Physical and Psychosocial Predictors of Work Retention After a Multidisciplinarym Rehabilitation Program
(1996 to 2002)
Marco Campello (PhD Research)
This research project is based upon the OIOC's Return to Work Program, which originates from the Model Back Clinic research project that was funded by the Center for Disease Control and the National Institute of Health.

The aim of this research project was to measure work retention after completion of a multidisciplinary, outpatient rehabilitation program. The abstract follows:

Aims: Multidimensional factors that predict the outcome for return to work of patients with non-specific low back pain (NSLBP) have been previously identified. However, predictors of work retention have not been well established and are examined in this study. The aim of the study is to identify physical and psychosocial factors that predict work retention for 24 months after treatment completion in patients with NSLBP.

Methods: The study design is a retrospective case series. Patients with NSLBP participated in a multidisciplinary rehabilitation program. Patients who returned to work after completion of the four-week program were followed for two years (n= 71). Physical baseline measures included performance and functional capacity tests. Psychosocial baseline measures were the Symptoms Checklist 90-R (SCL-90R), the Pain Beliefs and Perceptions Inventory, perceived disability (Oswestry), and the Quality of Life Scale. Physical parameters (trunk flexibility, lifting capacity, aerobic capacity) were tested at baseline and repeated at the end of the rehabilitation program. Perceived disability and quality of life were also assessed at program completion. The dependent variable, work retention, was defined as the length of time (days) that the subject worked during the two year follow-up, post-treatment period. Survival analysis was used to establish the predictive model.

Result: The average time out of work before the inclusion to the rehabilitation program was nine months (SD 12.8) for 67 subjects (mean age 40 [SD 9.6], 18 females and 49 males). Eighteen participants relapsed during the follow-up period resulting in a relapse rate of 25%. The average work retention was 660 days (range 47 to 600 days). Univariate factors included in the multivariate analysis were variables that reached p < 0.10. These variables were trunk flexion HR= 2.4 (95% CI 1.24-4.38) (p= 0.01), trunk extension HR= 2.1 (95% CI 1.02-4.16) (p= 0.04), Somatization HR= 2.0 (95% CI 1.03-4.05) (p= 0.04), and obsessive compulsive HR 0.4 (95% CI 0.12-1.15) (p= 0.09). The variables forced in the equation were post-test Oswestry (< 20% perceived disability, i.e. minimal level) HR= 1.0 (95% CI 0.98-1.06) (p= 0.10), post-test lifting capacity HR= 1.0 (95% CI 0.99-1.02) (p= 0.65), depression cognition HR= 0.7 (95% CI 0.22-2.44) (p= 0.60), and depression anxiety HR= 0.64 (95% CI 0.29-1.44) (p= 0.28). Results from the multivariate analysis showed that post-test trunk flexion, somatization and obsessive compulsive scales from SCL-90R were predictive for work retention. For final trunk flexion HR= 2.5 (95% CI 1.26-4.79, p= 0.01), somatization scale HR= 2.5 (95% CI 1.25-4.93, p=0.01, obsessive compulsion HR= 0.2 (95% CI 0.07-0.77, p= 0.02).

Conclusion: This study found that psychosocial factors and physical factors are associated with work retention for NSLBP patients. These results support the use of multidisciplinary treatment protocols for occupational NSLBP. Further studies should be conducted to confirm these predictive factors for work retention. Studies integrating these findings into clinical practice are also of great interest to enhance retention of work and well-being.