Abstract
Introduction
While there is extensive knowledge on the course of acute low back pain (LBP), little is known about the course of recovery of acute LBP patients as a function of depression. The aims of our study were to determine if the course of recovery in patients with acute LBP differs in relation to the presence/absence of depression and to identify the best time point for an intervention against LBP-associated depression.
Materials and Methods
This is a prospective cohort study of 286 patients with acute LBP. Patients were assessed at baseline and followed up over 6 months addressing psychological, occupational, biomedical, and demographic/lifestyle factors. Recovery was defined as improvement in functional limitation measured by the Oswestry disability index (ODI); depression was defined by the Zung depression scale. Repeated-measures analysis of covariance (ANCOVA) was employed with ODI as repeated factor, age, gender, and body mass index as covariates, depression and all other potential prognostic factors as between-subject factors. A second ANCOVA was performed with depression as dependent variable and functional limitation, pain intensity, and job stressors as potential predictor variables.
Results
A total of 18% of study participants were classified as depressive. In these patients, the course of recovery was slower than in nondepressive patients. ODI scores in the nondepression-LBP group decreased over time, whereas scores in the depression-LBP group remained at the same level (F(3.295, 431.607) = 4.63; p < 0.01, partial η2 = 0.034; Fig. 1). High functional limitation (F(1.261) = 15.79; p < 0.001, partial η2 = 0.057), high pain intensity (F(1.260) = 6.84; p < 0.01, partial η2 = 0.026), and a high job stressor index (F(1.252) = 8.95; p < 0.01, partial η2 = 0.034) were predictors of depression at baseline. Further, the presence of depression caused maintenance of LBP especially after 6 weeks.
Conclusion
The presence of depression has a negative influence on the course of recovery in patients presenting with a new episode of LBP. Therefore, depression should be included in screening instruments for patients with acute LBP to identify those at risk of delayed recovery at an early stage. Further research is required investigating interventions at different time points, to identify the optimal time at which to treat acute LBP patients with concomitant depression to reduce the socioeconomic costs of delayed recovery.
Yes
None declared