Abstract
Background and objectives
Low back pain (LBP) is a major health challenge globally. Research has identified common trajectories of pain over time. We aimed to investigate whether trajectories described in one primary care cohort can be confirmed in another, and to determine the prognostic value of factors collected 5 years prior to the identification of the trajectory.
Methods and results
The study was carried out on 281 patients who had consulted primary care for LBP, at that point completed a baseline questionnaire, and then returned a questionnaire at 5-years follow-up plus at least 3 (of 6) subsequent monthly questionnaires. Baseline factors were measured using validated tools. Pain intensity scores from the 5-year follow-up and monthly questionnaires were used to cluster participants into 4 previously derived pain trajectories (no or occasional mild, persistent mild, fluctuating, persistent severe), using latent class analysis. Posterior probabilities of belonging to each cluster were estimated for each participant. The posterior probabilities for the assigned clusters were very high (>0.90) for each cluster except for the smallest ‘fluctuating’ cluster (0.74). Lower social class (OR 2.9; 95% CI 1.2, 7.0), higher pain intensity (1.6 per unit; 1.2, 2.2), and pain duration greater than 3 years (2.7; 1.0, 7.3), were significantly associated with a more severe trajectory 5-years later, as were higher physical disability, emotional impact of pain, and perception pain will last a long time.
Conclusion
LBP trajectories identified previously appear generalizable. These allow better understanding of the long-term course of LBP and effective management tailored to individual trajectories needs to be identified.
Conflicts of interest
None.
Funding
This work was supported by the following grants: Arthritis Research UK [13413], the Wellcome Trust [083572] and the Medical Research Council Prognosis Research Strategy (PROGRESS) Partnership [G0902393/99558]. Time from NEF was supported by an NIHR Research Professorship (NIHR-RP-011-015). NEF is an NIHR Senior Investigator. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.
