13T. Females in the CBT and PT groups had a significantly lower risk of being granted full-time early retirement and females in the CBT and BM groups reported a significantly better health-related quality of life over the 18-month follow-up period, than females in the CG. A non-significant positive trend towards both decreased total absence from work and improved health-related quality of life was demonstrated among males in the BM and PT conditions compared to the CG.

Conclusions: The MPI-S (sections 1 and 2) is a reliable and valid instrument in the assessment of psychosocial and behavioural factors in LTSP patients and can be used as a tool to derive subgroups of patients which has been shown to be predictive of treatment outcome. For female LTSP patients, CBT was shown to decrease the risk of full-time early retirement and for improving the health-related quality of life. For male LTSP patients, the results indicated that BM or PT might be used as treatments for decreasing the total absence from work and improving the health-related quality of life. Further research is needed, however, regarding effective treatments for males.

List of scientific papers

I. Bergstrom G, Jensen IB, Bodin L, Linton SJ, Nygren AL, Carlsson SG (1998). "Reliability and factor structure of the Multidimensional Pain Inventory--Swedish Language Version (MPI-S). " Pain 75(1): 101-10
https://pubmed.ncbi.nlm.nih.gov/9539679

II. Bergstrom KG, Jensen IB, Linton SJ, Nygren AL (1999). "A psychometric evaluation of the Swedish version of the Multidimensional Pain Inventory (MPI-S): a gender differentiated evaluation" Eur J Pain 3(3): 261-273
https://pubmed.ncbi.nlm.nih.gov/10700354

III. Bergstrom G, Bodin L, Jensen IB, Linton SJ, Nygren AL (2001). "Long-term, non-specific spinal pain: reliable and valid subgroups of patients. " Behav Res Ther 39(1): 75-87
https://pubmed.ncbi.nlm.nih.gov/11125725

IV. Bergstrom G, Jensen IB, Bodin L, Linton SJ, Nygren AL (2000). "The impact of psychologically different patient groups on outcome after a vocational rehabilitation program for long-term spinal pain patients." (Submitted)

V. Jensen IB, Bergstrom G, Ljungquist T, Bodin L, Nygren AL (2001). "A randomized controlled component analysis of a behavioral medicine rehabilitation program for chronic spinal pain: are the effects dependent on gender? " Pain 91(1-2): 65-78 (In Print)
https://pubmed.ncbi.nlm.nih.gov/11240079