Back Pain of Six Weeks and Longer: Prognostic Factors

In Australia, the estimated cost of back pain problems to the community is $4.8 billion, with 75% of those expenses attributable to indirect costs such as time off work.1 Researchers have reached a consensus that a better understanding of prognostic indicators could lower societal expenses by helping to channel patients toward the most cost-effective care paths.2 A large volume of studies on prognostic indicators in back pain have resulted.3 One realization emerging from such studies is that occupational low back pain behaves as a different and more serious condition than non-occupational low back pain. Occupational low back pain can be distinguished as a different clinical challenge by these facts: the onset is more often sudden; treatment is more costly; subsequent disability is much more frequent; and the proven predictors for poor outcomes are different.4

[Convenient Hours Small] Recently Ivan Steenstra and colleagues further hypothesised that prognostic indicators in work-related low back pain would vary as time off work lengthened.3 Their ambitious meta-analysis was published recently by the Journal of Occupational Rehabilitation. Researchers used return to work as their primary outcome and divided return to work into three time frames: 0-6 weeks, 6-12 weeks, and 12+ weeks. Seventy-eight publications met their inclusion criteria, and 481 prognostic factors were considered.

One of the interesting observations is the waning prognostic power of pain and radiating pain. In the earliest time frame, more severe pain characteristics predict a lower likelihood of return to work. However, as time progresses, the level of pain or lack thereof becomes less predictive for return to work. This may suggest that managing pain early in the presentation of acute low back pain presents the greatest likelihood of improving return-to-work rates.

Similarly, work accommodations appear more likely to positively influence return-to-work rates when they occur in weeks 0-6 compared to later initiation of work accommodations.

On the other hand, delayed treatment predicts longer time off work whether the time frame is 0-6 weeks, 6-12, or 12+ weeks. The message is that workers who are off work for back pain should receive treatment as soon as possible. For instance, Fritz and colleagues found that starting physiotherapy within 14 days of the primary care consult correlated with numerous advantages compared to later referrals:5

• Medical costs reduced by $2,736 per patient
• Use of advanced imaging reduced by 74%
• Need for surgery reduced by 55%
• Need for injections reduced by 58%
• Use of opioids reduced by 22%

The content of treatment also predicts time off work in all time-frames. For instance, a study out of La Trobe University and The University of Melbourne finds that patients receiving individualised physiotherapy prove 1.8 times more likely to demonstrate clinically significant improvements in back pain ratings at 10 weeks, compared to patients receiving guideline-based advice without physiotherapy.6 At 52 weeks, physiotherapy patients prove 1.5 times more likely to have clinically significant improvement in the Oswestery Disability Index.

Overall, researchers in the current study found various prognostic indicators that seem to change in importance as weeks off work for low back pain progress. However, one general theme to emerge from understanding later prognostic indicators is that early-as-possible, individualised, active, and professionally supervised intervention appears to be the most cost-effective approach.

References

1. Australian Institute of Health and Welfare 2016. Impacts of chronic back problems. Bulletin 137. Cat. no. AUS 204. Canberra: AIHW.
2. Fairbank J, Gwilym S, France J, et al. The role of classification of chronic low back pain. Spine. 2011; 36 (21 Suppl): S19-42.
3. Steenstra I, Munhall C, irvin E, e tal. Systematic review of prognostic factors in return to work in workers with sub acute and chronic low back pain. J Occup Rehabil. 2016; DOI 10.1007/s10926-016-9666-x.
4. Pransky G, Verma S, Okurowski L, et al. Length of disability prognosis in acute occupational low back pain. Spine. 2006; 31 (6): 690-697.
5. Fritz J, Childs J, Wainner R, Flynn T. Primary care referral of patients with low back pain to physical therapy: impact on future health care utilization and costs. Spine. 2012; 37 (25): 2114-21.
6. Ford J, Hahne A, Surkitt L, et al. Individualised physiotherapy as an adjunct to guideline-based advice for low back disorders in primary care: a randomised controlled trial. Br J Sports Med. 2016; 50: 237-245.