Psychological and behavioral differences between low back pain populations: a comparative analysis of chiropractic, primary and secondary care patients.
BACKGROUND
Psychological, behavioral and social factors have long been considered important in the development of persistent pain. Little is known about how chiropractic low back pain (LBP) patients compare to other LBP patients in terms of psychological/behavioral characteristics.


METHODS
In this cross-sectional study, the aim was to investigate patients with LBP as regards to psychosocial/behavioral characteristics by describing a chiropractic primary care population and comparing this sample to three other populations using the MPI-S instrument. Thus, four different samples were compared. A: Four hundred eighty subjects from chiropractic primary care clinics. B: One hundred twenty-eight subjects from a gainfully employed population (sick listed with high risk of developing chronicity). C: Two hundred seventy-three subjects from a secondary care rehabilitation clinic. D: Two hundred thirty-five subjects from secondary care clinics. The Swedish version of the Multidimensional Pain Inventory (MPI-S) was used to collect data. Subjects were classified using a cluster analytic strategy into three pre-defined subgroups (named adaptive copers, dysfunctional and interpersonally distressed).


RESULTS
The data show statistically significant overall differences across samples for the subgroups based on psychological and behavioral characteristics. The cluster classifications placed (in terms of the proportions of the adaptive copers and dysfunctional subgroups) sample A between B and the two secondary care samples C and D.


CONCLUSIONS
The chiropractic primary care sample was more affected by pain and worse off with regards to psychological and behavioral characteristics compared to the other primary care sample. Based on our findings from the MPI-S instrument the 4 samples may be considered statistically and clinically different.


BACKGROUND
Sample A comes from an ongoing trial registered at clinical trials.gov; NCT01539863 , February 22, 2012.
Karolinska Institutet, Institute of Environmental Medicine, Unit of Intervention and Implementation Research, Nobels väg 13, S-171 77, Stockholm, Sweden. andreas.eklund@ki.se.
Andreas
A
Eklund
Karolinska Institutet, Institute of Environmental Medicine, Unit of Intervention and Implementation Research, Nobels väg 13, S-171 77, Stockholm, Sweden. gunnar.bergstrom@ki.se.
Gunnar
G
Bergström
Karolinska Institutet, Institute of Environmental Medicine, Unit of Intervention and Implementation Research, Nobels väg 13, S-171 77, Stockholm, Sweden. lennart.bodin@ki.se.
Lennart
L
Bodin
Karolinska Institutet, Institute of Environmental Medicine, Unit of Intervention and Implementation Research, Nobels väg 13, S-171 77, Stockholm, Sweden. iben.axen@ki.se.|Research Department, Spine Center of Southern Denmark, Hospital Lillebælt and Institute of Regional Health Research, Østre Hougvej 55, DK-5500, Middelfart, Denmark. iben.axen@ki.se.
Iben
I
Axén
D000328:Adult; D002684:Chiropractic; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000523:psychology*; D008297:Male; D008875:Middle Aged; D011320:Primary Health Care; D063127:Secondary Health Care; D018582:Sick Leave