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Three Part Question

[In patients presenting with acute lower back pain] is it possible to [predict] the [time to recovery, reduction in pain and return to work]

Clinical Scenario

A 31 year old man presents to the emergency department with acute lower back pain sustained whilst lifting a heavy box. He is normally fit and well. There are no neurological signs or symptoms. There are no other signs or symptoms to suggest a sinister cause of his back pain. You advise that he take NSAIDs and that he remain as active as possible. He is worried because his colleague at work has been off for months following a similar injury. He wonders if he will be the same. You wonder if there is any way of predicting if he is likely to recover quickly.

Search Strategy

Medline on OVID interface via ATHENS. 1966-Feb 2005
Cochrane via NELH
Medline
[back pain.mp. or exp Back Pain/ or exp Low Back Pain/ or lumbar pain.mp. or exp Back Pain/ ] limit to humans, english and abstracts and [prognosis filter (optimized)] and [reviews filter (optimized)]
Cochrane
low-back-pain and prognosis

Search Outcome

Medline
196 papers found. 1 recent (2003) well conducted systematic review was found. No papers after this date were directly related to the 3 part question.
Cochrane
6 citations. None directly relevant to 3 part question

Relevant Paper(s)

Author, date and country	Patient group	Study type (level of evidence)	Outcomes	Key results	Study Weaknesses
Pengel LHM 2003 Australia	The authors sought papers of prospective design with an inception cohort of patients with simple low back pain or sciatica of less than 3 weeks duration. Studies had to follow patients up for a minimum of 3 months.	Systematic review	No of papers found	4458 papers were examined. 15 were included in the review.	Focused report only looking at patients with pain of less than 3 weeks duration. Many papers did not specifically look at prognostic factors therefore difficult to ascertain what they are.
			Quality of included studies as assessed on an 84 point scale	No specific results given. Study quality reported as "variable".
			Pain reduction in first month (on 100 point scale)	Pooled mean difference reduction of 12-84% in first month. Pooled mean level of pain was 22/100 at one month
			Pain reduction at 3 months (on 100 point scale)	Pain continued to decrease over the following 2 months. Pooled mean pain was 15/100 at 3 months.
			Pain reduction at 3-12 months (on 100 point scale)	Only 2 studies followed patients beyond 3 months (6 and 12 months). Pooled mean pain score varied little up to final follow up.
			Return to work at one month	68-85% of patients returned to work within a month. Pooled estimate of 82% (CI 73-91%)
			Return to work at 6 months	One study only. 93% of patient returned to work by 6 months.
			Cumulative risk of recurrence within 3 months.	One study. 26% risk of recurrence (CI 19-34%)
			Cumulative risk of recurrence within 12 months.	Two studies. 66-84%. Pooled estimate of 73% (CI 59-88%)
			Cumulative risk of recurrence at 3 years	One study. 84%.
			Prognostic factors	Only one study considered methodologically sound to ascertain prognostic factors. Score less than 0.48 on the Vermont disability scale were predictive of a return to work at 3 months (OR 5.7, CI 3.9-8.5)

Comment(s)

Low back pain is a common presentation to primary care and emergency departments. This well conducted systematic review agrees with the common perception that most low back pain resolves rapidly. However, a significant proportion of patients have pain persisting beyond 3 months and have little further improvement in their pain up to 12 months. Of additional interest is the large number of patients who had recurrence of symptoms within a 12 month period. Unfortunatley there is insufficient robust information in thisn review to determine a method of predicting which patients will recover and which will not. The influence of additional treatment modalities was not assessed in this review, this may bias the effect in some studies. There is an interesting series of letters attached to the paper on the BMJ website. The authors were criticised for restricing the data to inception cohort studies. From the perspective of this BET and for EM practice it is entirely valid to limit the studies to inception cohorts of patients.

Clinical Bottom Line

Most patients with acute low back pain recover within weeks. However, a proportion have pain continuing beyond 3 months and recurrence within 12 months is common.

Level of Evidence

Level 1 - Recent well-done systematic review was considered or a study of high quality is available.

References

1. Pengel LHM, Herbert RD, Maher CG, Refshauge KM. Acute low back pain: systematic review of it's prognosis BMJ 2003:327:323-328